Efficient nitrogen management in wheat (Triticum aestivum) using leaf-colour chart and chlorophyll meter for optimizing growth, yield and nitrogen-use efficiency

Abstract

A field experiment was conducted at Pantnagar, Uttarkahand, during the winter (rabi) season of 201415, to study the effect of modern tools such as leaf colour chart (LCC) and chlorophyll meter (SPAD meter) on growth, yield and nitrogen-use efficiency in wheat [Triticum aestivum (L.) emend. Fiori & Paol.] crop. Application of N as 25 kg as basal + 40 kg (at LCC 4,5 and SPAD 35, 40) and 25 kg as basal + 40 kg at crown-root initiation + 40 kg at SPAD 40 (total 105 kg N/ha) resulted statistically similar growth and yield attributes, viz. shoot density, dry-matter accumulation, leaf-area index, number of spikes/m2, number of grains/spike, 1,000-grain weight, grain yield and higher values of agronomic efficiency, recovery efficiency than recommended nitrogen management with the sav- ing of 30% or 45 kg N/ha. Although result was at par in case of both, threshold value of LCC and SPAD, applica- tion of 40 kg N/ha at LCC 5 and SPAD 40 was found to be more effective than LCC 4 and SPAD 35. Higher re- turns of 3,292 were obtained in the recommended practice compared to next best treatment, i.e. application of 25 kg N as basal + 40 kg at SPAD 40. Therefore LCC and SPAD can be effective tool for efficient fertilizer N man- agement in wheat.