YIELD, KERNEL APPEARANCE, DENSITY AND BREAKAGE SUSCEPTIBILITY IN MAIZE HYBRIDS GROWN OFF-SEASON

Abstract

Kernel appearance is the physical quality parameter in Brazilian marketing instead of the quality standard tests. The cultivars with dent and semi-dent kernels are dismissed because their kernels are considered more susceptible to breakage. The aim of this study was to verify whether the appearance could be used to evaluate the kernel hardness and to determine relationship among kernel density parameters and breakage susceptibility in maize hybrids grown off-season. Three trials were performed in Assis, Cruzália and Votuporanga (SP) in 2003, using a complete randomized block design with 42 single and three-way crosses and three replications. Yield, kernel hardness appearance, kernel weight, percentage of kernel floaters in sodium nitrate standard solution, test weight and kernel breakage susceptibility were evaluated. The data were submitted to the analysis of variance by the F test and treatments were compared by Duncan test (P < 0.05). Pearson correlations among the parameters were calculated using SAS program. The evaluation of kernel hardness appearance was not efficient to screen cultivars regarding the kernel density and breakage susceptibility. There was no correlation between yield and kernel physical quality. Most of the hybrids had high kernel density, showing high average of test weight (825 g L-1) and very low percentage of kernel floaters. The kernel floaters were higher in the cultivars DAS 2C577 (82%), DKB 390 (33%) and DAS 2C522 (18%). All cultivars had low breakage susceptibility and with the following standing out negatively: Fort, A 4450, Exceler, XB 7011, A 2560 and 30F98 (2,7 a 4,5% of weight). In general, the breakage susceptibility was not correlated to kernel density. Only the kernel floaters were significantly associated to breakage susceptibility, but the correlation was very low (0,10).

Keywords

• Zea mays L.
• test weight
• kernel weight
• kernel hardness