SEED VIGOUR TESTS FOR PREDICTING FIELD EMERGENCE OF SELECTED CROPS IN ZIMBABWE

Abstract

Seed vigour testing provides valuable information for assessing seed lot quality, under less than optimum or diverse growing conditions, similar to those which occur in the field. A study was done to evaluate the effectiveness of vigour tests in distinguishing seedlots using cold test (CT), heat shock stress test (HSST), accelerated ageing test (AAT) and standard germination test (SGT) to predict field emergence of various crops, with farmer retained seed used as a control for all the crops. Analysis of variance revealed that the twelve genotypes (ZM401, SC403, local maize landrace, Macia, SV4, local sorghum landrace, Okashana, PMV3, local pearlmillet landrace, CBC 2, IT18 and local cowpea landrace) and five vigour test methods showed a significant difference (P<0.05) for germination percentage and days to 50% germination. There were significant interactions between crops × vigour tests and variety× vigour tests, indicating a differential performance of the vigour test in all the crops and varieties evaluated. This suggests that out of the vigour test methods evaluated, no single method can be used in isolation to accurately predict field emergence in the crops and varieties under study.