Optimizing Seed Rate and Cutting Stage for fodder quality traits and fodder yield in sorghum

Abstract

An experiment was conducted at Punjab Agricultural University, Ludhiana, during rainy seasons of 2023-24 and 2024-25. The experiment was carried out to investigate the effects of varying seeding rates (25, 37.5, 50, 62.5, and 75 kg/ha) and cutting stages (vegetative and flowering) on the nutritional quality and fodder productivity of sorghum (Sorghum bicolor (L.) Moench) which were laid in factorial experiment in a randomized complete block design with three replications. Results indicated that significant increase in green fodder yield was recorded only up to 37.5 kg/ha over the lowest seeding rate of 25 kg/ha, further increase in seed rate beyond 37.5 kg/ha brought only a marginal increase in yield up to 62.5 kg/ha and a slight decline in yield with 75 kg/ha. Whereas, significantly decreased neutral detergent fibre, acid detergent fibre and acid detergent lignin but in-vitro dry matter digestibility remains unaffected. However, ash content, crude protein and total soluble sugar were significantly highest with seed rates of 50 to 62.5 kg/ha being at par with 37.5 kg/ha. Increasing the seeding rate significantly increased hydrocyanic acid content. Between the cutting stages, flowering stage obtained significant increase of 10.8 % in green fodder yield with appreciable quality attributes over the vegetative stage. Thus, results indicate that production input of seed can be reduced without negative effects on performance of SL-46 high biomass producing and late maturing variety and cut at flowering stage (80-85 DAS) is recommended to achieve higher yield and satisfactory nutritional quality.