Diseases and insect pests that often attack fruit and nut trees, grapes, and brambles in spring and summer can be headed off during the winter. Dormant sprays—which kill overwintering pests and some diseases—are best applied when plants are in the dormant stage—after leaves have dropped in the fall and before leaf buds open in spring….
Plant Diseases
Bacterial Leaf Spot Disease
Bacterial leaf spot disease produces small, dark irregular spots on tomato and pepper leaves; leaves eventually turn yellow and drop off. This defoliation weakens plants and exposes developing fruits to sunscald. Small, dark, wartlike raised spots with slightly sunken centers may appear on green fruits. Rot organisms are able to enter the fruit at these…
Alternaria Leaf Spot
Small yellow spots that appear first on older leaves are a symptom of this fungal blight. These spots gradually enlarge and become dark-colored areas filled with concentric rings. Alternaria leaf blight is particularly problematic for plants in the cabbage and squash families. Strawberries and carrots are also susceptible. When alternaria infects broccoli and cauliflower plants,…
