Aspectos biometeorológicos do cultivo de híbridos de milho em diferentes estádios fenológicos e arranjos espaciais

Abstract

Corn is the second agricultural commodity more produced in Brazil, behind only soybeans. So its importance to the national economy is indispensable. But it is aculture very sensitive to climatic conditions, which are able to reduce up to 100% of the productive potential of commercial crops. In this context, the objective was with the work to evaluate the behavior of the agrometeorological variables during the cycle of maize hybrids submitted to different spatial arrangements. Work will be realized on the Experimental Station of the Federal Technological University of Paraná - Câmpus Dois Vizinhos, during the period from September 2016 to January 2017. Experiment will be realized in a factorial experimental 4x3x2, where two maize hybrids, P30F53 and P1630, were submitted to three spatial arrangements: single lines of 60 cm between lines, double lines of 60x30 cm between lines and single lines of 45 cm between lines The third factor to be considered was the corn cycle, subdivided into 4 main periods: P1, emergence up to 12 fully developed leaves (V12); P2, V12 until start of pollination; P3, pollination up to milky grain (R3) and P4, milky grain until physiological maturation. After the emergence of maize seedlings, weekly evaluations of the agrometeorological components were realize using two micrometeorological stations, models HOBO UX 120-006M and HOBO H21-002. Each measure day was subdivided into three rounds of readings, each starting at 9:00, 12:00 and 14:00 hours. In each plot the microestation was installed for 5 minutes until the stabilization of the sensors and correct reading of the agrometeorological components. To reduce the experimental error provided duration the day, the readings were started in alternate plots, starting with plot 1 in unpaired weeks and plot 24 in pair weeks. The treatments evaluated were not able to induce changes in relative humidity and soil temperature. The growth of corn plants is able to reduce wind speed by more than 800%. The plant arrangement factor was not significant to modify the behavior of the Global Solar Radiation and Photosynthetically Active Radiation. The P30F53 hybrid was more efficient in the use of the Agrometeorological components of Global Solar Radiation and Photosynthetically Active Radiation in the plant population tested when compared to the P1630 hybrid. None of the measure hybrids were able to change the microclimate of the crop before the pollination stage. After the senescence of the plants, they had less influence on thebehavior of the agrometeorological variables.