Control measures of black rot of flowers in New Zealand

Broccoli is a vegetable with high nutritional value. Due to the expansion of its market demand, its planting area is also increasing year by year, but the occurrence of black rot in the planting process seriously affects the planting efficiency of farmers. So how to control the black rot of broccoli? Come and have a look with the editor.

1. Symptoms

The disease can occur from the seedling stage to the adult stage, the seedling disease is that the cotyledons are immersed in water, then quickly die or spread to the true leaves; in the adult stage, the disease mainly harms the leaves, starting from the edge of the leaves, and then gradually expands into V-shaped withered spots, the disease spots are yellowish brown and the edges are yellowish. When the root is injured, the vascular bundle will blacken and gradually dry rot inside, until the whole plant dies. When the corm is sick, the disease spot spreads gradually from the spherical surface, and in serious cases, it will lead to the blackening and decay of the whole flower bulb.

2. The regularity of the disease

The bacterial disease of black rot is mainly transmitted by diseased plants, fertilizers, wind and rain and agricultural tools. Generally, the disease is easy to occur in seeds, improper management of fertilizer and water or continuous cropping with cruciferous crops, which is also beneficial to the disease in high temperature and humidity environment. The growth temperature of the pathogen is 5-39 degrees, and the most suitable temperature is 25-30 degrees. When the relative humidity is more than 95%, it will cause leaf dew, then the bacteria will take advantage of the opportunity, leading to leaf disease. When cultivated in the greenhouse, the environment in the greenhouse is hot and humid, and it is also prone to black rot. When broccoli is balling, once the water droplets on the greenhouse film are dripped on it, black rot is very easy to occur.

3. Prevention and control methods

The varieties with strong disease resistance and non-cruciferous vegetables were selected for 2-3 years rotation, deep sunning soil and border cultivation before planting, which can not only reduce the pathogen in the field, but also dredge the water in the field. In order to adjust the temperature and humidity in the greenhouse, we must first do a good job in the management of the seedbed. The temperature is relatively low in early spring cultivation. At this time, we should pay attention to the watering times and water quantity of the seedbed to avoid the occurrence of black rot. The temperature of raising seedlings is relatively high in other seasons, especially broccoli in winter, so we must pay attention to the cooling work. In addition, it is generally watered every 7-10 days after transplanting, and it is necessary to increase the fertilizer and water after budding, so it is necessary to increase the number of watering times and the amount of water, ventilation and cooling humidity after each watering. When there are diseased plants of black rot in the field, agricultural streptomycin, streptomycin sulfate, neophytomycin and other agents can be sprayed for control.

The above is the introduction of the prevention and control measures of black rot of broccoli, hope to help you, want to know more related knowledge, please pay attention to us.