Rice Solution

Symptoms:

Seedling Blast: occurs before clover in the way of the seed infection. Disease seedling gray base, the upper brown. If humidity is high, disease would generate a lot of gray and black mildew layer.

Leaf Blast: small, dark green spots appeared on leaves, gradually expanded to fusiform spots. Spots central is gray, brown edges, with pale yellow halo at outside.

Acute type of lesion: On leaves form a nearly round or oval, dark green spots. White spot lesion type: leaves after damaged, will produces small white nearly round spots, does not produce spores.

Occurrence Regularity:

1. Pathogens overwinter on diseased straw, rice stumps, and diseased grains, and are the primary source of infection in the following year.

2. The prevalence of rice blast is affected by factors such as climate, variety, cultivation, etc. The bacteria will multiply and infect faster at temperatures around 25°C. Rice is more likely to be infected when the average relative humidity is above 90% or even saturated.

Symptoms：

At the early stage of the disease, oval and dark green water-soaked lesions first appeared on the leaf sheaths close to the water surface, and then gradually expanded into a moiré shape, with gray-white in the middle, and gray-green when wet.

Occurrence Regularity:

Rice sheath blight can occur from the seedling stage to the ear stage. Generally, the disease starts at the peak tiller stage, accelerates at the jointing stage, reaches the peak before and after the booting stage, and declines at the milk maturity stage. The disease is more severe in periods of high temperature and high humidity.

Symptoms:

It first exposed small yellowish-green fungus at the joint of the glume, which gradually expanded, and finally wrapped the whole glume, which was dark green or olive, and finally cracked, and the rice ears were covered with dark green powder.

Occurrence Regularity:

1. The rice false smut pathogen can overwinter by the sclerotia that fall into the soil or the chlamydospores attached to the seeds, and become the primary infection source of the following year.

2. The incidence of rice false smut is closely related to varieties, fertilization and climatic conditions. From the formation of young ears to the booting stage, if there is heavy rainfall and high humidity, and low temperature rainfall during flowering, the incidence rate will increase.

3. Large amount of nitrogen fertilizer application, flooding, cluster irrigation and flood irrigation are also the main reasons for the spread of rice smut.