Prediction of fruit quality of plums (Prunus domestica L.)

The correlations between yield and climatic factors and plum fruit quality were studied. The fruit quality was measured as soluble solids content. Yield was judged according to a 0-5 scale, and climate parameters used were monthly mean temperature and monthly sum precipitation. Based on 19 years registrations of 11 plum cultivars, important factors affecting the fruit quality were found. In 8 of 11 cultivars yield had a strong negative influence on the fruit quality. The fruit quality was positively related to warm and dry weather in April and June, and to cool and wet weather in May. In Eastern Norway a negative correlation was found between July mean temperature and soluble solids content. In Western Norway, known for cooler and wetter climate, a warm and dry July improved the fruit quality.