Key techniques of Asarum Seedling raising

Asarum can be propagated by seed and rhizome, and seed propagation is the main method in production. Seed propagation is divided into seed direct seeding and seedling transplanting, which are commonly used in production. The emergence and preservation rate of Asarum seedlings and the quality of seedlings directly affect the growth and development of Asarum plants after transplanting.

Seed screening

Asarum seeds matured in the middle and late June. After picking and stacking for 2-3 days, when the fruit is cracked and the flesh is powdery, rub it on a sieve, wash the seeds and pulp that fall under the sieve, remove and throw away the shrunken seeds floating on the water, remove the semi-mature seeds suspended in the water and sow them separately, and use the full seeds sunk under the water to raise seedlings.

Seed disinfection

Asarum seeds often carry all kinds of germs. In order to avoid or reduce the seeds carrying all kinds of pathogens, the seeds should be disinfected before sowing. Soak the seeds with 1000 times of 50% carbendazim wettable powder or 1000 times of 50% carbendazim wettable powder for 30 minutes, remove them and dry them slightly before sowing.

Sowing at the right time

Asarum seeds have the characteristics of physiological post-ripening and can not be stored at dry room temperature. Therefore, seeds should be sowed immediately after mature harvest and washing in mid-and late June, and those seeds that cannot be sown in time for some reason should be treated with sand. Seeds treated with sand storage can be sown at any time, but no later than the previous sentence in August at the latest. It is easy to break the radicle if sowing too late, and the seeds that break the radicle will not emerge after sowing.

Thickness of soil cover

Asarum seed is small, germ top soil ability is weak, sowing soil is too thick will affect seedling emergence, reduce seedling emergence rate, and prolong seedling stage; cover soil is too thin, the surface soil is easy to cause buds after drying. Therefore, the thickness of soil cover should be properly controlled when sowing, and 1cm is generally appropriate.

Border cover

The growth and development of Asarum seed embryo needs to be completed under the condition of about 20 ℃ and 30% soil moisture. In order to maintain proper soil moisture, cover the border after sowing, preferably with larch leaves, straw and mountain grass. The suitable thickness of mulch is 3~5cm, which should be removed when the seedlings emerge.

Pest control

The main pest during the seedling raising of Asarum is mole cricket. Mole cricket has the characteristics of phototaxis, chemotaxis, humidity and feces. The border cover after careful sowing makes the soil moist, and the moist soil is easy to attract mole cricket. Mole cricket entering the border bed will dig holes in the surface soil to feed, which can not only break the radicles of Asarum seeds, but also cause soil loosening and ventilation, leading to neutron bud drying. Prevention and control method: ① poison dung trapping: mole cricket has fecal tendency, and manure with high fiber content such as horse dung and deer dung can be selected, and 0.5g80% trichlorfon wettable powder is mixed per 30~40kg, put into a small pile on the operation track of the seedling ground, and covered with grass, the trapping and killing effect is more obvious. ② medicament control: spray 50% phoxim 1000 times liquid on the border surface after sowing, then carry on the border, cover the surface and suffocate, the effect is better.

Adjust the light

The light resistance of 2-year-old Asarum seedlings is weak, so a sunshade should be set up immediately after emergence. At the initial stage of growth, the canopy density is 0.6 and the transmittance is 40%. For raising seedlings in farmland, mountain grass or leafy branches can be hung on the awning from early July to mid-August, reducing the canopy density to 0.7 and the transmittance to 30%. Remove the hanging in late August. This dimming method can prevent sunburn caused by excessive light, which is beneficial to the growth and development of plants.

Prevention of frost injury

Asarum is an early spring plant, older plants can tolerate low temperature of about 0 ℃ for a short time, 1-year-old seedlings only grow 2 young cotyledons and are not resistant to frost, low temperature below 0 ℃ can produce frost injury, dehydration and withering and death of the injured leaves, and no regeneration buds are produced in underground seed roots. The preventive measure is to set up a sunshade in time after emergence; pay attention to watch the weather forecast every day and find that the seedlings are buckled with plastic in frost weather to reduce or reduce frost injury.

Prevention of drug damage

Use the farmland to raise seedlings, plant corn in the surrounding plots, spray herbicides to seal off the corn after sowing, and the liquid falls on the stems and leaves of Asarum with the wind, or is fumigated by the smell of the solution, which will cause drug damage to the stems and leaves of Asarum, and in serious cases, it can cause the destruction of the whole field. Preventive measures: consult with the surrounding corn farmers, determine the spraying time, cover the Asarum seedlings strictly with plastic film before spraying, and remove after spraying, which can prevent the harm of medicine.