Control of common diseases in the middle and later stage of Pinellia ternata growth

Tuber rot

1. Etiological symptoms

High temperature, rainy season, excessive soil moisture for a long time, and the expansion period of tubers and bulbs occurred. At the initial stage of pathogen infecting Pinellia ternata tuber, irregular black spots appeared around the tuber, which expanded rapidly. After 4 days, many bacterial spots joined together and continued to infect the tuber. At this time, the root system of Pinellia ternata began to atrophy, and the aboveground leaves gradually changed from green to yellow and withered. A week later, the tuber of Pinellia ternata showed a round blister, like a ripe grape, the tuber was full of black water, and the whole plant died, leaving only a thin outer skin. The spreading pathogen will quickly infect other Pinellia ternata tubers, causing the whole Pinellia ternata land to rot and rot in a short time, first rotting large tubers, then spreading to small tubers, and finally leaving only bulbs smaller than 1cm. This disease is also the most common, difficult to treat, harmful and wide-ranging disease in artificially cultivated Pinellia ternata.

2. Prevention and treatment methods

(1) pay attention to the selection of improved varieties. When planting Pinellia ternata artificially, it is necessary to choose Pinellia ternata varieties with strong disease resistance and vigorous growth, such as "narrow clover", "willow leaf shape" and so on.

(2) disinfect the stem before sowing. Soak seeds with 50% carbendazim for 12 hours; 5% plant ash solution for 2 hours; 1 part of 50% carbendazim + 1 part of 40% aluminum phosphate 300x solution for half an hour; soak seeds with 300x vinegar and 50ml/-liter potassium permanganate respectively to prevent rot and increase production.

(3) strict selection of soil and topography. The soil must be medium loam or loam to ensure good filtration and ventilation; it is preferable to have a slope of 10 Mel 25 degrees. If the terrain is flat, a deep and dense seepage ditch should be dug.

(4) in case of continuous rainy weather and moist soil, as long as ploughing in the field can be carried out, various forms of ploughing and loosening the soil should be carried out for many times, so as to break the soil lamination, remove harmful gases from the soil, and enter the fresh oxygen in the air. increase the gas exchange between soil and air, this measure can effectively prevent and reduce the occurrence of rot. And timely spraying fungicides or 5kg/ per mu of raw lime powder.

(5) timely control of underground pest grubs and ground tigers. The use of a new pyrethroid pesticide, EC containing 50g/l and cyhalothrin, has an activating effect, which can drive pests to climb out of caves, come into contact with drugs, and act quickly on the nervous system of pests, resulting in poisoning and death. it has been widely used in the field in the past 2 years.

(6) rushing to harvest rotten stems. In the middle and later stages of Pinellia ternata growth, if you encounter continuous rainy weather and high soil moisture, you should frequently check the growth of Pinellia ternata, and if some Pinellia ternata plants are found to have rot, in this case, no matter whether or not the planing season is reached, it should be harvested decisively in time, without delay, otherwise, the tubers rot very quickly, the ones that rot big first, then those that rot small, resulting in reduced production or even extinction. At the same time of emergency harvest, the tubers of Pinellia ternata harvested from the wet mud should be peeled and processed immediately, so the interior of the fresh tubers is still rotting. If not processed, most of the tubers will rot 2 days later, so don't be careless.

Viral disease (leaf shrinkage disease)

1. Etiological symptoms

The disease is taro mosaic virus of potato virus Y group.

It is mainly due to the virus transmitted by insects such as stem virus or aphids of Pinellia ternata. It occurs and spreads in early summer, high temperature and heavy rain, aphids and so on. After the disease of Pinellia ternata, there are yellow irregular spots on the leaves of Pinellia ternata, which turn the leaves into flowers and leaves, wrinkle and twist, curl up, dwarf deformity of the plant and poor growth. The disease can also cause a lot of decay of Pinellia ternata during storage.

2. Prevention and treatment methods

The main results are as follows: (1) choose disease-free plots and areas for planting, and strictly screen the improved varieties of Pinellia ternata.

(2) applying fermented and mature organic fertilizer and applying phosphorus and potassium fertilizer properly.

(3) timely and thoroughly eliminate or prevent the occurrence and spread of aphids and other insect pests.

(4) after emergence of Pinellia ternata, 1500 times of 40% dimethoate or 80% dichlorvos should be sprayed continuously, once every 7 days, for 3 times in a row.

(5) at the initial stage of the disease, the patients were treated with new drugs with low toxicity and low residue, such as virus Qing, keduwei, duba and so on, once every 3 days for 3 times.

Quenching disease (leaf scald disease)

1. Etiological symptoms

This disease is one of the most common diseases in artificial planting Pinellia ternata, and its cause is being studied and observed. It is most likely to occur in the high temperature and rainy season and high humidity, especially when the ventilation and light transmission is poor, the disease is serious. In the early stage of the disease, green irregular disease spots appeared on the leaves and petioles, then the color of the disease spots deepened, the affected parts became soft, and the leaves were like boiling water, drooping in a translucent manner and sticking to each other. The disease is urgent and contagious. As soon as it is found, it spreads quickly and causes trouble in treatment. The soil and air of the whole plot gave off a strong fishy smell.

2. Prevention and treatment methods

The main results are as follows: (1) when selecting plots, we should choose the old vegetable fields where tomatoes, eggplant, cucumbers and cabbages have not been planted in the previous crop, or the plots where the crops on this plot have not experienced sudden collapse disease to plant Pinellia ternata.

(2) in rainy season and high temperature season, attention should be paid to reducing soil moisture.

(3) after the soil is selected, winter ploughing and drying should be carried out in winter. Do not apply immature fertilizer, properly apply or do not apply nitrogen fertilizer in chemical fertilizer.

(4) giving priority to prevention. Before the onset of high temperature and rain, use 75% chlorothalonil 800x solution; 50% methyl topiramate 1000 times solution; agricultural 200ppm streptomycin, neophytomycin; chloramphenicol of 300ppm; once every 7 days, alternately sprayed 3 times. Pay attention to spray evenly, so that do not re-spray, do not leak.

(5) the recent trial of 66.5% Prik 800 times, 72% DuPont Klu 500 times, spraying control, the effect is also good.