Broad bean is also a vegetable and grain crop, although the planting area is not large, but the planting is very extensive, in the annual broad bean planting, there will always be 15 fields, no pods or pods do not grow grains. The reason is that the disease is at work, after the beginning of spring, with the increase in temperature, some diseases are also active, such as not timely prevention and control, resulting in spreading, harming the whole field. For this reason, broad bean growers are reminded that broad bean disease prevention should be carried out in early spring.
What are the diseases of broad beans in early spring? According to the investigation, there are broad bean red spot, brown spot, wilt, rust and so on.
1. Red spot disease.
The disease is one of the main diseases in the growth process of broad bean, the disease is widely distributed, especially in the Yangtze River basin broad bean planting, the incidence rate is relatively high, and has a greater impact on the yield.
1. Post-harm symptoms:
Broad bean red spot disease mainly infects the leaves, stems, flowers and pods of broad beans, when the leaves are damaged, at the beginning there will be red dots on the leaves, with the aggravation of the disease, the small spots will become lesions, the shape is round or oval, the color in the middle is russet, and there are depressions, the color around the lesions is dark brown, and there are bulges, and the front and back sides of the leaves can be infected.
When the stem is infected, small red spots will appear at first, but as the disease progresses, the small spots will turn into streaks, dark brown in color, and cracks will form.
When the flowers are infected, they will initially have brown dots, but as the disease progresses, the corolla will wilt and the color will turn dark brown.
When the pod is infected with the disease, the surface of the pod has brown lesions, which can also penetrate into the pod and harm the seeds, resulting in small red spots on the seed skin in the pod, resulting in a decrease in yield and quality.
2. Onset time: It can be divided into three periods: sporadic onset period, sporadic lesions can be seen on the lower leaves in early spring in February, low temperature, and slow disease development; During the rising period of disease, broad beans entered the flowering stage in early to mid-March, the temperature rose to about 10, and the lesions began to develop from the lower leaves to the middle and upper leaves. During the peak season, from late March to mid-April, broad beans are in full bloom and podding, and the temperature is stable at about 14 degrees Celsius. In case of rainy and humid weather, the disease spreads rapidly.
3. Prevention and treatment of drugs.
In the initial stage, 50% carbendazim wettable powder can be sprayed 800 times, or 70% thiophanate-methyl (methyl tobuzin) wettable powder 1000 times, or 20% ** ketone (powder-rustin) wettable powder 1500 times to protect the leaves.
2. Brown spot disease.
1.Harmful symptoms: Harmful to broad bean leaves, stems, pods and seeds can be infected, but mainly to damage leaves, stems and pods.
Leaf infection: dark brown spots at the beginning of the disease, oval or irregular lesions after enlargement, russet edges of lesions, raised, gray-brown, sunken, when severe, the lesions are connected into irregularly shaped large lesions, the lesions are gray-brown when wet, and the lesions are gray-white when the weather is dry, dry and easy to perforate. The stem is infected, the lesions are mostly oval, **gray-white, slightly concave, the edges are russet, easy to break or die pods are infected, the initial production of light brown spots, expanded into dark brown oval lesions, depressions, small black spots on the lesions, the fungus can penetrate the pod to harm the seeds, and form brown lesions on the seed epidermis.
2. Onset time.
The initial onset of broad bean brown spot disease is after mid-March, and the peak period is after mid-April.
3. Prevention and treatment of drugs.
In the early stage of the disease, 1:1:200 Bordeaux liquid spray, or 50% carbendazim wettable powder 800 1000 times liquid, 70% thiophanate-methyl wettable powder 1000 times liquid spray, can achieve a certain control effect.
3. Blight.
1. Harmful symptoms: sometimes divided into base rot, root rot and wilting disease. Generally, the phenomenon of base rot, root rot and wilting occurs in the budding to the first flowering stage of broad beans, and the young pod stage is the most damaged. It mainly occurs in the root system and the base of the stem, after being infected by the disease, the growth of broad bean gradually weakens, the plant is short, the leaf color is light yellow, the leaf tip and leaf edge turn black, the stem base is black brown, the top stem and leaf are awed, and finally withered, showing obvious wilting symptoms. The leaves do not fall off, but the flower buds are easy to fall, and the young pods are not full and gradually dry up.
2. Onset: generally in March and April.
Pharmaceutical prevention and control:It can be used at the beginning of the disease21500 times of 5% fludioxonil suspension, or 2000 times of 25% propiconazole emulsifiable concentrate, can also be mixed with 50 carbendazim 1 part 50 parts of fine dry soil and evenly sprinkled at the base of the seedling, with 1 per mu5 kg.
Fourth, rust. Rust is the leaf, petiole, stalk and pod of broad bean, and the leaf is the most serious. Severely diseased fields with early onset of disease often appear to be burned. Yellowish-white spots first appear on the leaves, and soon turn into reddish-brown nearly circular protruding scar-like spots, often with yellow halos on the periphery. After enlargement, the epidermis ruptures and emits a red powder.
2. Onset: after mid-March.
3. Drug prevention and control: In the early stage of the disease, corresponding pesticides can be used for prevention and control. Specific drugs may include 30% solid stone sulfur mixture, 15% ketone wettable powder, 15% ketone wettable powder, 50% rust spirit emulsifiable concentrate, 50% sulfur suspension, 25% tebuconazole, 25% dili deemulsifiable concentrate and 15% ketone wettable powder.
In short, these diseases of broad beans should be prevented and controlled as soon as possible, and they should not be prevented until they are spread, but they should be prevented early, and before the end of February after the temperature rises in spring, targeted spraying should be prevented.
February** Dynamic Incentive Program