Page:Report of the Puerto Rico Experiment Station (IA CAT31294391015).pdf/12

 H. J. Cruzado and H. E. Warmke

Four Mayagüez selections (48209, 48210, 48211, and 48212) from crosses involving native tomatoes were included, for purposes of comparison, in local replicated trials of the 1948 selections from the Southern Tomato Exchange Program (STEP), sponsored by the U. S. D. A. Regional Vegetable Breeding Laboratory at Charleston, S. C. The best Mayagüez line significantly outyielded all STEP selections. The four hybrids yielded an average of 33.61 ounces per plant, or over twice the average of all the STEP lines (15.71 ounces per plant). The average for the hybrids was nearly five times that of Rutgers and over twice that of Grothen Globe, in these trials. Line 48209, although yielding somewhat less than either 48210 or 48212, is relatively stable and has fruit of acceptable market quality. This line is sufficiently promising that it has been introduced into the 1949 STEP trials as STEP 136. It will thus be tested by some 3 dozen cooperators throughout the southern United States and in Hawaii during the coming year.

Twenty-four new introductions to the Southern Regional Tomato Trials (STEP Nos. 80-103, inclusive) were also tested in local observational trials this past season. Some of these combine large fruit size with high yield and will be used in further crosses.

H. E. Warmke and H. J. Cruzado

Three Jersey varieties (Orange Little Stem, Maryland Golden, and Yellow Jersey) and 17 moist-flesh varieties (including Introductions 153655, 153907, and 153909) have flowered in experimental plots. Only 3 varieties out of the total of 23 included this year have failed to flower; all of these are Jersey types, and include Red Jersey, Big Stem Jersey, and Vineland Bush, which have made extremely poor growth.

Some of the common moist-flesh varieties, including B-5928, UPR-3, and Mameya. which began flowering last November, did not return to a vegetative state at the end of the usual flowering period. These varieties have flowered throughout the year. Original plants of the Jersey-type variety, Orange Little Stem, which flowered from early December until the middle of January last season, began to flower early in August and continued through the current season. None of the spring and summer blossoms appear to be as fertile, however, as those produced during the winter season.

H. J. Cruzado and H. E. Warmke Over 2,000 crosses were made during the past season as part of the sweetpotato improvement project started last year in cooperation with the Division of Vegetable Crops and Diseases of lie Bureau of Plant Industry, Soils, and Agricultural Engineering. From these crosses, 227 fruits were set (10.28 percent), which contained a total of 337 seeds (15.62 percent). This is a considerable improvement over last year's results, where 23 fruits (3.0 percent) and 24 seeds (3.7 percent) were obtained from 045 crosses.

Older and more vigorous plants and an improvement in technique (starting crosses at 7:00 a. m.) probably were responsible for the