Leaflet temperature of lettuce (Lactuca sativa) and air influenced by the vapor pressure deficit

Marcelo Tarqui Delgado; Freddy Carlos Mena Herrera; Juan Javier Quino Luna; Susana Gutiérrez Villalobos; Ronald Reynaldo Coela Poma

Abstract

The index of water stress of the crop (IWSC), is the determination of the rate of transpiration of the crop and the deficit of vapor pressure. The IWSC is based on the energy balance theory on a surface, which can be related to the linear functions of the temperature differential between culture, air and vapor pressure deficit, which from the infrared thermometry that is a Tool for the estimation of water stress, irrigation programming. The objective was to determine the relationship and influence between the temperature difference of the crop and the air with the pressure deficit of steam pressure in the lettuce culture, to verify the existence of a statistical correlation between the variables in temperate environments to determine The IWSC through different doses of irrigation. The study was carried out in a controlled environment, establishing a unifactorial experimental design with three levels of irrigation sheet or replacement sheets at 50, 75 and 100% of the ETC, at the Cota Cota Experimental Station, Universidad Mayor de San Andrés, in In the months of May, June and July, an infrared thermometer was used to obtain the culture temperature and the climatic variables were obtained with a DAVIS automatic station. Statistical analysis and statistical correlations between the variables were performed. The best treatments to determine the IWSC, are the 100% and 75% ETC replacement sheets, in terms of the temperature difference of the crop and air with the vapor pressure deficit, with the ratio for irrigation laminate 100 %Etc); Tc-Ta = -2.9315 * DPV + 1.2851, with a correlation coefficient of 0.72, the treatment of irrigation sheet 75% ETc, presents the model of Tc-Ta = -2.9623DPV + 1.2192, with a correlation of 0.70.