CHAPTER 4 : Strateqies To Improve The Quality Of Ginqer

Cultivated In Kerala

4.1 Introduction

Ginger (Zingiber offieinale Rosc.) is one of the oldest spices in the world, standing

third position after pepper and cardamom. lndia is the largest producer of ginger and one

of the leading exporters in the world (Gowda et a/., 1999; Sasikumar, 2000). lndia and

China are the two major suppliers of dried ginger. Around 40% of the world production of

ginger is handled by lndia from an area of 60,000 hectares (Anonymous, 1995). Ginger

produced in Jamaica and Sierra Leone are considered to be superior in trade circle on

account of their better flavour and aroma. Chinese ginger is widely accepted for its clean

appearance. However Indian ginger has the highest impression in Europe and North

American countries. Besides lndia and China, Nigeria, Sierra Leone, Fiji, Jamaica, Sri

Lanka, Malaysia, Taiwan, Mauritius, St. Vincent, Singapore, Indonesia and Thailand are

the other important ginger exporting countries (George, 1996b). Major bottleneck facing

Indian ginger industry are the reducing trend of dry ginger production, tuff competition

from China, and high fluctuation of prices.

Ginger is grown in tropical regions all over the world and plays part in the local

cuisines. Ginger is used generally in two forms viz. processed and fresh. Out of the total

production of ginger in lndia, the farmers retain 17-18% as seed rhizome, 36% is

consumed as green ginger, and 42-43% is dried for export and domestic consumption

(20-23% for export and 20% for use within the country), while 3-3.5% of the produce is

wasted in both forms during assembling and distribution (Anonymous, 1965). The recent

applications of ginger may be divided into three viz. food preparations, medicine (Joshy,

2001) and perfumery (Sambamurthy and Subrahmanyam, 1389). Processed ginger was

the only commodity being traded during the past; but now a number of different value

added products have entered the market (Appendix XIII).

Ginger is well known for its pungent aromatic flavour. In comparison with other

spices ginger is a rich natural resource of phytochemicals. These active principles are

110

. I n

responsible for flavouring compounds, which are present ill oil and oleoresin at various

proportions. Appendix XIV represents the active principles of ginger that is present in

volatile oil and oleoresin.

Ginger (Zingiber oficinale Rosc.) is believed to have originated in the tropical

regions of South East Asia. According to Purseglove (1972) though the country of origin is

not known with certainty, it is presumed to be in the region of lndia or China. The plant

does not occur in a truly wild state, and rarely flowers. No varietal diversity have been

discovered so far, however several commercial types are recognized (Kannan, 1998). In

lndia more than 30 cultivars of ginger are under regular cultivation. Details of some of the

outstanding and introduced ones are available in Appendix XV. Rio-de-Janeiro, Maran,

Himachal, Wayanad-Mananthavady and China are the main cultivars popular among the

farmers of Kerala.

Ginger of commerce produced in lndia is traded under different Agmark grades.

These grades are as follows (Anonymous, 1996)

1. NGK - Garbled, Non-bleached Calicut

2. NUGK - Ungarbled, Non-bleached ;3alicut

3. NGC - Garbled, Non-bleached Cochin

4. NUGC - Ungarbled, Non-bleached Cochin

5. BGC - Garbled bleached Cochin

6. BUGC - Ungarbled bleached Cochin

Major types of dried ginger traded globally are Jamaican and lndian. Two

outstanding grades of lndian ginger are 'Cochin' and 'Calicut'. Other internationally

reputed types are from China, Australia, Nigeria, and Sierra Leone. Indian (Agmark)

grades are based on appearance, size, incidence of physical contaminants, and lime

content. Post-harvest treatments have a profound influence on dried ginger quality.

Underground nature of the rhizome, high initial moisture content, and impermeability of

the rhizome skin makes the processing more difficult and labourious. Hence scientific

post-harvest methods have paramount accountability in retaining the overall quality.

Post-harvest technologies of ginger comprise cleaning, washing, peeling,

bleaching, curing (drying), polishing, cleaning, grading, and packaging, besides

harvesting. Like any other hygroscopic crops, drying is the most important step among

post-harvest treatment that determines the quality. Open sun drying is the prevailing

method in Kerala. However mechanical drying, electrical drying, and smoke drying are

also available in some industrial sectors.

Harvesting is the first step of all the post-harvest operations, since proper harvest

steer a better start to quality increase. In ginger, lining up tne clumps carefully with the

help of a digging fork or a spade or even with bare hands does harvesting, and the

rhizomes are separated from the dried up leaves. Lawrence (1984) describes various

harvesting operations prevailing in different countries like India, Australia, Nigeria,

Jamaica, Sierra Leone, Queensland etc., the chief production centres of the world.

Mechanical harvesting has been introduced in Queensland. Based on the requirement

harvesting time vary accordingly. For the preparation of 'green ginger' harvesting is done

at the 6Ih month onwards while 250-260 day's maturity is required for dried ginger

production. Similarly, the time of harvest for oleoresin extraction has been recommended

as not before 275 days of cultivation (Lal etal., 1988). According to Nybe etal. (1980) the

oleoresin and oil contents of all the cultivars of ginger reach maximum at 265 days of

planting. 'Tender ginger' is a value added product of ginger IIOW attracting wide attention.

This ginger contains very less or no fibre content. The present study has stressed only on

the production of dried ginger. For preparing dried ginger, roots, rhizoids, soil, dusts, and

other unwanted particles are removed after the harvesting of fresh rhizome. Some farmers

soak the cleaned rhizomes in water overnight in order to ease peeling and dirt removal.

Peeling is the most important pre-treatment. Removal of skin is called peeling.

This is carried out manually with the help of bamboo splinters or metal knives.

Conventional peeling is usually done partially on the wide surfaces only. Various studies

have been conducted so far on peeling of ginger. According to Charan (1995) peeling of

ginger is essential in hastening the process of drying. Abrassive and lye peeling are two

methods prevailing in mechanical peeling. Other studies or) peeling of ginger conducted

~ ~ ~ ~ - p p ~ ~ - 112

by Natarajan et a/. (1970), Agrawal et a/. (1983), and Ali et a/. (1987) have got wide

attention.

Drying is the subsequent step after peeling. It takes about 7 to 10 days in

traditional method. Dried rhizomes are subjected to a process called polishing in order to

remove the wrinkles developed during drying. Various study reports on ginger polishing

are available (Kachru and Srivasthava, 1988). Details on mechanized polishing are also

available (Mishra and Mahapatra 1959). Polished ginger is either marketed with or without

grading, or stored. Many studies are already conducted on the storage of ginger so far

(Goyal and Korla, 1993; Lana et a/., 1993). Bleaching is a process in which peeled

rhizomes are soaked in 2% limewater for about 6 hours. Then the produce is dried and

polished so that it will attain an attractive and uniform appear,lnce.

In conventional method of processing due to inadequate attention many kinds of

foreign bodies get into ginger. According to George (1996b) lot of extraneous and

unwanted materials enter into ginger regularly during processing, due to the mishandling

during the post-harvest operations. Farmers often do not give proper care for cleaning and

washing and dry ginger directly after a partial peeling. It is clearly understood that the

diminishing quality of dried ginger is mainly due to the poor post-harvest technological

infrastructure for handling the production of ginger (Lal et a/., 1988). Kachru and

Srivasthava (1988) admitted that very little attention had been given so far for the

research and development effort to developsuitable post-harvest technology for ginger.

New trends in the world market brings into focus the imperative need on the part of the

farmers, processors and traders to upgrade the quality of ginger through improved post-

harvest handling and processing (Jacob, 1996). Peeling is the most important single

operation in processing. Indigenous methods used in peeling are very laborious, time

consuming and also causes high loss of material and quality of the spice (Mani et a/.,

2000).

In Kerala cleaned ginger is dried under the sun by spreading it on the roads or in

places that are othetwise unclean, or on cowdung smeared floors. Lawrence (1984)

opined that if the rhizomes are dried with their roots and soil adhering they will tend to

darken on drying, and the end product is of low value. Harvested ginger contains about

80-93% moisture (w.b.), which is brought down to 11-12% by drying. Generally farmers

dry ginger up to final moisture content of 15-20% or sometimes 35%. At the same time

uneven and non-uniform drying promote the microbes especially fungus to start growth

immediately after the completion of drying. Pruthi (1993) claimed that traditional drying

method could result in the loss of volatile oil (up to 20%) by evaporation and also result in

the destruction of some of the heat sensitive pungent constituents. The quality of dried

ginger is certainly determined based on a number of factors viz. moisture content, volatile

oil, insect infestation, appearance, animal excreta, microbial incidence, and all other

organic and inorganic contaminants. Extent of these quality attributes is largely

determined by the methods of post-harvest operations and drying. Various attempts have

been made to study the disadvantages of conventional drying (Sivadasan, 1996b;

Sreekumar et a/., 2002).

No suitable and credible method is available in Kerale for safe and proper drying of

ginger so far. Dryers already developed have lot of disadvantages. At the same time

certain dryers developed abroad, though are functioning well, are costly and not

affordable to the farmers and processors of Kerala. Kachru and Srivasthava (1988)

recommended a tray type solar cabinet dryer, developed at Sukhadia University (Udaipur)

for best results.

In the present investigation, the post-harvest technology of ginger practiced in

Kerala is analyzed and methods to improve it using solar tunnel dyer and clean practices

is studied and recommendations based on this are presented.

4.2 Materials and Methods

4.2.1 Taxonomy of Zinaiber oficinale Rosco.

Division : Angiospermae

Class : Monocotyledons

Series : Epygynae

Family : Scitaminae

Sub-family : Zingiberaceae

Genus : Zingiber

Species : officinale

Origin of the species : Southern Asia, India or China

Distribution : India, Thailand, South Korea, Bangladesh, Indonesia, Sierra

Leone, China, Brazil, Jamaica, Nigeria, Australia, Sri Lanka.

Habit : Herbaceous perennial with underground rhizome. Rootstock

bears serial leafy shoots of 0.5 to 0.75m height; leaves

sheathy, alternately arranged, linear with 15 cm long and

sessile flowers born on a spike.

Climate : Wam and humid tropical climate

a Soil : Sandy or clay loam, red loam or laterite or a friable loam rich

in humus with enough fertility

Agro-ecological regions in Kerala

: High land, mid land and low land

Harvesting season : November to March

Morphology of the useful part : Underground rhizome

Major products : Bleached and unbleached ginger

4.2.2 Survev of ainqer ~roduct ion in Kerala

An extensive survey was conducted throughout the State. Details were collected

from the farmers on agro-climatic factors of ginger production and post-harvest

I a m p * SmtIen &mpk smtlon

i G l P 0 0 ~ d a l G23 Parheyannu? GB

1 G2 G24 Chalsk?$~~- Nedumaqafl G l

I G3 Panachsmoad G2S Kannara '0' - I . 04 Naflaninkara 026 Ottappelam Einakulam

/ G5 Pattmnawram'G2 G27 Karimba. ~9

I G6 Chithara 028 Chinoor I G7 Punslur ! 029 Man]en' GI0 , 0 8 Pramadam 030 Nilambur Konayam

i G9 Pethnamthttta'G3 G31 Psrinthalmsnna 014

/ G10 Ranni G32 %rwambadrGll G I 1

1 G11 Ma~likkara G33 Kunyadi

1 GI2 Chemutla' G4 G34 Kunnamangalam-

, 013 Harippad 035 Sulthan Sathsry

9" - 1 014 Kanjirappilly' G5 036 Kalpna' G12 I GI5 Athirarnplnhe G37 Mananttmvady : 016 Eranuptte 038 Pulpally

'. 017 Kumili 039 irtty

. stations selected for second season %. ...., ~~ -~. ..-~ ~

75" -

76" 77" Fig. 12 : District wise map of Kerala showing sampling stations selected for ginger

technologies prevailing. The questionnaire used for the fie!cl survey is same as that of

black pepper (Appendix VIII)

4.2.3 S a m ~ l e collection

Mature rhizomes of ginger were collected directly from the farmers of different

sampling stations immediately after the harvest. These sampling stations were located in

the 14 districts of the State (Fig. 12). Sampling was done during 1998 November to 1999

March (season one) from 44 sampling stations.

4.2.4 Selection of samplina stations

The number of sampling stations was identified on the basis of stratified

proportional random sampling method. The methodology is explained in 2.2.4 of Chapter

2. Sampling stations GI,G2,G3 ............ G44 (Fig. 12) were identified for ginger

collection.

The collected fresh rhizomes were weighed and divided into three subsamples.

Two subsamples were packed separately in clean polythene bags and transported to the

research centre. The third subsample was kept with the farmer for conducting commercial

drying.

4.2.5 Initial moisture content determination

The methodology is described in Chapter 2 (2.2.5)

4.2.6. Dwins methods adoDted for ainaer

Three different drying experiments were conducted. Methods employed for drying

are the following.

a. Drying experiments conducted in solar tunnel dryer (tunnel dried sample)

b. Conventional method of drying conducted in the research centre (conventional

sample)

c. Conventional processing by farmers (commercial sample)

4.2.7 Drvina ex~er iments conducted in solar tunnel drver (tunnel dried sample)

The post-harvest processing comprises pre-drying, drying and post-drying

treatments. Cleaning, peeling, and washing were the three pre-treatments adopted.

Pre-dtying treatment

Cleaning :- Rhizoids, roots, scale leaves, soil, dirt and other unwanted earthen materials

adhered to the harvested rhizomes were removed manually. A wire brush made up of

palm fibre, and a steel knife were used for this purpose. Diseased, under matured and

decayed rhizomes were removed from the experimental samples. Cleaned rhizomes were

heaped into one group.

Peeling :- Peeling was conducted by adopting lye abrasive method. Samples were

heated in 20% sodium hydroxide solution (lye) for two minutes at a temperature of 70°C.

Bamboo baskets of considerable hole size was used for dipping the rhizomes in lye

solution. After treating with lye solution rhizomes were taken out and placed in citric acid

for 2 hours. Rhizomes were taken out and allowed to drain.

Abrasive peeling was conducted manually by rubbing the chemically treated

rhizomes with coir carpet. After the peeling rhizomes were heaped in clean room.

Washing :- Jet flow of water was applied to the rhizomes to discard all the unwanted

materials. Washing was continued until the rhizomes were free of dirt and other impurities.

Then they were spread in clean bamboo mats for draining the excess water.

Drying of ginger

The pre-treated rhizomes were spread inside the tunnel dryer as single layer.

Spreading was done in such a way that maximum surface area was exposed to hot air

current and direct light coming through the plastic roof. The spread layer was maintained

strictly devoid of overlapping. Dryer was closed and allowed the samples to dry. The

rhizomes were turned every hour for providing a more or less uniform drying condition.

Completion of drying was confirmed manually by pressing and testing whether the

rhizome could be broken. After drying the rhizomes were gathered inside the dryer into a

heap. Dry weight and amount of spice recovery was calculated. The formula for

calculating the percentage spice recovery is already described in chapter 2 (2.2.7).

Post-drying treatments

Rubbing and cleaning were the post-drying treatments carried out. Before

releasing the heat rhizomes were squeezed together along with the plastic net in which

the spreading was done to remove all the remnants of the skin. Time taken for rubbing

was standardized. Cleaning the rhizomes was also done to throw away all the impurities

formed after rubbing. Small pieces measuring below 1.5 cm in length were also removed.

Random subsamples were taken in triplicate for conducting physico-chemical quality

analyses. Remaining samples were packed in thick walled jute bags with polythene lining.

These bags were kept on raised wooden platforms placed in clean rooms.

4.2.8 Conventional method of dwina conducted in the research centre (conven-

tional sample)

Second subsamples collected from each station were dried by conventional

method. Open sun drying method was employed for this drying. This was done

simultaneously along with tunnel drying.

Ginger rhizomes were peeled using iron knives and bamboo splinters. Cleaning,

chemical treatment, washing etc. were omitted in this method. The peeled rhizomes were

spread in bamboo mats for drying in open sun. Turning the crop was done every evening.

Completion of drying was assessed manually. After drying the rhizomes were rubbed

together to remove the skin parts. Subsamples were taken in triplicate at random for

quality evaluation.

4.2.9 Conventional ~rocess ina bv farmers (Commercial sample)

Respective farmers of each sampling station conducted third experiment with the

same sample. They had dried the samples in the routine drying method. Regional

variations in the drying by farmers were noted. For the quality evaluation known quantity

of subsamples were taken.

4.2.10 Repetition of experiments

The drying experiments were repeated for one more season to find out the

reproducibility of the results. These experiments were conducted during November 1999

to March 2000 (second season). However samples were collected only from 14 stations

out of the previously studied 44 sampling sites such that each station represented a

particular district. The stations selected were the locations of the highest production and

yield. Same methodology was adopted for the sampling, drying and quality evaluation of

ginger in the repetition experiments also.

4.2.1 1 Quality evaluation of ginger

Detailed physico-chemical analytical procedures are listed in chapter 2 (2.2.11).

The chemical parameters such as piperine content, and physical parameters like

pinheads and light berries were not analyzed for ginger.

4.2.12. Data Anaivses

Methods adopted for data analyses were also similar to that of black pepper

(Chapter 2.2.12). The significance of the differences belween the treatment means was

confirmed by analyzing t test.

4.3 Observations and Results

4.3.1 Observations on ainaer production in Kerala

The survey conducted during the study revealed the following.

Q p e of soil selected for ginger cultivation in Kerala

Thiruvananthapuram

Kollam

Pathanamthitta

Alappuzha

Kottayam

ldukki

Ernakulam

Thrissur

Palakkad

Malappuram

Kozhikkod

Wayanad

Kannur

: Any soils; sandy, red earth, other loose soils, paddy fields

etc. with drainage

: Any soils with good drainage

: Any soils other than black soil with drainage, red earth with

sandy soil is best

: Sandy (coastal areas), clayey loam, laterite, red with

drainage and moisture

: Top and laterite soils, both paddy field and above ground.

Not in marshy areas

: Any soils with moisture, interspaces and drainage. Red and

black are advisable

: Any soils, red and laterite soils are more (midland areas).

: Any soils with sticky and drainage properties; never be water

logged

: Any soils with moisture and interspaces, clayey sand is

good, never be dry and hot. Some prefer black soil

: Any soils with good drainage, both paddy fields and above

lands

: Soils with good drainage

: All types of soils with good drainage, both paddy fields and

above lands. More advisable is forest soils having intrinsic

fertility

: Soils with enough interspaces for easy spreading of roots

Kasaragod : Red and laterite soils of eastern parts of the district. Sandy

soils too (coastal)

Metlrod ofplanting

Preparation of land is carried out during the months of AprilIMay i.e. just after the

summer rains. Before planting, the area selected is ploughed and forged. Land is

excavated to a depth of 1-2 inches, and mixed with cowdung, ash and/or other manure.

Many prospective farmers apply bone meal, chemical manure, farmyard manure, compost

etc. into the soil during land preparation. Many farmers also apply quicklime in order to

avoid pest infestation. Organic fertilizer like green manure and leaf mulch are also in use.

Mixing cowdung with ash is considered unsuitable whereas addition of mussuriefose is

advisable. Normally the land is divided into beds of definite size. Generally a bed has a

breadth of 5' or 3' made into desired length. Height of the bed varies according to the area

in which the ginger is cultivated. The factor to be considered is that there should not be

water logging. In lands that are situated in low elevation (eg. Paddy field) the height is

adjusted to 1%' or 2'. However many farmers suggested that it is better to adjust the

height of bed to 2' or 3' minimum for getting more yield. A distance of 2' is always left free

between beds. Certain farmers leave 9" gap between beds. The planting material is seed

rhizome, which is prepared from the healthy mother rhizomes of previous year. Seed

rhizomes with a minimum length of 2-4" and having at least oneltwo bud are taken and

laid into the bed. According to many farmers it is far advantageous to immerse the

rhizome in cowdung water before laying down. Many others treat with sawdust and/or

calcium oxide. However in some high productive areas farmers always soak the seed

rhizome in pesticides such as furedan, indophil, emisan etc. This treated rhizome is kept 2

or 3 days for drainage before planting. Certain others put the seed rhizomes in water for

one day and plant it in pits. The pit is then filled with dried cowdung. It is suggested that

addition of bone meal with cowdung results in better sprouting rate. After planting the

entire bed is covered with green leaves. Leaves regularly used for the preparation of

mulch are Glim'scida (konna), Glycosmis (panal), Macamnga (vatta), Mangifem, Ricinus

and other easily decayed and nutrient rich leafy plants.

121

Preparation o f seed rhizome: - For the preparation of seed rhizomes healthy and

disease free mother rhizomes are selected from the previous crop. Seledion of desired

varieties/cultivars is also a major criterion. The rhizomes are cleaned off soil and kept in

shade for a few days for partial desiccation. After the partial drying the rhizomes are kept

in some specially made pits or caves. The method of seed rhizome preparation varies

slightly according to different areas. Many farmers put the rhizome in cavities made in the

soil and cover it with dry leaves (glycosmis, cassia, neem) and other materials like

sawdust, paddy husk etc. meant to resist rhizome borer. Some farmers belonging to

Palakkad district make cavities or caves on earthen walls or sides of hilly slopes, put sand

or soil at bottom, and store healthy ginger rhizome in it. The cavities are dosed with

wooden planks coated with soil paste and plastered. Buds arise during next season

(karthika njattuvela), after 4 or 6 months. Another group makes raised platforms (chew)

and put the selected rhizomes on the platform. Then the rhizomes are subjected to

smoking (green leaves are used for making smoke eg. Glycosmis) for partial dehydration.

However many farmers especially belonging to Wayanad and nearest areas keep the

rhizomes in dry soil surface and cover it with loose soil. Heaping up of seed rhizomes on

plain grounds for the next year without any treatment is also prevailing in Kerala. Soaking

the seed rhizomes in cowdung water before storage is considered to be good. Many

farmers cut the mother rhizomes selected for the preparation of seeds into small pieces

before storing. Generally the seed rhizome is stored for 3-5 months. AS the cropping

season approaches the seed rhizomes start sprouting. One finger length sized piece of

rhizome with two to three buds is generally used for planting. Approximately 500 kg d

seed rhizome is needed to plant one-acre area.

Cultivars

Survey results unveiled that only 21 cultivars are being cultivated in Kerala. Many

farmers do not know the name of the cultivar that is cultivated. Cultivar named as nadan

varies in appearance and quality in many places. A district wise list of cultivan is given

below.

Thiruvananthapuram

Kollam

Pathanamthitta

Alappuzha

Kottayam

ldukki

Ernakulam

Thrissur

Palakkad

Malappuram

Kozhikkod

Wayanad

Kannur

Kasaragod

: Kozhikkalan, Nadan

: Nadan

: Nadan (Vadakkan and Thekkan)

: Nadan

: Nadan, Nadan Malabar, Maran, Himachal

: Elakkallan, Maran, Nadan, Himachal, Ambalavayal

: Kuruppampadi, Wayanadan, Maran, Himachal, Manathavadi.

Vadakkanchery, Nadan, Chalu, Ambalavayalan

: Himachal, Maran, Nadan, Neerinchi, Kozhikkalan, Wayanadan

: Nadan, Kozhikkalan, Neelagiri

: Nadan

: Maran, Hirnachal, Nairobi (Neerinchi)

: Maran, Himachal, Nadan, Arnbalavayalan, Ragodi, Ellakkallan,

Rheo-de-Janeiro, Calcutta, Ernadan, Wayanadan

: Wayanadan, Nadan

: Nadan

Cropping metltods

Ginger is commonly cultivated as an intercrop. Extensive gardens of ginger are

seen in some regions of Ernakulam, Idukki, and Wayanad. However mixed cropping with

other vegetables is a major pattern of cultivation in Kerala. Intercropping partners may

also be coconut, areca nut, pepper, rubber etc. The frequency of cultivation is mainly

influenced by the price of the commodity. Now-a-days off-season cultivation in paddy

fields of high ranges has got enough attention. Mid land areas are the main centres of

production. Crop rotation system with cassava, banana, vegetables, rice etc. is also

prevailing in Kerala. Many areas of northern districts adopt a method in which ginger beds

are bounded with green chillies and brinjal. Turmeric is also used as a companion crop.

1 ime oj planting and watering

In southern districts of Kerala farmers prefer to plant ginger during the months of

Kumbham, Meenam (MarchlApril) just after receiving summer rains. Others (Eg. Palakkad

areas) choose Medam (Aswathi, Bharani, ~arthika %) month as the optimum time. The

festival of 'Vishu' (equinox) is the apt time for planting according to certain planters of

Northern areas. Where irrigation is available ginger is planted early. This makes early

harvest. In Kothamangalam, Moovattupuzha, Koothattukulam regions, which are the

highest ginger producing areas, farmers start cultivation by mid April and extend to early

June. Large number of farmers cultivate ginger throughout the year irrespective of

seasons. However for the production of dry ginger the optimum time recommended is

AprillMay months.

There exists a traditional proverb in Kerala regarding the time of planting of ginger

i.e. 'karthika njattuvelayil kasholam nattu kanjirathin chavaru moodanam', meaning,

Karthika njattuvela is the best season for planting ginger; it needs only very small piece of

seed ginger, and mulching with Ricinus leaves yields more.

Watering is not done commonly as majority of plantations are rain-fed. Some do

watering during the initial period of planting if rain is not enough, and also for inigated

crop.

Manuring

Commercial cultivation of ginger employs application of manure in high quantities.

Application is done twice or thrice a span. The quantity and variety of manures vary

according to different areas. Cowdung slurry is sprayed on aerial parts at regular intervals

(2 or 3 times a year). The treatment of chemical fertilizers starts only after the formation of

2-3 leaves. Factumphose, 17:17, 17:18, 8:8, 8:8:16, complex fertilizers, ammonium

manures, murriate of potash (MOP), rnussuriephose, urea, potash etc. are the chemical

manures generally used. Generally farmers apply manure twice in a year at the rate of 50

or 100 gm per plant. Farmers have different opinion regarding the time of application and

item to be applied. Cowdung (both dried and fresh) is the single most manure used in

large quantities. Some farmers use cowdung only. Organic fertilizers like groundnut cake,

coconut cake, neem cake, compost, green manure, bone meal, dried leaf, mulch, ash, etc.

are also applied regularly at various rates. Many farmers have the belief that the quantity

per plant in a span to be used is 50-250 grams as in the case of chemical manures and 1-

5kg or even more for organic manures, especially cowdung. According to many farmers f

urea and complex fertilizers are used in large quantities the yield would be high; at the

same time chances of disease incidence increase. Organic farming of ginger is still at an

infant stage in Kerala.

In places like Kanjoor and Kalady in Ernakulam district farmers had used poultry

droppings regularly and in large scale during the last decade. However this practice is not

followed now.

Farmtirtg operations

Mulching is the most important farming operation. This is done at the seed laying

time, and then two or three mulches are prepared during the entire period at regular

intervals. Mulching is meant for the protection of seed rhizome from heat and it is good

manure also. The system always maintains a cooling atmosphere that helps buds to

sprout. Moreover the chances of weed growth and disturbance by domestic animals are

also low. During the initial stages of growth many farmers protect the bed from sunlight by

covering with palm fronds or with other shade leaves.

After one month or 40 days the entire bed is reshaped and bounded. Removal of

weeds and mulching are also done during this time. Uprooted leaves and decayed ginger

leaves are used as mulch. Generally this resetting, mulching and weeding are done twice

or thrice. Aerial spraying of cowdung water is a subsequent process of every farming

operation stated above and is intended as a prophylactic measure.

Time ofjluwerirtg

Flowering happens in ginger rarely and it has no direct impact on crop production.

According to variety and climate flowering may or may not occur.

Pesticide application

Ginger is a plant very much susceptible to diseases. Prophylactic measures are

being carried out in general. Many of the marginal farmers do not apply any pesticides

except cowdung slurry; others do pesticide application only when disease appears.

Application of bordeaux mixture is a regular process. Farmers belonging to southern

districts of Kerala utilize a medicine prepared manually by mixing garlic, neem oil and

soap powder. Many prospective farmers of Kottayam district employ this decoction in a

different manner. A pesticide called 'Fois' (fish oil insecticidal soup) manufactured by

Kerala soaps and minerals limited has got appreciation from many farmers. Neem oil and

nicotine oil are also in regular use as reliable pesticides in Palakkad. Others apply

pesticides whenever there is a suggestion from Krishi bhavan. Furedan, ecalex,

monocrotophose, malathion, emisan, democran, roger, copper oxychoride (COC) etc. are

employed against many of the diseases. Farmers belonging to coastal belt use nuvacron

as a major biocide. Application of copper sulphate, calcium oxide (quick lime), dithane,

powdered sulfer, kerosene and DDT is not uncommon in Kerala. However the enormous

usage of bordeaux mixture in Kerala still underlines the farmers' reliance on it More over,

the survey revealed that the trend of organic farming in Kerala is increasing year by year.

Diseases

Soft rot or foot rot caused by Pithiurn aphanidematum remains the serious

disease of ginger. It is called as 'Mahali' in Malayalam. Large areas of ginger plantations

in Ernakulam and nearby districts were destroyed due to foot rot during last decade. The

affected rhizomes experience a smell of rotten egg. Slow wilt caused by bacteria is

another serious disease responsible for massive loss. Yellowing, wilt, curling of leaves

and leaf spot diseases are also reported. Except rhizome borer, leaf fodder, and 'munja'

no other observable pests are recorded in many regions of southern districts. Out of this

rhizome borer is the most dangerous. Some nematodes are also reported in ginger. Leaf

burning and bleaching are some of the diseases reported from some areas of ldukki

district. Mosaic disease caused by virus is also reported from ginger. However disease

free gardens also do occur.

Fungal infestation is very much possible in stored seed ginger also. Many farmers

surveyed are victims of drastic loss of stored ginger. So it is suggested that the seed

rhizomes are to be soaked in fungicides before storage.

Harvesting season

The harvesting of ginger depends upon maturity and the ultimate use. For culinary

uses fresh ginger is harvested every season as it is an indispensable item of most of the

South Indian cuisines. For the preparation of processed ginger harvesting is done from

November to February or may extend to March. According to a progressive farmer of

Thrissur district, if harvested during night and when there is lunar glow the resultant ginger

(processed) could achieve more shelf life. For the preparation of pickle, tender ginger, etc.

right maturity condition of ginger is crucial. Many industries have started processing of

ginger while the accumulation of chemical principles is at maximum, rather than attaining

full maturity. If any unforeseen problems happen during the harvesting season farmers

keep the mature ginger undisturbed. The beds are covered with mulch (leaves and other

plant parts) and harvested later. Many cultivators prefer to harvest during the next

Karkidakam season (after six months).

During the time of harvesting all the leaves and aerial parts of the plant tum yellow

and fall off subsequently. Maturity of the rhizome is detected by looking the above

appearance. Farmers belonging to Kottayam and some mid land areas detect the maturity

by breaking the rhizome and confirm by observing a tint of blue wlour. Wdh the help of

spade or other indigenous equipments (koonthali, para, manthi, muppalli, kothi) farmers

unearth rhizomes from the bed carefully.

Immediately after the harvest healthy rhizomes are selected first for making seeds

for next year. Rhizomes used for the preparation of seed are generally selected from the

beds of above land and not from the low rice fields, since the latter contain high initial

moisture content.

Yield of ginger

Ginger yield varies according to the cultivar and agro-ecological conditions of the

place in which they grow. Many farms yield a quantity of 200-250 gm (fresh ginger)/plant

as minimum, while the average being 500 gm. An yield of I-?% kg or even 4 kg (fresh

ginger)/plant is achieved regularly from gardens of Pathanapuram, Mavelikkara,

Pathanamthitta, Kanjirappillly, etc. Yield of ginger obtained from low fields is always higher

than that of high dry areas because of the high initial moisture. A mean yield of 500 gm

fresh gingerlplant is considered as standard yield.

Post-lzarvest operations

Pre-drying treatments: - The majority of farmers sell the harvested rhizome directly to

the market. Harvested ginger collected by intermediates from all over the State is

transferred into processing centres. There are a few who do processing at their own cost.

Cleaning, washing and peeling are the pre-treatments adopted. Many farmers do

not conduct any cleaning process but peel off partially before drying. Only some of the

prospective farmers do cleaning, by removing roots, rhizoids, dirts, soil particles and other

unwanted matters from the harvested rhizome. But survey revealed that no farmer do

washing before drying. Peeling is carried out by manual methods, in which the outer skin

of the rhizome is discarded partially especially from the broader surfaces. Different

equipments are used for peeling. Iron knife, sickle, bamboo splinters etc. are some of

them. Mechanized peeling is done in some industrial and research sectors. Skilled lady

labourers generally carry out peeling, otherwise loss of matter happens along with peel. In

some areas, processors of industries do not peel the skin; but slice the rhizome into cross

sections having a thickness of 3-5 mm. For the preparation of bleached ginger, large-

scale processors mainly do bleaching i.e. a treatment of immersing fresh ginger in 2%

quicklime solution for about 6 hours. Bleaching of ginger is meant to be done for achieving

a uniform attractive colouration and also for enhancing shelf life.

Drying operations: - Prevailing ginger drying method in Kerala is open sun drying. The

peeled rhizomes are spread on hard rocks of hills, sandy surfaces, cement floors.

terraces, bamboo mats, or even soil surfaces and allowed to dry. Some fanners apply

sand on mats and then spread ginger for maintaining hotness for a long time. There is

also a practice of smoke drying during adverse weather conditions. It is believed that

drying during post new moon season of Karkidaka month (namely velutha pakkam) results

in deterioration of rhizomes due to the attack of rhizome borer. Farmers of Thiruvambadi

suggest that the best time for conducting drying of ginger is during the period after 4 days

of full moon until new moon or full moon to amavasi (new moon). Respreading the crop is

done some times but not regularly. However, heaping is done in the evenings, and further

spreading during next day. In several mid-Travancore provinces farmers do a second

removal of skin from the inner areas of the rhizomes (called edakuthu) after the exposure

of rhizomes for 2 or 3 days. Then thls is again spread for complete drying. Some others

conduct open sun drying mixed with sulfur fumigation alternately. In areas of Thrissur

farmers used to spray quick lime during drying time; but this practice is stopped now.

Minimum of 5-10 days are needed for complete drying depending on the weather and

magnitude of inltial drying. In the opinion of majority of fanners and processors if the first

stage of drying has not achieved optimum level within the unit time the surface of the

ginger produces a pseudoskin, which hinder further dehydration. To complete the drying

process farmers belonging to lritti have adopted a special system in which the ginger

rhizomes with pseudoskin are subjected to further treatment. They create pits in the

ground and make fire inside it. After some time the fire is removed and the rhizomes are

placed in it and covered with dry soil. These treated rhizomes dry fast when spread in

open sun for a period ranging from I hour to 2 days. However this system has not

disseminated widely. The completion of ginger drying is confirmed by observing its

physical appearance and aroma. Some people break the dried rhizome and look for the

appearance of fibres on cut surfaces and determine drying completion.

Spice recovery varies according to the cultivar, maturity, location, ecological

factors and drying practices. In general one fourth is obtained from fully mature ginger.

129

Some cultivars, which are mainly cultivated for the production of fresh ginger, give only

20%. A farmer has got spice recovery of 35% from cultivar Maran with good fibre and

organic matter, 25% from Calcutta and 22% from Himachal. Farmers belonging to

Kothamangalam region claimed that if drying is conducted in February the recovery ww ld

be at 3.5:l ratio, whereas 3:l recovery could be achieved if the drying is in March.

Regarding dry recovery farmers belonging to various regions have different opinion; often

a recovery rate of 115'~,1/6'~, 1 ~ ' ~ etc. are attained by many farmers.

Post-drying operations: - Majority of the farmers does not conduct any post drying

operations. Only some export-oriented firms conduct this. Sulfur fumigation is the regular

process employed.

Separate rooms are equipped for conducting sulfur fumigation. Solid sulfur is

burned within a container kept at the centre of the room. Dried ginger is arranged as a

shielding wall around the container. Height is adjusted according to the quantity to be

fumigated, and room size.

At least in some areas people do rubbing off the dried rhizomes against each other

and remove the peel partially. According to some farmen trampling is being carried out in

some northeast regions of the country to remove debris. Many merchants and some of the

farmers often carry out Calcium hydroxide treatment after drying to improve storage lie.

After soaking rhizomes are again dried for 5-10 minutes.

Dried ginger is sold immediately after drying or within 2-3 months. Processed

ginger is stored in gunny or jute bags after sulfur fumigation. According to many growen

spreading of lemon grass leaves inside the storage room prevents the attack of insect

borer and enables storage up to many months. Sulfur fumigation retains the product only

for 2 or 3 months. Bleaching of ginger enhances storage life, may be up to some years.

Some farmers apply DDT over the sheet kept above the ginger sacks for keeping away

the insects. They never use plastic bags since it leads to wetting inside. Farmers

belonging to Cherthala and Pathanamthitta do conduct sun drying of dried ginger at

regular intervals during storage. Fungal patches appear upon storage due to improper

drying especially during the rainy season. Wooden platforms are raised for arranging

ginger bags as said by many people. Scientifically, dried ginger can also be stored in

chambers provided with aluminium phosphide capsules as suggested by a farmer of

Thiruvambadi (Kozhikkod). But now the usage of this chemical is banned.

4.3.2 Results of the dwina ex~er iments (season 1)

Daily average of solar radiation, temperature and relative humidity of ambient air

and tunnel dryer measured during the drying of ginger in solar tunnel dryer are

represented graphically (Fig. 13 to 15)

750 E

600

450 s k 300 - 31

150

0

m - - " - P u, - Tlme (hours)

Fig. 13: Daily average solar radiation during the drying of ginger in Solar Tunnel Dryer

The intensity of the solar radiation increased from the morning to noon, reached a

maximum at 1 pm and then decreased. The maximum and minimum solar radiation

recorded were 813 W/mZ and 98 W/mz respectively.

Time (hours)

Fig. 14: Mean daily temperature of ambient air and dryer during the drying of ginger

80 - +Ambient air

70 -

/*

- - - = 20 - -

T i m (hours)

Fig. 15: Mean daily relative humidity of Ambient Air and Dryer during the drying of ginger

in Solar Tunnel Dryer

The temperature inside the dryer varied from 32OC to 70°C and in the surroundings

30°C to 3E°C. The relative humidity inside the dryer was 29% to 59%, and in ambient air it

was 43% to 67%

Initial Moisture Content (IMC)

The mean initial moisture content of ginger samples collected from 44 stations is

represented in table 41. The average IMC of all the stations was 78.2%. Initial moisture

content of Harippad samples showed the maximum (79.9%) and Ranni station showed

minimum (76.1 %).

Table 41: Initial moisture content of ginger samples collected from 44 stations

Drying time

As estimated from the 44 samples the drying time varied from 40 to 56 hr for

commercial samples done by the farmers. Conventional drying also took 40 to 56 hr.

About 24 to 28 hr was required for solar tunnel drying (Table 42). The statistical test

shows there is highly significant variation in drying time. Out of the three-sample groups

tunnel dried samples took the lowest drying time.

Table 42: Time taken for drying of ginger collected from 44 stations (Gl-G44), results

of ANOVA, and critical ratio estimates of drying of ginger following three

different methods

Spice Recovery

The mean spice recovery of the commercial sample was 25.89%, conventional

26.32% and tunnel dried 24.67%. The analysis of variance indicates significant difference

in spice recovery of the three sample groups. Lowest spice recovery was observed in

tunnel-dried samples. Critical ratio and other analytical data are detailed in Table 43.

Table 43: Spice recovery of ginger collected from 44 stations, results of ANOVA, and

critical ratio estimates after drying following three different methods

4.3.3 Quality evaluation of ainaer

Final Moisture Content (FMC)

The final moisture content of commercially dried ginger sample was 13.64%,

conventional 12.65%, and tunnel dried 10.88%. Data analysis shows that the moisture

135

Critical Ratio Significance

P<O.01

P<O.01

P<0.05

Test

Commercial vs S.T.Dlyer

Conventional vs S.T.Dryer

Conventional vs Commercial

Value

7.18

9.94 2.47

content of the three sample groups varied significantly. Out of the three sample groups the

lowest moisture content was observed in tunnel dried samples (Table 44).

Table 44: Final moisture content of 44 ginger samples aialyzed after drying in three

methods, results of ANOVA and critical ratio estimates of the treatments

Volatile oil

The mean value of the volatile oil content of the commercial sample was 1.87%

vlw; conventional 2.08% vlw and tunnel dried 2.43% vlw (Table 45). The sample from

Rajakkad station recorded the highest percentage of volatile oil (3.5%), after drying in

solar tunnel dryer. Highly significant variation was noted in the volatile oil content of three

sample groups. Among the three samples the highest volatile oil content was observed in

tunnel dried samples.

Table 45: Volatile oil content of ginger dried according to three different methods,

results of ANOVA and critical ratio estimate

Oleoresin

The average oleoresin content of 44 samples belonging to commercial group was

5.58%; that of conventional 6.00% and tunnel dried 7.57% (Table 46). Solar tunnel dried

Neyyattinkara samples showed the highest percentage of oleoresin content (12.1%). The

statistical analysis indicates that there is highly significant difference in oleoresin content

of the three sample groups. The highest oleoresin content was obsewed in tunnel-dried

samples.

Table 46: Oleoresin content of ginger dried according to the three methods, results of

ANOVA, and critical ratio estimates of three tests followed

Wzole insects dead

The contamination incidence was 100% in commercial samples and 25% in

conventional samples. Only 18% of the solar dried samples were infected. The mean

number of dead insects counted in commercial samples was 4.82; in conventional

samples 0.82 and in tunnel dried 0.2 (Table 47). The count in commercial sample varied

highly than the other two. Significant difference was observed in dead insect count of the

three treatments. The lowest number of insects was observed in tunnel-dried samples.

Table 47: Whole insects dead count of ginger samples dried under three methods,

results of ANOVA and critical ratio estimates of various treatments

Excreta Mammalian

Solar tunnel dried samples were completely devoid of mammalian excreta. The

incidence was 81% in commercial and 30% in conventional samples. The mean of 44

samples was 20.07 mglpound and 3.34 mglpound respectively (Table 48). A maximum

value of 90 mgllb was recorded by a sample dried in commercial method. Statistical

analyses showed significant difference between the three sample groups. Among the

three sample groups tunnel-dried samples were totally hygienic in terms of mammalian

excreta.

Table 48: Excreta (mammalian) content of ginger samples dried under three methods,

results of ANOVA and critical ratio estimates of various treatments

Excreta Others

Test I Value I Significance

The presence of 'excreta others' content was negligible in all the samples dried

according to three different methods.

Mold

Conventional vs Commercial

Almost 93% of the commercial and 63% of the conventional samples showed mold

contamination. Mold was totally absent in solar dried samples. The contamination of

samples by mold estimated as percentage by weight was 26.98 in commercial, and 0.58

in conventional (Table 49). The mold infestation was notsbly low in the conventional

sample compared to commercial samples.

5.95 P<O.01

Table 49: Mold content of ginger samples dried as per three different methods, results

of ANOVA, and critical ratio estimates of different tests

Insect defiledlin fested

Insect infestation was 100% in commercial group, 91% in conventional set and

23% in tunnel-dried samples. The dried ginger infested with insects was 10.73% in

commercial, 1.47% in conventional and 0.11% in tunnel-dried sample (Table 50). The

ANOVA indicates highly significant difference in insect defiledlinfested quantity of the

three sample groups. The contamination was considerably low in solar tunnel dried

samples. The difference between pairs of sample means was also significant.

Extraneous/foreign matter The contamination incidence was 100% in the commercial, conventional and

Table 50: Insect defiledlinfested rhizomes of ginger samples dried under three

methods, results of ANOVA and critical ratio estimates of various tests

tunnel-dried sets. The mean value of extraneous matter in commercial sample was

Test - Commercial vs S.T.Dryer - Conventional vs S.T.Dryer

Conventional vs Commercial -

3.68%, conventional 2.98% and tunnel dried 0.85% (Table 51). Data analysis shows that

there is significant variation in extraneous matter of the three sample groups. Out of the

Value

8.85

8.00

7.65

three sample groups the lowest and ASTA qualified extraneous matter content was

Significance Pc0.01

Pc0.01

PcO.01

observed in tunnel dried samples. There was significant difference among all the

treatment pairs also.

Table 51: Extraneous/foreign matter of ginger samples dried under three methods,

results of ANOVA and critical ratio estimates of various treatments

4.3.4 Repetition of drvina experiments and quality analyses (season two)

Data on temperature, relative humidity and solar intensity measured during the

drying of ginger during the second season showed no significant difference. The t-test

results of various quality parameters also showed no significant difference between the

results obtained in season one and two (Appendix XVI). The mean initial moisture content

of 14 samples is 78.24%. Maximum IMC was recorded in Panachamood sample (79.2%)

and Manjeri sample showed the minimum (76.9%)

Data of spice recovery and drying time are recorded in tables 52 and 53. The spice

recovery of commercial, conventional and solar tunnel dried was 26.21%, 26.90% and

24.75% respectively. The least recovery was in the solar tunnel dried samples.

Critical Ratio

Test

Commercial vs S.T.Dryer

Conventional vs S.T.Dryer Conventional vs Commercial

Value

8.09

6.45

1.52

Significance

P<O.Ol

P<O.Ol

P<0.01

Commercial and conventional samples gave almost similar yield. The drying time taken

was 50 hours in both commercial, conventional drying and 26 hours for tunnel-dried

samples.

Table 52: Spice recovery from ginger collected from 14 stations (GI-G14), results of

ANOVA, and critical ratio estimates of drying of ginger following three

different methods

Table 53: Time taken for the drying of ginger collected from 14 stations (GI-G14),

results of ANOVA, and critical ratio estimates of drying of ginger following

three different methods

0 1 48.0 1 24.0 1 Critical Ratio 0 1 46.0 1 24.0 1 Test Value innifinnen G I0 1 48. -. . 5. ., . .--, , - -

GI1 1 48.0 1 56.0 1 26.0 1 CommercialvsS.T. Dryer I 17.99 P<0.01

0 1 54.0 1 27.0 1 Conventional vs S.T.Dlyer I 19.63

conventional 12.56%*0.62 and tunnel dried 10.55%*0. 57 (Table 54).

- 144

GI2 G I3 GI4

P<O.Ol

The mean final moisture content of 14 commercial samples was 14.72Y0k1.36;

56. 48.0 1 48.0 1 27.0 / Commercial vs Conventional I 3.08 Insignificant

44.0 1 48.0 1 25.0 / C1-Conventional, C2-Conventional, C3-Solar Tunnel Dryer

The mean value of the volatile oil content of the commercial sample was 1.5E0/oi

0.2 vlw; conventional 1.89%i0.14 vlw and tunnel dried 2.28%*0.14 vlw (Table 55). Out of

the three sample groups the highest volatile oil content was observed in tunnel dried

samples. Solar tunnel dried Pathanapuram and Pazhayannoor samples had the highest

volatile oil content (2.5% vlw).

Table 55: Volatile oil content of ginger dried according to three different methods,

results of ANOVA and critical ratio estimate

The mean data of oleoresin content of 14 samples of commercial outlets was

6.04%*1.22; conventional 6.16%*0.85 and tunnel dried 7.68%i1.12 (Table 56).

Thiruvambady station recorded the highest percentage of oleoresin (9.4% by weight).

Table 56: Oleoresin content results of ANOVA, critical ratio test conducted after drying

of ginger in three different methods

Almost all the samples dried under commercial, and about 71% of the

conventional samples contained dead insects; only one of :he tunnel-dried samples had

dead insect. The mean number of dead insects counted in commercial sample was 6.64,

in conventional samples 1.71 and in tunnel dried 0.07 (Table 57).

Table 57: Whole insects dead count of ginger samples dried under three methods,

results of ANOVA and critical ratio estimates of various treatments

Mammalian excreta was present only in commercial and conventional samples,

the incidence was 100% and 64% respectively (Table 58). The mean of 14 samples was

22.64 mgllb and 3.36 mgllb respectively. 'Excreta others' was absent in all the samples

dried under three methods.

Table 59 represents the result of analysis on mold. Cent percent of commercial set

Table 58: Excreta (mammalian) content of ginger samples dried under different

methods, results of ANOVA and critical ratio estimates of various treatments

Table 59: Mold content of ginger samples dried as per three different methods, results

of ANOVA and critical ratio estimates of different tests

and conventional group had molds. The contamination by mold was nil in tunnel dried

samples. The mean of 14 samples drawn from the commercial outlets was 16.78% and

conventional 0.90%. Critical ratio estimate between the three different tests also showed

high variation.

Insect defiledlinfested ginger rhizomes are 100% in samples dried under

commercial method and 78% in conventionally dried samples, but in the case of tunnel-

dried samples the incidence was zero. The mean data of infestation was 6.46% in

commercial and 1.09% in conventional sample (Table 60)

Table 60: Details of insect defiledlinfested ginger samples dried under three methods,

results of ANOVA and critical ratio estimates of various tests

The presence of extraneous matter was complete in all the ginger samples, but

tunnel dried samples showed a nominal quantity. The mean value of extraneous matter in

commercial sample was 5.09% by weight; conventional 2.19% by weight and tunnel dried

0.82% by weight (Table 61).

4.4 Discussion

Ginger is cultivated in a variety of soils. In Kerala ginger is a regular crop, in the

sandy coastal sea level soils to high altitude Wayanad soils. According to the farmers of

Kerala, though ginger thrives well in high fertile soils, any barren land can be effectively

utilized for ginger cultivation. Kumar et a/. (1997) reported that ginger thrives best in well-

drained soils like sandy or clay loam, red loam or laterite loam; ideal is a friable loam rich

in humus. As suggested by Spices Board (Anonymous, 1999) ginger can be effectively

cultivated in any soils with enough drainage but being an exhaustive crop it may not be

desirable to grow ginger in the same site year after year. Scientists from Kerala

Agricultural University opined that ginger cannot withstand waterlogging and hence soils

with good drainage are preferred for its cultivation (Rajamohanan, 1996). Recent studies

revealed that ginger gives more yield under coastal and sandy friable soil belts providing

enough drainage (Anonymous, 2001b). Present study shows that soil selected for ginger

cultivation by the farmers either possess good drainage or by providing additional

operations farmers make it desirable

Regarding land preparation and field operations for ginger cultivation, farmers of

Kerala have common methods. Except for some marginal growers, most of the farmers

thoroughly prepare the land into fertile and well-drained condition, by making raised beds

and adding manures especially dried cowdung into the soil and mixing well. According to

Valsala (1998) since the ginger cultivation in Kerala depends on rainfall, the cultivation

should be started at the receipt of summer rains for getting good yield. It is reported that

the land selected for cultivation should be ploughed 5-6 times before planting seed

rhizomes. This is meant for making the soil more friable and loose (Benjamin. 2001). As

per the recommendations of Spices Board solarization of the bed is beneficial in checking

the multiplication of pests and disease causing organisms (Anonymous, 1999). However,

survey results revealed that farmers sometimes use quick lime for checking pest

infestation. Use of green manure and mulch has got wide appreciation as fertilizer source

Application of ash is considered to be unscientific, however many farmers have adopted

this, rather than using chemical sources of phosphorous. Present survey noticed that for

the preparation of beds and associated operations farmers belonging to different areas

have their own options. However, ginger beds must be raised maximum where there are

chances for water logging.

Seed rhizomes are used as planting material. Many farmers told that seed

rhizomes must have a minimum size, say 2-4 inches. According to the studies conducted

in Regional Agricultural Research Station, Ambalavayal, a seed rhizome shall be weighed

at least 15 grns (Kannan, 1993). Some farmers adopt number of buds present in the seed

as the prime criteria. Pillai (1981) suggests that seed rhizome of ginger is preferably with a

weight not lower than 35 gms. However according to many traditional farmers of Kerala if

planting is conducted during 'Karthika njattuvela' (April-May) it needs only small sized

rhizomes.

Farmers have diverse opinion regarding the pretreatment of seed rhizomes in

fungicides andlor pesticides. Still majority farmers use cowdung slurry for soaking the

rhizomes. Though the methods are different most of the farmers use pretreated seed

rhizomes for planting. Pruthi (1993) reported that soaking of seed rhizomes in mancozeb

and malathion for 30 minutes is advantageous. However Spices Board suggested that

seed rhizomes should not be treated with any chemicals (Anonymous, 1999). This survey

disclosed that farmers are well aware of disease incidence on seed rhizomes. Hence by

either adopting traditional methods or soaking in chemicals they always try to discard the

chances of disease incidence.

Treated seeds may be kept in storage for 3 or 4 days especially for draining the

liquid and for giving time for the medicinelpesticide to work. Planting of seed pieces in

beds also has special methods. Some choose small pits inside the beds and fill the pit

with dried cowdung after planting. However Spices Board says that the seed rhizome bits

be put in shallow planting pits prepared with a hand hoe and covered with well rotten farm

yard manure and a thin layer of soil and leveled (Anonymous, 2001b). Mulching still

remains the major operation all over the State. Every farmer prepares mulch, with leaves

of a variety of plants, over the bed. It is reported that mulching ginger beds with green

leaves is essential to enhance germination and to prevent washing off of soil due to heavy

--

151

rain; it also adds organic matter to the soil and conserves moisture during the later part of

the cropping season (Kannan, 1993). Valsala (1998) has the opinion that ginger yield will

be more from mulched beds than unmulched cultivation. Survey findings obviously

confirm these scientific explanations.

Preparation of seed ginger varies according to the area of cultivation. Selection of

rhizomes from the previous crop and the criteria are same all over the State. Variation

occurs in the storage methods. Kannan (1993) recommended that selection of rhizomes

for the making of seeds is very crucial; seeds must be bold, without any incidence of

diseases and pests. Seed material should not be from beds nearest to diseased fields.

According to Rajan (2002) storage loss of ginger rhizomes is as large as 25-50% due to

the attack of pests and other diseases. A method suggested by Mathai (1999) however

needs to be considered. Selected healthy rhizomes are put in raised platforms made up of

wooden planks. Leaves of Glycosmis andlor neem are spread below and above the

rhizome spread. Next layer of ginger is spread over the leaves and so on. This is then

subject to smoking from below the platform. After one mol~th this rhizomes are treated

with cowdung water and again subject to smoking. He also suggested that spreading of

seed rhizomes over sand or paddy husk inside rooms is also advantageous.

Rajan (2001) suggests that seed rhizomes shall be immersed in any fungicides for

30 minutes before planting in order to avoid rhizome rot. Indian Institute of Spices

Research proposes a new methodology for producing good quality seed ginger (Rajan,

2002), but none of the farmers are reported to have adopted this as per the survey.

The present investigation unveiled that about 21 cultivars of ginger are cultivated

in various parts of the State. Himachal and Maran are the popular varieties. But cultivar

named 'nadan' occupies in majority household cultivation. Total number of cultivars

employed in India is perhaps a disputed question. Introduced and developed cultivars are

also used for cultivation. Among the introduced ones the type 'Rio-de-Janeiro' gives very

high yield of fresh rhizome, and is the most important introduction into the country

(Chadha, 1976). However Kannan (1993) reported that 'Maran', introduced from Assam

pedormed better than Rio-de-Janeiro in terms of fresh yield and dry recovery. Recently

released 'llSR varada' by Indian Institute of Spices Research, Calicut is becoming an

instant hit through out the country (Sasikumar, 2001).

Present investigation claims that though large number of high yielding varieties is

introduced and available, farmers of Kerala still have dependence on traditional varieties

up to a large extent. Survey also revealed that Emakulam, Wayanad, and Thrissur

districts have the highest diversity of cultivars.

It was noticed that ginger is rarely raised as a monocrop. Often it is cultivated as a

mixed crop along with coconut, arecanut, pepper and other vegetables. The observations

obviously agree with the findings of Pillai (1981).

Crop rotation is well established in Kerala. According to the farmers the system is

highly effective, since ginger is an exhaustive crop. Pruthi (1993) reported that ginger is

grown in rotation with chillies, vegetables, turmeric etc. Survey results are in agreement

with authoritative reports.

The time of planting of ginger is mainly MarchlApril after the summer rains.

According to Spices Board the best time for planting ginger in west coast of India is during

the first fortnight of May with the receipt of pre-monsoon sh3wers (Anonymous, 2001b).

Under irrigated conditions, it can be planted well in advance during the middle of February

or early March. In this survey it was found that majority of farmers adopted rain-fed

cropping. Some growers cultivate it as irrigated crop. Sudha et al., (2001) accounted that

watering should be conducted if ginger is cultivated as an intercrop with coconut in order

to avoid competition for water and manure by coconut and ginger.

It is a common belief that the yield of ginger can be increased by the addition of

manure at regular intervals. Spices Board recommends a dosage of 75 kg N, 50 kg P205

and 50 kg K20 per hectare. Application must be in three splits and at an interval of 40

days and then 90 days (Anonymous, 2001b). In addition to this 25-30 kg of compost or

cowdung and 2 tonnes of neem cake powder are also suggested for one hectare. This

survey revealed that except for a few farms majority use dried cowdung as the chief

source of manure. Application of neem cake @ 2 tonneslhectare is also desirable.

Majority farmers do not wish to supply huge amount of fertilizers. This may be the reason

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for the low productivity in ginger compared to other competing countries, where farmers

use very high amount of manures. Present survey observed that poultry droppings were

the chief manure for ginger in many parts of the Ernakulam and Thrissur districts during

early eighties. The reason for not continuing the method is, as told by farmers - the high

disease incidence coincident with this fertilizer application. Commercial cultivation of

ginger requires large amount of pesticides and fungicides. However majority 'of the

marginal farmers use only cowdung slurry and bordeaux mixture as the chief medicines.

Large farms are always provided with an array of chemical pesticides and spraying is

conducted as prophylactic measures. Recommendation of Spices Board regarding

protection of ginger (Anonymous, 2001 b) however does not provide methods credible to

the farmer.

According to Farm Information Bureau (Government of Kerala) prevention is the

ideal method against diseases and pest attacks. Providing proper drainage, adoption of

hygienic practices especially during rainy season, and selection of disease free seed

rhizomes keeps 90% of disease incidence away from ginger (Gangadharan, 1998b).

Majority of the farmers supported this view. However due to the high cost of production,

farmers are forced to adopt methods for high production by using more chemical

fertilizers. According to a good number of growers along with the use of high amount of

chemical fertilizers, a simultaneous application of a proportional quantity of pesticides

would become essential.

In this survey it was noticed that ginger farms of coastal belts especially in regions

of Cherthala are completely free of disease incidence. They do not apply pesticides too. It

is revealed by the farmers that since the soil is sandy survival ratio is very low especially

during the summer in the case of pests and fungus. At the same time due to friable nature

of soil spreading and growth of rhizomes will be more. Valsala and Prasannakumariamma

(1999) however reported that for the sustainable production of ginger adoption of organic

farming is a better alternative. Considerable number of farmers has the opinion that by the

adoption of phytosanitation and proper drainage, the incidence of foot rot can be

overcome.

Harvesting season of ginger is December to March. l'his harvesting is meant to be

for the production of dried ginger. However ginger is harves:ed in every season for fresh

use. Fresh ginger is harvested at 6Ih month onwards and mature ginger is harvested at Elh

month of cultivation. According to Pillai (1981) December - January period is the

harvesting season of ginger.

Reports say that productivity of ginger is very low in comparison with other

countries like Philippines, Queens land, China etc. (Kannan, 1993). Average yield of

ginger is 3290 kghectare (Peter, 1999). Present study however shows that even though

some plants produce high yield the average is low. Since the farms of Kerala are all mixed

or intercropped yield calculation per hectare some how may not be true. However ginger

cultivated as pure crop in other countries, hence the yield per hectare seems to be high.

Survey revealed that a good number of farmers do not opt high production technology. At

the same time more than 80% of ginger farms belong to marginal farmers. Lawrence

(1984) and Chadha (1976) reported that the average yield of ginger in Kerala is low,

however it has been postulated (Kannan and Nair, 1965) that if good farming practices

and high yielding varieties are used high yields can be realized, as adopted in other

countries. It has been established that infestation of insect pests is a major factor

responsible for the low productivity of ginger in India (Devasahayam and Koya, 1999).

Overall observations gathered so far obviously revealed that processing

operations adopted for ginger are unhygienic. A good number of farmers sell the product

as fresh ginger. Large scale processing units situated in various parts of the State do the

processing. Farmers said that problems underlying in this system are transportation loss,

delay in drying, fungal infestation, loss due to unscientific peeling, non-uniform and

uneven drying, low storage life etc. Labour problems are also reported.

In the absence of washing and cleaning processes, partial peeling is the only

pretreatment, and dried ginger contains lot of impurities. The results of previous studies

also state that conventional methods are unhygienic and unscientific leading to low quality

product (Pruthi, 1993; George, 1996b).

According to Purseglove et a/. (1988) in contrast to Jamaican gingers, which are

clean peeled, Indian gingers are usually rough-peeled or scrapped. This is considered to

be because of partial peeling before drying and improper rubbing after drying. Sasikumar

(1999) reported that in many northeast areas rubbing is conducted by trampling the dried

rhizomes with human legs. Regarding sulphur fumigation, the practice has now been

banned due to the high cost of sulphur and the prohibition by importing countries,due to

sulphur dioxide residues in the spice. Present survey revealed that, many processors and

farmers are still conducting this process. This study failed to observe proper post-drying

treatments that have been done by the farmers.

Farmers do not store dried ginger for more than more than 2-3 months as shelf life

is low and lack of safe methods for the protection of spice from insects and fungus.

Generally whole sellers or commission agents in gunny bags in their godowns store dried

ginger, and which is highly susceptible to insect infestation, however no precaution is

being taken. It is very clear that final moisture content is the chief influencing factor.

Survey findings point to improvising better post-harvest methodologies for the overall

quality improvement of dried ginger.

The average initial moisture content of ginger rhizomes collected from 44 stations

was 78.2%. According to Sreekumar et a/. (2002) fresh ginger contains about 85%

moisture. However studies conducted by Kachru and Srivastava (1988), and Kachru and

Gupta (1993) reported that the moisture content of ginger is about 80-93% (wet basis) at

the time of harvesting. Variation in initial moisture content can occur according to maturity

at harvest, cultivar variation, method and area of cultivation, and processing methods.

Solar tunnel drying required only 26 hours for effective drying of ginger. In contrast

to this commercial drying required 50 hours and conventional drying took 48 hours. This

reduction in drying time may be attributed to the high temperature and low relative

humidity inside the dryer than the ambient air. During the study period solar insolation was

comparatively high. This would have resulted in the generation of heat exponentially

inside the dryer. Jose eta/. (2001) have postulated that initial drying of ginger is crucial, if

failed to achieve, completion of drying happens in weeks. Mantri and Agarwal (1991) have

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attained reduction in drying time of ginger by multistage dehydration process, in which the

initial dehydration temperature is 80°C, giving great importance to initial fast drying.

Conventional method of drying needs 10-15 days of open exposure (Kachru and Gupta,

1993); sometimes need 20-25 days (Raghavan and Shankaranarayana, 1992). Present

study conducted in solar tunnel drying however succeeded to dry fast during the initial

period.

As far as drying of ginger is concerned solar drying can be effectively utilized for

the processing of ginger in order to reduce the drying time (Das and Sarma, 2001).

Investigations carried out by Jose and Joy (2002) revealed that during solar drying the

temperature rises according to the insolation, so that relative humidity reduces even in the

presence of evaporated moisture from the crop inside the dryer, and results in fast drying.

This study also shows that conventional drying cannot reduce the drying time significantly.

The mean spice recovery of samples dried in solar tunnel dryer was low,

compared to commercial and conventional drying. Values are 24.67%, 25.89% and

26.32% respectively. Recovery obtained is however related to the final moisture content.

The open sun drying resulted in a product of higher moisture content. Sivadasan (1996b)

reported that commercial samples contain huge quantity of final moisture content, up to

35%. Purseglove et a/. (1988) opined that conventional method of drying ginger do not

achieve optimum level of drying. Drying is completely dependent upon climatic conditions

and handling methods. According to Joy and Jose (1998b) solar tunnel dryer can be used

in adverse weather conditions also. The standard level of moisture content (maximum)

specified by USFDA (United States Food and Drugs Administration) for dried ginger is

12% by weight. As such tunnel drying produce a quality product in terms of final moisture

content.

The minimum standard value of volatile oil is 2% (v/w) as suggested by USFDA. In

the current experiment, solar tunnel dried and conventional samples qualified the standard

mark. Commercial samples had significantly low volatile oil content. Though the

conventional samples attained the standard level of quality in terms of volatile oil content,

the yield was comparatively low i.e. 2.08% compared to solar dried samples (2.43%). The

results clearly illustrate that open sun drying can retain volatile oil to the standard level,

but maximum retention of volatile oil can be achieved only through solar tunnel drying.

Purseglove et a/. (1988) postulated that traditional drying methods can result in the

loss of volatile oil (up to 20%) by evaporation and the destruction of some of the heat

Sensitive pUngent constituents. Peeling influences volatile oil retention greatly. Sreekurnar

eta/. (2002) reported that since the volatile oil cells are situated in the hypodermal areas

just below the skin, improper peeling leads to loss. According to Charan (1995) and Mani

et a/. (2000) traditional methods of peeling are very laborious, time consuming and also

cause high loss of volatile oil. Another study conducted by Bartley and Jacobs (2000)

claimed that unscientific and extended drying leads to loss of volatile oil and its quality.

Overall observations revealed that the unscientific peeling methods and duration of drying

might reduce volatile oil in commercial samples. A comparatively good volatile oil retention

in conventional samples obtained in this study may be due to the adoption of good

peeling.

Natarajan et a/. (1972) and Shankaracharya and Natarajan (1975) have

recommended an optimum temperature of 60°C for drying of ginger. But in the present

investigation higher temperature inside the dryer (30°C to 70°C) didn't affect the volatile oil

content. Hence scientific pretreatments like peeling, short duration of drying, and fast

initial dehydration would have helped to retain the volatile oil in solar tunnel dried samples.

Oleoresin of ginger is famous in international market of spice extracts, which is the

total extract that contains both volatile oil and pungent extractives. No standard value is

suggested by USFDA and ASTA for this. In the present investigation solar tunnel dried

samples retained maximum quantity of oleoresin. Ope, sun dried samples had

comparatively low retention of oleoresin.

Like volatile oil, retention of oleoresin of ginger is influenced by many factors other

than cultivar, maturity and agro-climatic factors. Mishandling in peeling operation and

prolonged drying may be the reason for oleoresin reduction. Jose et a/. (2001) have

succeeded to retain comparatively high oleoresin content (8.21%) through solar tunnel

drying than conventional drying (5.71%). It is suggested by Purseglove et a/. (1988), that

peeling may be the dominant factor for oleoresin retention, because these cells are also

situated in the nearest areas of the skin. However Shankaracharya and Natarajan (1975)

implicated that gingerols, the main pungent compounds in ginger oleoresin, readily

changed into non-pungent compounds on either uncontrolled dehydration or extended

drying. End result is the reduction in oleoresin quantity. In addition to proper drying,

scientific pretreatments are also important to produce ginger with maximum oleoresin.

Like any other spices, oleoresin of ginger is also a non-volatile compound. Hence

high temperature does not affect oleoresin in general. But since about 30-45% of

oleoresin consists of volatile oil, initially, the factors that influence volatile oil retention will

also influence the oleoresin quality (Clevenger, 1928). Sreekumar eta/. (2002) opined that

in addition to cultivar variation and processing problems method of extraction is very

important. It is suggested that supercritical C02 extraction is most efficient, though costly.

The observations on physical quality illustrates that method of conventional

processing of ginger usually create dried ginger of unhygienic quality, whereas solar

tunnel dried ginger rhizomes achieved significantly higher quality, totally exempt from

physical contaminants. It is revealed from the study conducted by Spices Board

(Anonymous, 1998c) that, Indian ginger has the advantage of superior intrinsic quality, but

contamination from external sources during harvesting, post-harvest handling, processing

and storage makes the Indian product unacceptable to importing countries. Microbial and

insect contamination happens during the unhygienic post-harvest operations.

Dried ginger is very much susceptible to the attack of insects especially during

storage. A survey conducted by Spices Board covering major growing areas of ginger

showed that about half of the samples collected from commercial market had dead insects

(Sivadasan, 1996b). Desai et a/. (1987) have reported the presence of three types of

insects in whole ginger under conventional storage. Since the spice consists of more

starchy components insects will always be attracted and infect readily if proper drying is

not achieved.

Solar tunnel dryer is completely protected from insects during drying, hence

chances of entry of insects is less (Esper, 1995). This may b3 the reason for the absence

of dead insects in solar tunnel dried samples. Rhizomes dried under this method however

have an impressive outer coating. This hard texture and odour of high aroma keep away

insects during the post-drying period.

Presence of mammalian excreta in dried ginger is considered to be the sign of

unhygienic processing practices so that only 3 mglpound is allowed by ASTA in the case

of whole ginger. Present observation on mammalian excreta showed that only solar tunnel

dried products secured good quality, none of the samples contained this contaminant.

Occurrence in commercial and conventional samples was 81% and 31% respectively.

This study revealed that solar tunnel drying only can achieve good quality dried ginger in

terms of mammalian excreta.

Mold incidence is a major problem facing every ginger processor. Rhizomes

infected with moldy patches are common in commercial ginger. In the present study 93%

of the commercial and 63% of the conventional samples had mold contamination. Solar

dried samples were completely devoid of mold. According to Menon (2000a) improper

drying and storage will facilitate the growth of harmful fungi like Pennicillium verucosum

and Aspegillus ochraceus and may lead to the production of mycotoxin in the product.

The formation of mold in ginger however has a direct link with the moisture content

of the product. Beyond a particular level of moisture, entry and proliferation of fungus will

be easy. In the present investigation commercial samples had high moisture content i.e.

13.75%, and that of conventional and solar tunnel dried samples were 12.65% and

10.88% respectively.

Result of the extensive survey conducted by Spices Board also agreed that the

final moisture content is the chief factor controlling mold growth (Sivadasan, 1996b). Philip

(2002) reported that mold contamination can be eliminated by solar drying. Bala et a/.

(1999) also states that solar drying can reduce the risk of mold growth.

Results of the drying experiments prove that solar tunnel drying is far superior to

open sun drying. Major advantages are that solar tunnel drying reduces the drying time by

half and enhance the physico-chemical quality to a great extent with respect to the

National and International export quality standards. Purseglove et a/. (1988) have

illustrated a number of mechanical and other artificial drying methods that have been

established in other countries like Australia, Queens land, Solomon Islands, China,

Jamaica etc. Rotating drum dryer is used in Buderim area of Australia (Richardson, 1967;

Lawrence, 1984). A small capacity tray dryer for ginger designed and developed by

Bhuyan et a/. (1990) performs satisfactorily well. Solar cabinet dryer developed for ginger

and turmeric by Sukhadia University, Udaipur has been reported to give best results

(Singh and Ali. 1986). However none of the dryers are established among the farmers and

processors of Kerala so far. The study has also revealed the importance of pre-drying,

post-drying and hygienic practices to be adopted. Open sun dried good quality ginger can

possibly be produced up to a certain extent if proper post-harvest operations are adopted.