1. Growth and development characteristics

It likes high temperature and humidity, is not drought-tolerant, is relatively shade-tolerant, and has the characteristics of aquatic plants. It can be cultivated in paddy fields or dry land. The root system has weak absorptive capacity and requires sufficient water throughout the growth period; it has wide adaptability to soil, and fertile, deep, clay soil with strong water retention capacity is suitable; seed taro begins to germinate at 13 to 15°C, and the suitable growth temperature is above 20°C, and bulbs It is formed under short-day conditions, and the optimal temperature for development is 27 to 30°C. In case of low temperature and drought, the growth will be poor and the yield will be seriously affected.

2. Requirements for environmental conditions of taro

1. Temperature requirements. Taro is native to high-temperature and humid areas. During the long-term cultivation process, cultivation types such as water taro, water and drought taro, and upland taro have been formed. However, both calla taro and upland taro require high temperature and humid environmental conditions. Taro bulbs begin to germinate at 13-15°C. The suitable growth temperature for the seedling stage is 20-25°C, and the suitable growth temperature for the sprouting stage is 20-30°C. A large temperature difference between day and night is conducive to the formation of bulbs. During the bulb formation period, 28-30°C during the day and 18-20°C at night are most suitable.

2. Moisture requirements. Both calla taro and upland taro like moist natural environmental conditions. During the growth period of upland taro, the soil needs to be moist, especially during the vigorous growth period of the leaves and the bulb formation period. It requires a large amount of water and requires increased watering or shallow water irrigation in the row trenches. At the same time, pay attention to spraying Diguo Zhuangdi Ling in the early stage of corm maturation to thicken the nutrient transport tubes of underground fruits, improve the expansion vitality of the underground fruits, make the fruit surface smooth, the fruit shape is strong, the quality is improved, and the yield is achieved. Calla taro requires a certain water layer during the growth period, and the water layer is 3-5 cm during the seedling stage. During the peak growth period of the leaves, the water depth should be 5-7 cm. Watering and irrigation should be controlled 6-7 days before harvesting to prevent the bulbs from containing too much water and not being able to withstand storage.

3. Lighting requirements. Taro is more tolerant of low light and does not have strict requirements on light intensity. Grows well in diffused light, requiring short day conditions for bulb formation and expansion.

4. Soil requirements. Water taro is suitable for growing in water and needs to be cultivated in paddy fields, low-lying land or ditches. Although taro can grow in dry land, it still maintains the ecotype of swamp plants and should be planted in humid areas. Taro is a fertilizer-loving crop, and its bulbs are formed in the underground soil layer. Therefore, loam or clay loam soil with rich organic matter and deep soil layer should be selected. The soil organic matter should be 1.05, available nitrogen 62.5ppm, available phosphorus 11.25ppm, and available potassium. 62ppm,

The most suitable pH value is 5.5-7.

3. Main technical measures for planting taro

1. Carefully select the land and prepare it, and apply sufficient base fertilizer

Taro is most avoidable from repeated cropping. Continuous cropping will reduce the yield by 20-20% in one year. 30. It is best to plant on land where the previous crop is sweet potato, followed by peanut crop. If the previous crop is corn and other grass crops, the yield will be reduced by 30. The edible organ of taro is underground corm, and the root system of taro is deep. It is advisable to choose a field with fertile soil, strong fertilizer and water retention capacity, deep, fertile, loose soil, easy drainage and irrigation, and a field where taro has not been planted in the first year. Deep plowing of more than 40 cm is required before sowing. Deep plowing is conducive to bulb enlargement and increased yield. It is one of the important cultivation measures. Before deep plowing, 2500 kg of organic fertilizer (or 6000 kg of soil fertilizer rich in organic matter) needs to be applied to 667 m2. kg) as base fertilizer, according to the standard of producing 100 kilograms of taro bulbs: 1-1.2 kilograms of pure nitrogen, 0.8-0.84 kilograms of phosphorus pentoxide, and 1.6-1.68 kilograms of potassium oxide, according to the standard of nitrogen:phosphorus:potassium=1.2:1: Apply base fertilizer at a ratio of 2. Generally, the amount of chemical fertilizer applied per acre is 35 kg of diammonium phosphate, 50 kg of compound fertilizer, 100 kg of bone meal, and 75 kg of ammonium bicarbonate. When taro is flourishing for a long time around mid-July, it is necessary to apply an appropriate amount of fertilizer. Apply ammonium bicarbonate, diammonium phosphate and other fertilizers. And appropriately apply phosphorus and potassium fertilizers such as potassium sulfate and superphosphate. When sowing, use 25 kilograms of potassium sulfate compound fertilizer and 50 kilograms of superphosphate per acre, and apply it between two plants as seed fertilizer.

2. Sow early at the appropriate time, cover with mulch, and plant reasonably densely

①Sowing time. Taro avoids frost and prefers a warm and humid climate. Sowing is usually carried out after the local last frost. Sowing too early may cause rotten seeds.

Taro has a long growth period and can only germinate when the temperature is above 13-15°C. Planting is usually started around early to mid-March (if conditions permit, mulch cultivation can be planted as early as February). As long as the taro seedlings are not frozen after emergence, the earlier the sowing date, the better. Planting early can extend the growth period and significantly increase production. Mulch taro to increase temperature and moisturize. Sow in the open field 20-30 days in advance. If you cover taro too early, the ground temperature will be low, which can easily lead to rotten seeds or weak seedlings. If it is too late, it will easily cause seedling burning due to high ground temperature. This should be flexibly controlled according to climate characteristics. . Film-covering cultivation can increase the yield by 38.5-50%, increase the proportion of taro, and have a high processing yield. It is required to carry out seeding after the winter solstice and before New Year's Day and cover with agricultural film to accelerate germination. After the roots have sprouted, choose sunny weather for planting in January to ensure that taro can be harvested and put on the market before mid-August to obtain high prices.

②Seed selection. The larger the seed taro, the more nutrients it contains and the better the plant growth. Research shows that sowing 50 grams of seed taro increases yield by more than 13% compared to 20 grams of seed taro. For seed taro of the same size, the yield of whole taro without cutting the stems is more than 6% higher than that with cutting stems. In production, medium-sized taro seeds are selected as seeds, and the taro seeds grown in the middle of the taro head are selected as seeds. The hairs on the seed taro are removed, and then the side buds other than the terminal buds are removed to prevent the side buds from germinating. When planting taro, it is advisable to choose corms that have no wounds, no rot from diseases, insect pests, and the tips of the terminal buds, weigh about 50 grams, and are spherical in shape.

③ Drying the seeds to accelerate germination. In order to ensure neat emergence of seedlings, germination in the sun, germination in wet sand, etc. must be carried out 15-20 days before sowing. During germination, the stored taro can be sun-dried for 1-2 days, and then the seed taro can be densely arranged in the germination plot. During germination, pay attention to moisture and control the temperature at 18-20°C. After 15-20 days, the buds will grow about 1 cm. Ready to sow.

④Plant reasonably densely to increase plant yield. The density should be determined according to the variety, soil, water and fertilizer. If the conditions are good, it will be denser, and if the conditions are poor, it will be thinner. From the perspective of economic benefits, it is most reasonable to plant 4,500-6,000 plants per acre. Use large and small row cultivation methods, with plant spacing of 27-33 cm, large row spacing of 60 cm, and small row spacing of 30 cm.

3. Raise the ridges and cover them with film for deep planting

Dig a trench at a large row spacing on the well-maintained land. The trench is 10 cm deep and 35 cm wide. Fill the planting trench with water. Create moisture, and after the water seeps in, place the taro seeds according to the determined density. Pay attention to the buds facing upwards and plant them in a triangle (dislocation). Apply appropriate fertilizer between the taro seeds and apply 15-20 of mature soybeans containing phoxim. The grains are used to control underground pests and as seed fertilizer. When ridging, the ridges should be raised high so that the ridge height is 20 cm and the ridge width is 50-60 cm. After the ridges are finished, rake the ridges flat. The thickness of the soil covering the taro seeds is about 8-15 cm, usually 12 cm. After autumn, there is no need to divide the soil into ridges, which will not damage the roots, and the yield is high. No or less green taro is produced, which improves the quality of taro. After spraying acetochlor herbicide, cover with mulch. Use 7-8 kilograms of transparent mulch film to cover it. It is required that the cabin surface is flat, the soil is finely crushed, and the edges of the film are compacted with soil along the edge of the cabin. Pay attention to inspection after covering with mulch film. Seedlings will emerge about 5 days after sowing. After emergence, the film should be broken in time and the holes should be sealed with soil. If any missing seedlings are found, they should be replaced in time. The mulching film covering time can last until the end of June and early July. When applying fertilizer, Peel off the film again.

4. Rational fertilization and scientific water management

① Rational fertilization.

Taro has a long growth period, high yield, and requires a large amount of fertilizer. In addition to applying sufficient base fertilizer, it should also be topdressed in stages. Fertilizer can be applied once in the early stage of seedlings, and 2-3 times in the early and middle stages of the growth period of the seedlings and bulbs. The amount of fertilizer should be less at first and more at the end, and gradually increase. Nitrogen, phosphorus, and potassium fertilizers should be applied in conjunction. Top dressing should be controlled in the later period to avoid being greedy for green and late maturity. The base fertilizer should be 40-50 kilograms of compound fertilizer per mu (N: P: K = 15: 15: 15) and 100-150 kilograms of calcium. Topdressing fertilizer should be started after the seedlings are ready, and the compound fertilizer should be applied per mu (N: P: K = 16: 10:20) 75-100 kg. Fertilization is combined with weeding, soil cultivation and mulching. Fertilization of taro is done by mixing fertilizer with water. Or on the premise of applying sufficient base fertilizer, you can apply thin biogas water or manure water appropriately in the early stage. When the taro grows to early June and begins to expand (3-4 leaf stage), use 1,000 kilograms of farmyard manure and 15 kilograms of potassium sulfate per acre. 50 kilograms of bio-organic fertilizer and 2 kilograms of boron, zinc and magnesium fertilizers are applied to the soil on the side of the box after retting for 30-45 days.

Before the severe heat in mid-July (5-6 leaf stage), use 25 kilograms of potassium sulfate compound fertilizer per acre and 15 kilograms of potassium sulfate, evenly mixed and applied to the box surface, with a shallow soil cover. Weeds around the field should be pulled out before fertilizing. No more fertilizing after August. During the rapid expansion period of taro (

June-July), you can spray expansion hormone plus potassium dihydrogen phosphate, etc. in combination with the prevention and control of pests and diseases, which can promote the expansion of taro and increase yield. The amount of top dressing for taro throughout the growth period: 20-30 kg of potassium sulfate, 30-40 kg of diammonium phosphate, and 60-70 kg of ammonium bicarbonate.

② Manage water scientifically. Taro tolerates waterlogging and is afraid of drought.

Taro has large leaves and strong transpiration, so it likes water and avoids dry soil, otherwise it will easily cause yellow leaves and dead leaves. In the early stage, the temperature is low and the growth is small, so you only need to maintain the soil moisture. Especially during the emergence period, avoid watering to avoid affecting rooting and emergence. In the middle and late stages, the temperature is high, the growth volume is large, and the water demand is large. The soil must be kept moist, but the irrigation time should be in the morning and evening. Especially in high temperature seasons, avoid watering at noon, otherwise the leaves will easily wither. Before fertilizing and removing the film, the surface of the box should be kept moist. On rainy days, water should be drained from the ditch. On dry days, the ditch should be filled with horse water to keep it moist. During the peak growth period (June-August), the bottom of the ditch should be kept 1 inch thick. The water should be moist; watering should be controlled 20 days before harvesting and stopped 10 days before harvesting (harvest and market before October).

5. Cultivating and cultivating the soil.

During the growth process, taro bulbs will gradually grow toward the surface as the leaves increase, thus affecting the yield and quality of taro. In addition, cultivating soil can also inhibit the germination of taro and sun taro top buds, which is a reduction in Nutrient consumption is an important technical measure to promote bulb expansion. Therefore, before sealing the ridges, it is necessary to remove the film and combine cultivating, weeding and soiling 2-3 times, covering 5-7 cm of soil each time with an interval of 15-20 days. Farming operations should minimize mechanical damage to above-ground and underground parts. There is no need to cultivate soil when planting with high ridges and mulching.

6. Timely apply chlormequat and excised taro

①Apply paclobutrazol and sapling agent. When the taro has 5-6 leaves and the plant height is about 45 cm, use 5 kg of seedling-strengthening agent and 150 g of paclobutrazol per acre for drenching, and then apply 150 g of paclobutrazol for drenching or foliar spraying every 20 days. The dosage can be increased or decreased depending on the growth of the plant. On a sunny day, add 15 grams of paclobutrazol and 40 kilograms of water, and fill 80-100 plants with core leaves. The plant height is 80 centimeters and there are more than 5 leaves. The rows are basically sealed.

② Remove the taro. When the taro grows to 7-8 leaves, it begins to produce taro seeds. In order to reduce the dispersion and consumption of nutrients and facilitate the expansion of the mother taro, when the child taro has one leaf and one center, carefully cut off the growth point of the child taro with a knife or a small shovel, and be careful not to cut the mother taro. Three or four seeds of taro seeds need to be saved but not removed.

7. Weeding

After sowing and watering, pre-emergent weeding is carried out, and the whole field is sprayed with pre-emergent herbicides. The herbicides can be Doer, Prometryn, etc. You can also use 20 ml of Herbicide Herbicide mixed with 60 kg of water per acre and spray evenly. Or use 150 grams of acetochlor herbicide per acre to spray the ground evenly. During the taro growth period, manual weeding is carried out in conjunction with fertilization, soil loosening and other processes.

4. Prevention and control of pests and diseases. Follow the policy of "prevention first, comprehensive prevention and control", based on agricultural prevention and control, give priority to physical and biological control, select high-efficiency, low-toxicity, low-residue pesticides, and do not use banned pesticides to ensure the quality and safety of taro.

1. Main diseases:

① Taro blight. It is a fungal disease that mainly damages petioles, leaves and bulbs. The peak period of disease is from June to August. High temperature, high humidity or sometimes rainy and sometimes sunny conditions are prone to occur. Excessive dense planting and partial application of nitrogen fertilizer will lead to vigorous growth and serious disease. Prevention and treatment methods: Prevention is the most important. Start using medication in mid-May before the onset of the disease. You can choose protective fungicides such as mancozeb, add Phosphate, Metalaxyl, Anker, etc. and use them alternately. Spray every 7-10 days. once. When applying pesticides, you should control the weather and choose to spray before rain. At the same time, spray the liquid evenly, covering the back, leaf surface, and petiole of the leaves.

②Soft rot. It is a bacterial disease that damages underground bulbs and the base of petioles, and can occur throughout the growth period. Prevention and control methods: Strengthen fertilizer and water management, remove diseased plants promptly and take them away when found, and spread lime around diseased holes.

Chemical control: Agricultural streptomycin and chlorothalonil can be used to irrigate the roots. They can be applied once before fertilizing, after soil cultivation, and after cutting taro. At the same time, agricultural streptomycin should be added to every pesticide application in areas with severe disease all year round to strictly prevent underground pests and control moisture.

③ Taro contamination disease. It only damages the leaves. Prevention and control methods: You can use chlorothalonil and thiophanate-methyl to start control at the early stage of the disease, and spray again every 7-10 days.

1. Main pests:

①Aphids. Adults and nymphs suck sap on the backs of leaves or young leaves, causing the leaves to curl and become deformed, causing poor growth and spreading viral diseases. In severe cases, the leaves are covered with black mold. Control methods: Spray with dimethoate and imidacloprid pesticides.

② Spodoptera litura. The larvae feed on leaves, and in severe cases only the veins remain. Generally, Kungfu or Lesben, imidacloprid, and Fipronil are sprayed to kill the larvae before they are 3 years old. When using pesticides, comprehensive prevention and control should be considered. For example, imidacloprid plus abamectin can prevent pests such as taro aphids and Spodoptera litura.

③Underground pests. Combined with two heavy fertilizer applications, phoxim, Miler or trichlorfon can be used for control.

④Red spider. Spray 1500 times monocrotophos or 800 times omethoate 40 or 800 times dicofol.

5. Harvesting and Storage

Generally, it can be harvested in the frost season. Irrigation should be stopped 20 days before harvesting. The best harvesting time is after the dew has dried on a sunny day. Taro is harvested before and after frost when the leaves are yellow, the roots are withered, and the bulbs are fully mature, which has a greater impact on yield. Seed taro must be fully mature before harvesting. Cut off the aboveground parts before harvesting, and harvest on sunny days after the wound dries and heals. When planting taro, you should select bulbs that are disease-free, free of mechanical wounds, and weigh about 50 grams. Store after drying for one day. During storage, wait until the taro is naturally air-dried, then turn the taro upside down, place a layer of taro, and cover it with a layer of fine sand. It can be stacked in a single layer or in multiple layers. Pay attention to remove damaged or diseased taro to avoid infection. The appropriate storage temperature is 10-15℃, and it should not be exposed to freezing. Cut off excess taro after harvesting, and be careful to avoid damage caused by collision and friction during harvesting, transportation and storage.