Detailed Explanation of Key Techniques for Greenhouse Potato Cultivation

The emergence of greenhouse vegetables lets everyone enjoy the vegetables and fruits they want to eat all year round, adding much convenience and ease to people's lives. Potato is a highly popular vegetable, and its annual market sales are fairly considerable, so combining potatoes with greenhouses is a natural progression.

Greenhouse Potato Cultivation Techniques

1. Site and Previous Crop Selection

Potato is a tuber plant; its tubers form and grow in the soil, so the soil is required to be loose and fertile with a deep soil layer, and sandy, neutral or slightly acidic (pH=5.8-7.0) plots with good drainage and aeration are needed, ideally with irrigation and drainage capability. Choose corn, wheat or millet as the previous crop. In particular, rotating potatoes with vegetables such as onions and garlic not only regulates soil nutrients and increases yield, but these vegetable crops can secrete a plant bactericide that kills late blight and other pathogens. Avoid rotating with root crops such as sugar beet, radish and carrot, as they likewise consume large amounts of potassium from the soil, leading to insufficient potassium fertilizer in the soil, and they also share common pests and diseases. Strictly avoid selecting plots where herbicides such as atrazine, pursuit and chlorsulfuron have been sprayed, otherwise serious yield reduction will result.

2. Land Preparation and Bed Making

Potato is a deep-plowing crop and requires a deep soil layer and loose soil. Deep plowing benefits root growth and development and tuber formation and expansion; it also loosens the soil, eliminates weeds, enhances aeration, promotes microbial activity, increases available nutrients in the soil, and improves drought resistance and drainage capacity. Therefore, land preparation advocates deep plowing and fine harrowing, requiring deep plowing of 20-25 cm, then fine harrowing and leveling to achieve a loose top and firm bottom with no clods, creating good soil conditions for potato growth, tuber setting and high yield. Organic fertilizer and farmyard manure are mixed into the soil before plowing; generally apply 30 tonnes/ha of decomposed livestock manure and mix it evenly with the soil to promote soil maturation and looseness. For chemical fertilizer, apply 300 kg/ha of potassium sulfate and 900 kg/ha of diammonium phosphate. To control underground pests, mix 40-50 kg/ha of 3% phoxim granules evenly with farmyard manure and plow it into the soil together. After land preparation, make beds 1.0-1.2 m wide, with furrows 30 cm wide and 20 cm deep. Open shallow ditches in the beds, 10-15 cm wide and 8-10 cm deep, for watering.

3. Seed Potato Cutting and Treatment

About 15 days before sowing, place the seed potatoes on the ground of a sunny room, greenhouse or plastic tunnel at 15-20 degrees C, spread in 2-3 layers, and turn them frequently so that every tuber is fully exposed to light. When the sprouts grow to 0.5-1 cm, cut the sprouted pieces and sow (first-grade original seed is sown as whole tubers). Cut large and medium tubers lengthwise from top to bottom into 4-5 pieces; generally cut pieces should be 40-50 g, containing at least 1 eye, and up to 2-3 eyes; seed potatoes smaller than 50 g are not cut, and whole-tuber sowing is advocated. Disinfect the cutting knife with potassium permanganate before reuse. After cutting the seed potatoes, dress them with plant ash mixed with fungicide to prevent the cut pieces from rotting.

4. Sowing and Density

(1) Sowing and Fertilizing

The suitable sowing period for potato is when the soil temperature at 10 cm remains 7-8 degrees C. For greenhouse potato sowing, depending on the greenhouse conditions, sowing can be chosen from early March to early April. Open ditches on the beds for dibbling; generally 2 rows on a 1.0-1.2 m bed, place the sprouts upward (pressed into the soil), with a sowing depth of 8-10 cm. After sowing, spray 2000-3000 ml/ha of 96% metolachlor, then cover with film. A small arch shed can be built over every 2 beds. This achieves 3 films: plastic mulch, ordinary small shed film, and greenhouse film. Before the potatoes emerge, watering is strictly prohibited to prevent seed rot. Greenhouse potato cultivation generally applies base fertilizer when making the beds.

(2) Reasonable Close Planting

Considering factors such as production purpose, variety type and natural conditions, and comprehensively referring to the field arrangement method, sowing density is an important part of increasing yield. Generally the row spacing is 60 cm (2 rows on a 1.2 m bed), and the plant spacing is 25-30 cm. Early-maturing varieties and soil with high fertility can be planted densely, keeping 60,000-70,000 plants/ha, while late-maturing varieties and soil with lower fertility should be planted sparsely, keeping 50,000-60,000 plants/ha.

The Growing Environment of Potatoes

1. Soil: sandy loam contains more sand and has good aeration, but its water- and fertilizer-holding capacity is relatively poor; it is a soil type that prefers acidity

1. Temperature: the most suitable temperature for plant growth is about 21 degrees, and the most suitable temperature for flowering is 15 degrees to 17 degrees; too high or too low a temperature is unfavorable to plant growth. Of course, due to differences in cold resistance among varieties, their responses to temperature also differ.

2. Water: it cannot be too dry or too wet.

4. Sunlight: potato is a light-loving crop, so place it in a spot indoors with sufficient light.

5. Fertilizer: among the three elements of nitrogen, phosphorus and potassium, potato needs the most potassium fertilizer, followed by nitrogen fertilizer, and needs relatively less phosphorus fertilizer.

Key Points for Selecting Potato Seed

1. Recognize the packaging clearly; some information on the packaging can help you identify it. Variety packaging and label completeness include: variety name, grade, variety characteristics, key cultivation techniques, place of origin, production unit, production date, and contact telephone number.

2. As with buying other items, after purchasing seed, ask the dealer for an invoice (noting the seed name, grade, quantity, price, etc.) that can prove the buying and selling relationship.

3. When selecting potato seed, buy varieties suited to the local environment and land; potato varieties should be those that have been successfully trial-planted locally and have good yield, disease resistance and appearance commodity traits.

4. Carefully identify them; potato has a high water content, so when selecting potato seed, carefully check whether they have sprouted; moldy, rotten or smelly ones cannot be used as seed potatoes.

5. When purchasing seed potatoes, choose potatoes with good color and uniform size, to prevent the illegal act of passing off commercial potatoes as seed potatoes.

When Did Potatoes Enter China

Due to the lack of early written records or confusion of crop names in written records, experts differ on when potatoes were introduced to China; some believe it was during the Wanli period of the Ming Dynasty (1573 to 1619), while others believe potatoes were first introduced to our country in the 18th century. According to Chinese scientists' textual research on the materials, the earliest introduction of potatoes to China was during the Wanli period of the Ming Dynasty (1573 to 1619). In Volume 2, "Huangdu Miscellaneous Records," of "Chang'an Kehua" written by Jiang Yikui during the Wanli period of the Ming Dynasty, the potatoes planted in the Beijing area are recorded as tudou.

Overall, the greenhouse cultivation technique for potatoes does not differ much from ordinary potato cultivation methods, but due to environmental differences, growers need to spend more effort. In addition, when growing greenhouse vegetables, it is best to pay attention to seed selection and choose higher-quality seed potatoes in order to grow better fruit.