PERFORMANCE OF SOYBEAN SEED LOTS SUBMITTED TO CONTROLLED DETERIORATION TEST

Abstract

Controlled deterioration test is based on the resistance of seeds to the stress caused by both high temperature and relative humidity exposure. In order to detect vigor differences on soybean seeds by using the controlled deterioration test, three seed lots were evaluated. The lots were evaluated regarding to physiological quality via germination, first germination count, classification of seedlings vigor, accelerated aging, modified cold, tetrazolium (1-3) and (1-5) and controlled deterioration tests at 40oC for 24 and 48 hours after adjusting seed humidity to 15; 20 and 25%. The experiment was carried out utilizing a completely randomized block design with four replications. The results were submitted to both variance and correlation analyses and the means compared by the criteria for grouping of Scott-Knott. The results have pointed out efficacy on the detection of physiological quality differences among the lots, on the modified cold test, accelerated aging test and also the tetrazolium test (vigor potential). The controlled deterioration test was consistent for the separation of the lots due to its physiological quality when the seeds are aged during 24 and48 hours, with an initial humidity of 15% and 20% at 40oC. The accelerated aging test was highly significant when it was correlated to 15% during 24 hours and 15% during 48 hours, respectively