Effect of nano-urea and herbicides on yield and yield attributes of wheat (Triticum aestivum)

A field experiment was conducted during the winter (rabi) season of 2021-22 at Indian Agricultural Research Institute, New Delhi, to investigate the effect of nano-urea and herbicides on yield and yield-attributing characters of wheat (Triticum aestivum L.). The experiment was tested in a split-plot design with 4-nano-urea based treatments, viz. control (no nitrogen), recommended dose of nitrogen (RDN) 120 kg N/ha, 50% RDN + 2 sprays of nano-urea, at 40 and 60 days after sowing (DAS) and 75% RDN + 1 spray of nano-urea (at 60 DAS) in main plots and 4 herbicides based weed management options, viz. sulfosulfuron 75% + metsulfuron methyl 5% WG (ready mix) @ 40 g a.i./ ha at 30 DAS; tank-mix of clodinafop propargyl and carfentrazone-ethyl (60 and 20 g a.i./ha) at 30 DAS; weed-free check and unweeded check, in subplots and replicated thrice. Results revealed that, yield attributes were significantly higher with 100% RDN. This treatment also resulted in 40 and 18% more grain yield with 100% RDN (5.21 t/ha) over 50% RDN + 2 sprays of nano-urea (3.7 t/ha) and 75% RDN + 1 spray of nano-urea (4.4 t/ha) respectively. Among the weed-management options, weed-free check was superior in yield and yield attributes followed by tank mixed carfentrazone ethyl + clodinafop propargyl (60 and 20g a.i./ha) at 30 DAS. However, tank mixed carfentrazone ethyl + clodinafop propargyl was significant superior to the ready-mixed metsulfuron methyl + sulfosulfuron in terms of number of ear-bearing tillers/m² and number of grains/spike which resulted in significantly higher grain yield. Thus, 100% RDN (120 kg N/ha) along with tank-mixed carfentrazone ethyl + clodinafop propargyl (60 and 20 g a.i./ha) at 30 DAS are the more productive options for wheat-growing farmers keeping view of the uprising labour cost in manual weeding.