Effect of Herbicides and Nitrogen Levels on Phalaris minor and Its Impact on Nutrient Uptake in Wheat (Triticum aestivum L.)

Abstract

In the agricultural research farm of Banaras Hindu University, Varanasi, a field research study was carried out during the winter (Rabi) season of 2018–19 to examine the impact of levels of nitrogen and herbicides on associated weeds and wheat production. Nine weed species, including Phalaris minor, Anagallis arvensis, Cynodon dactylon, Melilotus indicus, Chenopodium album, Vicia sativa, Medicago denticulata, Solanum nigrum, and Cyperus rotundus, were frequently seen infesting wheat fields. Among these, Phalaris minor was the major weed. Application of Sulfosulfuron (25 g ha-1) + 2, 4-DEE (750 ml ha-1) significantly recorded the lowest weed density and biomass and higher weed control efficiency. HW twice (30&60 DAS) in combination with 180 kg N ha-1 followed by application of Sulfosulfuron (25 g ha-1) + 2, 4-DEE (750 ml ha-1) in combination with 180 kg N ha-1 performed significantly with respect to reduction in density, the biomass of Phalaris minor, as well as increased weed control effectiveness. Nutrient uptake was significantly highest under HW twice plot (30&60 DAS) followed by application of sulfosulfuron (25 g ha-1) + 2, 4-DEE (750 ml ha-1). The overall intake of N, P, and K in wheat grain and straw increased when nitrogen levels were high (180 kg ha-1), but uptake of these nutrients was low when nitrogen levels were low, which was ascribed to reduced plant biomass (grain and straw) and a low proportion of these nutrients in the plant.