Jicama

Rotenone occurs throughout the plant above ground and is concentrated in the seed, where reported levels vary widely by cultivar and conditions. The practical consequences are direct: the seed is not food, the haulm is only used as fodder where flowering shoots have been removed, and seed handling is a safety matter. This is recorded as a fact about the crop and no thresholds or handling instructions are given.

Soil suitability should be assessed with local soil survey information and, where available, field testing.

Flowering diverts assimilate from the root, and removing flowering shoots as they appear is described as the single most consequential cultural practice in the crop, with substantial effects on root size. It is labour, repeated over weeks, and it is what separates a marketable jicama crop from a field of vines.

Cassava, sweet potato, yam and taro all take nitrogen from the soil. Jicama nodulates and fixes it, so it can occupy a place in a rotation that other root crops cannot and it leaves fertility rather than removing it. That combination is the reason it appears in agroecological system design well beyond its market size.

Fertilizer rates, timing, and forms should follow local soil tests and regional guidance. AgricultureID does not publish universal fertilizer recommendations.

The root is eaten raw, crisp and mildly sweet, and it holds that texture after cutting better than most vegetables, which is why it appears in fresh-cut and salad markets outside its home regions. Cooking is possible but is not what the crop is grown for.

Unlike cassava or sweet potato the plant produces a single large storage root, so plant population directly determines root count and each root carries a season's work. Spacing decisions therefore have an unusually direct effect on grade distribution.

The crop is intercropped with maize and beans and used in rotations, and the dried haulm serves as fodder where reproductive pruning has removed the toxic flowering shoots. It fits smallholder systems for the same reasons it fits agroecological design.

Management combines resistant varieties, rotation, monitoring, and — where justified — locally authorized control products applied according to their labels.

Roots store for weeks to months in cool dry conditions and are damaged by chilling below the range that suits most vegetables, so they are not held at ordinary refrigeration temperatures. Skin damage at harvest shortens storage life sharply.

Pachyrhizus erosus is the Mexican yam bean; P. tuberosus and P. ahipa are cultivated in South America and differ in root form and season. Records naming "yam bean" may describe any of them, and the name also collides with African Sphenostylis stenocarpa, an unrelated crop.

Mexico and Central America, and Southeast Asia — where it is bengkuang or sengkuang — are the principal production regions, and export is largely into North American and Asian fresh markets. It is a substantial vegetable in those regions and marginal in international statistics.