What are the occurrence and control methods of rust in small spring crops (big wheat, broad bean)?

Rust is a kind of plant disease caused by the parasitism of rust in fungi. It is widely distributed and harmful, mostly in cereal crops, legumes, pears and so on. The rust of many crops is worldwide, and some of them have the characteristics of regional epidemic, and the yield loss is often tens of thousands of tons. So what are the occurrence and control methods of rust in small spring crops (big wheat, broad bean)?

First, broad bean rust is mainly harmful to leaves and stems, and is also harmful to pods in serious cases. In the early stage, the small pale or yellowish spots on the front and back of the leaves became rust-brown, raised like a small pus scar, rust-brown powder was scattered after the rupture of the small pus scar epidermis, and then black oval spots were found in the later stage, and black powder was scattered after rupture. The damage of stems and pods is similar to that of leaves, and the plants with severe disease often die early.

Measures for the control of broad bean rust:

The main results are as follows: 1. Select high-yielding varieties with early maturity and disease resistance, early planting and early harvest to avoid the peak period of disease.

2. Crop rotation can be carried out with crops other than peas.

3. To do a good job of trenching and drainage, high beds and deep ditches should be made in low-lying land in order to reduce the groundwater level and field humidity.

4. remove the remains of diseased plants and carry out deep ploughing.

5. In the period of flowering and pod grafting, in case of rainy years, 0.4 degree lime-sulfur mixture or 120m / 150 potassium sulfide solution can be sprayed for 4 times, which has a better control effect.

Second, the prevention and control of wheat leaf rust is basically similar to that of rain stripe rust. When stripe rust and leaf rust are mixed, stripe rust is generally prevented and leaf rust is also cured. But we should also pay attention to the following points

1. Strengthen the breeding of resistance to leaf rust. Chronic disease varieties can also be used in production to delay the onset of disease and alleviate the disease.

2. Eliminate autogenic wheat seedlings and reduce the source of bacteria. Because wheat leaf rust can pass the summer on autogenous wheat seedlings, eliminating autogenous wheat seedlings in the field can reduce the amount of bacteria source and help to control the occurrence of leaf rust.

3. Chemical control of the same stripe rust, but the appropriate spraying period at the adult stage was carried out from booting to heading when the rate of diseased leaves reached 5%.

3. Barley leaf rust overwintered in the form of summer spores on the autogenous barley seedlings, infected the autumn seedlings after sowing and overwintered in the form of hyphae or summer spores on the wheat seedlings. The spring temperature rises again, resumes the development, the reproduction spreads the harm.

1. Disease-resistant varieties were selected. The disease resistance of different varieties is different, which can be selected according to local conditions.

2. Strengthen the field management. Reasonable fertilization, eradicate authigenic wheat seedlings and reduce bacterial sources.

3. Chemical control. Spraying agents have 20% trimethoprim EC, 95% sodium dicrust powder and 65% Dysen zinc wettable powder. For details, see the wheat rust control section.

Attached: symptoms of rust

Many light yellow spots appeared on the back of the leaf, and then gradually expanded and turned into yellowish-brown blister spots. after the epidermis covering the blister spot ruptured, the reddish-brown powder dispersed, and the corresponding part of the leaf front formed chlorotic spots. This blister is the pathogen's summer spore pile, which produces reddish-brown oval summer spores in the form of powder. The summer spore pile is sometimes born on the adaxial surface of the leaf. The heap of summer spores on a leaf can even reach more than 2000, and the diseased leaves dry up and fall off in severe cases. In the later stage of growth, dark-brown blister spots grow on the diseased leaves, that is, a pile of winter spores, and dark-brown winter spores are scattered after the epidermis is ruptured. The rate of rust disease in Yongping county is 30-85%, and the rate of diseased plants is more than 90%. Therefore, timely chemical control of diseases and insect pests to control the spread of diseases in the middle and later stages, and the degree of harm. It is recommended to choose 15% triadimefon and spray evenly with 80 grams (1 pack) of water per mu.