EDN ISSUE: # 18 DATE: JUNE 1987 WRITTEN BY: MARTIN L. PRICE

18-1 THE DEVELOPING COUNTRIES FARM RADIO NETWORK HAS A WEALTH OF INFORMATION FOR SMALL-SCALE THIRD WORLD FARMERS. George Atkins began this work in the late 1970's, with a grant from the Massey Ferguson company. Like ECHO, he is always on the lookout for items that would benefit the small Third World farmer who is working with limited resources and difficult conditions. See the next item as an example. Unlike ECHO, his material is meant to be read directly to the small farmer via radio segments lasting a few minutes per topic. (Our material is directed to development agents and assumes at least a high school education).

Because none of the items used by the DCFRN become "dated", they can be used anytime. Sometimes the cassette tapes are broadcast directly. More often the detailed script, which is available in English, Spanish or French, is translated into the local language and read by a local announcer. But its use is not limited to radio. Many have found that they can use the script (which is supplemented with diagrams and drawings) in preparing materials for their own person-to-person agricultural extension work.

If you would like see their materials, write to George Atkins, Developing Countries Farm Radio Network, c/o Massey-Ferguson Ltd., 595 Bay St, Toronto, Ontario M5G 2C3 Canada. He will send you the first unit, then wait for your reaction. There is no charge.

18-1 KEEPING ELEPHANTS FROM YOUR PLANTINGS. This item is excerpted from material from George Atkins (see previous note). "Henry and Jill Neusinger went as volunteers to Sri Lanka where they developed a demonstration smallholding. Although they had some fencing, in the early days they lost most of their crops and some fruit trees because of the elephants. So Henry set about developing an elephant proof fence and he managed to create one that really did work!

"The fence consisted of stakes about 2 feet long and 6 inches in diameter. The idea was to bury them in the ground with the points up. With the top sharpened the elephant cannot or will not put his foot on them. No damage is done because elephants kick forward when they walk. The points extend 6 to 9 inches above the ground. This height is very important. Too high out of the ground and the elephants pull them out, or push with their feet and lever them out of the ground. They are very intelligent and if they think they can push out the stakes they will. Of course, if the stakes are too low in the ground, the elephants can just tread on them. So they have to be high enough that the elephant cannot tread on them, yet not so high that he can push them over. They must also be pointed so he cannot get a grip on them with his trunk and pull them up.

"They did trials with tame elephants and tested 5 different methods: distance between stakes, height, point and no points. The only method that succeeded had 9 inches between stakes. The fence is 5 and a half feet wide and runs around the perimeter of the village. It took a lot of effort and expense to build a fence like this, but the village people were losing something like $8,000 worth of crops a year, less than the cost of the fence. They use hardwood. Maintenance consisted of spraying with herbicide to keep down the growth on the stakes. If white ants got to the wood, they also had to spray with pesticide. They expect it to last 20 years."

18-2 DR. FRANK MARTIN IS NOW A VOLUNTEER FOR THE ECHO NETWORK. His name is familiar to many of you because of his books (e. g. Techniques and Plants for the Tropical Subsistence Farm and Edible Leaves of the Tropics) or material from him that we have included in EDN. He retired this spring from the United States Department of Agriculture's Tropical Agriculture Research Station in Puerto Rico and moved into our area. He hopes to make about a day a week available to ECHO. This will help you in three ways.

First, he will be writing on some topics that will be of widespread interest to folks working with small farmers and urban gardeners in the tropics. Second, when you visit ECHO, if you would especially like to talk with him about problems of your region, we will try to arrange a time. Third, he will help me to answer questions that you submit to us. Frank is especially known for his work with root crops and will handle rootcrop questions for us. If you have specific questions related to root crops, drop us a line.

18-2 SEED FOR SEMINOLE PUMPKIN Cucurbita moschata NOW AVAILABLE. I have wanted to get seed for the Seminole pumpkin ever since Dr. Julia Morton sent me a copy of her article five years ago: "The Sturdy Seminole Pumpkin Provides Much Food with Little Effort." Last year we grew our first plants. We planted a single hill in an out of the way spot and gave it almost no attention. It vined through weeds in a large area and produced 20-30 pumpkins, which we ate using winter squash recipes. We love the flavor, finding it a great tropical substitute for the popular acorn squash. Each is a convenient size, somewhat larger than a grapefruit. Third World readers can write for a free seed packet (others send $1.50). If it produces in your climate, you will be able to save your own seed.

Julia Morton writes, "It will spread over the ground, drape a fence or climb a tree; needs to be fertilized only at planting time; requires no protection from insects. The fruit, variable in form and size, is hard-shelled when mature and keeps at room temperature for months, is excellent baked, steamed, or made into pies. The Indians sliced, sun-dried and stored surplus pumpkins. Very young tender fruits are delicious boiled and mashed; the male flowers excellent dipped in batter and fried. Thus the vine produces three totally different vegetables. This is an ideal crop for the home gardener. The portion of the vine which has borne will die back, but vigorous runners, which root at the nodes, will keep on growing, flowering and fruiting, yielding a continuous supply."

The fruits were seen hanging from oak trees by early settlers as they canoed through the everglades. Indians would girdle the bark of oak trees to kill them then plant the pumpkin at the base (a technique we are not recommending!).

18-2 "ETHIOPIAN KALE" SHOULD GIVE SEED IN THE TROPICS. Kale is the favorite green in my family, both for its taste, texture and nutrition. A drawback is that it does not set seed in the tropics. Dr. Warwick Kerr in Brazil sent us seed of the "Ethiopian kale" (sorry, I have no scientific name) which he said should bear seeds. Sure enough, we will be harvesting seeds in a couple weeks. We did not like it as well as our favorite "dwarf blue curled vates" variety, but if it was the only kale we could raise, we would be thankful for it. Seed packets free to the Third World, $1.50 in the USA.

18-2 CHAYA IS ONE OF THE MOST PRODUCTIVE LEAFY VEGETABLES AND AN INCREDIBLY RESISTANT PLANT. Chaya, Chayamansa cnidoscolus, is native to the drier parts of Central America and Mexico, where it is grown in dooryards, often as a hedge. Consequently it has been no surprise to find that it is very resistant to drought. Ross Clemenger planted some cuttings in northern Colombia after visiting us. The weather turned so dry that he had to sell a lot of cattle for lack of forage. The chaya, however, flourished. What has been surprising is that chaya is equally resistant to our terribly hot, humid, rainy summers. In five years I have never seen a diseased leaf nor lost more than one or two leaves to any insect. The only things that have harmed our chaya are freezes and standing water. It will come back from the ground after a freeze, but is killed by a few days of standing water. Plants reach 6 feet (2 meters) in height and about 4 feet (1.3 meters) in diameter.

The leaves are eaten cooked as greens or used to wrap tamales. They have a firmer texture than most greens I have eaten. If people in your area eat greens, I think they would likely develop a taste for chaya. For example, an American friend who married a Mexican woman has become quite fond of chaya, and says they like to serve it at least twice weekly. Another friend of chinese descent is enthusiastic when we take her a bag of chaya leaves, even though it is not a plant she had in China.

Chaya is one of the "underexploited" food plants popularized by the National Academy of Sciences. Leaves are reportedly high in protein, calcium, iron, carotene and various vitamins.

There are two problems with chaya, but both can be easily overcome. (1) It contains hydrocyanic glyco- sides, which can lead to cyanide poisoning. These are inactivated by cooking. (We discard the cooking water, but I do not know if that is essential). (2) The petioles of the leaves contain tiny stinging hairs. If I do not wear gloves when harvesting the leaves, my fingers feel like I have been handling glass wool. (NOTE: ECHO now has a non-stinging variety available for distribution.) Some have brushed against the plant with their bare skin and were left with a red rash.

Chaya is easily propagated by cuttings. Though it is frequently in bloom, it never sets seed. Fortunately, because it is so resistant to dry weather, we should be able to get live cuttings to you. We did a simulated tropical mailing. Several packages of chaya cuttings, prepared in different ways, were left in our hot workshop during the summer to simulate delayed overseas delivery. They were then removed at 1-4 week intervals and planted. We had good results at up to three weeks, and some survived after four weeks. We sent a package to Asia which was received 10 days later. They trimmed the bottoms and placed the cuttings in fresh coconut milk. In half an hour the surviving small leaflets had regained turgidity. Several cuttings survived. (Some of the edible hibiscus cuttings also survived the trip, so perhaps we can begin sending those as well). We sent some cuttings in a regular envelope to Dr. Warwick Kerr in Brazil. He reports that he is now distributing cuttings in the local church and that his family eats them at least twice a week.

If you want to try chaya in your area and think a small airmail package can reach you in three weeks, we will try to send you a few cuttings. This will cost us a few dollars in postage, so please only order if you will follow through promptly to care for the cuttings. Water the soil moderately but do not keep overly wet while cuttings are starting.

18-3 SUGAR CAN BE USED IN PIG DIETS. I do not know how cost effective this would be, but with the depressed prices of sugar it might be of interest to you. The April 1986 issue of Agricultural Science Digest summarized a report in Australian Agriculture that pigs will grow faster and produce a better quality carcass if they eat plenty of sugar. Sugar was used to replace the cereal content of a normal ration. Pigs were switched to a 75% sugar and 25% soybean, meat and blood meal plus trace elements diet when they weighed 25 kg. Pigs on the sugar diet reached their 80 kg slaughter weight 10 days earlier than those fed conventional rations (710 g weight gain per day compared to 612 g. The carcasses of the sugar-fed pigs was 80% edible compared to a more normal 75% for pigs fed the control diet. The authors point out that because sugar has no fiber content, protein sources that are too high in fiber to be used normally in pig rations can now be used. (The only problem with the low-fiber diet was some diarrhea the first day).

18-3 ARE FREE SEEDS A GOOD IDEA? We frequently get letters lamenting that gardeners cannot obtain vegetable seed. Dr. Henry Munger at Cornell University told me that a seed company tried to get started in the Philippines about 10 years ago. About the same time both a U. S. agency and Mrs. Marcos began a free seed distribution program. He believes this put the company out of business. The donors soon tired of giving away seeds, leaving the people with no place to buy them.

The owner of a small seed store in a Third World country told me there was an onion seed shortage in his region the year I visited him. He used his hard-earned foreign exchange to import onion seed the previous year. Then one day a nearby mission began selling onion seed at much below wholesale price. Apparently someone had given them the seed. The next year the seedsman was wise enough not to get caught with onion seed again, but the mission did not give away seed that year. Consequently there was a shortage of seed for one of the major crops of the region.

With very few exceptions, farmers can save their own seed from plants grown from the kind of seed that ECHO provides. We occasionally have a limited quantity of donated U. S. vegetable seeds to pass on to visiting missionaries. However, we do so only on their word that local gardeners would not be able to obtain seeds any other way.

In the long run, it is much more helpful to enable local people to take care of themselves than to bail them out sporadically with gifts. This is the ministry that ECHO is continuing and expanding. As it is put in our brochure, "Development is more lasting than relief."

18-3 HOW CAN WE GROW OUR OWN GRAFTED SUBTROPICAL VARIETIES OF DECIDUOUS FRUIT TREES. Dennis Desmond in Ecuador asked some interesting questions concerning a project to produce 5,000 fruit trees (subtropical varieties of temperate fruit) annually for local farmers. He already has a few apple, peach, pear, plum and apricot trees going that he can use for grafting material. Now he wants to begin growing rootstock [seedlings to which superior varieties will be grafted]. I know a lot of you have similar questions. For example, what kind of apple seed should he buy, where would he get it, what pretreatment is needed, etc. This prompted a call to Dr. Wayne Sherman in the Fruit Crops Department of the University of Florida. A summary of this most interesting conversation follows.

In the States nurseries buy rootstock (very young trees) from specialized companies, usually in Washington and Oregon. Unless a particular name is specified, they most likely were grown from seed collected at cider mills. Dr. Sherman said that the easiest solution in the tropics also gives the best results -- simply save seed from the subtropical fruits that are already bearing on your present trees. For example, Anna and Dorsett Golden apples will give better rootstock for a mountainous site in the tropics than would purchased seed taken from a cider mill in the States.

How can one get dwarf trees? He said that this is going to be expensive and hard to get. There is no good history of how they will do in the tropics, although the seedling stock is well adapted.

What about "clonal" propagation where trees are grown from root cuttings? The problem is that every tree will be genetically identical, in contrast to seedling trees which have a lot of genetic variability. If a particular pest comes along that is able to attack one of the trees, it will also successfully attack all the other clonally propagated trees! If trees came from seedlings there would be a much better chance that some would be resistant. For example, wooly aphids could wipe out an entire orchard if it were clonally propagated, but not if the rootstock came from seeds.

What kind of pretreatment is needed? After removing seeds from the apple, wash them. Put 100-500 moist seeds in a brown paper towel, roll the towel up, and place it in a refrigerator at normal refrigerator temperatures (40-50 degrees F) for a month. Keep the towel moist. After a month start checking to see if seeds are germinating. They will probably start to germinate after about six weeks (longer if you were not starting with seed from the subtropical apples). At that point plant the entire bunch of seeds.

You should likewise save your own seeds from subtropical peaches. Crack the shell and put only the kernel in the moist paper towel. They should be ready to plant in about eight weeks. In three months they will be over two feet tall and are ready to T-bud. Five months later they can be set into the field. (In contrast apple trees must grow a year before grafting and another year before being set into the field).

At higher elevations you may find a "Spanish" type of cling peach growing. If root knot nematodes are a problem in your area, however, you will have big trouble because peaches are susceptible to this pest. There is a nematode-resistant variety called nemaguard that is used for peach rootstock, but this would have to be purchased from a temperate country (importing a large package of peach seeds will not be easy or cheap). I asked if you could plant a nemaguard seed then in a few years have your own nematode resistant seeds. He doubts that it would ever produce because it requires such a long period of chilling. Clonal propagation of peach trees from the roots is very difficult.

Pears should be treated the same as apples, again using any locally available pear seed.

Plums are treated the same as peach. However, many prefer to graft plums onto the peach rootstock. Dr. Sherman said that plum seedlings vary so tremendously in vigor that three-fourths of them may not be usable. Apricots can likewise be grafted onto peach rootstock. (Do not graft peaches onto plum or apricot nor plum to apricot nor apricot to plum).

18-4 MANGO TREES THAT DO NOT PRODUCE. Jack Mahaney wrote us after visiting Gary Dawson in Venezuela. "While they have many large, mature mango trees, no fruit is borne. There are heavy crops at other stations within a hundred miles or less. What is needed in order to produce fruit?"

I called our old standby, Dr. Carl Campbell with the University of Florida. He is familiar with the problem. The most common cause is a location where the trees bloom during periods of high humidity and temperature. This leads to anthracnose infection of the flowers and no fruit set. It can be controlled by spraying with fungicides, such as those containing copper, carbamate (e. g. Maneb), or benylate. It is so humid in southern Florida that Florida growers are wiped out most years unless they spray. There are varieties from Southeast Asia that will do better under such conditions. He mentioned varieties Saigon, Florigon, Pico and Carabao.

It is very difficult to get tropical fruit trees shipped overseas. If you know someone who has the tree, can you have seed sent? The good news is that all of these varieties are polyembryonic and consequently most trees will be just like their parents (see EDN # 16 page 3). The bad news is that mango seeds are viable for only a couple weeks after removed from the seed and dried. I asked whether you could extend the life of the seed by wrapping it in wet paper towels. Carl explained that mold is a terrible problem with seeds stored this way. The best approach is to surface sterilize the seed by dipping it in 10% chlorox, then pack it in barely moist (no free moisture should be visible) activated charcoal and ship in a plastic bag. (Might regular charcoal substitute for activated charcoal?)

There are locations where the trees do not even bloom. (Carl said you need to be alert because sometimes people have insisted their trees do not bloom, but more careful observers contradict them). Fungicides will be no help there. For example, he has seen large areas in the Philippines where mangoes do not bloom. This appears to be due to the uniformity of high rainfall and temperature which does not permit the trees to have their normal dormancy. In 1972 scientists in the Philippines found that if they spray the leaves with as little as 10 grams per liter of potassium nitrate, the buds will start elongating within 2-3 weeks and will bloom within a month. Spraying is done only once, but the trees are drenched completely. They time the spray to have bloom and fruit growth during the least stressful season poss- ible. Apparently it is effective only when the tree has attained a "ripeness to flower." Signs of this stage include: leaves become dull green or greenish brown and brittle when crushed with the hand and the tree has an appearance of suspended growth. Another use of this technique is to induce earlier flowering to beat the market and get higher prices for the mangoes. The fruiting season can be advanced several months in the Philippines. [Readers elibible for free services can request articles Flowering in Mango induced with Potassium Nitrate and Key to Mango Flowering. Others send $1 to cover cost of copying].

18-5 BOOK REVIEW -- CITY FOOD: CROP SELECTION IN THIRD WORLD CITIES BY ISABEL WADE (54 pages). (Published by Urban Resource Systems, 783 Buena Vista West, San Francisco, CA 94117, USA). Many of our readers grew up in temperate climates. When they think of gardening, they naturally think of vegetables they grew back home. When called upon to help in a gardening project, their first question is, "Where can the people buy vegetable seeds?" Their program may even be stalled because they cannot find a source of seed for vegetables (cabbage, onion, carrots, green beans, peas etc.). Though temperate vegetables may have their place, it is probably the wrong place to start. City Food will help you become familiar with growing another world of "appropriate" vegetables.

"This manual emphasizes crops that are likely to be available locally so that seeds and vegetative parts can be obtained free or at minimum cost. Seeds for local crops can be scavenged from spoiled fruits and vegetables" or bought in the local market. Six categories of crops are reviewed: fruit and nut trees, tree leaves, green leafy vegetables, roots and tubers, legumes and miscellaneous others. For each, the special features, nutritional value, space and climatic requirements are sketched. Other chapters include: urban agriculture -- special conditions; techniques for intensive production; and year-round production planning.

Tables in the appendix will be especially helpful. These include: water requirements of selected fruit trees; temperature preferences of fruit trees; tolerance of fruit trees to salt, poor soils and acid soils; space requirements of fruit trees; crops with edible leaves for poor soil conditions; water and temperature requirements of selected green leafy crops; growing requirements of selected roots and tubers; drought tolerant and heavy rainfall tolerant legumes; altitude preference of principal legumes; and some sample planting calendars for three tropical cities. The price is $7.50 for the USA and Europe; $5 for orders from Third World countries. Prices include air-mail postage.

18-5 THE COMMUNITY SEEDBANK KIT. (Published by the Rural Advancement Fund International, P. O. Box 1029, Pittsboro, NC 27312, USA). Millions of people have been fed by the higher yields as farmers switched to new "green revolution" varieties. But what happens to all those varieties that farmers used to grow? Some of them are the result of plant selection through centuries. "The introduction of modern grain varieties in the Mid East has led to widespread losses of traditional varieties. African rice is nearly extinct in its native homelands. ...a variety called IR-36 now extends over 60% of the rice lands of Southeast Asia where, only a few years ago, thousands of farmer varieties were common. ...the black beauty egg plant is ... destroying its own diversity in the Sudan."

These lost varieties may have traits that would be invaluable if, for example, a new disease strikes. One of those varieties might be much better adapted to difficult growing conditions in another part of the country that wishes to begin growing the crop. They will also be invaluable to producing future "green revolution" crops. This loss of genetic diversity is of equal concern to the small farmer, the international center and the big seed company.

The purpose of the Community Seed Bank Kit is to help private volunteer agencies develop community seed banks to collect, preserve and assure easy community availability of seeds of crops in their region before further "genetic erosion" takes place. The kit is not a book. Rather, it is a loose collection of several 4-15 page sections. Topics include Building the bank (the need); Building the bank (practical); The role of the voluntary agency; Sources and resources; Overview and issues.

The section on building the bank (practical) discusses how to select the crops to be collected, the best time to collect, the collection strategy once you are in the field, documentation, seed cleaning and drying, seed storage, collection grow-outs and a table indicating whether a seed is self- or cross-pollin- ated and its relative storability index.

If you can envision your organization undertaking such a project, the kit will be a great help. They anticipate future revisions. If those include some case studies and greater detail on practical techniques such as testing seed viability and appropriate technology alternatives to seed drying and storage, the kit will be even more helpful. The price is $4.50 in North America, $5 surface and $8.50 airmail elsewhere. Indicate whether you prefer English, French or Spanish.