High-yield greenhouse cultivation techniques for jicama: getting these points right is key

Jicama is what we commonly call liangshu (Mexican yam bean). Its tuberous root is large, with white, crisp, tender and juicy flesh, rich in sugars and protein, and can be eaten raw or cooked. With the development of agricultural science and technology, in recent years the yield of greenhouse-grown jicama has been increasing year by year. So, what are the greenhouse cultivation techniques for jicama? To achieve high yield, getting these points right is very important!

1. Sowing time

For early-maturing greenhouse cultivation of jicama, the sowing period is chosen from late February to late March. Generally, the average temperature is required to reach above 12°C, and sowing is done on sunny days. The seeds should be excellent varieties suited to local conditions.

2. Site selection and land preparation

It is best to choose sandy loam soil with higher terrain, good drainage and loose, fertile texture for cultivation. One month before planting, apply sufficient organic fertilizer: 1500-2000 kg of chicken manure or 250-300 kg of rapeseed cake per mu, plus 50 kg of compound fertilizer. Use a rotary tiller or plow to turn the soil twice, so that the base fertilizer decomposes relatively quickly and the soil becomes fine and crumbly with fertilizer evenly mixed in. At the same time, erect a 6 m wide bamboo shed. After more than 20 days, begin making beds, that is, make 7 beds in a 6 m wide single-span bamboo shed, at 80 cm per bed; the bed surface is trapezoidal, 40 cm wide at the top and 60 cm wide at the bottom, with a bed ditch 20 cm wide and about 15 cm deep. After rain or after watering, when the soil has reached a moist state, cover with film and close the shed to raise the ground temperature.

3. Sowing method

Direct sowing is used, with 2 rows per bed, a plant spacing of 15-16 cm, and 8000-9000 plants per mu. To bring the crop to market earlier, pregermination can be carried out. Soak the seeds in warm water for 5-6 h, then pregerminate at 25-28°C, rinsing once a day with warm water to avoid seed rot; once more than 50% of the seeds have sprouted white, they can be direct-sown. To improve sowing efficiency while controlling spacing, vegetable growers generally use a hole punch to make holes for sowing, placing one sprouted seed per hole, then covering with a thin layer of soil.

4. Seedling stage management

The main task is to control field soil moisture well: too dry makes the plants susceptible to cold, too wet easily causes seed rot. When too dry, water with a watering can; when too wet, open the film at both ends of the shed around noon to strengthen ventilation and remove moisture, keeping the temperature inside the shed at 30-35°C. At the same time, inspect seedlings and fill gaps to ensure a full stand in one go. When the seedlings are 10 cm tall, apply a light seedling fertilizer, generally together with intertillage and weeding during the seedling stage, opening small furrows beside the jicama plants and applying 15-20 kg per mu of potassium sulfate-based ternary compound fertilizer, then covering with soil, combined with hilling to protect the base, promote roots and encourage early vigorous growth. Throughout the whole growth process, jicama has strong resistance and requires no insect or disease control.

5. Pruning and vine training

When jicama begins to run vines, stakes should be set up, about 1.2 m high, using small mountain bamboo as stake material. When the vines grow to 15-20 cm, insert one small mountain bamboo stick per plant, form a chevron trellis, then use small nylon string to connect the chevron trellises into straight lines, so that strong winds later will not blow them down. At the same time, manually twist the vines clockwise around the small mountain bamboo to let them climb onto the trellis.

6. Field management

Before staking, jicama should be intertilled and weeded. After staking, around early June, a heavy application of tuber-swelling fertilizer can be made, applying 25-30 kg per mu of potassium sulfate-based ternary compound fertilizer between the jicama plants after rain or during irrigation, along with one hilling.

During the growth of jicama, 4-5 rounds of axillary bud removal are needed, and flower buds must also be removed, which helps reduce nutrient consumption. When the vines grow to 1.1-1.2 m high, the main vine should be topped to control aboveground growth, so that nutrients are concentrated in supplying the underground tuberous root growth, achieving early maturity and high yield.

7. Water and fertilizer management

The watering schedule for liangshu is much the same as for other ordinary vegetables. Generally, before emergence, a small amount of water can be given once every three days to maintain 60% moisture. After emergence, apply a light fertilizer solution once to promote growth, and thereafter apply fertilizer solution once a week until before flowering. Do not water during the flowering period; compound phosphorus and potassium fertilizer plus trace element fertilizer should be applied to assist the shift to reproductive growth. During the swelling period, a large amount of water is needed to maintain root water content and transport nutrients produced by the leaves; water can be given once every 5 days, but only when the soil has become dry, generally keeping the soil below the top 2 cm moist. A dry surface makes disease less likely. Increase compound fertilizer application to balance leaf and root growth.

8. Timely harvesting

For greenhouse-cultivated jicama, early-maturing varieties generally aim to seize the market, so 4-5 months after planting they can be harvested successively, coming to market earlier than open-field cultivation and achieving high returns. According to market conditions, harvesting is generally carried out when individual jicama roots reach 350-400 g.

Finally, the editor reminds everyone that jicama likes high temperatures, and when the seeds germinate they need a higher temperature than that required for the germination of ordinary legume crops. The plants need sufficient light during vigorous photosynthesis and accumulation of assimilated nutrients, especially during the formation of the fleshy roots; only with sufficient light can there be a high yield.