Diseases of Panax notoginseng at seedling stage and its control

Because Panax notoginseng grows in a shady and humid environment all the year round, many diseases such as black spot, round spot, blight, rot, powdery mildew and other diseases are seriously harmed, and the perennial losses caused by various diseases amount to 30% to 40%, and the serious ones reach more than 80%. In the stage of emergence and long leaves of Panax notoginseng, the plant is tender, the root system is underdeveloped and the stress resistance is poor, which is an important period for the first infection of many kinds of pathogens. If the spring rain is early and frequent, the disease will spread rapidly and the damage will be serious. Panax notoginseng generally takes 60 to 75 days from sowing to emergence. Strengthening garden management during this period to promote the healthy growth of Panax notoginseng is closely related to the control of disease occurrence and development. Therefore, seizing the opportunity, making comprehensive control and controlling the occurrence and harm of diseases in the seedling stage of Panax notoginseng are the key to the comprehensive control of Panax notoginseng diseases. The main measures are:

1. Drought-resistant watering, waterlogging prevention and dehumidification as the saying goes, "Water is the life of seven, and it is also the disease of seven." that is to say, too much or too little water is harmful to the growth of Panax notoginseng. If the soil moisture is insufficient or dry, Panax notoginseng will dry and become "Xiangzi" after sowing, and the seeds will also become soft, then dry and moldy, and will not emerge normally. Therefore, it is the key to ensure the normal emergence of Panax notoginseng, improve plant disease resistance and reduce the incidence of Panax notoginseng by timely watering according to soil moisture in dry land, preventing excessive watering and avoiding sudden dryness and dampness.

two。 Adjusting the shade shed according to the light requirements and seasonal changes of Panax notoginseng in each year, repairing and adjusting the shade shed to meet the light requirements of Panax notoginseng is also an important measure to promote the robust growth of Panax notoginseng and control the occurrence and development of diseases.

3. The removal of weeds and the competition for nutrients, water and space between Panax notoginseng and Panax notoginseng have a great influence on the growth of Panax notoginseng. At the same time, weeds are the hosts of many kinds of diseases. Therefore, timely removal of weeds can promote the robust growth of Panax notoginseng and reduce the development and spread of the disease.

4. Reasonable topdressing of Panax notoginseng after emergence should be carried out according to soil fertility, bottom fertilizer and seedling condition, according to the ratio of nitrogen 2, phosphorus 1 and potassium 3, advocate a small amount of multiple topdressing, mixed application of nitrogen, phosphorus and potassium, and appropriate amount of potassium fertilizer to improve the disease resistance of the plant.

5. Before the emergence of Panax notoginseng, one part of carbendazim, 500 times of water and 600 times of water, or the mixture of 5 Baomidu stone sulfur was used to disinfect the surface of Panax notoginseng at intervals of 10 to 15 days, which can prevent powdery mildew and other diseases. It should be checked frequently after emergence, marked after diseased plants are found in the center, and focus on prevention and treatment after clearing the diseased and residual plants. Can choose the following medicament and formula to spray evenly as appropriate, spray once every 7-10 days, prevent and cure continuously for 2-3 times.

30% carbendazim 1000 times solution, or 50% carbendazim 200 times solution, or 1 ∶ 1 ∶ Bordeaux solution sprayed or irrigated to control seedling blight can block the disease center and control the spread of the disease.

The main diseases of Panax notoginseng seedling diseases in the past two or three years are blight, black spot, round spot, anthrax, scab, powdery mildew and stem rot. Before emergence, 20% carbendazim plus 70% methyl topiramate 800 × 1000 times solution, or 50% carbendazim plus 70% mancozeb 600 times solution, or carbendazim plus thiram 800 times solution spray can prevent diseases or reduce harm. After the emergence of Panax notoginseng seedlings, regular inspection, found that the disease center, timely clean up blockade, select the following drug punishment for timely prevention and treatment.

① control of Panax notoginseng black spot with 1.5% anti-mildew 150 times 200 times liquid, or 75% chlorothalonil 500 times 600 times solution, or 40% sclerotia net 400 times solution spray.

② control of Panax notoginseng round spot disease with 30% love seedling 2500 times solution, or with 10% Polaroid plus 50% tocopherol 1500 times solution, or with 60% Shida 800x solution spray.

③ used 80% triethyl aluminum phosphate 500x solution, or 72% Kelu 550x solution, 58% metalaxyl manganese zinc 500x solution, or 64% poisonous alum 500x solution to control Panax notoginseng blight.

④ control of panax notoginseng anthracnose with 70% mancozeb 500x solution, or with 70% methyl topiramate 1000 times solution, or with 30% furomycin 1000 times solution spray.

Two or more diseases often occur in the same period in the seedling stage of Panax notoginseng, so the mixed use of fungicides with different characteristics is advocated according to the disease, so as to reduce the times of spraying, expand the object of control, reduce the cost of control and improve the benefit of control.