Penicillin: Breakthrough to the Era of Antibiotics

this specialty fruit and was responsive to the industry need for reliably tested freestone varieties. A sequence of similar varieties over a period as long as for peaches is envisioned. As was true with peaches, main crop apricot varieties were static for many years. As a consequence, the varieties, mostly of European origin, became less well suited to changing market demands. Commercial drying of fruit became less prevalent, and the need for larger fruit and for resistance to pit burning—browning of flesh adjacent to the pit—became more important as more fruit was shipped fresh or canned. Weinberger realized the need for greater resistance to pit burning, improved firmness, and larger size in varieties similar to the major varieties. In 1963, 'Gastleton' was introduced by USD A because it fulfilled these objectives. The other selections which promise to complement this variety are in various stages of testing. Over 2,100 seedlings have not yet fruited. and additional crosses are made each year. There is reason to expect a complete replacement of present varieties. Weinberger's interest in improving Japanese-type plums led to a resumption of breeding for new varieties. An earlier, very productive, cooperative program between the USDA and the California Agricultural Experiment Station at Davis had developed *Burmosa,' 'Redheart,' 'Nubiana,' 'Laroda,' and several other varieties which became important to the industry. Using these and other varieties as parents, Weinberger produced over 17,000 hybrids and now is testing many promising selections. One was named 'Frontier' in 1967. It combines the high quality of the leading red-fleshed variety with much better exterior color, thus increasing its market appeal. 'Friar', an amber-fleshed and black-skinned variety, was introduced in March of 1968. Other selections are undergoing rigorous plot and commercial testing. Weinberger is growing some 3,200 plum seedlings which have not yet fruited.