INTEGRATING PRE AND POST-EMERGENCE HERBICIDES FOR CONTROLLING WEEDS IN DRILL-SEEDED RICE (ORYZA SATIVA L.)

Abstract

Two field experiments were carried out at the experimental farm of Sakha Agricultural Research Station, Kafrelsheikh, Egypt during the summer seasons of 2015 and 2016 to find out the optimum pre and post-emergence herbicide treatments from the recommended herbicides to control weeds under drillseeded rice conditions (Giza179 cv). Fourteen weed control treatments included two pre-emergence herbicides i.e. thiobencarb 50% at the rate of 3.57 kg ai ha-1 alone and followed by six weed control treatments included; penoxsulam 2.5% at 0.0238 kg ai ha- 1 , bispyribac-sodium 2% at 0.0381 kg ai ha-1 and fenoxaprop-ethyl 7.5% at 0.0625 kg ai ha-1 alone and mixed with halosulfuron 75% at 0.0357 kg ai ha-1, also pendimethalin 50% at rate of 2.023 kg ai ha-1 alone and followed by the previous six post-emergence weed control treatments as compared to weedy check (untreated). Randomized Complete Block Design (RCBD) with three replications was used. The results revealed that, spraying pendimethalin as pre-emergence herbicides at 4 days after seeding (DAS) recorded the best weed control, highest rice growth characters and grain yields, as compared to thiobencarb. Each of penoxsulam 2.5% or bispyribac-sodium 2% or fenoxaprop-ethyl 7.5% mixed with halosulfuron 75% gave the lowest dry weights of grasses, broadleaves and total weeds in addition to rice dry biomass, grain yield and its studied attributes. Based on obtained results, it can be concluded that pendimethalin as pre-emergence herbicide at 4 DAS followed by spraying any of penoxsulam 2.5% or bispyribac-sodium 2% or fenoxaprop-ethyl 7.5% mixed with halosulfuron 75% at recommended doses applied at 15, 22 and 35 DAS, respectively were the best combinations for controlling weeds and gave the highest grain yield in drill-seeded rice.