Key to Pecan Diseases

DISEASES OF THE LEAVES

Olive spots on underside page 5 Scab

Downy, buff, or greenish-yellow lesions page 7 Downy Spot

Small, reddish-brown to gray spots on page 6 Brown Leaf Spot

underside

Dark brown to black lesions on veins page 6 Vein Spot

and stems

Tiny white tufts of fungal growth on page 9 Articularia Leaf Mold

underside

Small olive green velvety spots. By page 7 Leaf Blotch

midsummer, black pimple-like dots

appear in the spots

Leaflets yellowish, mottled, narrowed page 8 Rosette

and crinkled with reddish-brown spots,

may be perforated

Broomy type of twig growth, bunching of page 8 Bunch Disease

leaves

DISEASES OF THE NUTS

Small black sunken or raised spots page 5 Scab

which may fuse to cover entire surface

of shuck

Pink spore masses on shuck surface page 9 Pink Mold

DISEASES OF THE ROOTS

Galls of various sizes on larger roots page 7 Crown Gall

Splitting and deterioration of bark of page 10 Cotton Root Rot

infected roots, strands of buff-colored

fungal growth may be present

NONPARASITIC PLANTS ON THE LIMBS AND BARK

Whitish-gray mosslike masses on the bark page 9 Lichens

Accumulations of grayish strands page 9 Spanish Moss, Ball Moss

hanging from limbs and twigs or

ball-like growth on limbs and branches

Pecan Diseases and Pests and Their Control · 第 1 / 40 题