How to prevent and treat lotus root leaf spot disease?

Lotus root is an aquatic plant planted in many areas. During the growth process of lotus root, leaf spot disease is prone to occur if it is not managed properly. So how to prevent and control lotus root leaf spot disease? Let’s learn more about it below.

Symptoms of Lotus Root Leaf Spot

Lotus root leaf spot disease mainly attacks the leaves. In the early stage of the disease, small yellow-brown spots the size of a needle appear on the leaves, which later expand into nearly circular or irregular ring-like spots, generally 0.6 to 1.5 cm in diameter, chestnut brown to yellow, more obvious on the back than on the front, with distinct edges of the spots, narrow yellow halos, slightly concentric rings, and often black mold inside. In severe cases, the spots expand and fuse, and the entire leaf except the veins is covered with spots, causing the leaves to dry up.

Occurrence pattern of lotus root leaf spot disease

The disease can occur in spring, summer and autumn, mostly in August and September. It is more likely to occur in hot weather and heavy rain, especially after a storm or when the lotus root is weak.

How to prevent and treat lotus root leaf spot disease?

1. Winter garden cleaning

After harvesting lotus roots, the dead branches and rotten leaves left behind must be cleaned out to minimize the number of pathogenic spores. Large-scale growers may find this troublesome, but it is indeed an effective measure.

2. Water-land rotation

If conditions permit, water-land rotation can be implemented. Implementing water-land rotation for 2 to 3 years can reduce the harm of continuous cropping.

3. Reasonable density planting

The amount of seeds used is relatively large, which causes the lotus leaves to be dense and poorly ventilated. When encountering windy and humid weather, leaf spot disease will occur more seriously. Therefore, 4,000 buds per acre can meet the basic seed requirement for high yield.

4. Water and fertilizer management

Strengthen water and fertilizer management, apply more organic fertilizer , avoid excessive application of nitrogen fertilizer, and increase the application of phosphorus, potassium fertilizer and micro-fertilizer. Maintain a suitable water level in the lotus field, and pay attention to maintaining a deeper water level during the stormy season to prevent wind damage.

5. Chemical control

During the disease season, apply 400-500 times diluted 30% basic copper sulfate suspension before the disease occurs for prevention. In the early stage of the disease, you can choose to use 50% carbendazim wettable powder or 1000 times diluted 75% thiophanate-methyl wettable powder, or 500 times diluted 58% metalaxyl·mancozeb wettable powder, and spray it once every 7 days for 2 to 3 times.

That’s it