Disease control of water lily

Water lily rot

Symptoms

This type of disease occurs in the entire plant, starting from the roots. In the early stages of the disease, the underground stems have no symptoms, but their cross-sections turn from yellow to light brown or brown and gradually spread. Some diseased stems do not change color significantly, but longitudinal wrinkles occur on the entire stem or on one side. The leaves born from the diseased stems will appear light green, and then begin to dry up from the leaf edges, causing the leaves to curl up and even die.

Prevention and treatment methods

Select disease-resistant varieties according to local conditions

Severely diseased fields should be rotated 2-3 years

Select disease-free lotus roots and use 800 times the liquid of 50% carbendazim or methyl thiophanate wettable powder

The lotus field is plowed and harrowed, and lime is applied at 1500-2250kg per hectare

Strengthen fertilizer and water management, apply sufficient decomposed organic fertilizer, apply topdressing in a timely and appropriate amount, combine organic fertilizer with chemical fertilizer, and combine nitrogen fertilizer with phosphorus and potassium fertilizer.

After removing the diseased plants in time, spray 600 times diluted 50% carbendazim wettable powder plus 600 times diluted 75% thiophanate-methyl wettable powder.

Water lily leaf rot

Symptoms

It mainly harms leaves close to the water surface. The symptoms of the spots are irregular, some are " S " shaped, some are earthworm-shaped, brown or dark brown. White wrinkled spherical mycelium masses appear in the necrotic part in the later stage, and then tea-brown spherical small sclerotia are produced. The leaves with severe disease turn brown and rot, and are difficult to pull out of the water.

Prevention and treatment methods

Reduce the source of bacteria, remove diseased and damaged plants when harvesting, bury them deeply or burn them in batches

At the early stage of the disease, spray 50% carbendazim wettable powder 800 times liquid, spray once every ten days or so, and continue to prevent and control 2-3 times.

Water lily spot rot

Symptoms

The shape of the lesions is irregular. Initially, small black spots resembling water stains appear on the leaves, which then expand into circular, polygonal or irregular shapes. The spots are black with yellow halos on the edges and gray-black with ring patterns in the middle. The diseased parts are prone to rupture or fall off, causing the leaves and leaf edges to be incomplete. In severe cases, most or even all of them turn black and brown and rot, with a gray-brown mold layer on top, which is the fruiting body of the pathogen.

Prevention and treatment methods

Collect diseased and damaged plants during the growing season and bury or burn them

Apply sufficient well-rotted organic fertilizer, apply topdressing in appropriate amounts and at appropriate times, combining organic fertilizer with chemical fertilizer, and nitrogen fertilizer with phosphorus and potassium fertilizer.

After removing the diseased plants in time, spray 600 times diluted 50% carbendazim wettable powder. One cycle is about 10 days, and spray 2-3 times continuously.

Water lily anthracnose

Symptoms

The disease occurs on leaves, initially with small brown spots, which then expand into nearly circular spots larger than 10 mm in size, with darker edges.

Prevention and treatment methods

During the growing season, collect diseased debris and bury or burn them.

Apply sufficient well-rotted organic fertilizer, apply topdressing in appropriate amounts and at appropriate times, combining organic fertilizer with chemical fertilizer, and nitrogen fertilizer with phosphorus and potassium fertilizer.

After removing the diseased plants in time, spray 600 times diluted 50 % carbendazim wettable powder, 600 times diluted 75 % thiophanate-methyl wettable powder, 500 times diluted 36 % methyl thiophanate suspension, 1500 times diluted 50 % benomyl wettable powder or 800 times diluted 80 % anthracnose thiramisu wettable powder. Spray once every 10 days or so, and carry out prevention and control for 2 to 3 times in succession.