Sweet corn variety trials in Ohio: Recent top performers and suggestions for future evaluations

Abstract

A total of 21 and 28 standard and experimental varieties of yellow and white se- and sh2-type sweet corn (Zea mays) were planted in 1999 and 2000 in Fremont and Wooster, Ohio, which are separated by 193.1 km (120 miles) and contain different soil types. Data are reported here for a subset of these varieties (eight yellow, two white) showing a consistently high level of use in Ohio and planted in both years. Endosperm types were planted in distinct, parallel experiments separated by a minimum of 79.9 m (262 ft) at each site. A randomized complete block design with four replications per variety (V) per location (L) was used, with measures of 13 production- and market-based variables taken from emergence to 48 hours after harvest. Soluble solids 48 hours after harvest were greater at Wooster than Fremont in the sh2 study. Variety had a significant, independent effect on mean plant and ear height in the se and sh2 study, respectively, although further analysis of year x variety (Y x V) and location x variety (L x V) interactions suggested that V affected additional traits. On average, 'Tuxedo' (se) and 'HMX6383S' (sh2) had superior combinations of grower- and consumer-oriented traits. However, varieties with the highest levels of percent emergence and marketable yield tended to have lower levels of soluble solids, regardless of endosperm type. Y x V interactions were primarily due to changes in the magnitude of values for individual varieties in each year, not from changes in their relative ranking. The Y x L x V interaction was significant (P ≤ 0.05) for marketable yield, plant and ear height, and the ratio of ear length to diameter in the se study, but zero variables in the sh2 study. Coefficients of determination (R 2) for selected plant and ear traits were unaffected by location. Overall, R2 values ranged from 0.04 (number of rows of kernels x ear diameter, sh2 study) to 0.83 (shank length x total ear length, sh2 study). These data reinforce that genetics strongly affect key traits in sweet corn and identify two potential top performers. The data also suggest that independent L or L x V effects may be minor relative to V effects, even when locations are separated by moderate distances and contain different soil types. Therefore, including more varieties but fewer sites may be warranted in future variety trials. The data also suggest that 1) ratings of variety performance should be based on objective measures of grower- and market-oriented traits and 2) shank length x total ear length and ear height x plant height relationships may be used to improve the efficiency of future evaluations.