Control Methods and Key Technical Points for Celery Soft Rot
Celery, also known as qin, early celery, fragrant celery, puqin, medicinal celery, wild coriander, is an annual or biennial herbaceous plant in the genus Apium of the family Apiaceae. It originated in the marshy areas along the Mediterranean coast and is now widely cultivated around the world. Celery cultivation in China began in the Han Dynasty and has a history of more than 2000 years. At first it was grown only as an ornamental plant, and later as a food crop. Through continuous domestication and breeding, the slender-petiole celery cultivar type was formed, namely benqin (Chinese celery). Benqin is widely distributed throughout China, and Zunhua in Hebei, Weixian and Huantai in Shandong, Shangqiu in Henan, and Jining in Inner Mongolia are all famous celery-producing areas.
Morphological Characteristics of Celery
Stem: herbaceous, 5-15 cm tall, with creeping stems, well-developed stolons, slender stems that creep along the ground and root at each node.
Leaves: perennial, fleshy, nearly round or kidney-shaped, with a V-shaped notch, leaf length 2-3 cm, width 1.8-2.5 cm, margins with 5-7 shallow lobes, lobes with blunt serrations, the shallow lobes approximately equal to the serration depth, base heart-shaped, palmate veins 7-9, leaf surface sparsely covered with short stiff hairs; petiole 5-15 cm long, densely covered with soft hairs; stipules membranous, apex blunt or shallowly lobed, 0.1-0.2 cm long.
Flowers: the flowers are umbels, scattered in the leaf axils of the stolons, the peduncle longer than the petiole, 5-15 cm long, covered with soft hairs; the umbel has 18-26 flowers, densely forming spherical capitula; pedicels very short, 0.1-0.15 cm long, the base of the pedicel has membranous, ovate or obovate small involucral bracts; no calyx teeth; 5 petals, acuminate, white or milky white; the style is involute when young and recurved outward after flowering, with a raised base. Flowering and fruiting period April to November.
Fruit: the fruit is a schizocarp, 0.12-0.15 cm long, 0.1-0.12 wide, flat round, base heart-shaped, smooth, often yellowish-brown when mature, with prominent middle and dorsal ribs, and two antenna-like styles at the top of the fruit.
How to control celery soft rot?
Celery soft rot, also known as rot disease or putrefactive disease, is a bacterial soil-borne disease that generally occurs readily when the rows close and shade the ground and the soil surface is moist during the middle and late growth stages.
The pathogen mainly overwinters in the soil and is spread by insects, handling, rain or irrigation water, entering through wounds. After the disease occurs, it can spread and expand through rain or irrigation water. The optimum temperature for disease development is 25-30°C. With more rain or frequent watering and high humidity, the disease occurs more often. With many wounds, continuous cropping land, low-lying land, and poorly drained land, the disease is more severe.
The control measures for celery soft rot are as follows:
1) Implement crop rotation of more than two years. Choose disease-resistant varieties and use disease-free soil for seedling raising.
2) Avoid damaging the roots; do not hill the soil too high; pay attention to drainage during the rainy season; during the disease period, water as little as possible or stop watering. Once diseased plants are found, they should be pulled out promptly. Disinfect the diseased holes with 1:20 formalin or replace with outside soil, or scatter some lime to disinfect the soil.
3) Use Nongkang 751 powder or Fengling soluble powder, mix seeds at 1% of seed weight before sowing, or use 15 ml of 2% Nongkang 751 aqueous solution to mix 200 g of seeds, dry them and then sow.
4) In the sowing furrow, use 5 kg of 2% Nongkang 751 aqueous solution or 1 kg of Fengling soluble powder, add 50 kg of water, and apply evenly in the furrows of one mu of land.
5) At the seedling stage, use 500 g of Fengling soluble powder, add 50 kg of water, pour it on the roots and spray the petioles and base, or when watering, add 2-3 kg of Nongkang 751 aqueous solution per mu along with the water.
6) In the early stage of the disease, spray agricultural streptomycin or Xinzhiomycin at 100-150 ppm solution, once every 7 days, 2-3 times in succession. Alternatively, use 30% DT wettable powder at 400-500 times solution or 95% CT fungicide at 600 times solution or 77% Keshade wettable powder at 600-800 times solution or 70% Dikesong wettable powder at 700 times solution, etc., spraying the plants and pouring on the root crown, then spray-irrigate once more after 10 days.