Analysis of Common Problems in Potato Cultivation and Solutions
Yutian County has a perennial potato planting area of 70,000 mu, with yields generally around 2,500-3,500 kg per mu. Most potato growers have some experience and good methods in cultivation management, but overall, there are still many problems in potato cultivation management, which are summarized as follows.
1. Variety degeneration phenomenon
After continuous planting for several years, potatoes often show stunted plants, clustering, weak growth, wrinkled, smaller, and brittle leaves, or ring spots and streak spots, leaf veins turning dark brown, leaves easily falling off, and in severe cases the entire plant dies. The main cause of variety degeneration is the invasion of various infectious bacteria and viruses. The only way to solve degeneration is through agricultural science and technology personnel using test-tube virus elimination to obtain virus-free seedlings, then producing mini seed potatoes, and then successively propagating them into foundation seed potatoes, first-generation seed potatoes, and second-generation seed potatoes. Only seed potatoes produced through this method are healthy seed potatoes.
2. Tuber deformity phenomenon
When harvesting potatoes, oddly shaped tubers different from normal ones are often seen. Some have a small protrusion growing on the top or side of the tuber, some look like dumbbells, and some have two, three, or multiple protrusions growing on the original tuber like tumors, among many other forms. Such tubers are called deformed tubers. This situation occurs because after tuber formation, the tubers grow normally for a period, then encounter high temperature or drought, causing the tubers to temporarily stop growing or grow very slowly, resulting in skin aging. Later, when the environment changes or the temperature becomes suitable, or water is supplied again after drought, the tubers cannot continue to expand uniformly, causing deformed tubers. To avoid this phenomenon, production conditions should be kept stable, water and fertilizer should be supplied normally, and tubers with severe secondary growth should be avoided as seed potatoes as much as possible, which can prevent the production of deformed tubers.
3. Improper variety selection
Multiple factors should be considered when selecting potato varieties for planting. First, choose varieties adapted to local climatic conditions. Taking this county as an example, potato sowing in Yutian County is generally in mid-March. Emergence time is around mid-April. By July, the monthly average temperature is 26°C. Based on the temperature requirements for potato growth and the climate conditions of this county, varieties with a growth period exceeding 95 days are not suitable for planting. Second, choose varieties that can capture the local market at that time. For example, the early-maturing variety "Zaodabai" has concentrated tuber formation and large, uniform tubers. It can not only be marketed early and sell for a good price, but also looks beautiful with white skin and white flesh. Third, choose varieties with good quality, high nutritional value, and good eating taste, such as "Favorita," which matures early, has shallow eyes, and smooth skin. Fourth, variety selection should also be based on factors such as maturity period and crop rotation arrangements to achieve consideration of both preceding and following crops and abundant harvests throughout the year.
4. Poor crop rotation and stubble shifting
Potato is a crop that avoids continuous cropping. In plots with continuous cropping and no stubble shifting, not only does yield decrease year by year, but more importantly, pests and diseases occur severely. Rotation with @#@245@#@, corn, millet, and other crops is better. It is best not to rotate with Solanaceae crops such as eggplant, tomato, and pepper, because they share cross-infection with similar infectious diseases. If crop rotation truly cannot be done due to land and other reasons, be sure to pay attention to the following two points: First, fertilize according to the fertilizer requirements of potatoes. Second, pay special attention to the occurrence of various infectious diseases. Measures: First, use virus-free seed potatoes. Second, conduct good field disease monitoring to detect disease as early as possible, and it is best to apply medication before disease onset.
5. Seed potato pieces too small
Small seed potato pieces are common in potato planting. Some people, to save money, specifically buy small seed potatoes, believing that cutting one piece per eye and planting large or small seed potatoes will produce the same potatoes. Some, when the seed potatoes are not large to begin with, cut only the flesh around the eyes together with the eyes into very small seed pieces, and keep the rest for eating. In fact, these practices all cause uneven emergence, thin and weak seedlings, and reduced yield. According to foreign data, seed pieces weighing 14 grams yield 1,440 kg per mu, while seed pieces weighing 56 grams yield 2,144.7 kg per mu, with large seed pieces increasing yield by 48.9% compared with small seed pieces. Domestic experiments using 30-gram seed pieces for sowing increased yield by more than 32.6% compared with 10-gram seed pieces. The issue is very simple; in one sentence, it is the principle that "a big mother makes fat children."
6. Excessive density and insufficient nutritional area
To increase yield, some adopt dense planting methods, believing more is better, with some densities reaching 6,000-7,000 plants per mu. With little fertilizer, stems become thin and weak, nutrition is insufficient, and high yield cannot be achieved. If the amount of fertilizer is large, the population is too large and shades each other, causing excessive stem and leaf growth, lodging, and even rotting of branches and leaves, reducing yield. No matter what variety is planted, reasonable dense planting must be based on the variety.
7. Too shallow sowing
In daily potato production, too shallow planting is common. Planting too shallow can cause tubers to be exposed, green heads, and underground stolons to be exposed and unable to form tubers. With too shallow sowing, the root system also grows shallowly, reducing its ability to absorb fertilizer and water, and the plant is not strong, affecting yield. A relatively reasonable sowing depth is about 10 cm, and after intertillage and hilling, the total burial depth reaches 15-20 cm.
8. Unreasonable fertilization
Nitrogen fertilizer plays a very important role in potato growth. After application, leaves become dark green, and the effect is very obvious, so it is deeply favored by farmers. However, potatoes require the most potassium throughout their life, followed by nitrogen, and the least phosphorus. The ratio of nitrogen, phosphorus, and potassium is 2.5:1:5. On this basis, when determining the amount of fertilizer to apply, the utilization ratio of various fertilizers in the current year should also be considered, because the current-year utilization rates differ: nitrogen fertilizer 60%, phosphorus fertilizer 20%, and potassium fertilizer 50%. In summary, when fertilizing, the ratio must be reasonable, and be sure to avoid excessive nitrogen fertilizer causing excessive stem and leaf growth and reduced yield.