Standardization of spray technique for pre-emergence herbicides in ZT-wheat (Triticum aestivum) with surface residue cover

Abstract

The present study was carried out at Regional Research Station, CCS Haryana Agricultural University, Karnal, Haryana during winter (rabi) seasons of 2019–20 and 2020–21. In this experiment, ZT-wheat (Triticum aestivum L.) was sown with happy seeder under surface residue load of 6 t/ha (chopped). Fourteen weed control treatments including pre-emergence herbicide (pendimethalin 1500 g/ha), sequential application of pre-emergence fb post-emergence (POE) herbicide (pendimethalin 1500 g/ha fb pinoxaden 50 g/ha), weedy check and weed-free were applied in a randomised block design (RBD) with 3 replications. Pre-emergence (PRE) herbicides were applied on the top of rice (Oryza sativa L.) residues using two water volumes (500 and 1000 litre/ha) with 3 types of nozzles (flat-fan, flood-jet and air-injection). Among weed species, Rumex dentatus (L.) and Phalaris minor (Retz.) showed significantly higher suppression under residue mulch and Medicago polymorpha (L). showed least suppression. Pendimethalin 1500 g/ha fb pinoxaden 50 g/ha (1000 l/ha) (Flood-jet) was statistically similar to weed-free in terms of grain yield, net returns and B:C ratio during both the years.