Response of tomato cultivars to irrigation management strategies employed by emerging farmers in the Greater Giyani Municipality

Intensification of low-tech agricultural production is required in the Greater Giyani Municipality (Limpopo province, South Africa) to respond to changing climatic conditions, water scarcity and increased food demand of the local market. Two years of field experiments were conducted on two typical small-scale farms under real-world conditions. The objective was to test the response of locally available tomato (Lycopersicon esculentum Mill.) cultivars (Rodade, STAR 9006, Commander, HTX 14 and MFH) to two different irrigation strategies (full irrigation FI and deficit irrigation DI). While results showed high tomato yield variability (ranging between 9.2 t ha−1 and 59.7 t ha−1) depending on the farms, environmental conditions (heatwaves, diseases) and irrigation management, STAR 9006 appeared to be the best performing cultivar and HTX 14 the worst. Seasonal evapotranspiration under FI was between 400 and 620 mm depending on the length of the season and harvesting time. Crop water productivity was generally higher for DI than FI treatments. Deficit irrigation appeared to be feasible to reduce water use for some cultivars (eg cv. STAR 9006), however, an economic analysis should be conducted at specific sites/farms to determine the impacts of DI on farmers’ income as some yield losses can be expected during drought years.