High-yielding planting techniques of Amorphophallus

Konjac, also known as Amorphophallus, Amorphophallus, etc., is a perennial herb of the Araceae family. China began to cultivate konjac more than 2000 years ago, and its edible history is also quite long. It is mainly distributed in Yunnan, Guizhou, Sichuan, southern Shaanxi and western Hubei. With the continuous development and utilization of konjac, its cultivation has a good development prospect. Let's take a look at the high-yield planting techniques of konjac.

Land selection and preparation

Amorphophallus konjac has strict requirements on light, heat, water, fertilizer and other conditions, and must adhere to suitable soil and planting according to the land. It is necessary to choose slightly acidic to neutral (pH6.5~7) soil with thick soil, loose soil and good drainage, and the gentle slope land with a small amount of gravel, light loam and bubble soil is the most suitable for planting konjac. Before sowing konjac soil, it is necessary to explore and dig the Kang field as soon as possible to remove stones, weeds and residual film from the soil.

Seed taro treatment

1. Seed production: in order to develop konjac production, we must first develop seed production and prepare sufficient seed taro. To achieve seed taro disinfection treatment, seed feces isolation, timely chemical control, timely eradication of diseased plants. The development of taro production is to adhere to the breeding of taro on the spot, mainly by taro farmers. The new development households must first develop the seed taro, and the old growers should match the corresponding planting area. Improve the quality and safety of taro. The ratio of seed to field area is generally 1:3.

2. Seed taro disinfection: seed taro disinfection treatment is to eliminate germs on seed taro from the source. First of all, dry the seeds and spread the taro for 2 days before sowing. The second is to soak the seeds, that is, soak the seeds with 500ppm's streptomycin sulfate solution for 30 minutes on a sunny morning, sow the seeds immediately after being dried, or mix the seeds with kitchen ash (wood ash), and sow the seeds after drying. Where there are conditions, the seeds of taro after seed drying and seed soaking should be seeded and transplanted to the field.

3. Sowing method: when sowing, taro and fertilizer are isolated from each other and should not be in direct contact. The method of opening the sowing ditch to sow seeds, covering the soil and then releasing dung is adopted to ensure the safe emergence of konjac seedlings. Before the emergence of konjac seedlings, agricultural streptomycin or Streptomyces were sprayed as preventive protective drugs. Once a diseased plant appears in the field, choose clear dew to dry, dig up the soil in the root and nest and bury it deep away from the cultivated land and disinfect it with lime. Do not take the diseased plant home as raw feed to feed pigs or litter at will, resulting in artificial transmission.

Scientific fertilization

1. Fertilization principle: konjac is a taboo chlorine tuber crop that needs a large amount of fertilizer, and it has the characteristics of being fond of fertilizer and thin, potassium and chlorine. It needs the most potash fertilizer, followed by nitrogen fertilizer, followed by phosphate fertilizer and trace elements such as calcium, zinc, magnesium, manganese and so on. Therefore, we must adhere to the principle of giving priority to base fertilizer and re-applying farm manure.

2. Base fertilizer management: in the konjac field with low soil fertility, more than 2000 kg of farm manure such as washer fertilizer, high-quality soil manure, turf fire manure and so on are applied per mu. In the base fertilizer, 2 kg of biological potassium fertilizer was applied according to the nutrient status of the soil, and proper amount of urea, calcium superphosphate or calcium magnesium phosphate fertilizer and other fertilizers were applied.

3. Fertilizer selection: in fertilization, it is forbidden to apply farm manure, chicken manure and chlorine-containing chemical fertilizer, and not to apply more nitrogen fertilizer. The application of a large amount of farm manure and less chemical fertilizer is not only beneficial to improve soil fertility and soil, but also make konjac grow sturdy and enhance disease resistance.

4. Reasonable topdressing

When ① topdressing seedling fertilizer for the first time is about 80% of konjac seedlings, those with insufficient base fertilizer should be re-applied with seedling fertilizer, with 20% 30 piculs of human feces and urine mixed with 40 piculs of water per mu, and about 5 jin of urea and 5 piculs of human feces and urine with water per mu with sufficient base fertilizer.

The second topdressing of ② was from the end of June to the beginning of July, using high quality farm manure such as gasket fertilizer or fire manure to mix urea 6kg 8jin and potassium sulfate 15kg 20jin slightly on the side of the box, combined with shallow soil cultivation.

③ applied tuber expansion fertilizer for the third time from late July to early August, covered soil with 20 kg potassium sulfate per mu, and foliar spraying 0.2% potassium dihydrogen phosphate solution 2 times from August to September.

Field management

1. Coverage management: after sowing, great efforts should be made to collect all kinds of crop straw, pod shell, withered leaves and other mulch. The long mulch had better be chopped, evenly, flat and tightly scattered on the ground of konjac, so as to reach the standard of "grass is not a mound and the land is not exposed white". Generally, about 2000 jin of mulch per mu is needed, and attention should be paid to removing the unrotten mulch after September.

2. Weed removal: the root system of Amorphophallus konjac is distributed shallowly. In order to prevent weeding from cutting the developing young roots and underground stems and affecting the normal growth of plants, weeds can be pulled out by hand. But it should be noted that people can only squat in the furrow to pull grass, do not step on the ridge surface, in order to prevent crushing the underground rhizome.

3. Clear ditches and cultivate soil: konjac is not only afraid of drought, but also not suitable for impregnation. Therefore, the fields planted in the rainy season, especially after the rainstorm, should go to the ground for inspection, dredge ditches and drainage, and ensure the smooth flow of waterways. Combined with ditch cleaning, the fine soil in the ditch was cultivated to the ridge surface, and the soil was cultivated for 2 times during the growth period to facilitate the formation, expansion and non-exposure of Amorphophallus, and to enhance the wind resistance of Amorphophallus.

Pest control

1. Soft rot

[symptoms] mainly affect petioles, bulbs and leaves, blackening and softening the tissue, giving off a foul smell, and even rotting and lodging the fruit into pieces, causing heavy losses.

[prevention and control] the management of cultivation of planted konjac should be strengthened, the soil should be ploughed deeply, drained and ventilated regularly, and the seeds without decay and wound should be carefully selected and properly preserved and transported. In addition, attention should be paid to vegetable crops that cannot be planted continuously or intercropped with konjac, such as Solanaceae. Before sowing konjac, it can be soaked in appropriate proportion of agricultural streptomycin solution, fished out and then dried.

2. White silk disease

[symptoms] mainly affect the base of the petiole, resulting in damage to the petiole or corm. When the base of the stalk is infected with white silk disease, dark brown spots will appear and continue to expand, eventually making the petiole grow white silk-like hyphae and show light red.

[prevention and control] in view of white silk disease, it is necessary to strengthen field cultivation management and timely eliminate stagnant water. Continuous and intercropping with peanuts, Solanaceae and soybeans should not be carried out during planting. At the same time, appropriate proportion of Bordeaux solution can be used to disinfect the four sides where the petiole is in contact with the soil surface during the period from konjac head change to bulb expansion.

3. Leaf blight

[symptoms] it mainly harms leaves. The pathogen will survive the winter in the soil and can splash on the leaves with Rain Water. In addition, it can also invade through wounds or stomata and spread through wind and rain. Therefore, the bacterial infection ability of leaf blight is very strong, resulting in the withering and death of konjac pieces.

[control] the prevention and control measures of leaf blight are basically the same as those of soft rot.

4. Insect pests

[symptoms] the main pests affecting the growth of konjac are sweet potato armyworm, konjac nematode, bean slug moth and so on.

[control] for the control of these insect pests, it is necessary to remove weeds and dead leaves in winter and spring, and intercropping konjac and corn in the field, which plays an important role in pest control. In addition, pesticides can be used artificially to remove insect pests, and pay attention to the use of mature farm manure when using farm manure.