Measures in the following section aim to create cooler conditions for a crop to grow in. Some do so by creating a more suitable micro-climate, others target to alter the crops’ physiological development.
Hanging shade nets that provide shade to the field crops during the warmest hours of the day can reduce the exposure to extreme air temperature stresses. The reduced incoming solar radiation can also have a beneficial effect on surficial soil and leaf temperatures, and on the crops’ water use efficiency (Mditshwa, Magwazaa, & Tesfay, 2019; Stamps, 2009). However, if the netting is applied such that air movement is hampered, temperatures under the netting are often increased under the netting, compared to outside (Stamps, 2009). The extent to which a net hampers air movement depends on net porosity, net location relative to the crop and the timing of installation of the net (Manja & Aoun, 2019).
Clear plastic rain shelters prevent saturation of the soil and the direct impact of extreme rainfall on developing fruits. Preventing flood damage and resulting in a reduced air temperature, plastic shelters have been responsible for the higher yields of crops. In combination with shade cloth, shelters can be used to reduce temperature stress. Shade shelters also prevent damage from direct rain impact and intense sunlight (De La Peña & Hughes, 2007).
In a low-tech greenhouse, cropping circumstances like temperature and water availability can be controlled mechanically. Farmers adopting the technology are less dependent on the seasons, allowing the farmer to cultivate crops year-round with a reduced chance of disease outbreaks (Pack & Mehta, 2012).