Impacts of Meteorological Attributes on Agronomic Characteristics of Sunflower Cultivated in the Cerrado

Abstract

The sunflower has adaptation for cultivation in Brazilian conditions and the main product is the oil extracted from the seeds. This study aimed to verify the impacts of meteorological attributes on agronomic characteristics of sunflower genotypes cultivated as a second crop, in Mato Grosso, Brazil. The experimental design was randomized complete block design (RCBD), cultivating the two sunflower genotypes, M734 and Hélio, in three years (2009, 2011, 2012) with four replications. The agronomic characteristics evaluated were: plant height, capitulum diameter, weight of a thousand achenes, yield of achenes, oil content and oil yield. Then, water deficit and the maximum crop yield are estimated for correlation analysis between meteorological attributes and agronomic characteristics. In both genotypes studied there was a very strong correlation between plant height with evapotranspiration (r=0.99*) and very strong negative correlation (r=-0.99*) with water deficit. For mass of a thousand achenes, there was a very strong negative correlation with the maximum (r=-0.98*) and minimum (r=-0.96*) temperatures, and with evapotranspiration (r=-0.98*) in the Helio 358. In addition, effect of the water deficit on the oil yield (r=-0.98*) was verified for the same genotype. Very strong negative correlation was found between maximum temperature and oil content (r=-0.96*) in genotype M734. In sunflower cultivation in Mato Grosso, Brazil, water deficit reduces plant height, capitulum diameter and oil yield. The oil content of the achenes reduces when the maximum temperature increases, during the cultivation. For those reasons, the use of sunflower genotypes with shorter cycles and the earlier sowing could benefit the crop developing, by suiting the management, to avoid unfavorable climatic conditions that can cause reduction in production parameters.