Detailed Explanation of Edamame Cultivation Techniques: From Sowing to Harvest
Early-maturing edamame, also called “spring green” edamame, is an edible-type edamame. It belongs to a new variety of edamame; it is of the indeterminate pod-setting type. Its main characteristics are early maturity, high yield and good quality. The full growth period for spring sowing is 80 days, making it a rather early-maturing variety, maturing 15 days earlier than the Taiwan, China variety “75-1”, with a yield 12.6% higher and outstanding quality. The beans are very sweet, pleasant to eat, and soften as soon as they are cooked, with excellent flavor. As an early-spring vegetable that seizes the market, it is an ideal cash crop for interplanting in large and medium tunnels, small hoop tunnels, and 1-2 year old new orchards, as well as for planting in combination with other multi-cropping crops. The main cultivation techniques are as follows:
Sowing period
The sowing period of edamame varies with the cultivation purpose and variety. In the Yangtze River basin, it can be divided into early edamame and mid-late edamame, and early edamame is further divided into early-maturing cultivation and ordinary cultivation.
(1) Early-maturing cultivation. From late February to early March, cold-frame seedling raising is generally used, with planting out in late March and harvest of tender pods in June-July; Siyuebai and Wuyuebai are used, while for direct sowing in early to mid-April, Wuyuebai or Wuyuewu is used.
(2) Mid-late maturing cultivation. For summer planting, mid-maturing varieties are direct sown from late April to mid-May and harvested in July-August, using Liuyuebai or Liuyuehuang. For autumn late-maturing cultivation, direct sowing is done in June-July and harvest in September to late October; in South China, autumn sowing can also be postponed to July-August, with harvest in September-November. Examples are Bayuebai and Hangzhou spiced edamame.
In southern regions, according to the characteristics of different varieties, selecting early and mid-late maturing varieties in combination can achieve production in all three seasons of spring, summer and autumn, thereby extending the supply period. Timely sowing: to supply the market with edamame in a balanced way, sowing must be carried out in stages and batches, and harvesting in batches, to improve economic returns. As for how many batches and how long the sowing interval should be, this should be flexibly controlled and scientifically arranged according to the planting area, product market volume, market sales trends, and production and marketing capacity.
Variety selection
Edamame varieties are mainly classified by growth period: long-growth-period edamame can reach more than 100 days, while short-growth-period edamame lasts only 50-60 days. Therefore, varieties should be selected according to the cultivation season. As far as possible, choose short-growth-period varieties with plump seeds, strong cold resistance, wide adaptability, the ability to be cultivated earlier or later, waxy quality that cooks soft easily, and relatively high yield.
Cultivation points
1. Sow at the right time: for spring sowing, from late March to early April (protected cultivation may be appropriately earlier), harvest in June-July; for summer sowing, sow from late April to June, harvest in July-September; for autumn sowing, sow in July-August, harvest in September-October.
2. Reasonable close planting: reasonable close planting plays an important role in increasing the number of pods, promoting plump beans and raising yield. Density is mainly related to the branching habit and spread of the plant. Early-maturing varieties have few branches and a compact plant type, with a general density of 40000-50000 plants/mu and row spacing of 20cm × 20cm; mid-maturing varieties are suitable at 18000-20000 plants per mu, with row spacing of 30cm × 30cm; late-maturing varieties are suitable at 15000-17000 plants per mu, with row spacing of 40cm × 35cm.
3. Increase phosphorus and potassium fertilizer: edamame needs large amounts of phosphorus and potassium fertilizer, so applying phosphorus and potassium fertilizer has a significant yield-increasing effect on edamame. Phosphorus and potassium fertilizer is generally mainly applied as base fertilizer, with topdressing as a supplement. Per mu, apply 1000-1500 kg of decomposed compost, about 25 kg of superphosphate, and 100-150 kg of plant ash as base fertilizer. During the growth period, topdressing can be applied in a timely manner according to growth conditions. At the seedling stage, when rhizobia have not yet formed, apply 10% human excrement and urine once. If growth is poor before flowering, apply 10%-20% human excrement and urine once more, 50-75 kg of plant ash, and 5-10 kg of superphosphate to promote plump pods. In the later stage, a 1%-2% superphosphate extract can also be used for foliar topdressing. Insufficient potassium fertilizer makes yellow-leaf disease likely to occur, and plant ash or potassium sulfate can be applied for control. During control, cover the seed with plant ash, or scatter plant ash on the edamame plants before the dew dries; generally scatter it 4 times in a row, and after about 7-8 days the leaves gradually turn green. Scatter 50 kg of ash per mu each time; this method is especially effective.
4. Pinching and topping: pinching can inhibit growth, prevent excessive vegetative growth, promote early maturity and increase yield. Experiments have shown that pinching can increase yield by 5%-10% and advance maturity by 3-6 days. For determinate-growth-type varieties, pinching is generally done at the early flowering stage, while for indeterminate-growth-type varieties, it should be done after the full flowering stage.
5. Pest and disease control: edamame pests include pod borer and soybean fruit borer, etc. For pod borer, irrigating once or twice during the flowering and pod-setting period of edamame can kill the larvae that enter the soil to pupate. Before the larvae roll leaves and enter the pods, 40% dimethoate emulsion at 1000 times dilution or 50% malathion emulsion can be sprayed for control. The main disease of edamame is rust. For rust control, first select disease-free seeds or disinfect the seeds, commonly soaking seeds in 200 times formalin solution for 30 minutes, then washing clean, drying and sowing. Second, practice crop rotation and avoid continuous cropping. Finally, spray medicine at the early stage of disease onset for prevention: spray twice at the seedling stage and 1-2 times at the pod-setting stage, with each interval of 5-7 days. The agents can be 65% zineb wettable powder at 500 times dilution or 75% chlorothalonil wettable powder at 600 times dilution for spraying.
6. Harvest: early-maturing varieties generally aim to seize the early market, that is, after entering the seed-filling stage, they can be harvested successively and can sell for a good price. However, it should not be too early, otherwise the beans will be shrunken and small, with poor marketability and low yield, which instead affects economic returns. Mid-late maturing varieties are generally harvested when the beans are already plump and the pods are still green, but it should not be too late either, otherwise the beans become hard and quality is reduced. At harvest, the whole plant can be harvested all at once, or harvested in 2-3 rounds. After harvest, they should be placed in a cool place to keep them fresh