Response of brinjal, Solanum melongena to different fertility regimes (variety PUSA purple round)

The nursery of Pusa Purple Round variety of brinjal was transplanted 25th April, 2003, keeping row to row spacing of 75 cm and plant to plant 50 cm. The plots were prepared in a three replicated randomized complete block design, with net plot size of 3 x 3.5 m (10.5 m2). All P and 1/3rd N was applied at the time of sowing, 1/3rd while remaining 2/3rd of N was divided into various split doses and applied at different stages. The nitrogen was applied in the form of urea (46% N) and P in the form of single superphosphate. The N-P levels tested were; Control, 50-40, 70-50, 90-60, 110-70 and 130-80 kg ha-1. Plots received higher N-P levels of 130-80 or 110- 70 kg ha-1 produced plants of significantly more height 92.80 and 91.84 cm, respectively. The LSD test envisaged that there was significant increase in plant height due to each increased level of N-P fertilizer up to 110-70 kg ha-1, further increase in the N-P levels was not economical. N-P leve ls of 130-80 or 110-70kg ha-1 produced significantly greater number of branches (9.84 and 9.70), followed by 7.31 and 6.86 average number of branches per plant recorded under N-P level of 90-60 and 70-50 kg ha-1, respectively. LSD suggested that N-P application beyond 110-70kg ha-1 was uneconomical. Plots receiving higher N-P levels of 130-80 or 110-70kg ha-1 produced significantly healthier fruits (7.72 cm and 7.53 cm), followed by fruit diameter of 7.16 cm and 6.82 cm recorded under N-P level of 90-60 and 70-50kg ha-1, respectively; LSD test illustrated that difference either within treated plots or when compared with control were significant with varied degree of significance except 110-70 and 130-80kg ha-1 levels, where non-significant differences were observed. Higher N-P levels of 130-80 or 110-70kg ha-1 produced fruits greater in weight (258.67 g and 254.67 g), followed by single fruit weight of 235.00 g and 223.67 g produced by the plants receiving N-P level of 90-60 and 70-50kg ha- 1, respectively. LSD test revealed significant differences between all the treatment means or as compared to control were significant except 130-80 and 110-70kg N-P ha-1 where differences were non-significant. N-P levels of 130-80 or 110-70kg ha-1 produced significantly more number of fruits per plant (12.60 and 12.26), while the N-P level 90-60 and 70-50kg ha-1 ranked third and fourth with average number of fruits 11.26 and 10.17 per plant, respectively. The LSD test shows that the increase in number of fruits per plant was negligible when N-P application exceeded 110-70kg ha-1. Fruit yield per plot (41.28kg and 41.08kg) was significantly greater in plots treated with N-P levels of 130-80 or 110-70kg ha-1, followed by N-P level of 90-60 and 70- 50kg ha-1 with average fruit yield of 37.76kg and 35.34kg per plot, respectively. The yield per plot was minimum (13.58kg) in control plots. Each increased N-P level caused significant improvement in the brinjal fruit yield. Similarly, this increase in fruit yield per plot was negligible when N-P application beyond 110-70kg ha-1. The LSD test revealed that N-P level up to 110-70 kg ha-1 can be considered as an optimum level for producing economical brinjal production. The crop receiving higher N-P levels of 130-80 or 110-70 kg ha-1 produced significantly maximum fruit yield (39.310 m.t ha-1 and 39.123 ha-1), followed by N-P level of 90-60 and 70-50kg ha-1 with average fruit yield of 35.963 m.t and 33.652 m.t ha-1, respectively. The increase in fruit yield per hectare was not so pronounced when N-P application exceeded 110-70kg ha-1. From the present study it was concluded that there was a linear effect of various N-P levels on all the growth and yield components of brinjal, but these effects were non-significant when N-P application exceeded 110-70kg ha-1. Thus, 110-70kg N P ha-1 was considered as an optimum level for obtaining economical crop harvest in brinjal.