Temperature and tree age interact to increase mango yields in the Lowveld, South Africa

Abstract

Mangoes, although typically a tropical crop, can be successfully cultivated pole-ward of the 25°N–S range under specific climatic conditions. As the Lowveld region of South Africa is outside the tropical zone, it is of interest to study mango yields from farms in the context of contemporary climate variability and future climate projections. Data analysed from Bavaria Estate, Hoedspruit, for the period 1995–2010, show a 2.5 t/ha increase in mango fruit yields per year. Through a multiple regression analysis incorporating tree age, daily maximum and minimum temperatures, and optimum and detrimental temperature days, 82% of the observed change in absolute yields and 70% of the change in area-relative yields were explained. The remaining difference between modelled and observed yields was explained by factors such as fertilization method, windbreaks and intrinsic biennial yield cycles, together with statistical and data limitations. Provided that increasing temperatures remain within critical optimal thresholds, and future water supply is sufficient for irrigation, it is likely that these positive trends will continue.