I have large, new crop of granny smith apples which are starting to show signs of black spot. Can I spray the tree now to save the tree if I am not going to eat the apples? -I figure it's too late to spray to save the crop...? Should I remove all apples now so that the infection is maintained?
04 February 2019 07:37 AM
It is likely it is a disease called Bitter Rot. The first signs of infection are small brown spots which usually appear when the fruit is almost fully grown. If conditions are humid, pink spores are formed on the surface of the spot and these spores can spread to other fruit. As the spots grow larger they become more and more sunken and the fruit will wrinkle and dry out. You are best to pick up and destroy any fruit that has fallen. It would also be a good idea to creat better air circulation within the canopy of the tree by pruning out any criss-crossing branches so humidity doesn't build up. It is too late to spray at this point but next year at the green tip stage (before leaf bud burst) spray with Yates Leaf Curl Copper Fungicide Spray to protect the emerging bud.