Production and Quality of Radish Seeds with Sulfur in Top Dressing and Organic Compost at Planting Fertilization

Aims: This study evaluates the effects of top dressing sulfur (S) fertilization, with and without organic compost before planting, on radish seed production and quality.

Study Design: Eight treatments were studied in a factorial scheme (4 x 2): four S doses in top dressing fertilization (0, 60, 120, 180 kg ha-1 of S), with or without organic compost (50 t ha-1) in fertilization before seeding.

Place and Duration of the Study: The experiment was carried out in the São Manuel Experimental Farm (22°46’ South, 48°34’ West, 740 m above sea level) in the School of Agriculture (FCA) of the Sao Paulo State University (UNESP) located in São Manuel, SP, Brazil. Radish sown happened in April, and harvest and seed analysis occurred in October 2017.

Methodology: Radish seeds were manually harvested (188 days after being sown), cleaned, and dried. Evaluations of seed production per plant, weight of 1000 seeds, and seed quality (germination (%), germination first count, germination speed index, and dry weight of normal seedlings) were performed.

Results: Applying organic compost increased radish seed production and the weight of 1000 seeds. Where no organic compost was applied, the higher the S dose, the greater the seed production per plant. With organic compost fertilization, the highest seed production and the weight of 1000 seeds were obtained with top dressing fertilization with 68 kg ha-1 of S. Germination and germination speed index were not affected by either factor, organic compost fertilization or S dose. Where no organic compost was applied, the higher the S dose, the lower the leachate level in the electrical conductivity test.

Conclusion: The radish base fertilization with organic compost plus top dressing S fertilization (68 kg ha-1) is indicated for radish seed production.