Revista Brasileira de Milho e Sorgo (Apr 2005)
PERFORMANCE OF ORGANICALLY PRODUCED MAIZE CULTIVARS AND CORRELATIONS AMONG TRAITS OF GREEN EARS
Abstract
The objective of this study was to evaluate the performance of ten organically produced maize cultivars and the correlation among ears characteristics harvested at R3 stage. The hybrids AG1051, AG4051, CO32, D170, D270, P3232 and SHS4040 and the varieties AL25, AL30 and UFVM100 were evaluated in an experimental design of complete random blocks, with three replications. The experimental plot consisted of four five-meter-long rows, spaced 0.90 m with a final density of five plants per meter. The two central rows were considered for evaluation. Basal fertilization consisted of 15,000 kg ha-1 of cattle manure, 440g of thermophosphate and 111 kg ha-1 of potassium sulphate. Cattle manure (15,000 kg ha-1) was applied as side dressing and the biofertilizer “supermagro” (5 % v/v) as leaf application. The ears were harvested 92 to 110 days after sowing and the hulled ear productivity varied from 5,581 to 10,511 kg ha-1. Seven cultivars produced above 7,100 kg ha-1, nine cultivars presented above 15 cm of ear length (commercial standard), all cultivars presented ear diameter higher than or equal to four cm (commercial standard) and six cultivars presented a useful ear weight above 150g. The cultivar AG4051 attained the highest ear weight, 184.5 g. High correlation was observed between the useful ear weight (PU) and ear length as well as between the PU and ear diameter. This indicates the possibility to use the PU as a base for maize cultivars selection to produce ears with higher length and diameter. Although the planting season caused yield reduction and this was the first year of organic cultivation in the experimental area, good productivity and quality of green ears were achieved. The hybrids AG4051 and D270 presented the best performance under the applied organic system, while AL25 and UFVM100 were outstanding among the evaluated varieties.
