How to Grow Jicama for High Yield: Latest Cultivation Techniques and Methods Tutorial
Jicama, also known as yam bean, Mexican turnip, and Mexican potato, is an annual or perennial twining herbaceous vine in the genus Pachyrhizus of the legume family Fabaceae that forms tuberous roots. It originated in tropical America and is now widely distributed in the tropical regions of the Eastern Hemisphere. It is commonly cultivated in the provinces of southwestern China, where its underground tuberous roots are harvested for raw or cooked consumption. Its cultivation economic value is slightly low, but its nutritional value is considerable. Let us take a look at the high-yield cultivation techniques for jicama!
Growth Habits of Jicama
Jicama is a warm- and light-loving vegetable. During its growing period it requires relatively high temperature conditions. The germination stage requires a temperature of 30°C, and the suitable temperature for the aboveground parts and the flowering and pod-setting stage is 25-30°C. The growth and development of the tuberous roots have broad adaptability to temperature and can expand and grow under relatively low temperature conditions. However, when the temperature is below 15°C, growth and development are inhibited. It has relatively strict soil requirements; suitable soil conditions are necessary to obtain high yield and good quality. It requires deep, loose, well-drained loam or sandy loam, and is not suitable for planting in clayey soil with poor permeability.
Site Selection and Land Preparation for Jicama
The edible part of jicama is the underground tuberous root, so it is advisable to choose sandy loam with deep soil layers, good drainage, medium fertility, and strong water- and fertilizer-retention capacity. After the previous crop is harvested, carry out land preparation. The shape of the jicama tuberous root is related to variety, soil, and cultivation. If flat-round varieties are cultivated too deep, the fleshy roots will grow downward, forming long roots with increased fiber, resulting in reduced quality. Generally, plowing to 17-20 cm is appropriate, while for sandy loam only 13-17 cm is needed; spindle-shaped varieties can be planted slightly deeper. Apply 500 kg of plant ash and 2000-3000 kg of decomposed farmyard manure per mu. Fifteen days before sowing, break up the clods and rake them level, and make high beds 1.2-1.3 m wide with furrow depth of about 25 cm to facilitate drainage.
Cultivated Varieties of Jicama
1. Early-maturing varieties: The plants have moderate growth vigor, relatively small leaves, tuberous roots that expand earlier, and a relatively short growing period. The tuberous roots are flat-round or spindle-shaped, with thin skin and little fiber, and a single root weighs 0.4-1 kg. They are eaten fresh or stir-fried. Varieties include Guizhou Huangping jicama, Sichuan Suining jicama, Chengdu Mumashan jicama, Taiwan Malay variety, and Guangdong Shunde yam bean.
2. Late-maturing varieties: The plants have strong growth vigor, a long growing period, and tuberous roots that mature relatively late. The tuberous roots are flat spindle-shaped or conical, with relatively thick skin, much fiber, high starch content, and less water. A single root weighs 1-1.5 kg, and larger ones can reach more than 5 kg. They are suitable for processing into starch. Commonly used varieties include Guangdong Zhanjiang large yam bean, Guangzhou suburb late yam bean, and Taiwan conical variety.
Sowing Methods for Jicama
1. Sprouting: Jicama seeds are hard. When dry seeds are sown, germination is slow and uneven, so sprouting before sowing is mostly used in production. Before sprouting, the seeds should be carefully selected, choosing old, plump, and fresh ones as seed. First soak the seeds for 10-12 hours; after they absorb water and swell, place them in a 25-28°C incubator to sprout. Take them out and rinse them once a day. After 4-5 days, select the seeds that have already sprouted and sow them, finishing in 2-3 batches.
2. Sowing: Jicama is generally direct-sown. The sowing methods can be divided into ground-creeping cultivation and trellis cultivation. In ground-creeping cultivation, the row spacing is generally 50 cm, plant spacing 33 cm, with 1-2 seeds sown per hole. About 3000 plants can be grown per mu, and the seed quantity used is about 2 kg. Trellis cultivation uses deep furrows and high beds, with bed height 20-25 cm, furrow width 50 cm, and bed surface 90 cm. Two rows are planted per bed, with row spacing 50 cm and plant spacing 33 cm. Place 3-4 seeds per hole, and use 2.5-3.0 kg of seed per mu. After sowing, cover with 2-3 cm of soil, and seedlings will emerge 15 days after sowing.
Field Management of Jicama
1. Thinning and replanting: Jicama seedlings emerge 15 days after sowing. After the first pair of basal leaves appears, carry out thinning and replanting, leaving 1-2 seedlings per hole, and finally leaving 1 plant as the final stand. Replanting should be done promptly, and seedlings should be transplanted with a soil ball on cloudy days.
2. Intertillage and weeding: For jicama, promptly carry out intertillage and weeding from when the seedlings are 7 cm tall until the side vines spread over the ground. Intertillage should be shallow, and it is essential not to damage the roots. During intertillage, earth can be hilled up 4-7 cm to prevent the fleshy roots from being exposed outside the soil, turning green in color, and deteriorating in quality. However, do not hill up too deeply, as the tuberous roots easily become elongated.
3. Water and fertilizer management: During the seedling stage of jicama, loosen the soil and apply topdressing in time. Each time the soil is loosened, apply human excrement and urine once to promote early growth. In early to mid-June, when the tuberous roots expand, apply a heavy topdressing once. If drought occurs, pay attention to watering. If heavy rain occurs, drain water in time. If waterlogging appears in the field, it can easily cause the skin color of jicama to turn brown or the tuberous roots to rot, affecting yield and quality.
4. Flower removal and pinching: Jicama begins to produce inflorescences at the 5th-6th node. Thereafter, as the vine elongates, inflorescences are produced at almost every node. If allowed to bloom freely, it will set numerous pods and waste nutrients in vain, and the roots will not easily become thick. Therefore, except for those intended for seed production, as soon as an inflorescence appears, it should be cut off immediately, while retaining the leaves for photosynthesis. This is generally done in 2-3 batches. Pinch the growing tip when the main vine has 18-24 leaves; after pinching, the vine stops growing.
5. Pruning and trellising: When jicama seedlings grow to 30 cm tall, insert 1 small bamboo or cotton stalk per hole and build a human-shaped trellis, tying adjacent jicama seedlings together so the vines can climb onto the trellis.
6. Harvesting and seed retention: Generally, the fleshy roots of jicama can be harvested 5-6 months after sowing. In the Yangtze River Basin, early- and medium-maturing varieties are harvested in September, while medium- and late-maturing varieties are harvested from late October to early November. Tuberous roots for raw consumption should be harvested early; the roots are crisp and tender, juicy, and sweet, but do not store well. The yam bean of medium- and late-maturing varieties has thin skin and is not tolerant of frost, so it should be harvested before frost. Generally, the yield per mu can reach more than 3000 kg.
Pest and Disease Control of Jicama
1. Sclerotinia disease
[Damage] It harms the base of the stems of jicama seedlings as well as adult plants. The base of the seedling stem becomes water-soaked and rots, which can cause damping-off. In affected adult plants, water-soaked light brown lesions occur mostly on the stem near the ground, petioles, and leaves, with indistinct edges, often causing rot of the leaves or stem base.
[Control] In the early stage of the disease, spray for control with 30% Huihuishaxing wettable powder at 800-1000 times dilution, 20% iprodione · carbendazim suspension concentrate at 1500-2000 times dilution, or 40% junningjing wettable powder at 1000 times dilution.
2. Viral disease
[Damage] It harms the leaves of jicama. Diseased leaves turn yellow. In severe cases, all upper leaves of the plant turn yellow, forming a yellow-top and green-bottom appearance, with plant dwarfing and obvious leaf drop.
[Control] Spray for control with 20% moroxydine acetate copper wettable powder at 800-1000 times dilution, 1.6% diethyl aminoethyl hexanoate aqueous solution at 2000 times dilution, or 1.45% Bingdubike at 500 times dilution.
3. Aboveground pests
[Damage] The aboveground pests of jicama include tobacco cutworm, cabbage moth, diamondback moth, bean leaf roller, and others, mainly harming the leaves of jicama.
[Control] In the young larval stage, spray to kill with 20% chlorantraniliprole suspension concentrate at 3000-5000 times dilution or chlorfenapyr at 1500 times dilution.
4. Underground pests
[Damage] The underground pests of jicama include white grubs, cutworms, mole crickets, earthworms, and others, mainly harming the tuberous roots of jicama.
[Control] After pinching the main vine and at the early stage of tuberous root expansion, drench the roots twice with 50% phoxim emulsifiable concentrate at 500 times dilution or 40% chlorpyrifos emulsifiable concentrate at 800-1000 times dilution.