Identification and Prevention of Yellow Dwarf Disease of Welsh onion

Recently, Mr. Cai Nongpan of Gangjing Village, Weicheng Town, Weixian County, Hebei Province, Hebei Province, Hebei Province, China, recently reported that scallion seedlings planted by themselves and a number of neighbors have recently undergone a kind of yellow-green piebald or yellow leaf with a twisted, dwarfed, yellowed, and varying length. The phenomenon of streaking, I do not know what the disease is, should be taken to prevent and control? According to the situation reflected by Mr. Pan, combined with the comprehensive analysis of the diseased leaf samples, the author believes: This is a typical symptom of yellow onion seedlings.

This disease occurs in the onion nursery period, after the onset of leaf distortion, slow growth, uneven foliage, the tip gradually yellow, and produce varying lengths, yellow and green spots or yellow strips, Severely impaired growth, dwarfed plants, yellowish or discontinued growth, dwarfing, atrophy, or withered plants.

This pathogen is called onion yellow dwarf virus and belongs to the potato Y virus family Potato virus Y genera. The host range is limited to Allium crops. The virus is mainly adsorbed on the bulb or overwintering with the diseased body in the field. In the field, it mainly depends on a variety of aphids, thrips, jumps, slugs, etc. to inoculate the virus by non-permanent methods or rubbing with the juice. Fewer rainwaters, high temperatures and droughts, insufficient fertilizers, extensive management, declining growth, neighboring crops with onions, and serious worms, fleas, and other poisonous insects will aggravate the disease.

Prevention and control measures: 1. Use anti-virus disease varieties, do not raise seedlings or neighboring plants near the onion cultivation field or planting area.

2. Apply sufficient organic fertilizer or organic-inorganic biological compound fertilizer containing humic acid according to the demand ratio of nitrogen, phosphorus and potassium of 0.75:0.27:0.99 for fertilization, timely spraying rich in high potassium and nitrogen , Phosphorus and a variety of medium and trace elements of 40% gold power potassium, 55% Europe and the United States and the United States, enhance plant resistance to disease.

3. Spray control agent. Use 22% olefinic hydroxyl copper sulfate wettable powder 937 times solution + 33% morpholine hydrazide aqueous solution 750 times solution + 0.5% rhodium (veratrol) solution 1500 times solution spray. Or use 58.8% of the toxic products (aminophenol gluco hydroxy) WP 750 times +1.8% erfurtima (avermectin + special additives) EC 750 times spray. Can also be used 51.4% poison doctor (aminophenol methyl ether fragrance) WP 750 times liquid + 0.5% mad kill armor (Vivacaine) solution 750 times spray control.

Piston Crown

it is full range of piston crown for the following type :

Piston Crown,Diesel Engine Piston Crown,Marine Engine Piston Crown

ZhouShan HeCheng Machinery Co., LTD. , https://www.hcmarineparts.com