Use of temperature and propolis in the alternative treatment of zucchini seeds

Abstract

In the organic production system, the use of fungicides for the treatment of seeds is prohibited. On account of that, thermotherapy and propolis are alternative methods of control of pathogens in seeds allowed in this system. This study was conducted to evaluate the zucchini seeds’ germination and vigor when subjected to thermotherapy and treatment with propolis. In the treatment with moist thermotherapy, three temperatures (50, 55, and 60 ºC) were evaluated in separate experiments. Four times of immersion of the seeds (15, 30, 45, and 60 minutes, besides the control treatment-time 0) were tested for each temperature. In the dry thermotherapy treatment, four times (24, 48, 72, and 96 hours) were evaluated in which the seeds remained in the oven at a constant temperature of 70 ºC. In the treatment with propolis, six concentrations (0.0, 0.2, 0.4, 0.6, 0.8, and 1.0%) were studied, with subsequent washing or without washing of the seeds, totaling 12 treatments. The germination test was installed in the complete randomized design, with four repetitions, and germination and vigor (germination speed index) were evaluated. The dry thermotherapy did not affect the germination and vigor of seeds. The moist thermotherapy at 50ºC reduced germination; besides, the values are within germination patterns. At 55oC, the treatment has to be for a lesser time, until 30 minutes, and it is not recommended the treatment at 60oC. For propolis, the treatment resulted in a little reduction in germination in the highest contents, the values are within the germination patterns.