The most serious diseases are brown rot, scab and leaf curl. Insect problems include scale, plum curculio, catfacing insects and peach tree borer. The first line of defense is good sanitation. Remove old diseased fruit and wood as it appears on the tree. Your county Extension office has information on timing, methods and materials to control diseases and insects.
Many garden centers sell home orchard fruit tree sprays containing an insecticide and fungicide.
Applying one of the products according to label directions usually controls most insect and disease pests. The following stone fruit varieties on pages 5 and 6 are listed according to the state's zones in which they are adaptable. See the map for the location of each zone. The nectarine is a fuzzless mutation of a peach and not a cross between a peach and a plum. Currently the recommended variety lest is small, but trials are underway by the Texas Agricultural Extension Service to evaluate new varieties.