Fruit ripening disorders in relation to the chemical composition of tomato fruit

The incidence of ripening disorders in relation to the chemical composition of tomato fruit from a 3 2 NK ×2 3 PMgCa factorial nutritional trial has been investigated for three seasons. Highly significant negative correlations were obtained between log 10 wt.‐% of unevenly ripened fruit and K content, specific conductivity, acidity (titratable, total and combined) and refractive index of the expressed fruit juices. The importance of K in these relationships is emphasised. Differences between the regressions relating fruit grading to the specific conductivity or to the K content of the expressed juices of the varieties studied are described and discussed. The use of specific conductivity together with the refractive index for the rapid assessment of tomato fruit quality is advocated.