Zucchini

Visual Description:

White, powdery coating appears on leaves, starting as small spots that spread to cover entire leaf surfaces. The powder can appear on both sides of leaves and stems. Affected leaves may become yellow and die. The disease spreads rapidly in humid conditions, and severe infections can defoliate plants, reducing yield and fruit quality.

Visual Description:

Dark, sunken areas develop at the blossom end of the fruit. The affected tissue becomes leathery and brown to black in color. The condition typically appears when fruits are about one-third grown. While the rest of the fruit may appear normal, the blossom end becomes increasingly dark and inedible.

Visual Description:

Adult bugs are large (5/8 inch), grayish-brown, and shield-shaped. They often cluster in groups and can be found on leaf undersides or near plant bases. Feeding causes yellow spots that later turn brown. Leaves may wilt and die. Nymphs are smaller and gray with black legs.

Visual Description:

Older leaves begin to yellow, starting from the bottom of the plant. The yellowing typically progresses from the leaf edges inward, while the veins may stay green slightly longer. In severe cases, leaves may develop brown spots and eventually drop off. New growth may be pale or lighter green than normal. The plant's overall vigor declines, and fruit production can be reduced. The yellow leaves might become brittle and eventually drop off.

Visual Description:

Female flowers drop off without developing fruits, or fruits start to develop but then shrivel and fall off. Small fruits may turn yellow and rot instead of developing normally. The plant might produce plenty of flowers but few viable fruits. Male and female flowers may not open at the same time, reducing pollination success.

Visual Description:

Circular to irregular spots appear on leaves, often with dark borders and lighter centers. Spots may have yellow halos and can enlarge and merge over time. Severely affected leaves may yellow and die. Spots can also appear on stems and fruit. The disease typically starts on older leaves and progresses upward. In wet conditions, spots may show fungal growth or bacterial ooze.

Visual Description:

Plants suddenly wilt despite adequate soil moisture. Individual runners or the entire plant may be affected. Leaves wilt and become dull green, then brown and crispy. A key diagnostic test is to cut a wilted stem and squeeze it - infected plants will show a sticky, white bacterial ooze that can be stretched into fine threads.

Visual Description:

Plants suddenly wilt despite adequate watering. Examination of stems reveals small holes with sawdust-like frass (insect waste) around them. The stem may be swollen or split where borers are feeding inside. Cutting open an affected stem reveals white, grub-like larvae tunneling through the tissue. Plants often collapse and die quickly once symptoms appear.

Visual Description:

Plants remain small and produce few leaves. New growth may be slow to develop, and leaves might be smaller than normal. The overall plant appears less vigorous, with shorter stems and reduced leaf size. Fruits, if produced, are often small and may be misshapen. The plant's color may be lighter green than healthy plants.