The latest symptoms and control methods of lotus root rot

The planting of lotus root is the main disease, which is widely distributed and common, and can occur in the whole growth period. the degree of disease varies greatly among plots and years, and the loss is less when the lotus root is light. when it is heavy, the plant dies in pieces, which seriously affects the yield and quality. So how to prevent and cure the rot of lotus root? Let's get to know it.

1. Symptoms

The disease mainly harms the underground stem nodes, causing the lotus root to turn brown and rot, the aboveground plants turn brown and die, and after the stem nodes are damaged, the initial symptoms are not obvious. with the development of the disease, the underground stem nodes gradually turn brown and expand, like the spread of new underground stem nodes. in severe cases, the whole underground stem node will turn brown and rotten and cannot be eaten. Due to the harvest of underground stem nodes, the transport tissue of the plant is blocked, the aboveground leaves will gradually fade to yellow, the leaf margin will turn brown and dry or curl inward, and finally bend to the top of the petiole and turn brown and dry. In severe cases, the lotus root is withered and yellow, as if it had been burned by fire, and it can be seen that there are filamentous mycelium and pink sticky matter on the lotus root node.

2. The regularity of the disease

The pathogen overwintered with mycelium in lotus root and soil, and the infected lotus root and soil were the main infection sources of the disease. when planted with bacteria-carrying lotus root, the seedlings became the central diseased plant after they were unearthed, and the disease occurred from the underground stem node and root system. gradually spread to petioles and leaves. The central diseased plant will produce a large number of spores, spread by water, invade from the wound and form re-infection. Lotus root with bacteria is the main factor for the prevalence of lotus root in this part. in addition, due to the difference of resistance among varieties, the disease of deep root varieties is lighter than that of shallow root varieties. The disease can be easily induced under the conditions of continuous rain, lack of light or frequent storms. Poor permeability of lotus root field, good acidity, underground pest culture, application of immature organic fertilizer, partial application of nitrogen fertilizer and other factors will lead to serious disease.

3. Prevention and control methods

Rotation with other crops for more than two years, ploughing the land deeply before planting, properly drying, disinfecting and sterilizing with quicklime, and selecting varieties with strong disease resistance when planting. Select disease-free lotus root for sowing, disinfect it with carbendazim solution before sowing, strengthen fertilizer and water management after planting, apply rotten organic fertilizer, reasonably match nitrogen, phosphorus and potassium fertilizer, topdressing timely and appropriately during the growing period, prevent partial application of nitrogen fertilizer, scientifically manage the water layer according to the needs of different growth stages of lotus root, moderate depth, adjust temperature and fertilizer with water. It is found that the diseased plants are removed in time and applied to prevent, the available agents are carbendazim, double effect, doxorubicin, etc., pay attention to the alternate use of agents, so as not to produce drug resistance.

The above is the introduction of lotus root rot symptoms and prevention methods, hope to help you, want to know more related knowledge, please pay attention to us.