Beans

Visual Description:

Dark, sunken lesions appear on pods, stems, and leaves. The lesions on pods are round or oval, reddish-brown to black, and may have a slightly raised border. On leaves, the spots follow veins and can cause leaf curling. In severe cases, the disease can spread to seeds, causing dark spots or completely discolored seeds. Under humid conditions, the centers of lesions may show pink spore masses.

Visual Description:

Round or irregular holes appear throughout the leaves, giving them a lace-like appearance. The beetles themselves are small (1/4 inch), oval-shaped, and vary in color from yellow to reddish-brown, often with black spots or stripes. Young leaves may be completely skeletonized, leaving only the veins. The damage typically starts at the leaf edges and works inward. Multiple holes may connect, creating larger irregular patches. The beetles are most active during warm days and will quickly drop from plants when disturbed.

Visual Description:

Leaves show a distinctive mosaic pattern of light and dark green areas. The leaves may be puckered, wrinkled, or have a bubbled appearance. Plants can be stunted, and pods may be deformed or have dark green blisters. The mosaic pattern often follows leaf veins, creating a mottled appearance. Younger leaves typically show the most severe symptoms. Pods from infected plants may be smaller than normal and can show dark green spots or streaks.

Visual Description:

Small, rusty-brown spots appear on leaf undersides, eventually breaking through to the upper surface. The spots are roughly circular and may have a yellow halo. As the disease progresses, the spots become darker and may produce masses of rust-colored spores that easily rub off. Severely infected leaves may yellow and drop prematurely. The rust pustules can also appear on pods and stems in advanced cases.

Visual Description:

Small, water-soaked spots appear on leaves, gradually enlarging and becoming brown with a yellow halo. Spots may merge, causing leaves to look burned or scalded. On pods, spots are circular, sunken, and dark brown with reddish edges. In severe cases, the spots may ooze a light cream-colored bacterial exudate. Leaf lesions often develop along the veins and leaf margins. The spots can appear translucent when held up to light. As the disease progresses, affected leaves become brittle and may shatter. Pod lesions can penetrate through to the developing beans.

Visual Description:

Adults are copper-colored beetles with 16 black spots. Larvae are yellow, spiny, and oval-shaped. Feeding damage appears as lacy skeletonized patches on leaves, where beetles and larvae eat the tissue between leaf veins. The damage typically starts on leaf undersides. Severely damaged leaves turn brown and may fall off. Both adults and larvae can also feed on pods and stems, causing scarring and reducing yield.

Visual Description:

The yellowing typically begins with the oldest leaves at the base of the plant and gradually moves upward. The yellowing pattern is uniform across the leaf, starting as a pale green that progresses to yellow. Leaf veins may remain green longer than the tissue between them, creating a netted appearance. In severe cases, the yellow leaves may develop brown edges and eventually drop off. The plant's overall growth may be stunted, and new leaves might emerge smaller than normal. This is particularly noteworthy in beans because, as nitrogen-fixing plants, they rarely show nitrogen deficiency unless there are underlying issues with soil pH, drainage, or root health.

Visual Description:

Flowers may drop without forming pods, or pods may be sparse and irregularly spaced. Existing pods might be small, misshapen, or contain few beans. In extreme cases, you'll see plenty of flowers but very few developing pods. The plant itself may appear healthy with good foliage. Flowers might appear withered or dried before falling off. When pods do form, they may be shorter than normal or have a pinched appearance. The spacing between pods on the plant is notably greater than usual, giving the plant a sparse, unproductive appearance despite healthy vegetative growth.

Visual Description:

Early symptoms include yellowing and wilting of lower leaves, even when soil is moist. The root system becomes dark brown or black, and the outer tissue easily sloughs off, leaving behind stringy central core. Plants may be stunted and can easily be pulled from the soil due to rotted roots. In severe cases, seeds may rot before emerging, or young seedlings may collapse at the soil line. The disease is often most severe in wet, poorly drained soils and can spread to nearby plants.

Visual Description:

Initial symptoms appear as water-soaked spots on stems, leaves, or pods, often starting where dead flower petals have fallen. White, cottony fungal growth develops on infected areas, particularly in humid conditions. As the disease progresses, hard, black sclerotia (fungal survival structures) form within the white mold. Infected stems become bleached and take on a dry, papery appearance. The disease can spread rapidly through dense plant canopies, causing entire plants to wilt and die.