Abdolreza Ahmadi
Abstract
The critical period of weeds refers to the stage of the plant's growth cycle during which weeds must be controlled to avoid crop damage. Understanding the critical period of weed control is beneficial for both biological and economic reasons when making weed control decisions and scheduling. Field experiments ...
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The critical period of weeds refers to the stage of the plant's growth cycle during which weeds must be controlled to avoid crop damage. Understanding the critical period of weed control is beneficial for both biological and economic reasons when making weed control decisions and scheduling. Field experiments were conducted in 2018 in Khorramabad, Iran to determine the critical period of weed control (CPWC) in rain-fed lentil. The treatments were divided into two series: weed interference with the crop from emergence to 10, 20, 30, 40, 50, or 70 days after emergence with a control treatment (weed infested), and weed-free treatments up to the aforementioned stages. The logistic and Gamprtz nonlinear models were used to determine the start and end of the critical period of weed control, respectively. Galium tricornutum, Turgenia latifolia, Cerastium dichotomum, and Lathyrus aphaca were the most significant weed species in the experiment due to their greater biomass and size. The results indicated that weed control and interference treatments significantly increased lentil yield. Grain yields were 471 and 187 kg ha-1 for weed-free and interference-control treatments, respectively. Thus, when compared to weed-free control, weed interference reduced grain yield by 60%. The critical period of weed control began and ended 43 and 26 days after emergence, respectively, based on acceptable yield reductions of 5% and 10%.
