Fruit Rot, Phytophthora

Your apple develops firm, tan-colored rot where overhead irrigation wets the fruit, typically on lower branches. Phytophthora cactorum from irrigation water causes this soilborne fruit rot. Prevent by using low-angle drip systems or microsprinklers that don't wet fruit. Susceptibility peaks ten days before harvest, so timing matters.

Use low-angle or microsprinkler heads, placed under trees, so water does not wet fruit. Drip irrigation can also be used.