Effect of fertility levels and weed management practices on growth and yield of linseed (Linum usitatissimum L.)

Context: Efficient nutrient supply and weed management practices are important components of crop productivity and profitability under semi-arid climatic conditions of Rajasthan. Optimising fertility levels and identifying effective weed management practices can enhance the yield sustainability and soil productivity of linseed in loamy sandy soils.
Objective: The study aimed to evaluate the effects of different fertility levels and weed management practices on growth, yield, yield dynamics and economics of the linseed.
Challenges: challenges such as soil fertility depletion, severe weed infestation reducing yields by 42-45% during early growth stages (20-50 DAS), and limited research on herbicide efficacy under semi-arid conditions necessitated targeted evaluation.
Methods: A field experiment was conducted at the Experimental Farm, Rajasthan Agricultural Research Institute, Durgapura, Jaipur, during the Rabi seasons of 2016-17 and 2017-18. The experiment was laid out in a factorial randomised block design with three replications, comprising 28 treatment combinations of four fertility levels and seven weed management practices.
Results: The 150% RDF treatment significantly improved crop growth parameters such as plant height, number of branches per plant, dry matter accumulation and leaf area index. Yield components, including number of capsules plant-1, seed yield, stover yield, and biological yield were also highest under 150% RDF. Among weed management practices, maximum seed and stover yields were recorded under weed-free treatments. However, the highest net returns and B:C ratio were obtained with the application of Pendimethalin 38.7 CS. The application of 150% RDF and weed-free management achieved the highest productivity, while 150% RDF and Pendimethalin 38.7 CS maximised profitability.
Contributions: These findings contribute optimized fertility (150% RDF) and weed management (Pendimethalin 38.7 CS pre-emergence) strategies that boost linseed productivity by up to 43% over weedy checks while maximizing economic returns in nutrient-poor loamy sand soils.
Implications: The findings resulted that applying 150% RDF and Pendimethalin 38.7 CS or adopting hand weeding offers an agronomically and economically sustainable strategy for enhancing crop productivity and profitability in loamy sand soils under semi-arid conditions of Rajasthan.