EFFECT OF PLANT GROWTH REGULATORS ON GROWTH AND YIELD PARAMETERS OF PAPRIKA cv.ktpl-19

Transcription

1 Agric. Sci. Digest, 29 (3) : , 2009 AGRICULTURAL RESEARCH COMMUNICATION CENTRE / indianjournals.com EFFECT OF PLANT GROWTH REGULATORS ON GROWTH AND YIELD PARAMETERS OF PAPRIKA cv.ktpl-19 K. Kannan, M. Jawaharlal and M. Prabhu Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore , India ABSTRACT The increased fruit drop, decreased percentage of fruit set and delay in flowering are the major issues lead to low productivity in paprika. Therefore, the field experiments on effect of growth regulators on paprika cv. KtPl-19 was carried out by using randomized block design at coconut garden of Tamil Nadu Agricultural University, Coimbatore during July 2002 and Dec The greatest plant height was observed at NAA 50 ppm at vegetative, flowering and harvest stages during winter and summer seasons. The application of GA 3 at 50 ppm showed the highest number of primary branches per plant during winter and summer seasons. The highest number of leaves per plant was observed with NAA at 50 ppm in vegetative stage in both the seasons, at flowering stage GA 3 at 50 ppm in winter and NAA at 50 ppm in summer and at harvest stage GA 3 at 50 ppm in winter and summer. Early flowering and highest fruit yield were achieved by the treatment with NAA 50 ppm during winter and summer seasons. Based on the results, it can be concluded that NAA 50 ppm had positive effect on plant growth, early flowering and yield potential. Key words : Fruit drop, Growth regulators, Papprika, Yield. Natural food colourants are added to food products to impact high aesthetic appeal to the foods, flavour, aroma and colour to foods. Paprika contains remarkable amount of the colouring material and is used as colourant in processed foods as they get the nod over synthetic products in the food colourant market. The commercial importance of paprika both as a spice and a vegetable with large scale cultivation in both tropical and sub tropical regions are increasing. The increased fruit drop, decreased percentage of fruit set and delay in flowering are the major issues leading to low productivity in paprika. Considering the above points in mind, the present study was taken up to overcome the problems associated with delay in flowering and higher rate of flower drop through foliar application of different growth regulators in paprika variety KtPl-19 under the coconut shade condition. The field experiments were carried out using paprika cv. KtPl-19 in the coconut garden, TNAU, Coimbatore during July 2002-Dec and Dec.2002 to May 2003 and the plot size was 3 m x 2 m for each treatment. The initial soil characters of the experimental field are given below Parameters Values Clay (per cent) 4.00 Silt (per cent) Fine sand (per cent) Coarse sand (per cent) Soil reaction (ph) 7.62 EC (d s m -1 ) 0.20 Organic matter content (per cent) 8.35 Available nitrogen (kg ha -1 ) Available phosphorus (kg ha -1 ) Available potassium (kg ha -1 ) Cation exchange capacity (meq100g -1 ) The experiment was laid out in randomized block design with three replications and treatment details are listed below.

2 158 AGRICULTURAL SCIENCE DIGEST Treatment details - Control (Without any spray) - Mepiquat chloride 50 ppm - Mepiquat chloride 100 ppm - 2,4-D 5 ppm - 2,4-D 10 ppm - NAA- 25 ppm - NAA- 50 ppm - GA 3 25 ppm - GA 3 50 ppm - Nitrobenzene 0.1 per cent 1 - Nitrobenzene 0.2 per cent The growth regulators were treated as foliar sprays with the help of a mini hand sprayer in morning hours. The first treatment was given at 25 days after transplanting and the second and third sprays were given at twenty days intervals after the first spray is on 45 th day and 65 th day after transplanting. The seedlings were transplanted at the spacing of 60 x 30 cm and the recommended dose of N: P: K at 120:100:120 kg/ha was applied as half of N and entire P and K was applied as basal dose along with 10 kg of neem cake and the remaining N was applied as top dressing. Observation on morphological, flowering and fruit characters were recorded and mean values were subjected to statistical analysis. Effect of growth regulators on growth attributes : The greatest plant height was observed at NAA 50 ppm as 24.40, and cm in winter and 22.46, and cm in summer at vegetative, flowering and harvest stages respectively (Table 1). The promoting effect on plant growth in paprika due to the application of NAA obtained in this experiment might be due to its action as a group of auxin compound which enhances the cell division and cell elongation. The treatments GA 3 and 2, 4-D were also increased the plant height significantly. Singh and Vashist (1984) also studied the effective increase in plant height due to GA 3 application in sweet pepper. The application of GA 3 at 50 ppm showed the highest number of primary branches per plant of 2.98 and 2.90 during winter and summer respectively. The greatest number of secondary branches per plant was registered with the treatment of GA 3 at 50 ppm in vegetative stage in winter (2.90) and summer (2.62). At flowering stage GA 3 at 25 ppm recorded the highest secondary branches (6.80) in winter and NAA at 50 ppm (Table.2). The increase in the number of primary branches due to auxins attributed to the activation of cell division and cell elongation in the axillary buds which had a promoting effect in increased number of primary branches and secondary branches. Interaction with the synthesis of native cytokinins present in the root cells and its transport at later stages to axillary buds, leads to the formation of more branches. This was quite obvious by the rapid increase in the number of branches of the crop in NAA treated plants as compared to a slower rate of increase in the control. Gupta and Gupta (2000) observed the similar results with NAA at 75 ppm treatment in tomato. The promoting effect of 2, 4- D on number of primary branches in tomato was studied by Kamruddin et al. (1978). The phenoxy compounds increased the cell division and cell enlargement which attributed to the increase in the number of primary branches. This was due to the check in the apical dominance and induction of cytokinesis in the axillary buds. The results obtained in the experiment regarding the leaf characters showed that all the treatments induced more number of leaves per plant at all the growth stages. Maximum number of leaves per plant was observed in the treatment of GA 3 at 50 ppm. This might be due to the increased plant height with the hormonal effect on cell division and cell elongation. The leaf area was found to be the highest with GA 3 50 ppm in winter (89.92 cm 2 ) and NAA 50 ppm (86.37 cm 2 ) in summer at vegetative stage and GA 3 50 ppm at flowering ( cm 2 and cm 2 ) and harvest stages ( cm 2 and cm 2 ) in both the seasons respectively. The results obtained in the experiment revealed that all the treatments induced greater leaf area than the control (Table.3). The treatment GA 3 and NAA showed maximum leaf area followed by 2, 4- D. This might be due to the increased number of leaves and through increased protein synthesis. The activity of auxinic compounds is evident in increasing the leaf area through cell division and elongation of cells. When the leaf area of the plant is increased, more carbohydrates are synthesised by plants. With more

3 Vol. 29, No. 3, Table 1. Effect of growth regulators on plant height, days to first flowering, days to 50% flowering and plant spread of paprika Cv. KtPl- 19 Treatments Plant height (cm) Days to first Days to 50% Plant spread Vegetative stage Flowering stage Harvest stage flowering flowering (cm 2 ) Mean SE d CD (0.05) Table 2. Effect of growth regulators on branches, fruit length and fruit girth of paprika Cv. KtPl- 19. Treatments Number of leaves per plant Leaf area (cm 2 ) Vegetative stage Flowering stage Harvest stage Vegetative stage Flowering stage Harvest stage Mean SE d CD (0.05)

4 160 AGRICULTURAL SCIENCE DIGEST leafy vegetation and more carbon assimilation, the nutrients absorbed are properly utilized. This result goes with the statement of Mehrotra et al. (1970), that GA3 and NAA gave increased number of leaves per plant in tomato. The significant effect on number of leaves due to 2, 4-D application might be due to the impairment of leaf senescence and abscission. This was in confirmation with the results obtained by Krishnamurthi and Bhandari (1957) in chilli, who observed that application of 2, 4-D at 2 ppm was able to maintain comparatively highest number of leaves than either the control or the higher concentrations. The 2, 4-D at lower concentrations acted as an growth promoter thereby inducing the cell division, elongation resulting in more number of leaves. Plant spread was highest in GA 3 at 25 ppm with cm 2 and cm 2 in winter and summer respectively. Foliar spray of GA 3, NAA and 2, 4-D exhibited maximum plant spread (Table.1) which might be due to the increased plant height and number of primary branches obtained by these treatments. The increase in length of internodes can also be attributed to the increased plant spread. Because of faster cell division and multiplication process, the length of stem and branches would have increased in the treated plants. The similar effect of GA 3 and NAA was reported by Revanappa et al. (1998) in green chilli. Early flowering was achieved by the treatment of NAA 50 ppm at and days after transplanting with first flowering in winter and summer respectively. The effect of NAA on the number of days taken for the first flower showed that NAA at 50 ppm concentration exhibited the earliest flowering while other treatments also had earliness than control. GA 3 at 25 ppm and NAA at 50 ppm imparted earliness in days to 50 per cent flowering. When compared to control, all the treatments exhibited earliness in flowering (Table 1). The increased synthesis of cytokinin and auxin in the root tissue by their enhanced activity due to the application of GA 3 and NAA and their simultaneous transport to the axillary buds would have resulted in a better sink for the mobilization of photo- assimilates at a faster rate. This would have helped in the early transformation from the vegetative phase to reproductive phase. The induction of early flower bud initiation might be influenced by triggering of such metabolic processes and narrowing of the carbon: nitrogen ratio by the significant accumulation of carbohydrates. The result on earliness in flowering in this experiment goes with the reports by Singh and Mukherjee (2000) in chilli. The highest dry matter production (9.86 and 9.61 g / plant) was obtained with the treatment of 2, 4-D at 10 ppm in both the seasons. The results obtained in the experiment regarding the dry matter production per plant revealed that all the treatments increased the dry matter production and the maximum being due to the 2, 4-D at 10 ppm treatment (Table 4). This might be due to the high vigour of the plant, increased plant height, plant spread and more vegetative growth obtained by the treatment. The increased degree of cell division, cell elongation and differentiation of tissues and acceleration of the centripetal cytokinesis, caused by the 2, 4-D treatment resulting the increased fresh weight of plants. Similar results were observed by Hariharan and Unnikrishnan (1985) in Piper nigrum. Effect of growth regulators on fruit characters and yield : The fruit length (14.52 and cm) and fruit girth (7.26 and 6.68 cm), were significantly influenced by NAA 50 ppm during winter and summer. The effect of the treatments on the fruit length and girth showed that NAA at 50 ppm exhibited maximum effect. The other growth regulators also produced significant influence on the fruit length and girth compared to the control (Table 2). The increase in fruit length and girth may be attributed to increase in the number of cells as well as elongation of cells which is characteristic action of any auxinic group of chemicals. These results were supported by Sharma et al. (1999) in bell pepper. The effect of 2, 4-D on increased fruit size was also noticed in this experiment and the results were similar to the previous reports made by Chandra and Shivraj (1972) in chilli. The number of seeds ( and ) and seed weight (1.11 and 1.09 g) per fruit was reduced in Nitrobenzene at 0.1 per cent during winter and summer respectively. With regard to number and weight of seeds per fruit, the results obtained in the present study showed that all the treatments

5 Vol. 29, No. 3, Table 3. Effect of growth regulators on number of leaves per plant and leaf area of paprika Cv. KtPl- 19. Treatments Number of leaves per plant Leaf area (cm 2 ) Vegetative stage Flowering stage Harvest stage Vegetative stage Flowering stage Harvest stage Mean SE d CD (0.05) Table 4. Effect of growth regulators on yield, seed characters and dry matter of paprika Kt Pl- 19. Treatments Fresh fruit yield/plant (g) Yield/plot (kg) Yield/ha (tonnes) No of seeds/fruit Seed weight/fruit (g) Dry matter/plant (g) Mean SE d CD (0.05)

6 162 AGRICULTURAL SCIENCE DIGEST decreased the number of seeds per fruit and seed weight per fruit (Table 4). Super imposition of treatments would have created a better sink in the fruit for the photosynthates. The enhanced concentration of auxin on the pericarp due to external application of auxin would have diverted the photo-assimilates to develop the cell wall of the pericarp instead of the ovules. This would have resulted in reduced weight of seeds per fruit. This might be due to the super optimal concentration of auxins either native or applied, leading to lesser development of seeds. The similar results were reported by Lyngdon and Sanyal (1992) in capsicum. The treatment NAA at 50 ppm recorded the greatest fresh fruit yield per plot (6.82 and 5.98 kg) and estimated yield per hectare (12.89 and t) REFERENCES Chandra, R. and Shivraj, A. (1972) Andhra Agric. J., 19(1&2): Fonnesbech, M. (1974) Physiologia Plantarum, 32(1): Gupta, P.K. and Gupta, A.K. (2000) Bioved., 11(1/2): Hariharan, M. and Unnikrishnan, K. (1985) Seed Sci. Tech., 13(1): Kamruddin, M.D. et al.(1978) Indian J. Hort., 35(2): Krishnamurthi, S. and Bhandari, Beeranna P. (1957). Indian. J. Hort., 14(3): Lyngdon, G.B. and Sanyal, D. (1992). Hort. J., 5(1): Mehrotra, O.N. et al. (1970). Prog. Hort., 2(1): Pampapathy, K. and Rao, S.N. (1975) Andhra Agric. J., 23(1&2): Revanappa, U. et al. (1998) Karnataka J. Agric. Sci., 11(2): Sharma, N. et al. (1999). J. Hill Res., 12(1): Singh, L. and Mukherjee, S. (2000).Agric. Sci. Digest, 20(2): Singh, J. and Vashist, V.K. (1984) Capsicum Eggplant Newslr., (3):33. during winter and summer respectively. The effect of different treatments on fruit yield per plant showed that NAA at 50 ppm induced the highest yield of fruits per plant. All the other treatments exhibited an increased effect on yield over control (Table 4). Increased yield due to NAA application was reported by Lyngdon and Sanyal (1992) in capsicum and Sharma et al. (1999) in bell pepper. Increased yield due to the application of 2, 4-D at 10 ppm was reported by Pampapathy and Rao (1975) in chilli. Based on the results, it can be concluded that higher concentration of NAA at 50 ppm had positive effect on plant growth, early flowering and yield potential compare to lower concentration of NAA viz, 25 ppm. Similar findings were reported by Fonnesbech (1974).