In any one location, as in Maryland, the great differences among varieties may be shown similarly. In this comparison, the Tennessee Shipper is shown to have too small a berry to be a good commercial variety, while Midland has the largest berry and the most productive plant. Suwannee is too soft to be a commercial variety, while Tennessee Shipper is the firmest variety. Tennessee Shipper is too tart to be a dessert strawberry, but Suwannee has the highest flavor oftener than the others. Thus, the breeder's ideal is to combine the size, productivity, and leaf spot resistance of Midland with the firmness of Tennessee Shipper, the flavor of Suwannee, and the appearance of Blakemore, plus whatever seasonal factors the grower desires. The special qualities of each of these varieties have all been bred into them by previous crossings. In the same way, further crossing may result in still finer varieties—a Midland, for example, that keeps its good size and productivity, and inherits Tennessee Shipper's firmness, Suwannee's flavor, Blakemore's appearance, and Redstar's late maturity or Maytime's early maturity.

But, furthermore, other characteristics must be sought for special conditions. In much of California, aphid- or virus-resistant varieties are necessary. In Oregon, resistance to mildew is important. In Florida, varieties must be able to grow and fruit during the short days of winter. In eastern North Carolina, resistance to leaf scorch is an important character. In all areas of the United States, drought resistance, abundant pollen in the flowers, bright color, and smoothness of fruit are needed. How can we get them? Extensive tests and an intimate knowledge of scores of varieties and scores of characteristics of each variety and of the inheritance of characters are essential for intelligent and effective breeding.

The objectives of the present work may be illustrated by the character of the seed collected from crosses made in the greenhouse at Beltsville in January and February 1946 by F. L. Goll and the writer. Other crossing was done by George F. Waldo at Corvallis, Oreg., and by Prof. E. B. Morrow of the North Carolina Experiment Station at Raleigh for the objectives of the breeding work in those States. Although not all the individual crosses are given in the following summary, a study of the list of varieties with superior qualities given above will suggest suitable parents for each objective.

A small part of this seed was sent to others for growing. The seed for red stele resistance was sowed on sifted sphagnum in July and about 50,000 seedlings transplanted during the fall to greenhouse benches filled with red stele-infested soil for a resistance test. The rest of the seed was held for later sowing.

In the field at Beltsville for fruiting are more than 7,000 seedlings, grouped as follows:

These seedlings were set in early summer. Runners were kept off most of them, and the plants grew large enough for the first selections to be made in May and June 1947.

THE AUTHOR

Much credit for many of the better berry varieties we have today is due to George M. Darrow, principal pomologist, Bureau of Plant Industry, Soils, and Agricultural Engineering. Except for time out during the First World War, he has been with the Department since 1911. Among the strawberry varieties he has originated in that time are Blakemore, Fairfax, Dorsett, Redheart, Redstar, Fairpeake, Midland, Massey, Maytime, and others; also to his credit are Sunrise red and Potomac Purple raspberries, and rabbiteye blueberries. Through Dr. Darrow's work on strawberries we know more about the factors that govern their yields and varieties that are adapted to different regions of the United States. He made studies on polyploidy and the botany of blackberries, blueberries, and strawberries.