Effects of misting used to improve the microclimate and productivity of a screenhouse crop.

摘要

One of the greatest challenges in screenhouse horticulture is the control of environmental conditions requiredto reduce the high vapour pressure deficits (VPD) recorded during most of the day in the summertime. This paper describes the results of the research conducted on evaluating the effect of low-pressure misting on the microclimate of a screenhouse on a green bean crop (Phaseolus vulgaris L. 'Festival') over two spring-summer production cycles in south-east Spain, together with a quantification of its water use efficiency (WUE). We compared a screenhouse equippedwith a low-pressure misting system (SM), with a screenhouse without a misting system (S) and with conventional open-field crops (OF). The main effect of misting was a fall in the temperature of the plant canopyand of the maximum air temperature and VPD recordedat times of highest radiation and evaporative demand, and an increase in total and commercial productivity compared to the other systems. The misting reducedthe light transmission with differences of 132.9 MJ m-2 in 2008 and 155.8 MJ m-2 in 2009 with respect to the S system. WUE was highest for the S system since SM required additional water for misting (29.3% in 2008 and 45.5% in 2009).