Synergistic integration of crop residue mulch and cultural practices with herbicides for managing weed complex in turmeric in North-Western India

Abstract

Turmeric being a wide spaced and long duration crop, weeds pose a serious problem due to its delayed emergence and slow initial growth which provide ideal environment for weeds to grow. This warrants for synergistic integration of residue mulch, cultural practices, and herbicides for effective weed management. Two field experiments were conducted during 2012-13 - 2013-14 and 2014-15 - 2015-16 at CCS Haryana Agricultural University, Regional Research Station, Karnal to evaluate different approaches involving integration of crop residue mulch and cultural practices with herbicides for effective and economical weed management in turmeric. The uncontrolled weeds caused 42-66% turmeric yield loss. Based on four years studies, it may be concluded that pre-emergence (PE) application of metribuzin 700 g/ha or pendimethalin 1000 g/ha or atrazine 750 g/ha integrated with rice straw mulching (10 t/ha) after herbicide application at 3 days after sowing (DAS) and hand weeding at 50 or 75 DAS provided effective control (86-100%) of complex weed flora in turmeric with improved rhizome yield (14.29 to18.60 t/ha), which was comparable to weed free, better economic returns without phyto-toxicity on the crop and detectable herbicidal residues in the turmeric rhizomes and soil at harvest. Integration of 2-hoeing with metribuzin 700 g/ha PE or pendimethalin 1000 g/ha PE were the two other viable options of integrated weed management (IWM) strategy. Among post-emergence (PoE) herbicides, fenoxaprop 67 g/ha 45 DAS, was safe to turmeric while metsulfuron 4 g/ha PoE was toxic. Glyphosate 0.3% PoE at 25 DAS could also be integrated with hoeing twice at 45 and 75 DAS for effective weed management in turmeric. Use of rice straw in IWM strategies in turmeric will also help in reducing herbicide dose, crop residue management without burning, conservation of soil moisture and other natural resources which will helps in long term sustainable and economical production system.