|Thought I had gummosis on my nectarine tree, but in addition to ooze on branches/fruit junctions, most leaves show browning at their edges. Flowering is spectacular (as are the bountiful bees), fruit set is booming, but lots of goo/shrivel/drop and then the leave-edge-browning-thing. I'm in zip code 86326, if that helps.
|I think you're dealing with two or three separate problems with your nectarine tree. First, not all nectarines will tolerate our summer heat so, depending upon which variety of nectarine you are growing, the browning leaf margins and small fruit may be due to environmental factors. Nectarines and peach trees naturally ooze sap so it's not necessarily a symptom of a disease unless you find entire branches dying. The browning leaf margins are usually a sign of heat stress and in our summers can be expected - at least to some degree. As for immature fruits beginning to form and then dropping, the most likely cause is incomplete pollination, although some fruit trees set far more fruit than they are physically able to hold to maturity. Pruning can affect fruit set, as well. To rule out bacterial gummosis you might want to prune an affected branch and take it into your local cooperative extension office for a positive diagnosis. Helpful folks there can use a microscope to look for tell-tale signs. You can help your tree avoid the brown leaf margins by waterind deeply during the hottest months of the year. I hope this information helps you help your nectarine tree!|