The influence of temperature and water supply on apple fruit growth and the development of orchard-grown trees

Abstract

SummaryThe growth of ‘Cox’s Orange Pippin’ apples in an orchard was studied in relation to temperature and irrigation. Temperature around a number of trees was raised by the use of polythene tunnels from bloom in May until harvest in September. These trees within the polytunnels received irrigation, while for comparative purposes some trees outside did not. Continuous measurements of the canopy environment, particularly temperature, were made until harvest. Throughout the growing season fruit size was repeatedly measured, non-destructively, on a large number of selected fruit. Despite differences in mean temperature and accumulated day-degrees between trees inside and outside the polytunnels, there was no benefit to fruit size from raised temperatures. Supplemental irrigation did have a number of effects; spur leaf area was enhanced without significant change in total leaf area, while in the absence of irrigation, final shoot length was greater. This greater shoot production was however associated with a ...