Dr. Frank is known to many of you as author of several books and articles on tropical subsistence farming. He works at the Mayaguez Institute of Tropical Agriculture (USDA) in Puerto Rico. Currently his research centers around sweet potato improvement for the tropics. We recently received from him the following interesting note:
It is possible that the water repellent just described would be especially helpful for treating wood that is to be used in constructing bee hives. But be careful if you add toxic chemicals to turn it into a water-repellent preservative.
Don Bernd wrote to ask what we would recommend to counter molding of "leather, books, accordion, and wood furniture" in extreme humidity in his part of Colombia. The U.S. Forest Service bulletin, "Wood Finishing: Water Repellents and Water-Repellent Preservatives," describes a method for treating wood that is exposed to weathering (but above ground).
Judging by the response to comments about tropical fruit trees in the last E D Notes, many of you are including tropical fruit trees in you development efforts. I have used the FAO book Propagation of Tropical Fruit Trees to answer several of your questions.
When scientists study how plants resist drought, they sometimes use the tepary bean as a model, according to graduate student Richard Pratt at Purdue University. Tepary beans are cultivated by Indian groups in the Sonoran desert of western North America. They thrive in arid regions which receive heavy but infrequent rains. They need ample moisture to germinate and advance growth to flowering. After flowers form, little additional moisture is needed. Teparies enjoy high temperatures and bright sunshine but are intolerant of frost and waterlogging. They require night temperatures over 46 degrees F (8 degrees C). In certain types of desert soils, after one of those rare times when the ground is flooded, the beans can reportedly be planted and produce a crop with no further rainfall.
Many of you are familiar with the book Under-exploited Tropical Plants with Promising Economic Value. In the early 1970s , the U.S. National Academy of Sciences surveyed scientists around the world to determine which plants had the greatest potential for introduction to other tropical countries. This book includes 36 plants chosen from among 400 that were nominated.