A Detailed Guide to the Latest Control Methods for Fusarium Wilt of Melon
Fusarium wilt of melon, also known as blight, is a plant disease caused by fungi or bacteria. It strikes suddenly, with symptoms including severe spotting, wilting, or the death of leaves, flowers, fruits, stems, or the entire plant. The rapidly growing young tissues of melon are often attacked, and it can affect the flowers, leaves, buds, seedlings, twigs, stems, and shoot tips of melon. Let us take a look together at the control methods for Fusarium wilt of melon!
Damage Symptoms
In the early stage of Fusarium wilt of melon, the leaves of the plant gradually wilt from the base toward the top, most obviously at noon; at first they can recover in the morning and evening, but after a few days all the leaves of the plant wilt and droop and no longer recover. The base of the stem vine becomes slightly constricted, the epidermis is rough, and longitudinal cracks often appear. When humid, the root and stem area becomes water-soaked and rots, and white or pink mold-like growth often appears on the surface. The roots of diseased plants turn brown and are easy to pull up; the cortex separates easily from the xylem, and the vascular bundles turn brown. The peak period of the disease occurs from flowering to fruit set.
Conditions for Onset
The optimum temperature for the development and infection of the pathogen of Fusarium wilt of melon is 24-25°C, with a maximum of 34°C and a minimum of 4°C. At a soil temperature of 15°C the incubation period is 15 days, at 20°C it is 9-10 days, and at 25-30°C it is 4-6 days. The suitable pH is 4.5-6. Surveys show that aged seedlings, continuous cropping, undecomposed organic fertilizer, excessively dry soil, or acidic soil with heavy texture are the main conditions causing the occurrence of this disease.
Control Methods
1. Select good varieties: choose disease-resistant (tolerant) varieties such as red-fleshed netted melon, Snow White, and Suizhou large white melon, and early-maturing varieties such as Elizabeth, Red Honey Dew, Xinmiza No. 7, Badi, Huangdanzi, and Green Pearl. At the same time, carry out rotation with non-cucurbit crops for more than 5 years, preferably paddy-upland rotation.
2. Soil adjustment: applying compost fermented with effective microorganisms or fully decomposed organic fertilizer, or adding 0.5% s-H additive (made from rice husks, bagasse, shrimp shell powder, etc. plus urea, superphosphate, and potassium nitrate) to the soil can reduce the occurrence of Fusarium wilt. For acidic soil, apply slaked lime at 100-150 kg per mu to adjust the soil pH to neutral.
3. Seed disinfection: for seed soaking, use a 150-fold dilution of 40% formalin for 30 minutes, then remove the seeds, rinse them clean with water, and then germinate and sow; you can also soak the seeds with 50% thiophanate-methyl or carbendazim wettable powder for 30-40 minutes. Dress the seeds with 40% seed dressing dual powder or 50% carbendazim wettable powder at 0.2-0.3% of the seed weight.
4. Chemical control: use nutrient pots for seedling raising. When transplanting, drench the holes with Shuangduo suspension concentrate (watermelon continuous cropping agent) and Shenqi Buxiu at 300-350-fold dilution, 0.5 kg per hole, using 1 kg of pesticide per mu. For direct seeding, drench with Shuangduo suspension concentrate at 600-700-fold dilution at sowing and when the melon has 5-6 true leaves respectively, drenching 0.5 kg of the prepared solution per hole, using 1 kg of pesticide twice per mu.