FIELD EMERGENCE OF SHRUNKEN-2 CORN PREDICTED BY SINGLE AND MULTIPLE VIGOR LABORATORY TESTS

Abstract

A rapid and reliable predictor of sweet corn seed field emergence is required to produce high-quality, uniform crops. Field emergence of seven sh2 sweet corn cultivars grown at 3 geographic locations in Florida over 2 planting periods (fall and spring) was correlated with laboratory vigor tests. Factor analysis was used to separate non-collinear vigor tests for subsequent multiple regression models. The best single predictor test (R2=0.93***) was an index based on conductivity of the leachate and germination percentage after complex stressing vigor test incubated at 15°C. Leakage conductivity after 3 h soaking at 25 or 30°C (R2=0.90***), cold test in soil (R2=0.90***), mean alternate temperature stress conductivity test (R2=0.88***), standard germination test incubated at 30°C (R2=0.88***), and the index incubated at 25°C (R2=0.88***) were also good predictors of field emergence. Non-collinear tests including the towel germination test at 25°C and an alternate temperature stress conductivity test generated the highest most significant two factor predictor (R2=0.89***), and with glutamic acid decarboxylase activity (GADA) the best three factor predictor (r2=0.93***). The index of conductivity and complex stressing vigor test (ICS) proposed as a predictor of seed emergence considered two main factors affecting emergence in sh2 sweet corn: the condition of the membrane of the seeds and potential pathogen infection.