Sweet potato bran heart symptom
Seedling stage suffer lower germination rate, potato stem yellow, is not long.Opened longitudinally stem base, the gap has brown, cut break emulsion latex or rarely don't flow.Suffer serious illness seedling chaff internal heart up to top of the seedling.
Field suffer, Lord tendril stem brown cracked patches, internal for brown chaff, strain stem short, yellow leaves, and slow growth.
Potato piece suffer performance: one is the type of chaff.Potato pipi formation in blue to dark purple, slightly concave or crack disease department.The second is the chaff, heart-shaped.Potato piece of cortex in good condition, internal brown, and white dry rot.Three is mixed.Heart disease serious, and bran chaff occurred at the same time.
Sweet potato bran heart causes
Using potato seedling, nematode invading from potato seedling stem attachment points, to move up and down along the cortex.Disease after seedlings planted in the field, parasitic nematodes mainly in the tendril, can also be into the soil.Knot potato period nematodes by tendril into new potato piece at the top, to extend the up and down, disease and healthy potato chips appearance, but the interior of the potato piece into brown, and white dry rot, commonly known as the chaff heart.Nematode disease soil or fertilizer, but also from the seedlings roots cut, or from a new small potato piece directly into.Directly into the nematodes, make potato piece of internal organization brown hair soft, a massive brown spots or small cracks, commonly known as chaff.
Sweet potato bran heart disease characteristics
Sweet potato stem nematode growth optimum temperature is about 25 ℃, the resistance to low temperature is not high temperature resistant.Under natural conditions, nematode more concentrated in the 10 ~ 15 cm soil layer.
Spring potato growing, nematode reproduction algebra, disease is better than summer potato.Continuous cropping plot accumulated insect source more, come on.Moist, osteoporosis, ventilation and drainage good sandy soil heavy disease;Sticky soil, organic matter content of light.
Sweet potato bran heart comprehensive prevention and cure
(1) strict quarantine for kinds of potato seedlings.
(2) selecting disease-resistant varieties.Can choose potato 3 lu, dhi, xu potato potato 10 18, dhi potato. 2, the United States disease resistance varieties such as red, Beijing 553.
(3) establish a disease-free for farming, breeding without disease to plant potatoes.Choose more than five years not planted sweet potatoes do disease-free for farming plots of land, strictly choose kinds of potatoes, with 800 ~ 1000 times of 5% phoxim oil immersion seedling 15 ~ 20 minutes.No disease to plant potatoes single receiving, use new pits one hidden.
(4) to eliminate the sick body.In seedling, transplanting, harvest sweet potato storage pit entry three phases, potato debris clean up disease, illness and disease, burned or buried.
(5) adopts a rotation.The sweet potato and other food crops for more than 3 years crop rotation.
6. Seedling.only before in 800 ~ 1000 times of 50% phoxim oil immersion seedling 15 ~ 20 minutes.
