EFFECT OF GROWTH REGULATORS AND FRUIT LOAD ON SEED YIELD AND QUALITY IN BRINJAL HYBRID SEED PRODUCTION

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1 Indian J. Agric. Res., 42 (1) : 25-30, 2008 EFFECT OF GROWTH REGULATORS AND FRUIT LOAD ON SEED YIELD AND QUALITY IN BRINJAL HYBRID SEED PRODUCTION Shivashankargouda B. Patil, M.N. Merwade and B.S. Vyakaranahal Department of Seed Science and Technology College of Agriculture, Dharwad , India ABSTRACT The results revealed that, GA 3 50 ppm recorded significantly more seed yield (33.96 g) per plant, germination (75.52%), root length (7.81 cm), shoot length (6.86 cm), seedling vigour index (1297) and seedling dry weight (14.12 mg) compared to NAA 40 ppm and control (30.97 g, 71.89%, 7.38 cm, 6.28 cm, 859 and mg, respectively) irrespective of growth, 4 fruit retention per plant recorded significantly highest germination, root length, shoot length, seedling vigour index and seedling dry weight (83.28%, 8.43 cm, 7.48 cm, 1136 and mg, re respectively) compared to retention of all fruits per plant. INTRODUCTION Brinjal belongs to family Solanaceae and is commonly Known as egg plant or Aeburgine is grown throughout the plains of India as well as in other parts of the globe. In brinjal hybrid seed production, the number of developing fruits retained on mother plant of the female parent after crossing will influence not only seed yield but also quality of the seeds harvested. Higher the number of fruits retained on the plant more is the seed yield but quality of seeds is poor on the other hand. The reverse trend of yield with better seed quality could be observed if fruit load on female plant is less (Chen, 2003). The growth regulators are known to influence various physiological and biochemical processes of the plant and enhance growth and productivity. In crops like brinjal, application of growth regulators like GA 3, NAA, IAA, etc., during flowering and fruiting period will enhance plant productivity with increase in fruit development, seed weight and seed number (Bisaria and Bhatnagar, 1978). However, such research work on fruit load per plant and application of growth regulators on seed yield and quality is scanty in brinjal. Hence, the present study was initiated. MATERIAL AND METHODS The field investigations were carried out to find out the effect of pollen viability on fruit set percentage, seed development and seed yield of brinjal hybrid cv. ArkaNavneet grown during late kharif season of 2003 and 2004 at the Main Agricultural Research Station, Dharwad. The experimental site consisted of red loam soil and neutral in ph reaction. In general, the experimental site was of medium fertility, well drained, porous and it was weed free site. The required seed material of female parent, IIHR 22-1 and male parent Supreme of brinjal hybrid cultivar Arka Navneeth was obtained from Indian Institute of Horticultural Research, Bangalore. Prior to sowing, the seeds of both parents were treated with fungicide at the rate of 2 g per kg of seeds. A raised nursery bed of 7 m length, 1.2 m width and 10 cm height was prepared to fine tilth. About five baskets of well decomposed farm yard manure was mixed with soil thoroughly. About 500 g of 15:15:15 complex fertilizer was added to the bed and mixed thoroughly into the soil. A day before sowing, bed was drenched with captan at the rate of 3 g per litre of water to avoid soil borne disease infection. Furrows were made at 10 cm spacing across the length of bed and bed was sown with seeds of female parent IIHR 22-1 and male parent Supreme separately in 3:1 row ratio. Male parent was sown in two installments, 10 days before and also on the day of female parent sowing. It was watered alternately and plant protection measures were taken regularly as required. The bed was kept * Part of Ph.D thesis submitted by the senior author to the University of Agricultural Sciences, Dharwad , India

2 26 INDIAN JOURNAL OF AGRICULTURAL RESEARCH weed free with manual weeding during the nursery period. Only uniform sized healthy true to type male and female seedlings of twenty five days old were transplanted in two adjacent parental blocks of the crossing field. One seedling per hill was planted with inter and intra-spacing of 75 and 75 cm and 60 and 60 cm for female and male parents respectively. A five meter distance was maintained between the female and male parental blocks. In the first batch only, 50 per cent male parent seedlings were transplanted 10 days before the female parent seedlings planting and in the second batch, remaining 50 per cent male and entire female parental seedlings were planted simultaneously in their respective parental blocks. Light irrigation was given immediately after planting to get quick and uniform plant establishment. A plot size of 4.5 x 4.5 m and 3.6 x 3.6 m was maintained for female and male parents respectively. The experiment was conducted in brinjal hybrid cv. ArkaNavneet during late kharif 2003 and 2004 in randomised block design with factorial concept in three replications with two factors. Factor I : Fruit load (L) : -Four crossed fruits per plant, -Eight crossed fruits per plant, -Twelve crossed fruits per plant and -All crossed fruits per plant and Factor II : Growth regulators (G) : -GA 50 ppm as foliar spray at fruit initiation stage, - 80 ppm as foliar spray at fruit initiation stage and -Water as foliar spray (Control) at fruit initiation stage. Fully opened flowers were plucked during blooming from the male parental block and were collected in polythene bag in early morning hours of the crossing day. Anther cones were separated out from floral buds and spread on a thin cloth and exposed to sun for three hours to ensure proper dehiscence of anthers. Anthers were kept in a steel cup covered with muslin cloth and another steel cup in an inverted position was kept over it and was agitated rigorously for couple of times to extract pollens. The pollens so separated from anthers were filtered through muslin cloth into another cup. The extracted pollens were then transferred to plastic vials by using camel brush. The plastic vials were kept in a cool place for over night period under ambient condition and also in a refrigerator until required for crossing. The hermophrodite flowers of female parent, IIHR 22-1 were emasculated in the previous evening hours between 2.0 to 6.0 pm. Only the floral buds likely to open in next day morning hours were only emasculated by using the forcep, needle, scalpel, etc.. Since female parent was of indeterminant growth habit, the emasculation work was restricted to first 30 days from start of flowering period wherein flowering was peak. The emasculated buds were covered with butter paper bag and labelled. The floral buds emerging out beyond 30 days of flowering were pinched off to ensure better fruit growth and development. The fresh pollens extracted from male parental flowers were filled up in the plastic rings specially designed for easy pollination. The stigmas of previously emasculated buds were gently dipped in pollen mass of plastic ring borne on left hand forefinger. Biometric, post-harvest and seed quality observations were recorded from each treatment randomly. The analysis of variance and interpretation of data were done as per procedures given by Panse and Sukhatme (1967) and Gomez and Gomez (1984). Levels of significance used in F test was P = Critical difference (CD) values were calculated only wherever the F test was found significant. The germination percentage data was converted into arc sine transformation and used for statistical analysis. RESULTS AND DISCUSSION Effect of growth regulators The pooled data exhibited significant differences for seed yield per plant due to growth regulators and fruit load per plant except their interaction effect.

3 Vol. 42, No. 1, TABLE 1: Effect of growth regulators and fruit load on seed yield per plant, germination percentage and root length in brinjal hybrid seed production Treatment Seed yield (g) per plant Germination (%) Root length (cm) Growth regulators (G) Mean Mean Mean (60.87) (59.80) (60.33) (59.41) (58.62) ) (58.12) (57.86) (57.92) SEm± % Fruit load (L) (66.50) (65.27) (65.88) (60.80) (59.74) (63.01) (56.66) (56.07) (56.42) (54.00) (54.63) (54.63) SEm± % 2.64 NS Interaction (MxP) (67.62)* (67.13) (67.86) (68.38) (60.87) (61.67) (67.98) (57.23) (57.61) (55.93) (55.00) (55.30) (66.74) (65.12) (65.89) (60.73) (60.13) (60.40) (56.48) (55.67) (56.01) (54.51) (54.45) (54.45) (64.45) (63.51) (63.94) (59.21) (58.34) (59.76) (55.01) (55.55) (55.55) (53.01) (54.45) (54.15) SEm± % NS NS NS NS NS NS NS NS NS NS Non significant * Figures in the parenthesis indicates arcsine transformed values - GA 50 ppm - Four crossed fruits per plant - 40 ppm - Eight crossed fruits per plant - Control (water spray) - Twelve crossed fruits per plant - All crossed fruits per plant

4 28 INDIAN JOURNAL OF AGRICULTURAL RESEARCH Significantly the highest seed yield per plant, (33.96 g) was noticed with GA 3 50 ppm and it was lowest (30.97 g) in control treatment irrespective of the fruit load per plant. The marked increase in seed yield per plant and its components recorded with GA 50 ppm may be attributed to higher fruit weight as noticed in this study. These findings are supported by heavier build up of sufficient food reserves in the developing fruits and seeds in the physiologically active plant due to spraying of growth regulators. This might have favoured increased supply of photosynthates and mobilization efficiency in plants giving rise to more and were developed seeds in the fruits and ultimately resulted in higher seed yield. These results are in agreement with the findings of Singh and Lal (1995) and Balaraj (1999) in chilli. In the pooled analysis significant differences were observed for germination percentage as influenced by growth regulators and fruit load per plant except their interaction effect. Significantly higher germination (75.52%), root length (7.81 cm), shoot length (6.83 cm), seedling vigour index (1297) and seedling dry weight (14.12 mg) were noticed in GA 3 50 ppm followed by NAA 40 ppm. Whereas, all these parameters were significantly lowest (71.89%, 7.38 cm, 6.28 cm, 859 and mg, respectively) with control treatment.(table 1) Among seed quality parameters, germination percentage, root length, shoot length, vigour index and seedling dry weight exhibited marked variations due to growth regulators over the fruit load. All these quality parameters were significantly more in GA 50 ppm ( ) followed by 40 ppm ( ). Whereas, they were less in the control ( ). The increase in seed quality parameters obtained due to spraying of GA 50 ppm may be due to higher percentage of bolder seeds coupled with the heavier seed weight due to increased translocation and assimilation of photosynthates from source to the sink (seeds). Similar findings are also reported by Balakumar and Balasubramanian (1988) in tomato, Revanappa (1993) and Balaraj (1999) in chilli, Jolli (2004) Yogeesha, et.al.,(1999)in tomato. The results of the study indicated that foliar spraying of GA 50 ppm at the time of fruit formation stage of brinjal plants was proved to be better in recording higher seed quality parameters compared to water sprayed plants. Effect of fruit load Seed yield per plant was significantly maximum (41.07 g) in the all crossed fruits per plant ( ) which was on par with 12 crossed fruits per plant, (38.86 g). While, it was significantly minimum (26.67 g) in four crossed fruits per plant ( ). Whereas, seed weight (5.37 g) per fruit was maximum in 4 crossed fruits per plant ( ) followed by (5.06 g) and in (3.82 g) irrespective of growth regulators. Four fruit load per plant recorded significantly maximum in germination (83.28%), root length (8.43 cm), shoot length (7.48 cm), seedling vigour index (1136) and seedling dry weight (16.85 mg) followed by and. Whereas, significantly minimum (66.53%, 6.75 cm, 5.77 cm, 980 and 9.39 mg, respectively) was noticed in the all crossed fruits per plant ( ). In contrast to these results seed yield per plant was significantly more in higher fruit load per plant i.e., in the load of all fruits per plant which was followed by 12 and 8 fruits per plant The increase in seed yield per plant may be due to retention of more number of fruits per plant. Whereas, seed yield per plant (26.67 g) was significantly less in the four fruit retained per plant in view of its lower fruit load per plant. The fruit weight, number of seeds per fruit and seed weight were significantly higher in the four fruit load per plant ( ) ( g,

5 Vol. 42, No. 1, TABLE 2: Effect of growth regulators and fruit load on shoot length, seedling vigour index and seedling dry weight in brinjal hybrid seed production Treatment Shoot length (cm) Seedling vigour index Seedling dry weight (mg) Mean Mean Mean Growth regulators (G) SEm± % NS Fruit load (L) SEm± % Interaction (MxP) SEm± % NS NS NS NS NS NS NS NS NS NS Non significant - GA 50 ppm - 40 ppm - Control (water spray) - Four crossed fruits per plant - Eight crossed fruits per plant - Twelve crossed fruits per plant - All crossed fruits per plant , and 5.37 g, respectively) followed by eight fruits per plant ( ) and it might be attributed to less load of fruits on plant favouring more availability and translocation of photosynthates from source to the developing fruits (sinks) and thus resulted in increased fruit weight, seed number and seed weight as compared to other treatments. Significant differences due to fruit load per plant were noticed for germination percentage, root length, shoot length, vigour index and seedling dry weight. All these seed quality parameters were significantly higher in the four fruit load per plant. Similar findings are also reported by Balakumar and Balasubramanian (1988) in tomato, Revanappa (1993) and Balaraj (1999) in chilli, Jolli (2004) Yogeesha, et.al.,(1999)in tomato. From the above results it can be revealed that for hybrid seed production of brinjal, retention of all fruits recorded higher seed yield per plant whereas better seed quality could be obtained from four fruit load per plant as compared to other fruit load treatments. Interaction of growth regulator and fruit load

6 30 INDIAN JOURNAL OF AGRICULTURAL RESEARCH Interaction effect of growth regulators and fruit retention per plant (G x L) showed nonsignificant variations for seed yield per plant. However, the interaction of recorded numerically more seed yield per plant (43.36 g) followed by, and (41.24, and g) respectively. Whereas, numerically less seed yield was seen in (20.16 g) treatment combination. In non-significant interaction effect between growth regulator and fruit load, numerically higher germination (85.76%), root length (8.62 cm), shoot length (7.66 cm), seedling vigour index (1394) and seedling dry weight (19.22 mg) was observed in followed by, and and it was lower (65.72%, 6.55 cm, 7.25 cm, 809 and mg, respectively) in. The interaction effect between fruit load and growth regulator (L x G) was found to be non-significant for most of the seed yield and quality parameters studied. However, seed yield and quality parameters were numerically more in interaction of GA 50 ppm and four crossed fruits per plant ( ) followed by 40 ppm and four crossed fruits per plant ( ) and water spray and four crossed fruits per plant ( ) whereas seed yield was more in GA 50 ppm and all crossed fruits per plant and followed by 40 ppm and all crossed fruits per plant ( ) and water spray and all crossed fruits per plant ( ). Similar findings are also reported by Balakumar and Balasubramanian (1988) in tomato, Revanappa (1993) and Balaraj (1999) in chilli. It can concluded that for hybrid seed production of brinjal spraying of NAA 40 ppm and retention of all fruits per plant gave better seed yield and quality parameters. REFERENCES Balakumar, T. and Balasubrananian, D. A.,(1988), Trop Agric, 65 : Balaraj, R.,(1999), Ph.D. Thesis, University of Agricultural Sciences, Dharwad. Gomez, K. A. and Gomez, A. A.,(1984), Statistical Procedures for Agriculture Research. Second Edition, A Wiley Interscience Publication, New York (USA). Jolli, R. B., (2004), Ph.D. Thesis, University of Agricultural Sciences, Dharwad. Panse, N. G. and Sukhatme, P. V.,(1967), Statistical Methods for Agricultural Workers. Indian Council of Agricultural Research, Publication, New Delhi, India. Revenappa,(1993), Ph.D. Thesis, University of Agricultural Sciences, Dharwad. Singh, D. K. and Lal, G.,(1995),Adva Hortic Forestry, 4 : Yogeesha, H.S., et.al.,(1999), Seed Scie and Tech, 27: