Back to grafting and budding basics in Hannibal, Mo.

They gathered this year, here on the banks of the mighty Mississippi -- in Tom Sawyer's backyard, so to speak -- to share experiences, cultivate techniques , and listen to lectures on the culture and preservation of virtually every fruit and nut species that grows or can be grown in North America.

The group, known as the North American Fruit Explorers -- NAFEX, for short -- meets every August to further its cause. The 2,000-plus members are amateur backyard fruit growers for the most part, whose experimental efforts may involve a single backyard apple tree and a barrel filled with strawberries to orchards that extend over many acres.

A feature of this summer's gathering is the bundles of tree prunings many members bring along, wrapped in spaghnum moss and plastic to prevent them from drying out. They are, in fact, bundles of scion wood and bud wood that members exchange or sell to others for a nominal fee. This way the members share among themselves -- and also make available to the general public -- fruit and nut species that are not generally available through commercial outlets. In the process they help to perpetuate, through grafting in the spring and by budding in the summer and fall, many old-time favorites that might otherwise die out.

(Grafting is the attaching of a branch or twig [scion] of one tree to a branch on another tree; budding is the insertion of a piece of bark containing a bud into an incision made into the bark of another tree.)

Experienced NAFEX members are old hands at grafting or budding. But there are always new members eager to learn and, as one longtime grower put it, "I'm always keen to see how the other fellow does it." This year the how-to demonstrations were put on by the skilled hands at the Stark Brothers Nurseries in neighboring Louisiana, Mo.

Stark Brothers uses the T-budding method through July and August and then begins chip budding Sept. 1.

Budding is much easier than grafting. First-timers can readily succeed. The real skill, apparently, lies in selecting bud wood of the right maturity. As a general rule, bark buds for T-budding should be taken from the mother tree when it is growing strongly; chip buds can ba taken when growth has slowed, but be sure to take the buds from the current year's growth.

Robert Kurle, a longtime NAFEX member from Hinsdale, Ill., says: "Look for mature buds. If they are too small to see easily, they are too immature." He suggests cutting off all leaves "except about one-quarter inch of leaf stem to be used as a handle on the bud."

You might like to try some budding yourself. Here is how it is done: T-budding:

* Make a T-cut in the bark of the tree you wish to bud.

* Cut out a bud shield (a bud with surrounding bark) from the scion wood and insert it under the bark in the T-cut.

* Bind bark closed with rubber or plastic budding strips (electrician's tape is said to be good). In about two weeks the cut bark should have healed over and the binding can be removed. Chip budding:

* Cut away a slice or chip of the bark from the understock (tree that is to be budded) and place a similar-size chip in its place.

* Press the bud down so that the bottom of the bud bark rests firmly against the bark of the tree. It is not vital that the top of the bud shield and the bark of the tree meet exactly, but they should be close; however, it must not extend above it. Nor is it important that the sides of the bud match perfectly with the sides of the slice taken from the tree.

* Bind up the bud. The bark should have healed over within three weeks, after which the binding can be removed.

Some people recommend removing the tiny piece of wood that comes away with the bud when it is cut. Mr. Stark advises this approach with chip budding if it is done late in the season. To leave the wood encourages the bud to grow. His approach with late-season budding, however, is to have the bud remain dormant until the following spring. On the other hand, if the bud eye comes away when the wood is removed, then leave the wood on the chip.

The following spring prune away the branch above the new bud. This will direct the sap into the bud, encouraging rapid growth.

Always work with a sharp knife. Grafting and budding fail because of a blunt knife more than for any other cause. A blunt knife compresses and bruises the bark, making it difficult for the two pieces of bark to join together.

NAFEX is a nonprofit, tax-exempt organization that is open to anyone interested in fruit and nut growing. A $5 annual membership fee sent to PO Box 771, Saint Louis, MO 63188 includes a subscription to the quarterly publication, Pomona. All other inquiries should include a stamped, self-addressed envelope.