Physiological and Sanitary Quality Evaluation of Organic Seeds of Snap bean (Phaseolus vulgaris L.) Subjected to Freezing

Abstract

With the advancement of organic agriculture, the demand for quality seed by this system of production are. The use of Chemical fungicide are banned throughout the handling of the organic system, them, the alternative treatments should be used efficiently, preserving the physical, physiological and sanitary quality of the seed. This study aimed to evaluate the physiological and sanitary quality of bean seed pods produced under organic cultivation and submitted to freezing. The experiments were conducted at the Laboratory of Seed Quality Control by Institute of Agronomy in the University Federal Rural do Rio de Janeiro, and in the laboratory of Seed Analysis of the State Center for Research in Organic Agriculture (CEPAO) Agricultural research undertaking in the State of Rio de Janeiro (RJ PESAGRO-RIO), both located in the district of Seropédica-RJ. Two seed lots of organic green beans, with moisture of 9 and 12% were placed in PET bottles (polyethylene terephthalate) in the freezer at -18 ° C for 24 and 48 hours. We evaluated the physiological quality through germination and vigor tests (first count and electrical conductivity) and sanity through Blotter test. It was used a completely randomized design with four repetitions in a factorial scheme 2 x 2 x 2 (two lots x two moisture x two periods of exposure to exposure to -18°C). Seeds with moisture content 9 and 12 % submitted to -18 ° C showed no reduction in the physiological quality when the exposure time used was 24 hours. The freezing during 24 hours decreased the incidence of fungi on seeds of both lots evaluated