Common Problems And Control Measures In Yam Production

By Author: doris zhang
Total Articles: 76
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In the process of yam planting, due to lack of experience or non-standard planting technology, there are often one or another problems, such as yam yield decreasing year by year, poor quality, deformity and rotten seeds. It is precisely these problems that seriously affect the quality and commercialization of yam, reduce yield and benefit, and frustrate the planting enthusiasm of farmers. The following lists several common problems in yam production, and introduces the causes and preventive measures. Farmers should take warning in cultivation mobile grow system.

Generation and prevention of deformed yam. In the cultivation process of yam, due to the influence of adverse environmental conditions, cultivation measures and management methods, the internal organizational structure is changed, resulting in various strange shapes, such as the upper branch of yam tuber, the lower branch, snake shape, flat head shape, foot shape, gourd shape, pockmarked face shape, etc. These are collectively referred to as abnormal yam.

1. Cause ...
... of formation

(1) influence of foreign matters in soil. There are hard objects such as stones, bricks, gravel and clay blocks in the yam ditch, which are not carefully removed or fully crushed when filling the ditch. These hard objects are encountered in the growth of yam tubers, the growth point is blocked and the growth direction is changed, forming a variety of deformities such as bifurcation and flat head.

⑵ blindly apply seed fertilizer. When planting yam, vegetable farmers apply all kinds of seed fertilizer in order to make the seedlings strong and grow rapidly after emergence (sprinkle them into the ditch after ditching and before placing yam plants). However, due to excessive application of seed fertilizer or failure to fully mix with the soil, when placing yam plants, the plants contact with the seed fertilizer and burn out the buds or growth points, resulting in tuber branching, multiple heads and other deformities.

(3) apply unripe organic fertilizer in yam ditch. Yam has a long growth period and needs a continuous supply of fertilizer to ensure its normal growth and development. Therefore, organic fertilizers with long fertilizer efficiency are applied during planting, such as manure, compost, human manure, cake fertilizer, etc. these organic fertilizers should be fully fermented and decomposed before being applied to the field. However, some vegetable farmers fail to fully ferment and decompose the organic fertilizer in the summer or autumn of the previous year in order to save time and effort, Instead, in the spring of that year, animal manure or immature human manure and urine just transported from the farm were directly applied to the soil. After these immature organic fertilizers were applied to the field, they must undergo the decomposition process of fermentation and maturity, and the heat generated during fermentation is easy to damage yam roots and tubers. Farmers commonly call it "root burning", especially the tip of tubers, with soft tissues and cells, It is the growth point of the whole tuber. It is easy to be burned when encountering the immature fecal block, so that the juice of the basal meristem seeps out, forming branching or pockmarked appearance of the tuber. If the capillary root of yam is burned, it will affect the absorption of nutrients, and it is easy to produce snake shaped and gourd shaped deformities.

(4) underground pest hazards. During the planting of yam, there is no agent for controlling underground pests in the ditch. The underground pests do harm to the growth of yam tubers during the growth process, such as biting and cutting off the growth point, so that the yam tubers can not grow normally and cause yam deformity.

2. Preventive measures

(1) remove foreign matters in the ditch. The manual excavation of yam ditch shall be carried out before winter. The soil blocks shall be fully crushed after being eroded, frozen and weathered by rain and snow in winter and spring. The ditch shall be filled after thawing with weathering. When filling the ditch, stones, bricks, gravel and other hard objects in the soil shall be carefully removed, and large soil blocks shall not be filled into the ditch.

(2) the planting shall be carried out according to the technical regulations. When planting yam, do not apply seed fertilizer in the planting ditch. In order to prevent underground pests, do not blindly increase the dose of poisonous soil and bait. The method is to fry bean cake, wet it with 30 times of 90% trichlorfon crystal, or mix 30 kg of fine soil with 3-4.5 kg gram of Clematis per mu, evenly sprinkle it in the planting ditch, and draw it with a pout to make the bait fully mixed with the soil, which can effectively prevent mole cricket, grub Occurrence of underground pests such as needle worm and nematode. Then pour a small amount of water along the ditch, place the plants after water infiltration, and cover the soil to form a ridge.

(3) apply rotten organic fertilizer. Such as human excrement and urine, compost, stable manure and high-quality soil and miscellaneous manure, which are complete fertilizers rich in N, P, K and other nutrient elements. Retting should be carried out in advance by taking advantage of the favorable opportunity of high temperature and easy fermentation and ripening in summer and autumn to avoid root burning in the soil. On the other hand, it is advocated to apply organic fertilizer and some chemical fertilizer into the yam row after planting yams, spread the rotten organic fertilizer on the border between the two rows of yams, and then cut and turn the soil about 15cm to fully mix the soil and fertilizer, and then cover the fertile soil on the border on both sides of the yam ridge.

Causes and Prevention Countermeasures of rotten and dead seedlings of yam

1. Causes of rotten seeds and dead seedlings

⑴ seed block quality. The quality of seed block is the key to determine the full seedling, strong seedling and yield of yam. Planting with injured or not dried seeds is easy to cause slow emergence and weak seedlings, and in serious cases, it will cause rotten seeds and dead seedlings. According to the survey, using plants with fresh wounds for sowing, the rate of rotten seeds and dead seedlings is as high as more than 50%. Therefore, direct sowing of yam plants with fresh wounds or without sufficient drying is an important reason for the rotten and dead seedlings of yam mobile vertical rack.

(2) rainy and high temperature, little sunshine and low temperature. During the seedling emergence period of yam planting (April 15-may 15), the rainfall is too much, the soil humidity is too high, and the low temperature for a long time is also an important reason for the rotten seeds and dead seedlings of yam. The lower the temperature, the greater the rainfall, the more serious the rotten seeds and dead seedlings.

(3) sowing depth. According to the survey, about 65% of the fields with rotten seeds and dead seedlings are buried too deep. This shows that under the adverse climatic conditions such as rainy, high humidity, few light and low temperature, too deep sowing is another important reason for large area rotten seeds and dead seedlings.

(4) variety difference. The degree of rotten and dead seedlings of different yam varieties was significantly different. Among the main cultivated varieties, the rotten and dead seedlings of vegetable yam were significantly heavier than that of rice yam.

2. Prevention and control measures

(1) select high-quality plants to ensure their quality. The planting quantity shall be determined according to the planting area of yam in the next year. The wound shall be minimized when harvesting yam plants. When using plants or segments for 2-3 years, the wound shall be dipped in lime powder or carbendazim powder and fully dried. It shall be properly kept to prevent freezing injury.

(2) sun the mountain herb. Seed drying can not only accelerate wound healing and prevent bacterial invasion, but also promote the life activities of yam seed blocks, make adventitious buds sprout and grow strong buds. When drying, it shall be placed on the grass cover or on the ground in a single layer, and it shall be turned frequently to prevent rain. It is strictly prohibited to put the seed block directly on the cement yard to dry the seed. When the seed drying time reaches more than 25 days, the skin at one end of the seed block turns brown green, and the seed drying can be stopped when the water evaporates 30-40%.

(3) dig ditches and dry the fields early. The ditching and ridging of yam should be completed 10 days before sowing, which can improve the ground temperature, be conducive to germination and emergence and reduce rotten seeds and dead seedlings.

(4) sowing at appropriate time. When the ground temperature of 10cm is stable above 10 ℃ and there is no continuous rainy weather 7-10 days before planting, it is the best sowing date of yam.

(5) control the sowing depth. Practice has proved that the optimum sowing depth of yam is 8-10 cm. Sowing is too shallow. If the weather is dry and the soil moisture is insufficient, it is not conducive to germination. Sowing is too deep. At the same time, it is easy to rot and die seedlings in case of low temperature, little light or continuous cloudy and rainy weather.

Species degeneration

1. Causes. First, yam plants are used year after year, resulting in decline in vitality, quality, poor merchantability and reduced stress resistance. Second, the continuous cropping of yam plots caused a large accumulation of nematodes in the soil, aggravated the erythema disease on the upper stem of yam plots year by year, and the yield decreased year by year. Yam is a vegetative crop. In the cultivation process, yam plants are mainly used for production year after year. In some places, yam plants are planted in the same plot for many years, so it is very easy to have species degradation in the process of yam planting.

2. Preventive measures. In production, on the one hand, the yam plants are renewed, and the yam beans are re bred every 3-4 years or the yam segments are renewed, which can effectively prevent the seed degeneration of yam; On the other hand, the cultivation method of crop rotation can reduce the accumulation of nematodes in soil and reduce the speed of species degradation.