Akademik Veri Yönetim Sistemi
Journal of Crop Health, cilt.77, sa.5, 2025 (SCI-Expanded, Scopus)
Weeds significantly reduce black cumin (Nigella sativa L.) productivity, mostly due to slow initial development of crop and limited canopy cover. Determining the critical period for weed control (CPWC) is essential for preventing significant production losses and improving weed management strategies. This study aimed to determine the CPWC in black cumin under field conditions in Kayseri, Türkiye, during the 2023 and 2024 growing seasons. Treatments included weedy and weed-free intervals of differing periods, and crop yield was analyzed using a four-parameter log-logistic regression based on growing degree days (GDD). Results indicated that complete-season weed competition decreased seed production by almost 98% in 2023 and 99% in 2024. With a 5% acceptable yield loss criteria, the CPWC varied from 274 to 801 GDD (38 to 79 days after emergence) in 2023, and from 184 GDD (27 days after emergence) to 1819 GDD (harvest) in 2024. The data indicate that weed management is not required during the first 27–38 days post-crop emergence, but must be maintained until 79 days following emergence, depending upon seasonal circumstances. The results provide a significant decision-making framework for weed management in black cumin cultivation and aid in the formulation of integrated weed control methods.