Production and quality of zucchini seeds after applying sulphur as top dressing and organic compost at planting

Abstract

The recommendation of fertilization for zucchini (Cucurbita pepo) cultivation is usually made with no differentiation from the other cucurbit crops. Thus, there is a need to examine the doses of fertilizers used for zucchini production, as well as the suitability for cultivars, seasons, and cultivation regions. The aim of this study was to evaluate the influence of sulfur doses at topdressing fertilization and the supply of organic compost at planting on the production and quality of zucchini seeds. A total of eight treatments were studied in a randomized block design with a factorial scheme 4x2, corresponding to four sulfur doses at topdressing (0, 57, 114 and 173 kg ha-1 of S), in the presence (30 t ha-1) and absence of organic compost at planting. The fruits were harvested 62 DAT, and after harvest, the fruits remained in rest for 15 days in order to reach the uniformity of the physiological maturity of the seeds. The production characteristics evaluated were average fresh weight, diameter, dry weight and length of the fruits, fruit yield per plant, weight of a thousand seeds, number and seed weight. Regarding the seed quality, the percentage of germination, germination speed index, first count of the germination test, and electric conductivity, were evaluated. The supply of organic compost at planting had a positive effect on the production and physiological quality of the seeds of zucchini produced. The sulfur applied at topdressing improved the presence of the organic compost and also the production of seeds. Hence, it is recommended to apply 30 t ha-1 of organic compost at planting in association with 57 kg ha-1 of S at topdressing for higher seed yield and quality.

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

“…The application of organic compost increased radish 1000 seed weight, and this was also observed in other crops, such as zucchini [11], lettuce [12], and broccoli [4,6]. According to Carvalho and Nakagawa [28], most plant species present higher nutritional needs during the reproductive stage and seed formation, and adequate fertilization during this stage favors the formation of more and larger seeds [29,30].…”

“…Besides this, making or buying 50 t ha -1 of organic compost is more complex and expensive than purchasing ammonium sulfate to provide 180 kg ha -1 of S. On the other hand, the results show that organic compost can provide the sulfur necessary for radish seed which is essential for production in an organic seed production system. Bardiviesso et al [11] reported a quadratic effect on the production of zucchini seeds with the application of sulfur in top dressing fertilization associated with organic compost before planting. The maximum zucchini (Cucurbita pepo) seed production was estimated for the dose of 59 kg ha -1 of S; after this dose, a pronounced reduction in seed production was observed, similar to the results obtained in the present research.…”

“…In recent decades, reports on S deficiency in crops have become regular, and using concentrated fertilizers without S is the leading cause [8,9]. The soil organic matter is the primary S source for the plants [10,11], and applying organic composts in large quantities can supply the necessity of S to plants. However, sizeable organic compost quantities are not always available.…”

“…italica), both with organic compost fertilization before planting and with S fertilization in top dressing. The organic matter also favors the increase of seed production of other horticultural crop species [4,11,12,13]. However, there are no reports for radish seed production about the importance of S and organic fertilization in seed production.…”

Calcium and Boron Foliar Application in the Production and Quality of Zucchini Seeds

“…Although there are studies and fertilization recommendations for commercial cultivation of various vegetables, there are few studies about the effects of nutrients on seed production and quality [5].…”