Chemical Control of Grassy Weeds in Drill-Seeded Rice (Oryza Sativa L.)

Abstract

Weeds are the main obstruction under drill-seeded rice system so that two field experiments were conducted at the experimental farm of Rice Research & Training Center, Sakha Agricultural Research Station, Kafrelsheikh, Egypt in the summer seasons of 2020 and 2021 to reset the best chemical control program against grassy weeds in drill-seeded rice (Giza 179 cv.). Randomized Complete Block Design (RCBD) with three replications was used during both seasons of study. Ten chemical weed control were applied; (1) pendimethalin 50% EC (2.023 kg ai ha -1 ) at 4 DAS as preemergence herbicide, (2) pendimethalin as per-emergence followed by (fb) penoxsulam 2.5% OD (0.0238 kg ai ha -1 ) at 15 DAS as post-emergence herbicide, (3) pendimethalin as per-emergence fb bispyribacsodium 2% SL (0.0381 kg ai ha -1 ) at 25 DAS, (4) pendimethalin as pre-emergence fb ready mix of cyhalofop-butyl 7% + quinclorac 10% OD (0.238+0.1667 Kg ai ha -1 ) at 20 DAS, (5) pendimethalin as pre-emergence fb fenoxaprop-ethyl 7.5% EW (0.0625 kg ai ha -1 ) at 40 DAS, (6) thiobencarb 50% EC (3.57 kg ai ha -1 ) at 4 DAS as pre-emergence herbicide fb bispyribac-sodium, (7) penoxsulam fb bispyribac-sodium, (8) penoxsulam at 15 DAS fb ready mix of cyhalofop-butyl 7% + quinclorac 10% OD at 25 DAS, (9) penoxsulam at 15 DAS fb fenoxaprop-ethyl and (10) tank mix of penoxsulam (0.0119 kg ai ha -1 ) + fenoxaprop-ethyl (0.0357 kg ai ha -1 ) at 35 DAS as compared to un-treated plots (weedy check) and weed free. The obtained results showed that, sequential application of pendimethalin 50% at 4 DAS pre-emergence herbicide followed by fenoxaprop-ethyl 7.5% at 40 DAS or ready mix of cyhalofop-butyl 7%+quinclorac 10% at 20 DAS recorded the lowest density and biomass of grasses and highest weed control efficiency, highest rice vegetative growth, grain yield and its attributes and reduced yield losses to 3.2 and 3.9%, respectively as compared to weed free during both studing seasons. Based on the obtained data, it could be concluded that sequential application of pre-emergence fb post-emergence herbicides was the best in grassy weed management and improved rice grain yield (87.1% and 9.203 t ha -1 ), while sequential application of early post-emergence fb late post-emergence herbicides ranked second (83.2% and 8.011 t ha -1 ) and exceeded single application of pre-emergence herbicide (40.3% and 4.317 t ha -1 ) and post-emergence herbicide tank mix (72.6% and 7.351 t ha -1 ) under dill-seeded rice conditions.

Impact of Hydrogel Polymer on Water Productivity, Weed Control Efficiency and Yield of Broadcast-Seeded Rice

“…The considerable increase of rice growth and yield and its components in case of using sequential application of Saturn followed by Nominee 2% + Inpul 75% reflex the high efficiency of such treatment in controlling weeds and enhancing more favorable conditions of moisture, nutrients, sun light and space for rice crop. These results are in harmony with those found by Abd El-Naby et al [40] and Abd El-Naby and El-Ghandor [16].…”

“…Singh et al, [31] 2016 found that sequential application of pendimethalin as preemergence herbicide followed by postemergence application of bispyribac-sodium surpassed the application of pre or postemergence herbicides alone in weed control. These results are in harmony with those obtained by Abd El-Naby and El-Ghandor [16].…”

“…Delaying irrigation period to 15 days resulted in the highest dry weight to total weeds while irrigation every 5 days recorded the lowest values, the same trend was obtained during two seasons. The reduction of total weeds under five days irrigation period may be related to the reduction of germination of some weed species especially grassy weeds under flooding conditions [16]. While the high biomass of grassy weeds under irrigation interval every 15 days as aerobic conditions may be due to encourage of such weeds to germinate and have strong growth and high competitiveness ability against rice plants.…”

“…Chemical weed control in direct seeded rice especially under water scarcity is the main defines line and best choice to avoid high yield losses caused by weeds because of herbicides as selective chemical substances kill weeds early, keep optimum conditions for rice growth, moreover less labor. Sequential application as well as herbicide mixtures (more than one active ingredient differ in mode of action on weeds) increases the efficacy of weed control and wide spectrum in one time which reduced weedcompetition to the minimum limits and delay appearance of resistant weeds against the used herbicides [16]. In this research, it will be detected how hydrogels can enhance water use and improve herbicide efficiency in broadcastseeded rice.…”

“…Weeds is the main limiting factor in rice production system because of many problems which it cause such as competition on growth demands for rice, high yield losses (93 % in drillseeded rice in Egypt as reported by Abd El-Naby and El Ghandor [16] while in aerobic direct seeded rice ranged from 50-91% as cited by Rao et al [17], difficulties in mechanical harvest, bad seed quality, damage seed production system by increase moisture content of stored rice seeds, moreover increasing production cost and playing as a host for many insects and diseases which attack rice plants. Reddy et al [18] stated that weed flora under direct seeded rice conditions included grasses, sedges and broad leaf weeds.…”