ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Prediction model of bitter pit risk incidence at post-harvest in Golden apples.

Sio, J., Usall, J., Vinas, I. and Boixadera, J.

Bulletin OILB/SROP. Volume 24, Number 5, 2001. Pages 305-312.

2001

บทคัดย่อ

Preharvest factors involved in fruit quality were studied in 60 commercial plantations of Golden apples in Lleida, northeast Spain, during the 1995-1998 period making a total of 238 field-year situations. To evaluate which field factors affect bitter pit susceptibility under field conditions, these orchards were distributed around the whole Lleida fruit growing area (150 000 ha) to obtain a good sample of all soil types, irrigation systems and management conditions. In spite of all the efforts carried out in recent years to solve the problems it causes, bitter pit continues to be responsible for the most important postharvest losses. The Lleida area has more than 10 000 ha of Golden apples and susceptibility to bitter pit incidence is by no means uniform. Some sets of fruits show incidence of 25%, while the general mean is about 3%. During the trial, systematic samples were taken to characterize the behaviour of the orchards. Moreover, all the agronomic techniques applied were recorded. Bitter pit incidence was evaluated at harvest and after storage. A regression model was built up with the most significant variables and validated in 1999 on 32 new orchards. This model permits a high degree of success in the prediction of the fruit sets with high or low risk of bitter pit incidence. The variables that showed a high correlation with the incidence of bitter pit were yield efficiency (kg/cm2), K/Ca relation and N in fruit. Soil type also has a significant influence on bitter pit incidence and its inclusion significantly improves the model.