Effect of graded levels of fertilizer on growth and yield of niger varieties under rainfed condition of Assam

Abstract

During the rabi season of 2019-20, a field experiment entitled “Effect of graded levels of fertilizer on growth and yield of niger varieties under rainfed condition of Assam” was conducted at Instructional-cum-Research (ICR) Farm, Assam Agricultural University, Jorhat with a view to assess the influence of graded levels of NPK and varieties on growth and yield of niger. With three replications, the experiment was laid out in a Randomized Block Design (Factorial). The treatments comprised of four grades of NPK viz., F1: 10-5-5 kg N-P2O5-K2O/ha, F2: 20-10-10 kg N-P2O5-K2O/ha, F3: 30-15-15 kg N-P2O5-K2O/ha and F4: 40-20-20 kg NP 2O5-K2O/ha and four varieties viz., V1: NG-1, V2: GA-10, V3: JNS-9 and V4: NB-1. Experimental findings revealed that application of 40-20-20 kg N-P2O5-K2O/ha, 30-15-15 kg N-P2O5-K2O/ha and 20-10-10 kg NP2O5-K2O/ha gave statistically at par values in respect of all growth parameters studied viz., plant height, number of leaves per plant, leaf area index, number of branches per plant, dry matter production per plant and chlorophyll content of leaves. Application of 40-20-20 kg N-P2O5-K2O/ha proved superior in terms of yield attributing characters like capitula per plant, number of seeds per capitulum, seed (534.15 kg/ha) and stover yield (2981.05 kg/ha) and oil yield (204.12 kg/ha). No treatment differences were observed in respect of 1000-seed weight and harvest index. Among the varieties, NB-1 gave significantly higher values in almost all the growth characters (viz., plant height, number of leaves per plant, leaf area index, number of branches per plant and dry matter production per plant) under study except chlorophyll content of leaves, which was higher in the variety GA-10. On the other hand, the variety GA-10 gave significantly higher values in respect of yield attributing characters like number of capitula per plant, number of seeds per capitulum and 1000-seed weight which were at par with JNS-9. Significantly higher seed yield was obtained in GA-10 (491.87 kg/ha) which was at par with JNS-9 (470.24 kg/ha), whereas, the stover yield was the highest in NB-1 (2866.84 kg/ha). Harvest index was significantly higher in GA-10 (16.44%) and was at par with JNS-9 (15.90%) and NG-1 (15.50%). The variety GA-10 also produced significantly oil yield (191.96 kg/ha). The highest interaction effect was recorded under the treatment combination- V2F4 (40-20-20 kg NP2O5-K2O /ha was applied to GA-10) in respect of number of capitula per plant (35.64), seed yield (623.90 kg/ha).