Polinização na produção de híbrido simples de milho: ação de fatores edafoclimáticos

Abstract

Corn (Zea mays L.) is a worldwide-cultivated grass, which has high adaptation to the diverse climatic conditions. Brazil is the third largest producer of grain, and its wide use, however, its maximum yield is dependent on specific requirements regarding edaphic and climatic aspects. Maize from the first 2016/2017 crop was increased in area due to the favorable climatic conditions of the plant, resulting in a production of 29.3 million tons. The second harvest has a production estimate of 59.67 million tons grown on 11.25 million hectares. The simple hybrids of corn, resulting from crossing between genetically distinct and homozygous plants, aim at heterosis and at high vigor and yield. The simple hybrid is indicated in systems of production that use high technology, because it has high productive potential. It is more expensive, but exhibits genetics favorable for uniformity. It can present disadvantages when the environment causes biotic or abiotic stresses. This work aimed to determine the influence of edaphoclimatic factors on pollination of production fields of a simple corn hybrid, in the 2016/2017 crop, in the Formosa, Goiás region, at different altitudes. The information provided will be useful for the proper positioning in different regions and soil and climatic conditions, as a way to obtain stability and maximize crop productivity. The data of the work were extracted from fields of production of simple hybrid corn, in the region of Formosa - GO, crop 16-17. For this study, 3 altitudes were evaluated: Low (Fields with altitudes less than 700 meters), Transition (fields with altitudes between 700 and 1000 meters) and High (fields with altitudes above 1000 meters). After the data collection of the pollination evaluations, graphs were prepared to show the field pollination curve at different altitudes, where the development and evolution of the percentage of stigmata receptacles of the females and pollination of the male of the first and second sowing were observed. The final yield in kg ha-1 was determined after field harvesting, threshing and drying at 13% moisture. The field pollination plot shows high yield and granulation index. The lowest relative RH found in the pollination period was 29% and the maximum temperature did not exceed 30 ° C.