New cultivars: physiological challenges to commercial success
The foundation for the global kiwifruit industry is the green-fleshed 'Hayward' cultivar, which was bred in New Zealand but is now grown in all major kiwifruit-exporting countries. More recently, increasing numbers of new cultivars have been commercialised, with differentiating traits including earliness, size, sweetness and flesh colour. The commercial success of these new cultivars depends on numerous factors, both pre- and postharvest, with the genetically defined phenotype being modulated by the growing and storage environments. Key pre-harvest factors include the relative timings of different aspects of fruit development, including flesh colour change and softening. The physiological state of the fruit at harvest dictates storage potential, and thus knowledge of fruit development is essential for making decisions about when to harvest. The key postharvest factors include the rate and extent of softening that occurs in storage and the susceptibility of the fruit to chilling damage. Prolonging storage tends to require the use of low temperatures, and the response to this storage may make or break a new cultivar. The postharvest performance of 'Hayward' fruit is often considered a commercial strength, with the capacity for long storage at low temperature being the basis for successful global commercialisation. Many newer cultivars appear to have a less robust postharvest performance, because of either rapid softening or greater sensitivity to low temperatures. In this paper, physiological aspects of fruit development and postharvest performance are discussed. A particular focus is on the physiological basis for susceptibility to, and expression of, chilling symptoms.
Burdon, J. (2018). New cultivars: physiological challenges to commercial success. Acta Hortic. 1218, 45-60
kiwifruit, Actinidia, storage, quality, softening, disorder, chilling, environment