INFLUENCE OF CULTIVARS AND ROOTSTOCKS ON THE INCIDENCE OF SUNBURN DAMAGE ON APPLE FRUIT IN THE NORTHERN AND SOUTHERN HEMISPHERES

Sunburn damage is a disorder which has serious economic impacts in many apple-growing regions including both the Northern and Southern Hemispheres.
Field surveys, in Hungary and South Africa, have been conducted to assess the incidence and severity of sunburn damage as related to cultivars and rootstocks.
In Hungary, the evaluation of 586 cultivars in an apple gene bank showed that most cultivars are more or less susceptible to sunburn.
Generally, sunburn incidence was observed on fruit of autumnal and winter ripe cultivars, summer ripe cultivars were damaged in a lesser amount.
In Hungary, sunburn decreased on rootstocks in the following order: M.9, MM.106 and seedling, and in South Africa sunburn was also highest on M.9. In general, sunburn damage was higher on rootstocks which favored cropping over vegetative growth thus causing fruit to be exposed to strong direct radiation.
Future cultivar development and rootstock use should consider sunburn as an important pre-harvest quality determinants in many regions exposed to the effects of global warming.

IX International Symposium on Integrating Canopy, Rootstock and Environmental Physiology in Orchard Systems

J. Racsko, D.D. Miller, S.J.E. Midgley, L. Lakatos, M. Soltész, Z. Szabó, J. Nyéki, C. Costa

Malus × domestica, apple, heat stress, sunscald, sunburn, rootstock, cultivar

https://doi.org/10.17660/ActaHortic.2011.903.145