Control methods of sunflower brown spot

Brown spot is one of the frequent diseases of sunflower, which is one of the main diseases that cause sunflower yield reduction and blighted grain, and one of the main reasons affecting its yield. So how to control brown spot for sunflowers? Come and have a look with the editor.

1. Occurrence of symptoms

Seedling disease is the formation of near-round disease spots on cotyledons or young leaves, with brown on the front, yellow halos around and grayish-white on the back. In the adult stage, the disease will form an irregular or polygonal brown half on the leaves, surrounded by a yellow halo ring, gray in the center of the disease spot, scattered black spots, that is, pathogen conidia. In severe cases, the disease spot is continuous, the leaf withered, the petiole and stem can also be infected with brown narrow stripes, and its symptoms are similar to leaf spot, but the disease spot of black spot is larger, and has concentric wheel lines, and brown mildew grows on the disease spot when the weather is wet.

2. Occurrence regularity

Brown spot overwinters with conidia or hyphae on the remains of the disease. when the temperature is suitable in spring and summer, especially in continuous rainy days, the pathogen will multiply in large numbers, distribute a large number of conidia and spread by wind and rain. Generally in the continuous cropping land and low-lying land, the disease is more serious in the land with serious disease last year, and when the field humidity is high.

3. Agricultural prevention and control

Crop rotation is the best way to prevent the disease, and rotation of Gramineae crops for more than 3 years can greatly reduce the possibility of the disease. Before planting, we should thoroughly remove the diseased and residual leaves, dig deep into the soil, reduce the source of bacteria, select varieties with strong disease resistance according to local conditions, plant them in close planting reasonably, and apply sufficient mature organic fertilizer to strengthen the disease resistance of the plant. Strengthen field management, timely drainage after rain, reduce field humidity, irrigation must be reasonable, should not be flooded.

4. Chemical control

The diseased leaves can be removed in time and sprayed at the same time. Brown spot is a fungal disease, and many fungicides have a good effect on it. For example, carbendazim, methyl thiophanate, basic copper sulfate, basic copper sulfate and other agents, generally sprayed every 10 days, continuous prevention and control 1-2 times.

The above is the introduction of sunflower brown spot control methods, hope to help you, want to know more related knowledge, please pay attention to us.