J. Agronomy & Crop Science 166, 40—47 (1991)© 1991 Paul Parey Scientific Publishers, Berlin and HamburgISSN 0931-2250

Pla}U Physiology Laboratoyy, Department of Botany, The M. S. University of Baroda (hidia)

Effect of CCC on the Growth and Yield of Mung Bean{Vigna radiate [L.] Wilczek var. Guj-2)

T. SHAH and G. PRATHAPASENAN

Authors' address: T. SHAH and Dr. G. PR,̂ THAPASENAN, Plant Physiology Laborator>', Department ofBotany, The M. S. University of Baroda, Baroda — 390002 (India).

5 figttres and 6 tables

Received December 21, 1989; accepted April 24, 1990

Abstract

Pot experiments were conducted on mung bean by spraying 500, 1000 and 1500 ppm CCC, 14 days after theemergence of seedlings. Results showed that:

CCC application at 1000 and 1500 ppm led to stem shortening.Dr}' weight of shoot system, leaf area, leaf thickness and total chlorophyll content were significantly

increased by 1000 ppm CCC.CCC at 1000 ppm increased amylase and invertase activity in the leaf tissue.CCC at 1000 ppm increased the pod number/plant, seed number/pod, leading to increased seed yield/plant.CCC had no effect on the 1000 seed weight.

Key words: Crowth, Yield, Vigna radiata, CCC, (2-chloroeihyl) trimethyl ammonium chloride, amylase,invertase.

I. Introduction

Inhibition of culmgrowth and the subsequentincrease of yield is a well documented responseof cereals to treatment with CCC (LINSER et al.1963, HUMPHRIES et al. 1965, SCHULTZ 1971,

KoRANTENG and MATTHEWS 1982, CARTWRIGHT

and WADDINGTON 1982, GOUDREDDY et al.

1986). GGC is known to retard the extensiongrowth in plants by inhibiting the gibberellinbiosynthesis (SEMBDNER et al. 1980). This mightresuit in the inhibition of subapical meristema-tic activity (SACHS 1965) leading to reducedstature of plants.

Although CCC has widely been used as apotential plantgrowth regulator in cereals, itseffect on legumes is not yet fully understood.The present study aims at evaluating the effectof CGC on growth and yield of mung bean.

II. Materials and Methods

Plant material and growth conditions

Certified seeds of Vigna radiata (L.) Wilczek var.Giij~2 were obtained from the State Department ofAgriculture, Gujarat. Rhizobium inoculum (Cow-pea Rhizobium-GAU) was obtained from the PlantPathology Division of Gujarat Agricultural Univer-sity (GAU), Anand, Gujarat. Plants were raised inpots containing 7.0 kg garden soil. Rhizobium in-oculated seeds of mung bean, 10 per pot, were sownat a depth of 1 cm and were allowed to germinate.When seedlings were a week old they were thinnedto 3 per pot. Po:s were divided into four groups fordifferent treatments. On day 14, plants in the first,second and third groups of pots were sprayed with500, 1000 and 1500 ppm solution of (2-chIoroethyl)trimethyl ammonium chloride (CCC) in 0.02 % (v/v) Tween 20 respectively to the point of run off. Thefourth group (control plants) received only sprays of

U.S. Copyright Clearance Center Code Staumcnt: 093 1-2250/91/660 1-0040$02.50/0

Effect of CCC on the Growth and Yield of Mung Bean 41

distilled water containing 0.02 % (v/v) Tween 20, Allpots received sufficient amount of water every threedays. The maximum/minimum temperatures duringthe growth period were 31 ± 3 °C and 21 ± 2 °Crespectively.

Growth Measurements

Plants were harvested every 14 days, washed withwater, blotted and extension growth of shoot systemwas recorded mimediately. After determinmg theextension growth, shoot system was separated, driedat 80 °C for 72 hours and dr)^ weight was deter-mined. Length of internodes was measured at thetime of final harvest.

Leaf area measurements

Leaf area measurements were made planimetncally.Total leaf area was tabulated and expressed as cm*.The 3rd trifoliate leaves of each group of plants weretagged on the day of flowering (32nd day) and theirarea was measured separately every 10 days.

Leaf thickness

The leaf samples (terminal leaf let of the 5th trifoliateleaf) were collected from each group of plants andfixed on the spot in Craf III (BERLYN and MiKSCHE1976). Later each sample was trimmed to the re-quired size and aspirated for 2*1—48 hours. Dehy-dration of the samples was carried out in a TBAseries and infiltrated with paraffm (56—58 °C) (BER-lYN and MiKSCHE 1976). Transverse sections of8—10 ^m thickness were cut on Weswox rotarymicrotome, and stained with aqueous Toluidine blue0 (pH 4.4) (SAKAI 1973). The photographs weretaken on orwo black and white film using Leitzdialux 22 photomicroscope. Leaf thickness wasmeasured with the help of a micrometer.

Estimation of total chlorophyll

A known amount of fresh leaf tissue washomogenized in 80 % acetone and centrifuged at3,000 g for 10 min. The chlorophyll level in thesupernatant, after appropriate dilution was deter-mined spectrophotometrically according to themethod described by HARBORNE (1984).

Preparation of enzyme extract

Fresh leaf samples (trifoliate leaves of same age ofeach group of plants were tagged on the day offlowering (32nd day) and harvested every 10 days(for preparing enzyme extract) was homogenized incold 0.2 M borate buffer (pH 8.6; 8 ml/g fr. wt.)along with a pinch of glasspowder, for 5 min using achilled mortar and pestle. The homogenate was fil-tered through four layers of cheese cloth and cen-trifuged at 10,000 g for 10 min at 0 °C. The protein

present in the extract was precipitated by mixing itwith chilled acetone at a ratio of 1 : 2 v/v at 0 ''C. Theprecipitated protein was sedimented by centrifuga-tion (15,000 g) at 2 °C for 15 min and dissolved in0.5 M acetate buffer (pH 4.6) for the assay of amy-lase and invertase.

Total amylase assay

Total amylase activity was determined by themethod of BERNFIELD (1955). The assay system(2.0 ml) consisted of 0.5 ml 0.1 M acetate buffer(pH 4.6), 0.5 ml 1 % soluble starch and 1.0 mlenzyme. The reaction was carried out at 30 ± 1 °Cfor 60 min and an aliquot of 1.0 ml of the reactionmixture was estimated for the amount of maltosereleased using 3,5 dinitro salicylic acid. The enzymeunit is defined as the amount of enzyme required toliberate 1 ,t(mole of maltose per hour under the assaycondition and the activity is expressed as units permg protein.

Invertase assay

The activity of invertase was measured by estimatingthe reducing sugar produced in the assay system afteran incubation period of one hour. The assay system(2.0 ml) contained 1.0 ml of 0.1 M acetate buffer(pH 4.6), 0.5 ml of 2 % sucrose and 0.5 ml enzymeextract. The reaction mixture was incubated at30 ± 1 °C for 60 min and the reaction was termi-nated by keeping it in boiling water bath for 10 min.An aliquot from the reaction mixture was used forthe estimation of reducing sugars according to theprocedure of SOMOGYI (1952). The enzyme unit isdefined as the amount of enzyme required to pro-duce 1 (̂g of glucose per hour under the assay condi-tion and the enzyme activity is expressed as units permg protein.

Seed yield

Yield parameters analyzed included — (a) totalnumber of pods per plant; (b) number of seeds perpod; (c) total number of seeds per plant and(d) weight of 1000 seeds of each treatment.

Statistical analysis

Results of all experiments, except biochemical ana-lyses, are subjected to Duncan's multiple range test(DUNCAN 1955). Data shown are the mean values of10 replicates except for biochemical analyses wherethe reported values are the average of four replicates± S.E.

III. Results

Extension growth and dry weight of shootsystem:

42 SHAH and PRATHAPASENAN

The application of CCC at 500 ppm failed tobring about a marked reduction in the exten-sion growth of the shoot system (Table 1).However, CCC at 1000 and 1500 ppm mar-kedly reduced the extension growth of theshoot system. This reduction was 31 and 41 %at 1000 and 1500 ppm respectively comparedto control on day 70. The dry weight (Table 2)of the shoot system of plants which received1000 ppm CCC spray was increased by14.3 % over the control on day 70. But CCCat 500 and 1500 ppm failed to increase the dryweight of shoot system.

Internode length

The length of internodes at the end of theexperiment is presented in Table 3. Among thethree concentrations of CCC tried (500, 1000and 1500 ppm), 1000 and 1500 ppm broughtabout a very conspicuous reduction in thelength of 3rd, 4th and 5th internodes. Thereduction in the length of internode was max-imum at 1500 ppm. The 5th internode regis-tered the maximum reduction in the extensiongrowth at 1000 (59.8%) and 1500 ppm(67.7 %) levels.

Table 1. Effect of C C C on the extension growdi (cm) of shoot system of mung bean (Vigtia radmta). Readingon Hth day is the average ± S.E. (0.75) of ten separate measurements

TreatmentCCC ppm

0500

1000

1500

14

15.46

15.56

15.46

15.46

28

35.93;--

32.73,

24.60t,

20.26,

Days after emergence42

49.06^

45.20j

32.73e26.00f

56

53.86h

49.66h35.96i

30.00K

70

57.86,

56.71

39.66.,34.40.

''' In each column figures with the same letter are not significantly different but the figure with different letterare significantly different from each other according to Duncan's Multiple-Range Test at 0.05 probabilitylevel.

Table 2. Effect of CCC on dry weight (g) of shoot system of mung bean (Vig?7ais the average ± S.E. (0,05) of ten separate measurements

^). Reading on Hthdav

TreatmentCCC ppm

0

500

1000

1500

14

0.246

0.246

0.246

0.246

28

0.821;:-

O.S38,

0.978b0.856,

Days after emergence42

3.48c3.56,

4.10d

3.S4L,

56

5.40,

5.44,

6.60(

5.94,

70

7.30,.

7.35h8.35,

7.40h

'•• In each column figures with same letter are not significantly different but the figures with different letter aresignificantly different from each other according to Duncan's Multiple-Range Test at 0.05 probability level.

Table 3. Effect of C C C on the length (mm) of internode of mung bean {Vigtia radiata)

TreatmentCCC ppm

0

500

1000

1500

1st

32.2;-^

31.8329.5.

2nd

29.2,

27.8,

20.2,

16.6,,

Internode3rd

48.0,

46.0,

24.0,

16.0,

(70th day)4th

59.0,

56.0,

29.2f

26.6i

5th

62.0,59.4,

28.8,

21.5,

6th

52.6d45.0d

41.0,

39.0,

'•' In each column figures with same letter are not significantly different but the figures with different letter aresignificantly different from each other according to Duncan's Multiple-Range Test at 0.05 probability level.

Effect of C C C on the Growth and Yield of Mung Bean 43

Table 4. Effect of C C C on total leaf area (cm^) of mung bean {Vigna radiata). Reading on 14th day is theaverage ± S.E. (1.6) of ten separate measurements

TreatmentCCC ppm 14 28

Days after emergence42 56 70

0500

1000

1500

66.8

66.8

66.8

66.8

392.8,=--

406.6,

474.2b

425.0b

589.2,

604.3,

687.5d

632.5,

942.4,

956.0,

1025.0,

965.0,

593.8h

612.0,

655.0,

620.0,

=:• In each column figures with same letter are not significantly different but the figures with different letter aresignificantly different from each other according to Duncan's Multiple-Range Test at 0.05 probability level.

Total leaf area

The total leaf area of plants (Table 4) increasedsteadily till 56th and declined thereafter. Ap-plication of CCC (1000 ppm) significantly in-creased the total leaf area by 16.6 % on day 42over the control.

Area of 3rd trifoliate leaf

The area of the 3rd leaf (Fig. 1) registered asteady increase till day 52 and it remainedalmost constant thereafter. Among the differ-ent concentrations of CCC tested, the max-imum increase in leaf area was observed at aconcentration of 1000 ppm on day 42 and thisincrease was more than 31 % over the control.

Leaf thickness

The transverse section of the terminal leaf let ofthe mature trifoliate leaf at the 5th nodeshowed an increase in length and size of

200

A2 52 62 70Days after emergence

Fig. 1. Effect of CCC on the area of the 3rd trifoliateleaf of mung bean control (O), CCC 500 ppm (A),1000 ppm (•) , 1500 ppm (A)

palisade and spongy cells in response to CCCtreatment. However, the number of cell layerswas not affected consequent to CCC treatment(Fig. 2). Leaf thickness of CCC treated plantswas increased by 54.6 (1000 ppm) and 15.9 %(1500 ppm) over the control (Table 5). How-ever, CCC at 500 ppm failed to increase theleaf thickness appreciably.

Table 5. Effect of CCC on mean leaf thicknessof munt; bean (mean of 3 replicates)

500CCC ppm

1000 1500

104.72 107.6 161.92 121.44

Total chlorophyll content

The maximum content of chlorophyll was pre-sent on day 42 in control as well as CCCtreated plants (Fig. 3). Application of CCC at1000 ppm increased the total chlorophyll con-tent by 52.6 % on day 42 over the control.

Amalyse and invertase activity

Activity of total amylase and invertase of leaftissue rose sharply registering their peak on42nd day and declined thereafter to reach a lowlevel on day 70. On day 42, the activity of totalamylase and invertase was increased by 13 and48 % respectively over the control in responseto treatment with 1000 ppm CCC (Figs. 4 and

5).

Yield components and seed yield

Application of CCC at 1000 ppm significantlyincreased the total number of pods per plant aswell as seeds per pod (Table 6). The number ofpods per plant and number of seeds per plant

44 SHAH and PRATHAPASENAN

a b

Fig. 2. Transverse sections of the middle leaflet of the mature fifth trifoliate leaf of Vigna radiata (L.) Wilczekas affected by CCC. (200 x) a: control, b: CCC 500 ppm, c: CCC 1000 ppm, d: CCC 1500 ppm. UE: upperepidermis, P: palisade cells, S: spongy cells, LE: lower epidermis

Table 6. Effect of CCC on the yield of mung bean {Vigna radiata)

TreatmentCCC ppm

0500

10001500

Number ofpods per plant

9.10/9.30,

12.06t,9.50,,

Number ofseeds per pod

10.16,10.20,11.40b10.34,

Number ofseeds per plant

92.45,94.86,

137.40b98.23,

1000 seedweight (g)

33.37,33.42,35.61,33.50,

"" In each column figures with same letter are not significantly different but the figures with different letter aresignificantly different from each other according to Duncan's Multiple-Range Test at 0.05 probability level.

were increased by 32.5 and 48.5 % respective-ly over the control by CCC administration(Table 6). However, no significant increase in1000 seed weigbt was observed following CCCapplication.

IV. Discussion

The observation on the effect of CCC on theextension growth of shoot system was in linewith earlier reports (LINSER and KtiiiN 1962,

LiNSER et al. 1963, BRUCKNER and HOFNER

1980, KoRANTENG and MATTHEWS 1982, NAY-

LOR et al. 1986, ADLER and WILCOX 1987, EL-

FouLY et al. 1988). The effect of CCC on thelinear growth of shoot system was manifestedin reduced length of internodes. Reduced in-ternodal length is one of the morphologicalalterations pointed out by CATHEY (1964) inresponse to CCC treatment. Administration ofCCC (1000 ppm) significantly increased thedry weight of the shoot system. Similar in-

Effect of CGC on the Growth and Yield of Mung Bean 45

100

50

I 25o

S 0-1-/ /

^ 12

U 28 A2 56Days ofler emergence

70

Fig. 3. Effect of CGC on the total chlorophyll con-tent of mung bean. Control (O), CCC 500 ppm(A), 1000 ppm (•) , 1500 ppm (A)

0 32 i2 52 62

Doys after emergence

Fig. 4. Effect of CCC on the activity of invertase inmung bean leaves. Control (O), CCC 500 ppm (A),1000 ppm (•), 1500 ppm (A)

crease in the dry weight of the shoot systemfollowing CCC treatment has been reported intomato (WiTTWER and TOLBERT 1960), tobacco(HUMPHRIES 1963), wheat (KHAN and WASTI

1982), and maize (KOTTING et al. 1988).In the present investigation CCC at a con-

centration of 1000 ppm significantly increasedleaf area, leaf thickness, total chlorophyll con-tent and activity of amylase and invertase in theleaves. Anatomical studies revealed that theincrease in the thickness of leaves is due to theexpansion of mesophyll tissues. A similar in-crease in thickness of leaves due to the expan-sion of mesophyll tissues following CCC ap-

32 7042 52 62Days after emergence

Fig. 5. Effect of CCC on the activity of total amyl-ase in mung bean leaves. Control (O), CCC 500ppm (A), 1000 ppm (•)» 1500 ppm (A)

plication has been reported in cotton (BHATT

and NATHAN 1970) and kidney bean (EL-FOULY

et al. 19S8), HAWKER and WALKER (197S)studied the relationship between leaf expansionrate, invertase activity and reducing sugar con-tent in Pbaseolus vtilgaris, Zea mays and Hor-deum vulgare and suggested a role for inver-tase in the growth of leaves. In the presentstudy, CCC (1000 ppm) has been found toincrease considerably the activity of invertasein the leaf tissues. EL-FOULY et al. (1988) alsoobserved a similar enhancement of invertaseactivity and increased leaf area following CCCtreatment. The increased leaf area observedhere might therefore be due to a positive effectof CCC on the expansion of mesophyll tissuesby stimulating the invertase activity.

Many investigators agree that plants treatedwith CCC produce greener leaves with highchlorophyll content. In the present investiga-tion also we found a significant increase in thechlorophyll content in plants treated with 1000ppm CCC. Increase in chlorophyll contentfollowing CCC treatment has been observed intomato (HUMPHRIES 1963), Cotton (BHATT andRAMANUJAM 1970, EL-FOULY and ASHOUR

1970), Barley (BADANOVA and LEVINA 1970) andwheat (HoFNER et al. 1984, FAKRAHI-ASCHTIANI

et al. 1987). STODDART (1965) observed thatchlorophyll production in Loliivn temitlen-tuyn L. was stimulated in presence of CCC. Healso found a correlation between chlorophyll

46 SHAH and PRATHAPASENAN

production and protein accumulation. KNYPL

(1967) observed that CCC arrestedchlorophyll degradation in kale leaf tissue.HUMPHRIES (1968) suggested that promotion ofchlorophyll content in response to treatmentwith CCC is a consequence of growth retarda-tion and accumulation of protein in leaves dueto restricted mobilization of protein. BHATT

and NATHAN (1970) in their studies with cottonsuggested that the increase in chlorophyll con-tent in leaves of plants treated with CCC canbe attributed to the expansion of mesophylltissues in such plants.

The increase in the number of seeds perplant observed under the influence of CCC hasbeen found due to the increase in the numberof pods per plant as well as number of seedsper pod. Similar increase in seed yield in re-sponse to CCC administration has been re-ported in kidney bean (GUNASENA and CLEM-

ANTS 1970, EL-FOULY et al. 1988). However, nosignificant increase in 1000 seed weight couldbe observed. The number of pods per plantand seeds per pod are the main factors con-tributmg to yield mcrease. Generally higherseed yield is related to higher number of seedsper plant. There are considerable evidence toshow that seed yield is principally a function ofseed number produced and not seed size(EVANS 1976). The increased invertase andamylase activity indicates that CCC might beinfluencing carbohydrate metabolism in leavesand might be stimulating the mobilization andtranslocation of photosynthates from thesource to the sink resulting in the increasedseed number. Enhanced activity of amylaseand invertase following CCC application hasalso been reported in wheat (HASSAN et al.1975, FiRGANY et al. 1980). EL-FOULY (1988)suggested that in kidney bean, increased leafgrowth and diameter of vascular elements inaddition to cell shortening may lead to moremobilization of photosynthate towards active-ly growing reproductive parts (normal sink)leading to more pod formation, more seedfilling and consequent more seed yield perplant in response to CCC treatment. The im-provement of yield following CCC applicationin mung bean might be due to the availabilityof more photosynthate to the sink.

In conclusion, the present study suggestthat, CCC application can successfully be em-ployed to increase the yield of mung bean.

Zusammenfassung

Einflufi von CCC auf Wachstum und Ertragder Mung-Bohne {Vigna radkta [L.] Wilczekvar. Guj-2)

Gefaf^experimente wurden mit Mung-Bohnendurchgefiihrt; 14 Tage nach dem Auflaufen derSamlinge wurden diese mit 500, 1000 und15000 ppm CCC behandelt. Die Ergebnissezeigen, da£ CCC-Applikationen mit 1000 und15000 ppm zu einer Verkurzung der Sprol^ach-sen fuhrten. Das Trockengewicht des SproEsy-stems, die Blattflache, die Blattdicke und derGesamtchlorophyllgehalt waren bei einer Be-handlung mit 1000 ppm CCC signifikant er-hoht. CGC mit 1000 ppm erhohte die Amyla-se- und Invertase-Aktivitat des Blattgewebes.CCC mit 1000 ppm erhohte die Anzahl derHiilsen/Pflanze, die Anzahl der Samen/Hulseund fiihrte so zu einer Erhohung des Samener-trages/Pflanze. CCC hatte keine Wirkung aufdas 1000-Samen-Gewicht.

References

ADLER, P . R., and G. E. WiLCOX, 1987: Influenceof thigmatic stress or chlormequat chloride on to-mato morphology and elemental uptake, J. PlantNutr. 10, 831—S40,

BADANOVA, K. A., and V. V, LEVINA, 1970: Effectof gibberellin and the retardant CCC (chlorocholme chloride) on drought hardiness of barley.Fiziol. Rast. 17, 568—574.

BERLYN, G. P., and J. P. MiKSCHE, 1976: BotanicalCytochemistry. The Iowe State University Press,Ames, Iowa.

BERNFELD, P., 1955: Amylases, a and ^. Metho.Enzym. 1, 149—155.

BHATT, J. G., and A. R. S. NATHAN, 1970: Changesin foliar anatomy of cotton caused by growth retar-dants. Indian J. Agri. Sci. 40, 1142—n46.

, and T. RAMANUJAM, 1970: Effect of cycocelon yield, chlorophyll content and fibre propertiesof lint of MGU cottons. Indian J. Plant Physiol. 13,ISO—1S4.

BRUCKNER, U. , und W. HOFNER, 1980: VerstarkieHalmverkiJrzung und Ertragssteigerung durclikombinierte Anwendung der Wachstumsregulato-ren CCG und Ancymidol bei Sommerweizen. Z.Acker- und Pflanzenbau 149, 328—334.

GARTWRIGFIT, P. M. , and S. R. WADDINGTON,

1982: Growth Regulators and grain yield in springcereals. In: HAWKINS, A. F., and B. JEFFCOAT(eds.), Opportunities for manipulation of cerealProductivity, Monograph BPGR Group No. 7, pp.61—70.

Effect of CCC on the Growth and Yield of Mung Bean 47

CATHEY, H . M. , 1964: Physiology of growth retard-ing chemicals. Annu. Rev. Plant Physiol. 151,271—302.

DUNCAN, D . B., 1955; Multiple range and multipleF tests. Biometrics 11, 1—42.

EL-FOULV, M . M. , and N. ASHOUR, 1970: Interac-tive effect of chlorocholine chloride and gibberellicacid on photosynthetic pigment contents in leavesof cotton seedling. Biochem. Physiol. Pflanz.(BPP) 161, 225—230.

, R. SAKR, M . K. FOUAD, A. M . ZAHIR, andA. E. FAWZI, 1988: Effect of GA, GCC and B-9 onniorphophysiological characters and yield of kid-ney beans {Phaseolus vulgaris L.). J. Agron. CropSci'. 160,94—101,

EVANS, L. T., 1976: The physiological basis of cropyield. In: EVANS, L. T . (ed.). Crop Physiology, pp.327—355. Cambridge University Press, London.

FARRAHI-ASCIITIANI, S., M . RAJAI, H . EHSADOUST,and H. SALMAT, 1987: The changes of N.P. andphytate p-in grams of winter wheat after treatmentwith CCC, Copper and Sulphur. Ann. Meet.Amer. Soc. Plant physiologist. July 19—23, 1987,Louis, Missouri.

FiRGANY, A. H., A. ZAHER, M . K. FOAD, and M.M. EL-FOULY, 1980: Chlormequat induced mor-phological and anatomical modifications andchanges in amylase and invertase activities in wheatplants (Giza 155) grown in pots. Field Crop Abstr.33, 9758.

GouDREDDY, B, S., V, S. PATIL, and G. P. RADDER,1986: Effect of CCC and hormones on growth andyield of irrigated Rabi sorghum. J, MaharashtraAgric. Univ. 11, 156—158.

GLNASENA, H . P. M. . and R. F ,̂ G. CLEMANTS,1970: A preliminary investigation into the effect of(2-chloroethyl) trimethyl ammonium chloride,CCC, on growth and development of dwarf bean,Phaseolits vulgaris L. J. Natl. Agric. Soc. Cylon. 7,14—24.

HARBORNE, J. B., 1984: Phytochemical Methods. Aguide to Modern Techniques of Plant Analysis.Chapman and Hall. London.

HASSAN, H . M . . M . M . EI.-FOULY, S. L EL-BAS-SIONY, and K. A. ATTIA, 1975: Response of wheatto combined treatment of chlormequat and 2,4-Don plant properties and CCC-residue content.s. Z.Acker- u. Pflanzenbau 141, 55—70.

HAWKER, J. S., and R. R. WALKER, 1978: Effect ofsodium chloride on expansion rates and invertase ofleaves. Aust. J. Plant Physiol. 5, 73—80,

HOFNER, W., D. FEUCHT, and M. SCHMITZ, 1984:Modification of morphological and physiologicalyield formation factors in wheat by N-Fertilizationand growth regulator application. Ber. Deutsch.Bot. Ges. Bd. 97, 139—150.

HUMPHRIES, E, C, 1963: Effect of (2-chloroethyl)trimethyl ammonium chloride on plant growth,leaf area, and net assimilation rate, Ann. Bot. 27,517—531.

, p. J. WELBANK, and K.J. WiTTS, 1965: Effectof CCC (Chlorocholine chloride) on growth and

yield of spring wheat in the field. Ann. Appl. Biol.56, 351—361.

, 1968: The effect of growth regulators, CCCand B.9 on protein and total nitrogen of bean leaves{Phaseolus vulgaris) during development. Ann.Bot. 32, 497—507.

KHAN, K., and A. K. WASTI, 1982: Influence of (2-chloroethyl) trimethyl ammonium chloride on thegrowth and development of wheat {Triticum aes-tivum cultivar C-591). Pak. J. Sci. Ind. Res. 25,239—241.

KNVPL, J. S., 1967: Coumarin, phosphon-D andCCC — the* inhibitors of chlorophyll and proteindegradation in senescing leaf tissue of kale. FloraAbt. Physiol, Biochem. 158, 230—240.

KORANTENG, G. O., and S. MATTHI-WS, 1982: Mod-ification of the development of the spring barley byearly application of CCC and GA3 and the subse-quent effects of yield components and yield. In:MCLAREN, J. S. (ed.). Chemical manipulation ofcrop growth and development, pp. 343—357. But-terworths, London.

KOTTING, K., K. HOFMAN. und \V. HOFNER, 1988:Moglichkeiten zur Beeinflussung dor Ertragsleis-tung von Mais {2ea tnays L.) durch Wachstumsre-gulatoren. J. Agron. Crop Sci. 160, 64—71.

LiNSER, H., and H. KuHN, 1962: Prevention oflodging by using gibberellin antagonists such as,CCC (chloro chloline chloride) Z. Pfl.-Ernahr.Dung-Bodenk. 96, 231—247.

, , and J. BoHRiNG, 1963: Investigationson the effect of CCC on different species andvarieties of summer cereals. Z. Acker- u. Pflanzen-bau 117, 129—154.

NAYLOR, R. E. K., M . E. SALEH, and J. M. FARQHARSEN, 1986: The response to chlormequat ofwinter barley growing at different temperatures.Crop Res. 26, lV—31.

SACHS, R. M. , 1965: Stem elongation. Annu. Rev.Plant Physiol. 16, 73—96.

SAKAI, W . S., 1973: Simple method for differentialstaining of paraffin embedded plant material usingtoluidine blue O. Stain Technol. 48, 247—249.

SCHULTZ, J. E., 1971: The effect of trimethyl am-monium chloride (CCC) on the growth an yield ofwheat. Aust. J. Exp. Agric. Anim. Husb. 11,450-^54.

SEMBDNER, G. , D . GKOSS, H . \V. LIEBISH, and G.SCHNEIDER. 1980: Biosynthesis and metabolism ofplant hormones. In: MACMILLAN, J. (ed.). Ency-clopedia of Plant Physiology, New Series, pp.281—444. Springer-Vcrlag, Berlin.

SOMOGYI, M., 1952: Notes on sugar determination.J. Biol. Chem. 195, 19—23.

STODDART, J. L., 1965: Chemical changes in Loliumteryiulentum L. after treatment with (2-chlorocthyl)trimethyl ammonium chloride (CCC). J. Exp. Bot.16,604—613.

WiTTWER, S. H., and N. E. Toi,BCRT, 1960: (2-chloroethyl) trimethyl ammonium chloride and re-lated compounds as plant growth substances III.Effect on growth and flowering of tomato. Amer.J. Bot. 47, 560—565.