The Latest Control Methods for White Rust in Water Spinach

Water spinach originated in the tropical regions of China and is widely distributed across Southeast Asia. It is now commonly cultivated throughout South China, Central China, East China and Southwest China. White rust is a common disease of water spinach, widely distributed and relatively serious in harm. It damages leaves, petioles and tender stems, and when it occurs severely it significantly reduces yield and quality, and can even cause total crop failure. Let us take a look together at the control methods for white rust in water spinach!

Symptoms

The lesions appear on the underside of the leaves. On the upper surface of the leaf, pale yellow to yellow spots first appear, later gradually turning brown. The lesions are relatively large. On the underside of the leaf, white raised blister-like spots form, nearly round or oval to irregular in shape, sometimes merging into larger blisters. In the later stage, the blisters rupture and release white sporangia. When the leaves are severely affected, the lesions are dense, the diseased leaves become deformed, and the leaves drop off.

Conditions for Disease Development

1. Continuous cropping land, a previous crop with severe disease, and large amounts of bacteria remaining in the soil, or low-lying waterlogged land with poor drainage, or heavy clay soil that tends to be acidic.

2. Excessive application of nitrogen fertilizer, over-dense cultivation, crowded plants and rows, and poor ventilation and light penetration.

3. Seeds carrying the pathogen, nutrient soil used for raising seedlings carrying the pathogen, or organic fertilizer that is not fully decomposed or carries the pathogen.

4. The disease easily occurs in early spring when there is much rain or the plum rain season comes early, with a warm climate and high air humidity, or in autumn when there is much rain, heavy fog, heavy dew, or an early cold snap.

5. In greenhouse cultivation, ventilation is often omitted to keep the temperature up and expel moisture, causing excessive humidity, which makes the disease likely to occur.

Control Methods

1. Choose fields on high, dry terrain and cultivate with deep furrows and high beds so that water does not accumulate after rain stops.

2. After sowing, use medicated soil as a covering soil, and spray an insecticidal and sterilizing agent once before transplanting. This is an important measure for controlling diseases and pests.

3. The organic fertilizer used must be fully decomposed and must not be mixed with residues of this crop from the previous season.

4. Use rotation between paddy and dry land. The nutrient soil for raising seedlings should be sterile soil, sun-dried for more than three weeks before use.

5. For greenhouse cultivation, during the summer fallow period, irrigate inside the greenhouse, cover the ground with plastic film, and keep the greenhouse closed for several days to sterilize using high temperatures.

6. Choose disease-resistant, coated seeds. If not coated, sterilize with a seed dressing agent or seed soaking agent.

7. Plant at a reasonable density, promptly remove diseased branches, leaves and plants, and carry them out of the field to burn. Apply medicine or quicklime to the diseased planting holes.

8. Plastic film mulching cultivation can prevent soil-borne pathogens from harming the above-ground parts of the plants.