Analysis of Common Problems in Potato Cultivation Techniques
????1 Improper Variety Selection
When planting potatoes, if the variety is not suitable, the potatoes produced will be difficult to sell, or even if they can be sold, the price will not be very high. Some growers do not select varieties according to local climatic conditions, and as a result, the product cannot fetch a good price and the next crop is also delayed. A few growers lack sufficient understanding of virus-free seed potatoes, find it hard to accept the relatively high price of seed potatoes, and are accustomed to exchanging seed potatoes once and then using them continuously for many years.
????2 Poor Crop Rotation and Stubble Change
Potato is a crop that should not be continuously cropped. In plots where rotation is not carried out and continuous cropping is practiced, the yield will decrease in the second year, and tuber quality will also decline, especially with more serious occurrence of pests and diseases. In potato plots continuously cropped for 8 years, the incidence of scab can reach more than 90%, and the occurrence of fungal and bacterial diseases such as bacterial wilt and blackleg is higher than in plots with stubble change. In addition, because continuous cropping of potatoes leads to single-nutrient absorption, the potassium fertilizer content in the soil can decline quickly, affecting soil fertility and the yield of the next crop. The best preceding crops for rotation are millet, wheat crops, corn and other crops. It is best not to use Solanaceae crops as preceding crops, such as tomato, eggplant, pepper, etc. If rotation cannot be arranged and continuous cropping must be practiced, it should not exceed two years at most.
????3 Misunderstandings in Cutting Seed Potatoes
3.1 The belief that the bigger the cut piece the better and the smaller the better are both wrong. Too large wastes seed potatoes, while too small is prone to rotting after sowing and produces weak seedlings. The correct cutting method is that seed pieces of 20-30 g are suitable, and each cut piece should carry 1-2 bud eyes. If the seed potatoes are small, whole-tuber sowing can be used.
3.2 The erroneous practice of gouging out dense apical buds should not be done. When cutting potatoes, the apical bud advantage should be fully utilized, and the apical buds should be allowed to produce as many seed pieces as possible.
3.3 Failure to disinfect the cutting knife can easily lead to the spread and expansion of tuber diseases, so attention must be paid to disinfecting the cutting knife.
????4 Misunderstandings in Pre-sprouting Seed Potatoes
4.1 Not pre-sprouting before sowing is a relatively common wrong practice in production. Some believe the pre-sprouting process is complicated, while direct sowing is simple to operate and will not affect planting benefits. Adopting pre-sprouting before sowing can ensure uniform seedling emergence, and with good seedlings there will naturally be yield.
4.2 The belief that pre-sprouting does not need light is also a common mistaken understanding in the pre-sprouting process. Long-term pre-sprouting in darkness causes the sprouts to be slender, fragile and tender, easily damaged during sowing, and prone to secondary sprouting, resulting in several plants emerging from one tuber. In low temperatures, it can also produce smothered tubers, affecting yield.
????5 Misunderstandings in Fertilization
5.1 The amount of fertilizer applied is too small. Potato is a crop with high input and high output. Only by supplying enough nutrients can high-yield returns be obtained.
5.2 Excessive application of nitrogen fertilizer. Applying too much nitrogen fertilizer will delay tuber setting of underground stems and tuber maturation, reduce starch content, and make the potatoes less storage-tolerant.
5.3 Application of potassium chloride. Potato is a chlorine-sensitive crop. Applying potassium chloride will affect potato quality, so potassium sulfate is best.
????6 Unreasonable Planting Density and Depth
6.1 Blind dense planting and sparse planting are both unreasonable. Planting density should be adjusted appropriately according to variety characteristics. Generally speaking, early-maturing varieties should be planted densely, with a plant spacing of about 20 cm, while late-maturing varieties should be planted sparsely, with a plant spacing of about 30 cm.
6.2 If sowing is too shallow, the concentration of underground stems is insufficient, which is unfavorable to the formation of stolons and the formation and expansion of tubers. It is also prone to the phenomenon of stolons "shooting arrows", and tubers are easily exposed above the ground to form green-headed potatoes. The suitable sowing concentration should be trenching to about 13 cm, with 2-3 cm of fallen soil settling back into the furrow, sowing seed pieces at a place 10 cm from the ground, then covering with soil and pressing. For clay soil, it can be slightly shallower.
????7 Water Management
Potato is a crop that requires relatively more water but also has relatively strong drought resistance. Potato's need for water is continuous. Soil moisture should be maintained throughout each growth period of the potato to ensure normal growth and development and yield formation. If water supply is unbalanced during tuber formation and expansion, tubers will stop growing and form deformed potatoes. In addition, irrigation after severe drying and drought can also cause tuber cracking. If there is too much rain in the later growth stage of potato, tubers will rot and be less storage-tolerant.
????8 Intertillage and Earthing Up Are Both Too Late and Too Shallow
Intertillage and earthing up should be completed before potatoes bud and flower. If earthing up is done afterward, it will affect the normal growth of the plants, easily damage the stolons, and also cause the "arrow shooting" phenomenon, seriously affecting yield. If the earthing up is too shallow, during the tuber expansion period the temperature is likely to rise, water dissipates quickly, and tubers become exposed above the ground and form green heads, affecting quality. Whether intertillage is done once or twice, the final earthing up must reach 15-18 cm, that is, measured from the upper part of the seed piece to the ridge crest.
????9 Misunderstandings in Pest and Disease Control
In pest and disease control, growers may treat only without preventing, or emphasize treatment over prevention. Once fungal and bacterial diseases of potato occur, they can only be controlled and are difficult to cure. Once they occur over a large area, it is also difficult to control them with chemicals. Therefore, the correct approach of giving priority to prevention should be established.
Author: Liang Shuhua