PHYSICAL AND PHYSIOLOGICAL MAIZE SEED QUALITY AS INFLUENCED BY THE PLANTING PATTERN OF PARENTS

The use of quality seed for maize production is one of the most profitable investments by farmers and amply justifies the research on adequate techniques to generate it. The choice of the planting pattern (PP) of parents in the production of hybrid maize seed is important to achieve a balance between yield and seed quality. The objective of this study was to determine the effect of PP on the physical and physiological seed quality of the H-135 maize hybrid. Five PP were evaluated in regard to female-to-male ratio, four of them were compact planting patterns (CPP) 4:1, 6:1, 8:1, 10:1 plus the traditional 6: 2 standard pattern, used as a check. In addition, the effect of three seed sizes (large, medium, and small) and two shapes (flat and round) was studied. The experiment was carried out under a completely randomized design with factorial arrangement. Results showed significant differences (P <= 0.05) between PP in the expression of test weight (TW), seed germination (SG) and seed vigor (SV). The highest SV was observed in the 8:1 CPP (P <= 0.05). There were differences between seed shapes for SV, SG, and one-thousand seed weight (TSW). Round seeds surpassed the flat ones by 13 % (P <= 0.05) in TSW; however, flat seeds were 6 % higher than round seeds in SV. Seed size significantly affected TSW, TW and SG, where medium sized seeds showed the highest TW (76.1 kg hL(-1)). Large seeds were superior in SG (94.4 %) while medium and small seeds germinated 93.7 % and 91.8 %, respectively. The best results were obtained with 4:1 and 8:1 CPPs and with flat-shaped and large-sized seeds.