The main limiting factors of maca production are availability of good-quality seed, adequate weed control, acid soils in the present area of cultivation and post-harvest handling. Seed is often sufficient for planting only small plots, sincelarge quantities are hard or impossible to find from a single source. The presence of floral debris and soil mixed with the seed makes it difficult to know how much actual seed is really available. Other limitations are lack of information on soil management practices as well as weed, insect and disease control.
9.2 Research needs
Better seed-cleaning methods must be adopted.
The seed bulked from many plants of different characteristics makes it impossible to determine the root colours that will be obtained in the crop. This makes necessary the systematic selection of plants of different traits to generate cultivars possessing predictable traits. Simple breeding and selection schemes along with good seed-production practices will rapidly solve this limitation.
Effective practices for weed control are necessary to increase yields.
Soil acidity could be solved by application of amendments to increase the pH. Little research has been done on this problem, whose solution could result in substantial yield increases (Quirós et al. 1996). At the present time, it is possible that maca is not being grown to its full potential because of the lack of optimal soil in the production areas.
The current practice of drying the plants after harvesting needs improvement. Often it results in losses of 30-50% of the harvest due to rotting caused by overheating of foliage still present in the plants. Research is necessary to determine the optimal practices for root drying to minimize losses.
9.3 Prospects
Maca is one of a few crops that can be grown at high altitudes. It has gained great popularity as a nutritious food and its reputed medicinal properties open up the opportunity to grow it on a larger scale in the highlands of the Andean region. Its amenability for processing in a large number of products, including health supplements, makes this crop quite attractive for regions where other crops cannot be grown. Further, the unmet demand of maca at the present time provides the challenge to expand the area dedicated to this crop and to work toward the solutions of its present limitations.
Acknowledgements
We are indebted to M. Holle and Francisco Delgado de la Flor for supporting research on maca, to Vincent D’Antonio and Francisco Jarrín and Judith Toledo for technical assistance, to Michael Hermann for supplying seeds of some of the wild species and to Dr I. Al-Shahbaz for species identification. Research was supported in part by a grant from the Consortium for the Sustainable Development of the Andean Ecoregion at the International Potato Center (CIP-COTESU).
The International Plant Genetic Resources Institute would like to thank Prof. Timothy Johns for his critical review of the manuscript.
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