How to deal with the Prevention and treatment of abnormal Chinese Yam

yam is a tuber plant of potato family. The tuber is rich in nutrition and delicious. In recent years, with the adjustment of agricultural structure, Yanzhou planting area increased year by year, bringing considerable economic benefits to farmers. However, in the process of yam cultivation, due to the influence of bad environmental conditions, cultivation measures and management methods, the internal organizational structure of yam in the growth process is changed and deformed, such as upper branch, lower branch, snake shape, flat head shape, foot shape, gourd shape, hemp face shape, etc., which seriously affects the commodity performance and internal quality of yam, causes yield reduction and benefit decline, and dampens the planting enthusiasm of vegetable farmers. Therefore, through extensive field investigation, field experiment, data collection and analysis, we have basically clarified the causes of Chinese yam malformation in Southwest Shandong Province, and put forward some control countermeasures.

1. forming reason

(1) Effects of foreign matter in soil. When yam ditch is backfilled, hard objects such as stones, bricks, gravel and daub blocks mixed in soil are not carefully removed or fully crushed, resulting in yam tuber encountering hard objects in the growth process, the growth point is blocked and the growth direction is changed to form branches, flat heads and other malformations.

(2) Blind application of seed fertilizer. In order to make the seedlings strong and grow rapidly after emergence, vegetable farmers apply various kinds of seed fertilizers before placing yam seeds after ditching, so that due to excessive application of seed fertilizers or insufficient mixing with soil, the seeds contact with seed fertilizers when placing yam seeds, the buds and growth points are burned, and tubers are divided and multi-headed.

(3) Application of undecomposed organic fertilizer. Yam has a long growth period and needs continuous supply of fertilizer to ensure its normal growth and development. Therefore, it is necessary to reapply organic fertilizers with longer fertilizer efficiency when planting, such as: Housing manure, compost, human manure, cake manure, etc., these organic fertilizers should be fully fermented and decomposed before being applied to the field, but some vegetable farmers directly apply manure or undecomposed human manure transported from the farm to the soil in order to save time and effort. After these undecomposed organic fertilizers are applied to the field, they also have to undergo fermentation and decomposition process. The heat generated during fermentation is easy to damage the roots, tubers and seeds of Chinese yam, which is commonly known as "watering the roots". Especially the tender tissue cells at the tip of the tuber are the growth point of the whole tuber. When encountering undecomposed organic fertilizer, it is easy to be burned out, affecting the absorption of nutrients, resulting in snake and gourd-like deformity.

(4) Underground pest damage. Yams are planted without pesticides in the yam ditches to control underground pests. Insects such as insects, grubs, mole crickets and root knot nematodes can cause harm to yam tubers during the whole growth period, such as biting, cutting off growth points, yam tubers can not grow normally, resulting in yam deformity.

2. control countermeasures

(1) Carefully remove foreign bodies from the ditch. Artificial digging of yam ditch should be carried out before winter, so that through winter rain and snow erosion, freezing weathering to thoroughly crush the soil. When filling ditches, carefully remove hard objects such as stones, bricks and gravel from the soil, and do not fill large pieces of soil into ditches.

(2) Apply decomposed organic fertilizer. Manure, compost, manure and soil manure are all complete fertilizers rich in nitrogen, phosphorus, potassium and various trace elements. To take advantage of the summer and autumn season high temperature, easy fermentation decomposition of the favorable opportunity to retting ahead of time, avoid direct application of raw fertilizer into the soil and cause "burning roots" phenomenon. It is advocated to spread decomposed organic fertilizer and part of chemical fertilizer on the ridge surface between two rows of yam after planting yam, and draw a layer to mix soil and fertilizer evenly on both sides of the ridge.

(3) Strictly operate in accordance with planting technical regulations. Do not apply seed fertilizer before placing yam seeds in the planting ditch. Underground pests can be controlled by 90% trichlorfon crystal 30 times solution mixed with fried bean cake grits, or every 667 square meters mixed with 4kg root thread and 3~4.5kg root thread dan mixed with 30kg fine soil evenly scattered in the sowing ditch, once with the head, so that pesticides and soil are fully mixed, then small water is poured once along the ditch, after water infiltration, seeds are placed to cover the soil to form ridges, which can effectively reduce the harm of mole cricket, white grubs, insects, nematodes and other underground pests. Do not blindly use drugs or arbitrarily increase the dose. Crop rotation was adopted to reduce the accumulation of nematodes in soil. Yam is a vegetative crop, mainly used in the cultivation process of yam seeds for year-after-year production. Yam seed use year after year easy to cause vitality decline, stress resistance reduction and species degeneration and deformity. In production, the seedlings of yam should be renewed and rejuvenated in time, with 3~4 years as a cycle, and the seedlings should be re-bred with yam beans or renewed once with yam segments.