Recobrimento de sementes crioulas de arroz: aspectos fisiológicos e sanitários

Abstract

Rice cultivation has always occupied a prominent place, as it is a product of great economic and social value due to its important role in the diet of the people of Maranhão. Most of the rice production comes from the cultivation system carried out by family farmers, which is normally cultivated in the upland system, characterized by the low use of agricultural inputs and low use of technologies. Among the obstacles in the production chain are the acquisition of seeds and the best way to store them. The use of native seeds is an excellent option for these farmers, giving them a sustainable agriculture option. Since these seeds are in a constant process of evolution and adaptation to the environment and management practices. Over the last few decades, plant disease control has been carried out using synthetic fungicides. The search for new control alternatives has been carried out and alternative methods such as the use of vegetable extracts and oils are efficient in the management of phytopathogens present in seeds. The aggregation of value to seeds, using production methods and technologies such as coating, has been a market demand for large crops. The objective of this study was to evaluate the effect of coating and treatment of native rice seeds with vegetable oil on the physiological and health attributes before and after storage for 120 days under controlled environmental conditions. The coating material was neem leaf powder, and a solution of water and polyvinyl acetate (PVA) glue was used as the cementing material. In addition, cinnamon (Cinnamomum zeylanicum), babassu (Orbignya phalerata) and neem (Azadirachta indica) oils were used to treat the seeds. The germination, first count, emergence, IVG and IVE tests were used to evaluate the physiological quality and vigor. The sanitary quality was evaluated through the blotter test, in addition to the percentage of fungal control in the infested seeds, provided by the effects of the oils. The coating did not affect the physiological quality, the germination and emergence speed index, or the dynamics of the hygroscopic balance of the seeds. However, seed treatments with neem, babassu and cinnamon oils showed allelopathic and phytotoxic effects on germination, emergence, IVG and EVI, thus impairing the physiological potential and vigor of the seeds. The main fungi identified in the sanitary evaluation are classified as storage fungi or contaminants. The treatments Neem Powder + PVA + Cinnamon Oil and Cinnamon provided a higher percentage of control over the fungi affecting the seeds, confirming the efficiency of cinnamon oil in controlling several phytopathogens