EFFECT OF PLANT DENSITIES AND FERTILIZER LEVELS ON GROWTH AND NPZN UPTAKE BY EXTRA EARLY SORGHUM (SORGHUM BICOLOR L. MONECH) GENOTYPE

摘要

A field experiment in split plot design with three replications was conducted during kharif 2003 and 2004 to study the effect of plant densities and fertilizer levels on growth and NPZn uptake by an extra early sorghum genotype (SPV-1489). Significantincreases in plant height, dry matter accumulation/plant and number of green leaves under plant density at 2.90 lac plants/ha were observed as compared to plant density at 1.50 lac plants/ha. Plant population with increasing densities from 1.50 to 2.90lac plants/ha gave significant increase in leaf area index and specific leaf weight. Plant density at 2.20 lac plants ha~(-1) gace significantly higher grain yield over plant density at 1.50 lac plants/ha which was higher by 9.24 q/ha. Plant density at 2.20 lac plants/ha gave significant increase in nitrogen and phosphorus uptake as well as zinc uptake by grain and stover. Application of 80 kg N + 40 kg P,Og/ha produced significantly higher plant height and dry matter accumulation, leaf area index, number of green leaves and grain yield as well as NPZn uptake by grain and stover application of 60 kg N + 30 kg P,0./ha. Application of 100 kg N + kg P,0./ha and 80 kg N + 40 kg P,Og/ha levels gave increases in grain yield by 20.4 and 18.7 per cent, respectively over application of 60 kg N + 30 kg P_2O_5/ha. Further, maximum specific leaf weight was obtained under application of 60 kg N + 30 kg P_2O_5/ha. Application of zinc sulphate @ 25 kg/ha significantly increased dry matter accumulation, leaf area index and number of leaves, grain yield and zinc uptake by grain and stover as compared to control.