The effect of leaf:fruit ratio and UV-C illumination on colour, sugar:acid ratio and Botrytis cinerea infection of strawberries (Fragaria x ananassa cv. Sonata)
MSc-thesis abstract (submitted 8 June 2017): The effect of fruit load and especially UV-C on postharvest qualities of strawberries is not frequently researched, where there is a indication that those have an effect on colour, carbohydrate and acid content and Botrytis cinerea of strawberries. Therefore the effect of leaf:fruit ratio and UV-C illumination on colour, sugar:acid ratio and B. cinerea infection of strawberries was researched.
A dose-response test for UV-C was done for green, white and red strawberries. The fruit load treatments consisted of an eight to nine fruits fruit load and a three fruits fruit load.
After concluding that red fruits are less susceptible to UV-C, the red strawberries were illuminated after harvest with 6.000 mJ cm-2 of UV-C light.
Fruits of a reduced fruit load treatment coloured more homogenously and malate content and thereby acidity decreased.
A combination a reduced fruit load and UV-C resulted in higher total carbohydrate content because of more produced sucrose.
This combination also resulted in a change in rate constant for B. cinerea infection spots from 0.242 and 0.223 by killing, active and non-active conidia.
An interesting next step could be to identify the relation between malate, citrate and B. cinerea as malate is a by-product or source for B. cinerea.
Keywords: Leaf:fruit ratio ; Fruit load ; UV-C ; Colour ; Sugars; Acids ; Botrytis cinerea ; Strawberry ; Fragaria x ananassa cv. Sonata