High-quality, high-yield and high-efficiency cultivation techniques for potatoes in dry hilly and mountainous areas
About 85% of the potato planting area in our province is mainly distributed in hilly and mountainous areas, where the climate is cool, the frost-free period is short, sunlight is abundant, the temperature difference between day and night is large, and the annual rainfall is only about 400 mm, mostly concentrated in July and August. Every spring is dry, windy, and has high evaporation, creating ecological conditions of drought in nine out of ten years. The unfavorable factor of drought and water shortage seriously hinders the development of agricultural production. The five supporting techniques centered on drought resistance - "selecting improved virus-free seed potatoes, planting small whole tubers, sprouting and sunning seed potatoes, and one late and four deep" - are a new path to achieving high quality, high yield and high efficiency of virus-free potatoes in dry hilly and mountainous areas.
(1) Selecting improved varieties
Select virus-free seed potatoes of the varieties Jinshu No. 7, Jinshu No. 2, Jinshu No. 1, Zihuabai and Xishu No. 1, which are resistant to degeneration and late blight and have high and stable yields.
(2) Virus-free seed potatoes
They overcome the problems of short, thin and weak plants, shrunken or barrel-rolled leaves, small tubers and markedly reduced yields, achieving the goals of good quality and health, and high and stable yields. They generally increase yield by 50-80%, and some even double it.
(3) Planting whole tubers
On the basis of virus-free seed potatoes, strictly select tubers the size of walnuts, 2-4 cm in diameter, with fresh color and smooth, tender skin, to use as seed.
(4) Sprouting and sunning seed potatoes
Sprouting and sunning small whole tubers cultivates short, sturdy internodes and increases the number of tuber-setting layers, which has a clear yield-increasing effect on promoting more tubers and larger tubers.
About 20 days before potato planting, take the virus-free seed potatoes out of the storage cellar and place them at room temperature to sprout. Generally, the indoor temperature is required to be 15-20°C, with good ventilation and light, and the tubers are piled 2 to 3 layers thick. After about 10 days of sprouting and sunning, short sturdy sprouts 0.3-0.5 cm long can be produced. Handle them gently, turning them over once from top to bottom, then sun them for another 7-10 days before planting. Sprouting and sunning greatly improve seed potato quality and provide a reliable guarantee for full stands, strong seedlings and vigorous growth.
(5) One late and four deep
"One late" means suitable late sowing. The normal sowing period of potatoes is delayed by about 10-15 days. In this way, the peak tuber-bulking period of potatoes can avoid the adverse effects of high summer temperatures. Production practice has proved that proper late sowing can make the flowering period and the peak underground tuber-bulking period of potatoes coincide with the local rainy season in July and August, achieving the maximum effect of factors such as water, fertilizer, light, temperature and air, and attaining the goals of robust plant development and large, uniform, high-quality, high-yield and high-benefit tubers. Generally, sowing in mid-May in the Yantong Basin is relatively suitable, while the sowing period in the eastern and western mountains and hilly mountainous areas of our province can be appropriately advanced.
"Four deep" fine cultivation and management:
(1) Deep plowing. Deep plowing in autumn increases the active soil layer and stores water and fertilizer. Generally, deep plowing of about 30 cm can not only take in autumn and winter rain, resist drought and preserve seedlings in spring sowing, and use autumn rain in spring, but also, because deep plowing creates a condition of loose on top and firm below with sufficient fertilizer and water, creates good environmental conditions for potato root growth and tuber bulking.
(2) Deep planting. Adopting appropriately deep planting can not only increase the tuber-setting layers of the plant, producing more tubers and larger tubers, but also promote the plant roots to develop deeper, absorb more water and fertilizer, improve the utilization rate of soil water and fertilizer by potatoes, and at the same time enhance drought resistance.
(3) Deep application of ammonium bicarbonate. The amount of fertilizer should be applied according to the planned yield: for every 100 kg of tubers produced, 0.6 kg of nitrogen, 0.2 kg of phosphorus and 1.5 kg of potassium need to be absorbed from the soil to calculate the fertilizer application rate. Generally, apply 100 loads of farm manure and 50 kg of superphosphate, composted with the farm manure, and 50 kg of ammonium bicarbonate. Production practice has proved that deep application of ammonium bicarbonate at the plow sole combined with potato sowing can give a more obvious yield-increasing effect, generally increasing yield by 30-50%.
(4) Deep intertillage. Since potatoes are tuber crops that grow and bulk up in the soil tillage layer, they not only need loose soil, which is favorable for tuber bulking, but also require soil that stores water and fertilizer and has good air permeability. Only in an environment with good water, fertilizer and air can the tuber-bulking characteristic be fully brought into play. At the same time, deep intertillage and high hilling can also promote good root development and promote the decomposition of organic matter by soil microorganisms.