Uso da termometria de infravermelho na predição de tolerância ao calor em trigo em dois ambientes de cultivo

• Autor(a) principal: Tobar, Laura Maritza Saavedra
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4624
• topic: Termometria; Trigo; Tolerância ao calor; Thermometry; Wheat; Heat Tolerance; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

Even though wheat is originated from cold climates, the use of adapted cultivars allows its production in regions with tropical climates, but high temperatures during the crop cycle may become one of the main factors that cause abiotic stress, limiting the well development of the plant and, consequently, a drastic decline in the productivity potential. The wheat production in the central region of Brazil is observed to have been affected because of the increases in temperature which are presented during the different phenological stages, becoming alike to the main limiting factor to its full development. The knowledge of methodologies that are easy to access and are of practical use, which are efficient for plant selection in field conditions is indispensable for the recognition and obtainment of cultivars with tolerance to heat. The objective of this work was to Evaluate canopy temperature depression through the use of infrared thermometry and agronomic traits in wheat cultivars, sown in pots with soil in through conventional cultivation with the intent to compare cultivar reaction to each environment, aiming to confirm which of these present tolerance to heat stress.The experiment was conducted at the Experimental Station Professor Diogo Alves de Melo - of the Federal University of Viçosa (UFV), Viçosa-MG. A completely randomized design was utilized. Six cultivars are utilized for use in the central region of Brazil: Aliança, Anahuac, Embrapa 22, BRS 254, BRS 264 and BRS 207. The cultivars were sown towards the end of July with varying temperatures throughout the development of the plant. There were no significant differences between cultivars when comparing the decline in the temperature of the evaluated plant organs. Only local effects were existent, which was attributed to the fact that, during the general culture development the average air temperature didn't reach values that are considered stressful, being found between 18 and 21° which is considered an C, ideal temperature range for wheat culture. The occurrence of winds may have reduced the canopy temperature of the plants sown in pots, which made these present higher temperature decline values when compared to plants cultivated in the environment's soil. Most of the agronomic traits evaluated present significant differences between environments and between cultivars, being that the pots' environment had the highest average values except for the harvesting index and the weight of one thousand grains, which were bigger in the conventional cultivation.