Grass Weed Competition in Wheat in Relation to its Time of Planting and Weed Emergence
Abstract
Field trials were conducted for two years to study the time of emergence of wild oats (Avena ludoviciana) and Phalaris minor relative to crop planted at different dates. The wheat was planted at 15 days interval starting from November through 1 January and weed seeding was done at 0, 10 or 20 days after wheat seeding. The density and biomass of both P. minor and A. ludoviciana were highest with 15 November planting and decreased thereafter with each delay in planting. The decrease was significant in P. minor. The grain yield of wheat was maximum when planted on 1 November. Although the wheat yields decreased with later plantings the yields obtained at 1 December planting were on par with 1 and 15 November plantings. The maximum grain yields were recorded under weed free treatments and minimum when weed seeding was done at wheat planting. Delay in weed seeding by 10 or 20 days relative to wheat reducedthe wheat yields only marginally as compared to weed free yields.
