Vineyard microclimate and yield under different plastic covers.

The use of plastic cover in vineyards minimizes effects of adverse weather conditions. The northwest of São Paulo State is one of the largest grape producing regions in Brazil; however, few studies investigate the effects of different plastic covers on vineyards in this region. This study compared the effect of black shading screen (BSS) and braided polypropylene film (BPF) on BRS Morena vineyard microclimate, grown on an overhead trellis system in the northwestern São Paulo. The experiments were carried out during three growing seasons (2012-2014). BSS allowed superior incoming solar radiation (SR) transmissivity, resulting in higher net radiation (Rn), and higher ratio between photosynthetically active (PAR) and SR. No differences were observed between the average air temperatures (T) and relative humidity (RH) of covered environments (BPF and BSS) and outside condition (automatic weather station-AWS), due to high air circulation, despite wind speed (WS) reduction caused by plastic covers. BPF provided better conditions for vineyard growth with higher fruit yield than vineyard under BSS regarding the number of shoots with bunches per plant, bunch and stem weights, longitudinal diameter of berries, quantity of fertile buds per shoot, and yield per shoot and per plant. BPF covers also influenced leaf size and growth speed of plants in vineyards.

Demanda hídrica e coeficientes de cultura (Kc) para macieiras em Vacaria, RS / Water requirement and crop coefficients (Kc) for apple trees in Vacaria, RS, Brazil

O objetivo do presente trabalho foi determinar a demanda hídrica e os coeficientes de cultura (Kc) para macieiras cultivadas na região de Vacaria, RS. O trabalho foi desenvolvido na Estação Experimental de Fruticultura Temperada (EEFT) da Embrapa Uva e Vinho, localizada em Vacaria, RS, em plantas da cultivar 'Royal Gala' (Malus domestica) sobre porta-enxerto M9. Foram determinados os valores do potencial matricial da água no solo, empregando-se tensiômetros de punção. Com base nesses valores, determinou-se a umidade volumétrica e o balanço hídrico mensal. O consumo hídrico da cultura variou entre 0,3mm dia-1 a 4,5mm dia-1, com média de 1,9mm dia-1. O coeficiente da cultura (Kc) apresentou tendência quadrática, variando entre 0,19 e 0,88, com média igual a 0,58.

The objective of this study was to determine the water requirement and the crop coefficients (Kc) values for apple trees cultivated in Vacaria, RS. The study was conducted at the Experimental Station of Temperate Fruits (EEFT) of Embrapa Grape and Wine, located in Vacaria, RS, in plants of the cultivar 'Royal Gala' (Malus domestica) on the rootstock M9. The soil water matric potential values, that were determined employing tensiometers, were used to obtain the soil moisture and the monthly soil water balance. The water consumption of the culture ranged from 0.3mm day-1 to 4.5mm day-1, with an average of 1.9mm day-1. The crop coefficient (Kc) presented a quadratic trend, ranging between 0.19 and 0.88, with mean value of 0.58.