GROWTH, WATER CONSUMPTION AND USE EFFICIENCY OF SUMMER SQUASH CROP IN CLOSED RICE HUSK MEDIUM GROWING SYSTEM
The determination of both crop water consumption and use efficiency provides important information for the irrigation management, especially in soilless culture in which all water must be supplied by the irrigation. In this system, the water consumption, as well as plant growth and crop yield, is affected by the ionic concentration of nutrient solution. Therefore, the aim of this work was to evaluate growth, yield and water consumption and use efficiency (WUE) of summer squash plants growing in raw rice husk medium with recirculating nutrient solution according to the ionic concentration of nutrient solution. Two experiments were conducted in spring-summer and summer-autumn crop-seasons, in Pelotas RS, south of Brazil. Four ionic concentrations of nutrient solution supplied to the crop were evaluated: 1.3, 1.7, 2.1 and 4.2 dS/m. The water consumption was not affected by the ionic concentration in spring-summer (139.9 L/plant). In summer-autumn, the increasing of ionic concentration increased the water consumption (from 41.6 to 71.6 L/plant). Ionic concentrations equal or lower than 1.7 dS/m decreased growth and yield in both crop-seasons and, in spring-summer, reduced the WUE related to fresh and dry mass fruits production. In summer-autumn, ionic concentration did not affect WUE (37.8 L of water per kg of fruit fresh weight and 0.98 g of fruit dry mass production per L of water). According to the adjusted mathematics models, the electrical conductivity that maximizes (respectively in spring-summer and summer-autumn) the fruits dry mass (259.4 and 78.31 g/plant) and crop yield (7.8 and 3.7 kg/m2) for both crop-seasons and WUE (21.5 L of water/kg of fruit fresh weight and 1.94 g of fruit dry mass/L of water) in spring-summer is approximately 3.0 dS/m. Ionic concentrations greater than 3.0 dS/m reduced fruits and shoot dry mass, yield and WUE in spring-summer.
Peil, R.M.N., Strassburger , A.S. and da Fonseca, L.A. (2012). GROWTH, WATER CONSUMPTION AND USE EFFICIENCY OF SUMMER SQUASH CROP IN CLOSED RICE HUSK MEDIUM GROWING SYSTEM. Acta Hortic. 952, 645-650
Cucurbita pepo, soilless system, recirculating nutrient solution, ionic concentration, electrical conductivity, biomass production