Optimizing Planting Date and Density for Enhanced Seed Yield and Quality in Cyamopsis tetragonoloba (L.) Taub.

Considering the arid and low-rainfall climatic conditions of South Khorasan province and the necessity for cultivating low-water-demanding and industrial medicinal plants, guar was selected as a medicinal crop to evaluate the effects of planting date and density on its biochemical properties and quality traits of guar seeds. A split-plot design with three replications was employed in ۲۰۲۳ at two locations: Birjand and Sarayan, South Khorasan province, Iran. Treatments included three planting dates (May ۱۲th, June ۱۲th, and July ۱۳th) as main plots and five plant densities (۱۰, ۲۰, ۳۰, ۴۰, and ۵۰ plants/m²) as subplots. Analysis of variance revealed that planting date significantly affected seed yield, oil content, protein content, galactomannan content, carbohydrate content, total ash, and protein yield. Notably, delayed planting resulted in a substantial decrease in seed yield (by approximately ۵۲.۳۶%), carbohydrate content, galactomannan content, total ash, protein yield, and oil yield. Plant density also significantly influenced seed yield, oil content, protein content, galactomannan content, carbohydrate content, phosphorus content, total ash, protein yield, and oil yield. The highest seed yield (۲۱۲۵.۳ kg/ha) was observed with a June ۱۲th planting date at a density of ۳۰ plants/m². Both planting date and density significantly affected yield and seed quality, with optimal results for protein, galactomannan, carbohydrate, and oil content achieved with the June ۱۲th planting date and a density of ۳۰ plants/m². This combination, likely benefiting from a longer growing season and favorable climatic conditions, yielded the highest seed yield. These findings demonstrate the potential of guar as a low-input crop for sustainable cropping systems in arid climates like South Khorasan, offering significant benefits for regional agriculture.

کلیدواژه ها:

cluster bean ، galactomannan ، Medicinal plants ، quantitative traits ، South Khorasan