The effect of plastic tunnels on air and soil temperatures in relation to observations of cloud-cover

Abstract

This investigation was undertaken to determine the extent to which ordinary meteorological observations of cloud-cover could be employed as a basis for expressing the efficacy of plastic (PE and PVC) tunnels. The data presented give the effect of tunnels on maximum day-time temperatures, night-time minima, diurnal range, diurnal averages, and daily sequence of temperatures. For the relationships between the effect of the tunnels and cloud-cover, observations including maximum day-time temperatures had the highest correlation coefficients. The relationship between the effect of the tunnels on the night-time minima and the mean cloud-cover was less. The effect of the tunnels on the night-time minima was positively correlated with the cloud-cover in April and September, but not in July. This investigation clearly showed the danger to plant growth in closed tunnels owing to extremely high day-time temperatures.