Ginger eye spot

(pathogen name) Drechsleraspicifera (Bain) v.Arx

(host crop) ginger.

(disease diagnosis) is a damaged leaf. Leaf disease, at the beginning of the emergence of small brown spots, after expansion of the disease spot fusiform, the size of 5 to 10 mm, grayish white, the edge of light brown, surrounded by obvious or inobvious yellow halo. When the humidity is high, the disease spot produces dark gray to black mildew on both sides. When the disease is serious, there are a series of disease spots on the leaves, causing the disease to wither and die. The pathogenic bacteria is Desporium. The conidiophores of the pathogen are solitary, upright and unbranched, olive yellow, the top color is slightly light, the basal cells are enlarged, the sporogenic cells multiply and elongate symmetrically. The conidia are long oval, obtusely round at both ends, upright, light olive yellow, with 3-7 septum. Conidia solitary or apical lateral.

The pathogen overwintered on the diseased body in conidia and then in the soil. In the following year, the overwintering bacteria produced conidia infection which caused the disease of plants in the field, and the diseased plants produced a large number of conidia, which spread by wind and rain, resulting in re-infection and continuous spread of the disease. Bacteria like warm and humid conditions, warm and humid conditions are conducive to the occurrence and development of the disease. The terrain is low-lying, wet and insufficient fertilizer, especially potash fertilizer. The management is extensive, the plant growth is poor, and the disease is obviously aggravated.

(prevention and control measures) (1) choose fertile land with high topography and good drainage for planting. Do a good job of ploughing and soil preparation. (2) adequate application of rotten manure and additional application of phosphorus and potash fertilizer, especially potash fertilizer, must not be lacking. (3) proper irrigation, clear ditch and drainage after rain, and reduce field humidity. (4) pull out the diseased plant or remove the diseased leaf in time in the early stage of the disease so as to reduce the source of bacteria in the field. After harvest, thoroughly remove the disease and residue in the field, burn it or bury it deeply, and then dig deep into the soil. (5) in the early stage of the disease, the medicament can be used to prevent and cure the disease in time, such as 600x solution of 30% cupric oxychloride suspension, 500x solution of 12% green EC, 400x liquid of 30g Ludebao suspension, or 600x solution of 77% wettable particulate powder, or 1500 times of 50% Sukeling wettable powder, or 1500 times of 40% Baishuangjing suspension.