Weed Dynamics and Nutrient Uptake of Maize as Influenced by Different Weed Management Practices

Background: Maize (Zea mays L.) is the most versatile and emerging food crop of global importance. Weeds are ubiquitous but their presence in wide spaced and initially slow growing crop like maize acts as an obstacle for plentiful harvest. Nutrient uptake by weeds during the first thirty days of maize growth was 59 kg N, 10 kg P₂O₅ and 59 kg K₂O per ha, which was 7-10 times higher than the nutrient uptake by maize.
Methods: The present field experiment was conducted during Rabi, 2018-19 under irrigated conditions at wetland farm of S.V. Agricultural College, Tirupati andhra Pradesh, with ten treatments and three replications in a randomized block design.
Result: Lower density and dry weight of weeds with higher weed control efficiency, lower nutrient uptake by weeds and higher nutrient up take by maize at 80 DAS, kernel and stover yield was recorded with hand weeding twice at 15 and 30 DAS, which was statistically at par with atrazine 1.0 kg ha^-1 as PE fb topramezone 30 g ha^-1 or tembotrione 120 g ha^-1 as PoE or atrazine 1.0 kg ha^-1 as PE fb HW at 30 DAS, while these were lowest with weedy check. Higher benefit cost ratio of maize was noticed with both atrazine 1.0 kg ha^-1 as PE fb topramezone 30 g ha^-1 as PoE (T₃), which was in parity with atrazine 1.0 kg ha^-1 as PE fb tembotrione 120 g ha^-1 as PoE (T₂) and hand weeding twice at 15 and 30 DAS (T₉). From the present study it may be concluded that atrazine 1.0 kg ha^-1 as PE fb topramezone 30 g ha^-1 or tembotrione 120 g ha^-1 as PoE were considered to be the most effective and economic weed management practices to increase the productivity of Rabi maize at times of labour scarcity.