Large-scale water balance indicators for different pruning dates of tropical wine grape

Abstract

-The objective of this work was to develop and apply water balance indicators to be scaled up in the wine grape (Vitis vinifera) growing regions of the municipalities of Petrolina and Juazeiro, in the states of Pernambuco and Bahia, respectively, Brazil, simulating different pruning dates along the year. Previous energy balance measurements were used to relate the crop coefficient (Kc) with the accumulated degree-days (DD ac ). This model was applied to scale up the water balance indicators during the growing seasons. When irrigation water was available, the best pruning periods were from May to July, due to the better natural thermal and hidrological conditions. More care should be taken for pruning done in other periods of the year, regarding the effect of increasing thermal conditions of wine quality. The water balance indicators, both successfully developed and applied, allow large-scale analyses of the thermohydrological conditions for wine grape production under the semiarid conditions of the Brazilian Northeast.

Water Productivity Modeling by Remote Sensing in the Semiarid Region of Minas Gerais State, Brazil

“…In well-irrigated crops, the actual to reference evapotranspiration ratio (ET r ) values, called in this case the crop coefficient (K c ), may be used for estimating the water requirements at different spatial scales [15]. On the other hand, in natural vegetation, this ratio characterizes the degree of the water stress in the plant root zones [16].…”

Índices Hídricos Para Áreas Irrigadas Na Região De Desenvolvimento Agrícola Petrolina/Juazeiro

“…Por outro lado, valores muito maiores que 1,00 podem indicar problemas de excesso de água para as culturas, independentemente da quantidade de água aplicada na irrigação, embora estes excessos possam ser armazenados para períodos posteriores naturalmente mais secos. Baixos valores de IH significa possibilidade de deficiência hídrica e o grau de necessidade de irrigação de acordo com a fenologia das culturas (TEIXEIRA et al, 2015(TEIXEIRA et al, , 2016 Dois picos para IH são observados durante o período chuvoso, de DJ 049-064 (fevereiro a março) e de DJ 097-112, em abril (Figura 5a). Por outro lado, valores próximos de 0,00 após estes períodos sinalizam condições de escassez hídrica natural, causando estresse nas plantas caso os requerimentos hídricos não sejam satisfeitos via irrigação.…”