David Ross, age 12, of Costa Mesa, Calif., for his question:
HOW DO WALNUTS GROW?
Leading producer of walnuts in the world is the United States, followed by France, Italy, India and Turkey. California is the nation's leading walnut producing state with about 735,000 tons sent to market each year. The state's walnut industry is centered in the area around Stockton, California. Oregon wins second state honors with its 2,000 ton annual walnut crop.
There are two leading types of walnuts: the English walnut and the black walnut.
The English walnut, which is also called the Persian walnut, was brought to the United States from southern Europe many years ago. It is the type that is commercially grown in California and Oregon.
English walnut trees have gray bark and large leaves. The tree had been grown in Europe since ancient Roman times.
Two types of English walnuts can be found: the Santa Barbara and the French, The Santa Barbara type is less able to resist heat and cold and requires a longer growing season than the French type. Santa Barbaras grow on the coastal plains and valleys of southern California while the French group, which can resist extremes of heat and cold, grow from central California to Oregon.
The trees need deep, well drained fertile soil to give their best yield and quality. English walnut trees are also sensitive to alkali salts and must have pure irrigation water. Growers plant them 60 feet apart so they'll have lots of room to spread
Small flowers, which may be cross pollinated or self¬pollinated, are produced by the English walnut trees. The fruit is a thin shelled nut that has a sweet taste.
Black walnuts are native to the East. The trees are grown mainly for lumber although nuts are also harvested and sold. Their shells are hard and thick and the nuts are usually shelled before they are sold.
Black walnut wood is dark purplish brown, with a very fine grain and rich luster. It is a very valuable wood because it is becoming rare. It is used for interior finishing, fine furniture and gunstocks.
In harvesting English walnuts, the nuts are shaken down from the trees when they are ripe and are then hulled and dried. When the nuts reach the packing house, they are sorted, sized, bleached, blended, branded and finally sacked for shipment. Poor grades of nuts are shelled and the meat is used to make walnut oil and shell flour.