Problems with apple fruit
we have 4 apple trees together and they bare but they are noty, yellow delicious are scabby and dappled spots apples drop off tree prematurely some look good but when you slice them they are all bad inside with like worm runner lines in it . I don't and have never seen a worm. Planning to rake all apples and limbs away from under area. Just don't know what to use --not one of all the apples are good. been reading and thought the lime sulfur an dormant oil spray might help but don't know when to spray which one and when to stop one or the other Help is greatly appreciated or we will have to just cut them down.
Cass County Michigan
I assume you do not spray at all. The symptoms you describe for the apples sounds a lot like apple maggot which cause lumpy fruit and internal feeding tracks. Apple maggot is sometimes called railroad worm because of these tracks.
Apple maggot emerges during the late summer following rains that wet the soil. The fly flies around for about a week and then starts laying eggs inside the apple. To control this pest you need to spray in July and August following rains of more than a quarter inch. You can use any of the home owner fruit sprays that are available in garden or big box stores. Look for apple maggot in the pest controlled section and follow the label instructions on use. The dormant oil spray will help control insect pest that overwinter on the tree but apple maggot overwinters in the ground. Lime sulfur is an old control for apple scab. This material is considered organic but it is hard to find and hard to use. Use this material in the spring time to control apple scab.