Effect of harvesting time on seed physiological quality, chemical composition and storability of soybeans

J Marcos-Filho,H.M.C.P Chamma,M.A.B Regitano-D'Arce,E.A Marcos,J.R R Casagrande

doi:10.1590/s0103-90161994000200016

Abstract

Soybeans IAC-8 were harvested in the growth stages R7 and R8 commercial harvesting time and at two other subsequent times to compare their physiological and technological characteristics. Seeds were stored at two moisture levels, 12% and 15%, for 6 months. Germination and vigor (acelerated aging, electrical conductivity), oil and free fatty acids, peroxide and iodine values were evaluated periodically. As expected, the time of harvesting and seed moisture content affected seed performance, while oil content did not correlate to physiological quality as did acidity, peroxide value and iodine number.

Highlights

The harvesting time is one of the critical steps in soybean seeds production
These seed moisture contents were checked at the beginning, at 3 and 6 months of storage
Seed moisture (TABLE 1) was high at R7 and R8 harvests. This point has been characterized by TeKRONY et al (1979) as the physiological maturity stage, when the seeds would have accumulated maximum dry matter. These data have not been statistically analysed, the moisture content of the seeds has decreased from R7 to R8 and, in the subsequent harvest times, the observed variations may reflect the different hygroscopic equilibrium points attained with the air relative humidity

Summary

Introduction

The harvesting time is one of the critical steps in soybean seeds production. Unavoidable delays or those resulting from careless farmer's attention cause the exposition of the seeds to unfavorable environmental conditions and the acceleration of the deterioration process. It is necessary to harvest at a time as close as possible to the physiological maturity, that is, after the stabilization of dry matter translocation to the seeds, when they reach the maximum germination and vigor potential (JACINTHO e CARVALHO, 1974; MARCOS-FILHO et al, 1981; MARCOSFILHO et al, 1975). According to ROBERTSON et al (1973) field-damaged soybean seeds stored at high moisture levels deteriorated even faster.

Results

Conclusion