Seed agronomy of jute. III. Production and quality of Corchorus olitorius L. seed as influenced by growth regulators.

The study investigated the role of growth regulators on seed production of jute and its quality during May to November, 1994 and 1995. Under field conditions, gibberellic acid (GA 3 ) at different doses (5, 15 and 25 mg l -1 ) as seed soaking for 6 hours and as foliar application of the same at 25 mg 14 at 25 days after sowing (DAS) or during flowering besides rice necrosis mosaic virus induced seed (RNMV) were tried in a randomized block design in presence with either chlormequat chloride (CCC) at 750 mg l -1 or traditional manual topping both at 45 DAS. Harvesting was done at full maturity of pods. Quality parameters (viability and vigour) of the graded seed were assessed in the laboratory and green house using completely randomised designs. The data was analysed statistically and differences between treatment means were measured through least significant difference (LSD) test. Treatments with growth promoter GA 3 , particularly as foliar applications at 25 mg l -1 at 25 DAS or during flowering resulted in increased production and quality (emergence, emergence rate index, seed weight, seedling dry matter and seedling vigour index) of the seed but no significant differences between them were detected. Application of growth retardant CCC was also found superior to manual topping in quality seed production. Significant interaction between growth promoter and growth retardant was evident on pod number, pod weight and production of large and medium grade seeds.