Scientific Control Technology of Potato Late Blight

Potato (scientific name: Solanum tuberosum, English: potato), Solanaceae, annual herbs, also known as egg, potato, potato and so on. The earliest artificial cultivation of potatoes can be traced back to southern Peru from about 8000 to 5000 BC. Potatoes, 15-80 cm tall, glabrous or sparsely pilose. The stem is divided into two parts: the above ground stem and the underground stem. Potato is one of the five staple foods in China, with high nutritional value, strong adaptability and high yield. it is the third most important food crop in the world, second only to wheat and corn. Potato is a tuber reproduction, can be used as medicine, sexual flat taste sweet, can treat stomachache, ribs, carbuncle swelling and other diseases. As a food, its preservation period should not be too long, it must be kept at low temperature, dry and airtight. (note: young buds are slightly toxic), there is evidence that the vitamin C content of potatoes is about 4 times that of apples.

The morphological characteristics of potato are herbaceous, underground stem block, oblate or 15-80 cm tall, glabrous or sparsely pilose. The stem is divided into two parts: the above ground stem and the underground stem. Oblong, about 3-10 cm in diameter, the skin is white, reddish or purple. The color of potato skin is white, yellow, pink, red, purple and black, and the meat of potato is white, yellowish, yellow, black, cyan, purple and dark purple. Plants grown from seeds form slender taproots and branched lateral roots, while plants propagated from tubers have no taproot but only whisker roots. The aboveground stem is rhomboid and hairy. The primary leaf is simple, entire. With the growth of the plant, odd and unequal pinnately compound leaves were gradually formed. Leaflets often alternate in size, 10-20 cm long; petiole ca. 2.5-5 cm; leaflets, 6-8 pairs, ovate to oblong, maximum up to 6 cm long and 3.2 cm wide, smallest less than 1 cm in length and width, apex pointed, base slightly unequal, entire, white sparsely pilose on both surfaces, lateral veins 6-7 on each side, apex slightly curved, petiolule ca. 1-8 mm. Corymbose terminal, posterior lateral, flowers white or blue-purple; calyx campanulate, ca. 1 cm in diam., outside sparsely pilose, 5-lobed, lobes lanceolate, apex long acuminate; Corolla radiate, ca. 2.5-3 cm in diameter, Corolla tube concealed in calyx, ca. 2 mm long, limb ca. 1.5 cm long, lobes 5, triangular, ca. 5 mm long; stamens ca. 6 mm, anthers 5 times as long as filament length Ovary ovoid, glabrous, style ca. 8 mm, stigma capitate. Potatoes globose, smooth, green or purplish brown, about 1.5 cm in diameter. Seeds reniform, yellow. Flowering in summer. Scientific control methods of potato late blight symptoms of potato late blight:

The disease can infect leaves, stems and potato pieces. When the leaves get sick, most of them start from the middle and lower leaves, and there are water-stained green-brown spots at the tip or along the edge of the leaves, with a wide gray-green halo around them. when the humidity is high, the disease spots rapidly expand into large yellow-brown to dark brown spots, the edge is gray-green, and the boundary is not obvious. a circle of sparse white mold is often produced at the junction of disease and health, especially after rain or in the early morning. The air is dry, and the disease spot becomes brown, dry, ruptured or curled. When the stem and petiole were infected, irregular brown stripes were formed, which in severe cases led to leaf weight curling and black rot of the whole plant. Potato pieces infected, primary light brown spots, and then become irregular brown to purple brown disease spots, slightly sunken, the edge is not obvious, the diseased part of the subcutaneous potato meat is light brown to dark brown, resulting in potato rotting.

The incidence conditions and transmission routes of potato late blight:

The day is warm and the night is cool, the air is humid, rainy and foggy, and the average temperature is 10 ℃ 22 min, which is beneficial to the occurrence of the disease. The pathogen overwintered mainly as mycelia in potato lumps. The germ-carrying tubers were sown and unearthed to become the central diseased plant, and the diseased part produced sporangia. Sporangia are re-infected by airflow transmission to form the center of the disease. The sporangium of the pathogen can also infiltrate into the soil with Rain Water or watering to infect potato tubers and produce diseased potatoes, which can be used as the main source of infection in the next season.

Scientific control techniques of potato late blight:

The main results are as follows: 1) choose virus-free seed potato. The introduction and breeding of new virus-free seed potatoes, such as Fewurita, Zhongzhi No. 2 and Weidi No. 3, can be popularized and planted.

2) seed potato treatment. Strictly select disease-free seed potato as seed potato, soak in 600 times solution of 72.2% Pulick water agent or 600 times solution of 72% Kelu wettable powder for 10 minutes and then dry for 15 minutes.

3) cultivation management. Select the land with loose soil and good drainage; avoid partial application of nitrogen fertilizer and stagnant water in the field after rain; find the central diseased plant and remove it in time.

4) Pesticide control. At the initial stage of the disease, choose 72% Kluo powder 600 murine 800 times liquid, or 72.2% Pulike water agent 600 murine 800 times liquid, or 40% Phytophthorin powder 250 times liquid, or 58% Metalaxyl manganese zinc powder 500 times solution, or 30% chlorothalonil 500 times solution spray prevention and treatment.