Responses of cucumbers to mulching in an unheated plastic greenhouse

Abstract

SummaryPlastic greenhouses have become widespread in recent decades, predominantly as low–cost structures. Those using plastic houses often adopt techniques developed for more sophisticated glasshouses without prior studies to see if it is necessary to adapt them. White plastic mulching is used widely in heated glasshouses to increase available light during periods of low radiation, and thus benefit plant growth. A 2-year study was conducted to determine the response of a soilless cucumber crop to white plastic mulching, compared with an unmulched treatment, in unheated plastic greenhouses in southern Spain. The reflection of solar radiation by the plastic mulch reduced the mean substrate and air temperatures by up to 3.0ºC and 1.5ºC, respectively, during the early stages of canopy development. When substrate and air temperatures are sub-optimal, small temperature differences can be detrimental to crop growth and yield.The increase in available photosynthetically-active radiation (PAR) in mulched cucumbers could not compensate for the delay in growth in unheated greenhouses, and so yields were less than for unmulched cucumbers.