Modifying Low Tunnels to Mitigate Heat Stress on Cucumber Grown on Salt-Affected Soil under Late Summer Season Conditions

INCREASING agricultural revenues and productivity is crucial to getting food and reducing poverty. At the same time, rising air temperatures because of climate changes considered real safety threatens agrarian production. Hence, to cope with these challenges, particularly in arid and semi-arid regions, it is vital to modify current agricultural practices. In this context, the current study was conducted to investigate the possibility of improving cucumber productivity under heat-stress conditions during the late summer seasons. The treatments included different protected cultivation techniques of cucumber, i.e., using soil mulch with a white plastic cover, an anti-stressor spray of aluminum silicate, shaded tunnel by net cover, misting under shaded tunnel by net cover, top white plastic sheet, misting without cover. The soils of all studied protected treatments were covered by white plastic mulch to decrease soil temperature and evaporation. All protected cultivation techniques were compared with the common open-field cultivation without any protection (control). The results revealed that all modifications of the low tunnels ameliorated heat stress and reflected better cucumber growth and fruit yield compared to open-field cultivation. The tunnel with mist under the net cover produced the highest plant growth, leaf area, and chlorophyll content. The favorable effect of the treatments on flowering was related to the increase in number of female flowers not the number of male ones. Rather than increasing fruit productivity, the modified tunnels also enhanced fruit quality (weight, size, firmness and TSS %).