Efeito da temperatura no desenvolvimento do trigo no Cerrado

Abstract

The estimation of crop development stages based on calendar days can inaccurately represent plant growth, as fluctuations in air temperature may significantly impact the time required for the plant to complete its development. The aim of this study was to determine the base temperatures and thermal requirements necessary to complete the maturation stage of the BRS 264 wheat cultivar grown in the Cerrado. The experiment was conducted in the municipality of Campo Verde, Mato Grosso, Brazil. Sowing took place on four distinct dates, with 14-day intervals on the following dates: February 21, March 9, March 22, and April 6, 2017. Four wheat plants were randomly selected in each plot for monitoring, with their phenological stage determined daily until maturation was complete. After all plants had completed their maturation, the lower base temperature for the cultivar was determined using the method of the lowest coefficient of variation for thermal sum in growing degree days, selecting the temperature with the lowest coefficient of variation for completing the maturation stage. It was observed that each sowing date required a different number of days to complete the maturation stage. The lower base temperature for the BRS 264 wheat cultivar was determined to be 13°C, requiring an average of 1,020.7 growing degree days to reach full maturation.