PSO/PL,IPMP, IPEP,

NARC, Islamabad

Mrs. Naheed Akhtar

Presented By:

Effect of Water Extract of Neem on Cabbage Aphid (Brevicoryne brassicae) under Field Conditions during Year

2009-2010

The cabbage is a popular cultivar of the species Brassica oleracea of the Family Brassicaceae or Cruciferae and is used as a leafy green vegetable.

It is a herbaceous, biennial, dicotyledonous, flowering plant.

The plant is also called head cabbage or heading cabbage.

The cultivated cabbage is derived from a leafy plant called the wild mustard plant.

INTRODUCTION

The only part of the plant that is normally eaten is the leafy head.

It is an excellent source of vitamin C. It also contains significant amounts of glutamine, an amino acid that has anti-inflammatory properties.

In European folk medicine, cabbage leaves are used to treat acute inflammation.

Fresh cabbage juice has been shown to promote rapid healing of peptic ulcers.

Importance of cabbage

The cabbage aphid (Brevicoryne brassicae L.) is found on cole crops worldwide.

It founds only on plants in the Cruciferae family (cole crops, mustard, etc.), with serious outbreaks occurring only sporadically.

Cabbage Aphid (Brevicoryne brassicae)

Cabbage Aphid (Brevicoryne

brassicae)

Cabbage aphids (CA) are grayish-green with a waxy covering that gives them a grayish-white appearance.

It have short cornicles (tube-like structures at the tip of the abdomen) and feed on the underside of leaves in large clusters, in the center of cabbage heads, or on the youngest leaves.

Biology of cabbage aphid

Biology of cabbage aphid

Aphid outbreaks and damaging populations will usually occur only under dry hot weather.

Feeding damage from large numbers of aphids can kill seedlings and young transplants.

On larger plants, feeding damage results in curling and yellowing leaves, stunting plant growth, and deforming developing heads.

Dead aphids do not wash off easily and will cause a head to be unsuitable for fresh market sales.

Aphid Damage

Many insects and other pests infest cabbage plants, among them:

Other Pests Of Cabbage

Cabbage Butterfly:

h

Other Pests Conti….

Cabbage worm:

Other Pests Conti….

Mealy bug:

Other Pests Conti….

Thrips:

wingless females producing live young (nymphs), are the most common.

Asexual reproduction (males not needed), and extended reproductive life-span (30+ days at 5-6 nymphs/day).

It complete up to 15 generations (often overlapping) during the growing season.

It over winters as black eggs in host plant debris near the soil surface.

LIFE CYCLE

Repellent

Antifeedant (Feeding Deterrent)

Oviposition Deterrent

Chemo-sterillant

Growth inhibitor

Mode of Action of Plant Material

Diaeretiella rapae, (Hymenoptera: Aphididae), is the most common parasite of cabbage aphid.

D. rapae itself may often be killed by hyperparasites. Small colonies of aphids can be effectively controlled by

predators such as ladybird beetles, syrphid fly larvae, and lacewing larvae.

in wet or humid weather, fungal epidemics can help control aphid populations.

Biological Control

Since the Cabbage aphid over winters as a black egg in host plant debris, the destruction of these remains at the end of the season will help in killing over wintering aphids.

Aphids may also be controlled with insecticidal (fatty-acid) soaps used at the recommended rates (e.g., Safer Soap ); however we have very little data on the effectiveness of these products.

For the most effective control, time applications of insecticides early in infestation

OTHER CONTROL METHODS

Bring the desired plant parts Dry it in shed for 7 days Clean it from unwanted material Grind it in grinder Pass through 40 mesh sieve

Preparation of Plant Extracts

Industrial scale neem extraction process make use of solvents such as alcohol, ether, and hydrocarbons instead of water.

Aqueous extracts are said to work nearly as well as others.

The choice of method and solvent will depend on the nature of chemical compound to be extracted.

Method of Neem Extraction

1. Neem Leaf Extract

2. Neem Seed Extract

3. Neem Bark Extract

Types of Neem Extracts

Neem leaf extract has a fruit like smell and contains essential fatty acids

They are used in a number of pesticides and insecticides,

high potency extracts are used to manufacture personal products like facial creams, skin creams, cleansers and oral care products.

Neem Leaf Extract

Mature green leaves are collected and allowed to dry partially.

These dried leaves are then crushed and powdered.

The crushed leaves are then subjected to either aqueous or organic solvent to get a concentrated extract.

Certain extraction process utilizes carbon dioxide at critical temperatures and pressures to extract the active ingredients of the neem leaf

Process of Neem Leaf Extraction

To screen out the effective method to control cabbage aphid (B. brassicae) population experiments were conducted in Insect Pest Management Program (IPMP) at NARC, Islamabad.

There was grown a check variety of cabbage (B. oleracea) and cauliflower in field in four and three different plots respectively. Four different concentrations (2%, 1%, 0.5% and no spray) of Neem water extract were sprayed on cabbage (B. oleracea) and three concentrations (2%, 1% and no spray) were sprayed on cauliflower to determine the level of effectiveness against aphid (B. brassicae).

MATERIALS AND METHODS

There was grown a check variety of cabbage (B.oleracea) in field in four different plots.

Four different concentrations(2%, 1%, 0.5% and no spray) of Neem water extract were sprayed on cabbage (B. oleracea) to determine the level of effectiveness against aphid (B.brassicae).

Data was recorded before and after spray as shown in table No 1.

RESULT AND DISCUSSIONS

Average total population of aphids 32.9, 27.8, 30.2 and 21.6 of the four fields

these fields were sprayed three times with the concentrations of neem extract 2%, 1%, 0.50% and control (no spray) respectively.

Data was recorded after each spray, after 3rd spray the population of aphids decreased (graph 1) and the best control is showed by 2% concentration of neem water extract and the aphid population decreases to the average of 2.3.

RESULT AND DISCUSSIONS

Conc.

Before Spray

1st Spray 2nd Spray 3rd Spray

19.11.09

23.11.09

4.12.09

7.12.09

9.12.09

11.12.09

17.12.09

24.12.09

1.1.105.1.1

07.1.1

012.1.1

014.1.10 18.1.10

20.1.10

22.1.10  

2% 32.9 25.2 3.4 8.7 23.1 20.6 8.6 6.4 15.9 4.6 9.3 6.8 8.4 3.4 3.2 4.8  

1% 27.8 29.2 4.4 2.2 17.6 13.5 8.8 13.7 12.3 5.8 10.9 6.3 13.7 6.1 9.4 12.8  

0.50% 30.2 21.3 18.2 3.2 11.9 15 5.9 14.1 17.8 4.4 3.7 5.7 12.3 4.9 7.9 8.5  

Control 21.6 30.4 23 20.6 34 32.3 22.4 34.3 21.1 10.6 10.5 12.5 10.2 6.6 12.3 10.8  

TABLE1:-Effect of Water Extract of Neem on Cabbage Aphid Under Field Conditions in 2009-10

Graph

Effect of Water Extract of Neem on Cabbage Aphid(Bravicornae brassicae ) on Cabbage Under Field Conditions

0

5

10

15

20

25

30

35

40

19.1

1.09

23.1

1.09

4.12

.09

7.12

.09

9.12

.09

11.1

2.09

17.1

2.09

24.1

2.09

1.1.

10

5.1.

10

7.1.

10

12.1

.10

14.1

.10

18.1

.10

20.1

.10

22.1

.10

25.1

.10

27.1

.10

Before Spray 1st Spray 2nd Spray 3rd Spray

Dates

Pop

ulat

ion

2% 1% 0.50% Control

Experiment was conducted at NARC field Islamabad on Cabbage to evaluate effect of Neem water Extract against Aphid population.

Cabbage variety was grown in field in four different plots. Four different concentrations of Neem water extract (0.5%, 1%, 2% and

no spray) were sprayed on cabbage (Brassica oleracea) to determine the level of neem effectiveness against aphid (B. brassicae).

Data was recorded after each spray, after 3rd spray the population of aphids decreased and the best control was recorded at 2% conc. Of neem water extaract and the aphid population decreased to the average of 2.3.

Neem water extract may possess bioactive chemical which make neem extract unfavorable for aphid.

These studies of Neem water Extract need more studies and thus should be included in the breeding programs for further evaluation.

SUMMARY