Identification of common confounding symptoms in rice

One, several kinds of green

1. Sclerotinia sclerotiorum blight. More common in late rice, often occurs in clusters in the field, there are also a hole in a few plants disease. Rice base tissue soft rot, black brown spots. Peel off the base leaf sheath and stem, visible than amaranth seed there are many small black sclerotia.

2. Bacterial base rot and blight. Sporadic occurrence in the field, generally 1 - 3 in 1 hole disease, the base of the diseased plant was gray rot, the root system was rare decay, peeling the base stem, full of smelly water, sterile nucleus.

3. Physiological blight. Rice plant stem dry shrink, hand pinch rice stem base dry, easy to lodge, like brown planthopper sclerotium damage. However, there are no insect bodies and disease spots at the base of stems, and there are no sterile nuclei in leaf sheaths and culms at the base. Most of them occur near the mature stage of late rice, and they wither into pieces.

Two, several dry heart

1. The withered heart of borers. Insect holes or dung can be seen in the lower part of rice plants, and the withered heart is easy to pull up.

2, mole cricket harm dry heart. Rice stems without insect holes, no insect dung, withered heart easy to pull up, stem base and roots were scattered broken shape.

3. Stripe blight. The heart leaf of diseased plant has yellow stripe, curl into paper twist shape, bend and droop into "false withered heart". The base has no wormhole, does not rot, and the withered heart is not easy to pull up.

4. Wilting bacterial blight. Rice stems without insect holes, basal stem nodes yellow white pus, no odor, peeling just green roll of the heart leaves, but also often yellow bead-like pus.

III. Several leaf spots

1. Rice blast leaf spot. Acute type, the disease spots are small spots of fine brown at first, then become oval, the back of the leaves have gray-green mold, chronic type, the disease spots into prismatic, red brown next to the central gray-white, there is a brown line running through the middle of the disease spots. When the tide is warm, gray green mold can be seen on the back of the lesion.

2. Leaf spot of flax disease. At first, the spots looked like pinheads, and then gradually formed oval spots, similar to sesame seeds. Roughly, the disease spots are black-brown, darker than rice blast spots, and the color is divided into three layers: yellow halo in the periphery, wider edge layer, black-brown, and yellow in the center. No necrotic lines at both ends of the lesion, and moldy linings are rarely seen in the diseased part.

3. Brown streak leaf spot. The disease spot is short line shape stripe spot, brown, parallel with vein, with leaf tip place many, mold layer hard to see. The diseased part breaks and squeezes out milky white juice. The lower part of the seriously diseased plant rotted, giving off a rotten smell, the diseased leaves withered, and the heart leaves died in the grass.

4. Several kinds of yellow leaves

1. Bacterial blight yellow leaves. On the leaf tip or leaf margin of the leaf blade, yellow-green or dark green spots are produced first, and then along the vein extension, the surface spots are gray, the boundary between the diseased part and the healthy part is obvious, and yellow glue "bacterial pus" is often seen on the diseased spot.

2. Yellow dwarf yellow leaves. First from the top leaf below 1 - 2 leaf tip disease, then gradually develop to the whole leaf yellow, or become spotted mosaic, plant dwarf internode short, grass leaves droop flat, black roots more, new roots less, often vertical roll yellow withered death.

3. Physiological premature senescence yellow leaves. From below upward spread, the disease leaves show orange yellow, there is a certain metallic luster, into pieces or the whole field occurred. There are no spots on the yellow leaves, no pus.

4. Yellow leaves are damaged by fertilizer. Ammonium bicarbonate, ammonia, pesticides, etc., if not properly applied, will cause poisoning, resulting in pieces of rice leaves, smoked into bright yellow or golden yellow, sometimes yellow leaves have scorched spots.

V. Several white ears

1. Chilo suppressalis white spike. There are insect holes and dung on rice stems, white panicles are easy to pull up, panicle neck is not diseased, white panicle mass in field is obvious.

2. Rice neck blast white ear. There are no wormholes on rice stems, white ears are not easy to pull up, and there are dark brown spots on ear neck, ear axis and branch stalk. Spike neck or branch peduncle easy to break, wet, the disease has gray brown velour mold.

3. White ear of sheath blight. Dark green spots appeared on leaf sheath, leaf or ear neck and stem at the initial stage, and then expanded into oval moire spots with brown edges and pale brown to gray centers. There were no wormholes in stem, soft tissues at the base, and white ears lodging on the ground.

4. Bacterial base rot white ear. Sporadic occurrence in the field, white ears are not easy to lodge, do not break, stem base and root are gray soft rot, have rotten smell, stem without wormholes, roots are rare decay, peel off base leaf sheath and stem sterile nucleus, white ears are not easy to pull up.