Comparisons between Granny Smith apples from healthy and green crinkle virus infected trees

Abstract

Fruits harvested from Granny Smith trees known to be affected to varying degrees by apple green crinkle virus were held in cool store for five months before analysis for their total nitrogen and protein nitrogen contents. Fruit seed number, cell number, and dry matter content were also determined. There tended to be a greater incidence of superficial scald in fruit from infected trees. Fruits from infected trees were smaller, had a higher dry matter content, a greater proportion of protein nitrogen to total nitrogen, and fewer cells than those picked from healthy trees. Within infected trees the total nitrogen content decreased as the severity of fruit crinkling increased. The results are discussed in relation to effects of the virus on yield, the physiological status of infected trees, and a consideration of the likely storage disorders to be encountered in fruit from healthy and infected trees.