In making plans for our summer crop, Valorie and I thought it would be fun to try some Jicama. We checked in with Richelle, who is the produce team leader at La Montanita Co-Op in Santa Fe, and she said she had never been able to buy certified organic Jicama. Sounded good! Jicama (Pachyrhizus erosus; links: Wikipedia, Sunset Plant Finder) is a member of the pea family. It is a tropical vine and the leaves and stems are loaded with rotenone, a potent natural insecticide, so there should not be any pest problems. Sounds even better! The crisp, fleshy roots are the part of the plant used in cooking.
We started checking out the cultural requirements and it still looked promising. High heat. Check. We can do that in our greenhouse during the summer. Then we hit the snag. Jicama needs a relatively short day length to develop the delicious fleshy roots. By the time we have shortening days in Tecolotito, we would not be able to maintain the high heat Jicama requires in our unheated greenhouse. For the time being, Jicama has been removed from our list of possible crops.
At some point in the future we may come back to considering Jicama as a crop once again. It would require a heated greenhouse or using black cloth like commercial growers use in chrysanthemum production to simulate a short day condition. Another alternative would be if plant breeders can develop a day neutral Jicama. Any of these developments are far off in the future. Sorry about that. You will have to do without or buy conventional Jicama. Even conventional Jicama should not have any pesticide residues because the plant protects itself by loading up its leaves with rotenone.