Déficit hídrico em híbridos de milho na Região Médio-Norte de Mato Grosso

Abstract

Corn is an important agricultural crop in the world, Brazil has the second largest cultivated area, accounting for 37% of national grain production, 70% of which is due to the cultivation of second crop maize. In this scenario, the state of Mato Grosso stands out as the country's largest producer, with the middle northern region accounting for 44.32% of the state's corn production. However, maize presents high sensitivity to water stress in a short period of time, which corresponds to flowering, and due to the fact that it is planted outside the favorable season and high rainfall variability during this period, the occurrence of water stress in this period may productivity. Due to this, the selection of hybrids that present some mechanism of tolerance to the water stress is one of the alternatives to minimize the climatic limitations imposed on the corn. Thus, an experiment aimed at comparing three simple maize hybrids submitted to water stress during the flowering period was installed in Lucas do Rio Verde, state of Mato Grosso. The design was a randomized complete block with two factors and three replications. The main factor corresponds to the irrigation management and the secondary one to the corn hybrids. For the irrigation management, subsurface drippers were used, using two irrigation conditions, the first soil being kept in the water content close to the field capacity (cc) throughout the crop cycle, and in the second condition the contents of water in the soil was maintained at 1 atm in the interval between the pumping stage and the R1 stage. Hybrids of corn NS45 VIP3, P30F53 VYH and SYN533 VIP were used. Water stress reduced the height of plants and the weight of one hundred grains. The hybrid P30F53 had the largest diameter of stem and dry mass. Hybrids NS45 VIP3 and SYN533 VIP had increase in root length when submitted to water stress. Hybrids NS45 VIP3 and SYN533 VIP were the most productive when submitted to water stress.