Efficiency of Certain Herbicides and Adjuvants Combinations Against Weeds in Wheat Fields

Document Type : Original Article

Authors

Plant Protection Department, Faculty of Agriculture, Al-Azhar University, Nasr city, Cairo, Egypt

Abstract

Two field experiments were carried out at El-Dalangat district, El-Beheira Governorate, Egypt during two successive winter seasons of 2017-2018 and 2018-2019, to evaluate the efficiency of post-emergence herbicides: Clodimex (clodinafop-propargyl 24% EC),Pallas (pyroxsulam 4.5% OD), Skylla (tribenuron-methyl 75% WG) at their recommended rates or at reduced rates without adjuvants or in combination with Argal at 0.2% v/v and Techno oil at 0.3% v/v adjuvants in combination with clodinafop-propargyl + tribenuron-methyl at half recommended rate combined with Argal or Techno oil adjuvants and hand weeding at 25 and 40 days after sowing (DAS) for controlling predominant weeds in wheat crop compared to unweeded check. The results indicated that the dominant weed species in the experimental wheat field were, two grassy weeds, Phalaris minor and Eragrostis ciliagensis, and six broad-leaved weeds: Malva parviflora, Sonchus oleraceus, Coronopus squamatus, Rumex dentatus, Anagallis arvensis and Medicago polymorpha during the both seasons. In addition, Eclipta alba weed was found only in the second season. Results also showed that all herbicidal treatments significantly decreased the total weed biomass compared to the unweeded check 60 and 90 DAS. Among herbicidal treatments applied, pyroxsulam herbicide at ¾ of recommended rate with Argal recorded the highest weed control efficiency against grassy and broad-leaved weeds followed by pyroxsulam treated plots at ¾ of recommended rate combined with Techno oil 60 and 90 DAS throughout the two studiedseasons. On the other hand, regardless of application rates or adjuvants, tribenuron-methyl and clodinafop-propargyl seemed to be the least effective treatments against the total weeds 60 and 90 DAS during the both seasons in comparison with unweeded plots. The maximum increase in wheat grain yield was observed in pyroxsulam treated plots at ¾ recommended rate with Argal or Techno oil combinations. It could be concluded that the addition of Argal or Techno oil to herbicides spray solutions at reduced rates especially at ¾ of the recommended rate resulted in enhancing the herbicidal activity against weeds and increasing wheat grain yield.

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