Critical evaluation of the agro-ecological system of the Republic of South Africa (30◦S) in response to unclassified claims of cocoa farming beyond 20◦S of the equator

Abstract

Cocoa is a climate sensitive species that has never been reported to grow or survive outside its natural climate belt (20◦N-20◦S of the equator). Recent reports claimed that cocoa is currently cultivated in Eswatini (26◦S), Botswana (22◦S), Namibia (22◦S), Lesotho (29◦S), and the Republic of South Africa “RSA” (30◦S). How true are these reports? Climatological and epidemiological investigations were setup to debunk or support these claims. The clime of RSA was investigated since it was the farthest from the cocoa production clime. A review of the climate data of RSA showed 12.4 and 6.1% increase in night-time and day-time temperatures, respectively i.e., from 9.7 and 24.4◦C (1901–1930) to 10.9 and 25.9◦C (1991–2020), affirming the influence of global warming. The consistent increase in the moving average from 1901–2021 with a fluctuation in the seasonal variation, validates this research. A global connection was established between climate suitability for cocoa production and cocoa disease/pathogen establishment (r = -0.39, P-value = 0.089) at P<0.05. Further analysis showed that the annual temperature (10.8◦C≥Temp≥25.8◦C), humidity (62%) and sunshine distribution (8.4hours/month) of RSA was suitable for cocoa farming, even though water availability was below the recommended level (rainfall≥463.6mm and rainy_days≤5days/ month), farm irrigation systems are currently in use. Other findings showed that KwaZulu-Natal was 100% suitable for cocoa farming, followed by Gauteng, Mpumalanga (86%), Eastern Cape, Limpopo, Northwest (71%), Free State, Northern Cape, and Western Cape (57%). The estimated black pod disease status of KwaZulu-Natal (8.6%) and Eastern Cape (6.6%) affirmed the conduciveness of RSA for cocoa farming.