The effects of root temperature on growth and dry matter production of Annona species

High root temperatures increased shoot extension, leaf and flower production, and leaf and root dry weight in Annona species. With clonally propagated trees of the custard apple cultivar ‘African Pride’ (Annona cherimola × A. squamosa), significant increases in root dry matter production were recorded at root temperatures between 17 and 22°C. High root temperatures (27°C) were not detrimental to plant growth. Most cherimoya (A. cherimola) cultivars produced more dry matter at the low root temperature (15°C) compared to the more tropical species (Annona cherimola × A. squamosa, A. squamosa and A. glabra).