Evaluation of nutrient levels and plant geometry under high density planting system in compact cotton for mechanized harvesting

Abstract

Field experiments were conducted during summer 2019 and rabi 2019-20 at Central newlineFarm, Agricultural College and Research Institute, Tamil Nadu Agricultural University, newlineMadurai, Tamil Nadu to evaluate of nutrient levels and plant geometry under high density newlineplanting system (HDPS) in compact cotton for mechanised harvesting. newlineField experiments were laid out in split plot design with three replications. The main newlineplots are allotted with four levels of crop geometry namely, S1 : Plant spacing with 100 cm newline×10 cm (1,00,000 plants ha-1 newline), S2 : Plant spacing with 75 cm ×15 cm (88,888 plants ha-1 newline), S3 newline: Plant spacing with 60 cm ×15 cm (1,11,111 plants ha-1 newline) and S4 : Plant spacing with 45 cm newline×15 cm (1,48,148 plants ha-1 newline). The sub plots comprised of four different levels of N, P and K newlineviz., C : Control (nil nutrients), F1 : 100% RDF (80:40:40 kg NPK ha-1 newline), F2 : 125% RDF newline(100:50:50 kg NPK ha-1 newline) and F3 :150% RDF (120:60:60 kg NPK ha-1 newline). The compact cotton newlinevariety cv. CO 17 (TCH 1819) with zero monopodial, short sympodial and erect type has newlinebeen used for the present investigation. newlineAmong the treatment combinations, S3F3 (60 x 15 cm with NPK at 120:60:60 newlinekg NPK ha-1 newline) registered the highest NPK uptake in both seasons and also pooled mean. The newlineapplication of different levels of NPK enhanced the uptake of Ca, Mg, Zn, Cu, Fe and Mn newlineuptake. newlineThe economic analysis based on the mean data of both seasons revealed that the newlinetreatment combination of S3F2 (60 x 15 cm with NPK at 100:50:50 kg NPK ha-1 newline) recorded newlinethe highest gross return (and#8377; 1,60,875), net return (and#8377; 1,07,689) and B:C ratio (3.02) and it was newlinefound to be closely followed by S1F3 (100 x 10 cm with NPK at 100:50:50 kg NPK ha-1 newline) newlinewhich registered and#8377; 1,55,643 as gross return, and#8377; 1,03,816 as net return and 3.00 as B:C ratio. newlineBased on the results, it could be concluded that adoption of spacing of 60 x 15 cm newlinealong with the application 125% RDF (NPK at 100:50:50 kg ha-1 newline) recorded significantly newlinehighest seed cotton yield (2475 kg ha-1 newline) with B:C ratio (3.02).