What are the control methods for Pinellia tuber rot?

Pinellia tuber rot causes huge losses to Pinellia production, so we must do a good job of preventing and controlling Pinellia tuber rot to ensure the production efficiency of Pinellia. What are the symptoms and characteristics of Pinellia tuber rot? Let's find out together below!

Symptoms and characteristics of Pinellia tuber rot

In the early stage when the pathogen infects the Pinellia tuber, irregular black spots appear around the edge of the tuber. These spots spread rapidly in all directions. After 3 to 4 days, numerous pathogen spots join together and continue to infect the interior of the tuber. At this point, the Pinellia root system begins to shrink, and the aboveground leaves gradually turn from green to yellow and wither. After one week, the Pinellia tuber becomes round and blister-like, as if it were a fully ripe grape, and the inside of the tuber is entirely black liquid. The whole plant dies, and finally only a thin outer skin remains. The spreading pathogen quickly infects other Pinellia tubers, causing the entire Pinellia plot to become infected and rot within a short period. The soil and air where Pinellia is cultivated give off a foul, fishy odor.

Control methods for Pinellia tuber rot

1. When selecting varieties for planting Pinellia, choose Pinellia varieties with strong disease resistance and vigorous growth, such as excellent varieties with leaf shapes like “narrow three-leaf” and “willow-leaf shape”, and select disease-free tubers or bulbils as seed tubers.

2. Seed tuber treatment. Before sowing, the selected seed tubers must be treated and disinfected, such as by sun-drying the seeds and dressing the seeds with chemicals, to prevent the seed tubers themselves from carrying pathogens.

3. Land selection. Pinellia must be planted in loam or sandy loam with a pH value between 6.5 and 7, and the plot must not have previously experienced root rot or rot disease. In areas with heavy autumn rain, the selected plot should have a 20% slope. In plain areas and relatively flat plots, during the early planning for Pinellia cultivation, a drainage ditch 30 cm wide and 30 cm deep should be left every other intercropping bed to ensure that during continuous rainy weather, the water in the soil of the Pinellia field can thoroughly seep into the drainage ditch and be drained from the plot in time.

4. Remedial measures. During continuous rainy weather and when the soil is relatively moist, carry out various forms of intertillage and soil loosening multiple times to break up the compacted layer of the soil, allow harmful gases in the soil to escape, let fresh oxygen from the air enter, and increase gas exchange between the soil and the air. This measure can effectively prevent and reduce the occurrence of rot disease.

5. Emergency harvest of rotten stems. In the middle and late stages of Pinellia growth, if continuous rainy weather occurs and soil moisture is relatively high, frequently inspect the growth of Pinellia. If some Pinellia plants are found to have rot disease, in this situation, regardless of whether the digging and harvest season has arrived, an emergency harvest should be carried out in time without delay. Otherwise, the tubers rot very quickly, with the large ones rotting first and the small ones afterward, causing reduced yield or even total loss. At the same time as the emergency harvest, the Pinellia tubers dug out from the wet mud should be immediately peeled and processed, because at this time the fresh tubers are still rotting internally. If not processed, most tubers will rot away after 1 to 2 days. Medicinal herb growers should not be careless.

Efficacy and effects of Pinellia  

1. Effect of relieving cough and removing phlegm  

Pinellia is pungent in flavor, warm in nature, and drying, and is an important medicine for drying dampness and transforming phlegm, and for warming and transforming cold phlegm. Symptoms such as cough with excessive phlegm caused by colds can be treated by taking Pinellia.  

2. Effect of stopping vomiting  

Pinellia is bitter in flavor, directs rebellious qi downward, and harmonizes the stomach. It is a medicine with a very good effect on stopping vomiting. Vomiting from various causes can all be treated with it in formulations according to syndrome differentiation, and the curative effect is very remarkable.  

3. Reducing swelling and relieving pain  

External use of Pinellia can treat sores, ulcers, swelling, toxin, and venomous snake bites. Its role in reducing swelling and relieving pain is very great.  

4. Effect of resisting early pregnancy  

Pinellia protein is considered to be an effective component or one of the effective components in Pinellia for resisting early pregnancy.  

5. Sedative and hypnotic effect  

Gavage administration to mice of the 75% ethanol extract of Qing Pinellia can significantly prolong the latency of the mouse tail-flick response to thermal pain stimulation and reduce the number of acetic acid-induced writhing responses in mice, showing a very good sedative and hypnotic effect.  

6. Effect of inhibiting gland secretion  

Intraperitoneal injection of Pinellia preparations has a significant inhibitory effect on pilocarpine-induced salivary secretion. It has also been reported that when the decoction is taken orally, salivary secretion first increases and then decreases.  

7. Used for symptoms such as chest and epigastric stuffiness, chest impediment, and clumping in the chest.  

Pinellia functions to disperse with pungency, warm and unblock, transform phlegm, and dry dampness, so it can be used for phlegm internal obstruction and chest and epigastric stuffiness, and can be used together with dried tangerine peel, Poria, and the like.

What kind of land should be chosen for planting Pinellia  

1. Choose moist, fertile sandy loam or loamy land with relatively strong water and fertilizer retention, loose texture, good drainage and irrigation, and a neutral reaction for planting. A gentle-slope mountain land with half shade and half sun can also be chosen.  

2. When planting Pinellia in plain areas, choose a plot that can be irrigated and drained and has relatively high terrain. Before planting, drainage ditches must be dug well.  

3. After selecting the land, in winter from October to November, plow the land deeply to about 20 cm, remove stones, gravel, and weeds, and let it weather and mature.

 Everyone may not be very familiar with Pinellia. It is a Chinese herbal medicine and has very good conditioning effects on many human diseases. It is just that perhaps not many people know about it at present, its application is not yet particularly widespread, and there is still great room for market development.