Plum Tree Diseases

Asked June 22, 2019, 12:42 PM EDT

Hello I have two Toka Plum which are about 5 years old. The second year I had a bit of fruit from the first, the third year none from either, and the fourth year I noticed that fruit had begun, but each fruit - quite quickly - began showing small black spots and subsequently turned into a small hard black ball. I did a little reading and decided that perhaps brown rot was a problem. This year I began spraying with Captan when the tress just began to bud and have followed at weekly intervals. I have also looked at intervals and picked any fruit that had black spots (I also noticed, at times, near such fruit wilted black blossoms) I have seen a great increase in fruit begun; however I am still seeing fruit with black spots which appear to subsequently spit (I am not sure this always happens as some of the smaller fruit still seem to become small hard black ball). However, this doesn't look like the pictures of brown rot I have seen and I am wondering if I am following the right treatment for whatever is going on. I have upload a few pictures which may clarify. The images are in order: a fruit that is turning black and two that are splitting I do not, by the way, notice any unhealthy leaves or limbs. Thanks

Aitkin County Minnesota stone fruit plum trees trees

1 Response

Stone fruit splitting is usually caused by an environmental stress like too much or too little water. This years very heavy rains and then very hot weather could be the cause. https://www.gardeningknowhow.com/edible/fruits/fegen/stone-fruit-pit-split.htm Be sure you are following the spraying schedule on the label. Weekly may be too often so it is important to check. https://www.starkbros.com/growing-guide/article/all-about-brown-rot Also pruning for air circulation, this should be done in winter, is important.