South Africa has over 100 species of ALV recorded including Amaranthus and Corchorus, both of which perform well in warm conditions and are almost solely collected from the wild. The Department of Agriculture Fisheries and Forestry has reported that ALVs can be tolerant to drought, pests and diseases, requiring a lower-input growth regime than exotic species. This pre-existing adaption to the South African landscape is precisely why these vegetables are being targeted as more water-efficient alternatives to exotic species. Many smallholders are continually battling with poor growing conditions, namely water scarcity, with water availability looking to decrease to <1000 m3 person year-1 in the next few decades.
ALVs are also suggested to help solve the problem of nutritional deficiency and food insecurity in South Africa as some can contain high levels of calcium, iron, vitamins A and C, fibre and proteins, exceeding that in exotic vegetables such as cabbage. They are also a good source of antioxidants and phenolic compounds. However, the exact nutritional composition of ALVs has varied between studies as environmental conditions can strongly influence wild collected samples.
So what is preventing these water-efficient and nutrient dense foods being utilized in South Africa? Currently, only dried forms of ALVs are actively marketed and fresh produce is often sold simply in bunches at markets. In order to increase acceptance of ALVs farmers will require increased understanding of modern production techniques, quality control and standardization of selling units. Postharvest losses also contribute to difficulty in marketing as poor handling and storage conditions mean the crop must be sold quickly and is often absent of packaging. Use of cold storage can help alleviate this but the effects on nutritional composition are currently unknown. The use of packaging could also increase shelf-life and greatly increase marketability with consumer opinion studies corroborating this.
As many ALVs are wild collected the risk of over-exploitation also requires addressing; if popularity of crops was to increase and was not matched by production efficiency then harvesting could be damaging to wild populations. Therefore guidance on production practices needs to be better developed so that ALVs could be integrated into cropping systems. Uses of nitrogen and manure, irrigation management and informed plant density/date, have all reported to increase productivity but robust guidance is lacking on all of these factors. Currently, there is also no formal seed production, an important pre-requisite for commercial development of any crop.
Whilst the review makes a strong case for the promotion of ALVs it is also at pains to point out how much information is still needed for them to be utilized effectively. Coordination is needed to ensure increased interest is matched by greater production capabilities. If the promotion of ALVs is indeed successful they will also require focus from a conservation perspective to ensure genetic resources are preserved.
Source: CABI