BREEDING PROCESSING TOMATOES FOR THE WORLD FROM PETOSEED

P. Thomas
Petoseed actively became involved in breeding tomatoes for the world in the early 1960's. This came about by the intense interest of incorporating higher viscosity into the California breeding program. The background of this program came out of the H.J. Heinz varieties of H1350 and E.S. 24 with a number of California breeding lines. By growing the segregating populations in such locations as Parma, Italy, Napolian, Ohio, Woodland and Stockton, California we were able to select for better setting ability at higher temperatures, slightly higher viscosity than the California breeding lines used and crack tolerance, which was important to late plantings in California, as well as the main plantings in the midwestern U.S. and, of course, Italy. The major variety to come out of this program was Mecheast 22. The biggest problems with the material coming out of this program was lighter interior color and lateness in maturity. A major break through in variety development in obtaining a variety, or varieties, adaptable throughout the world came out of the Professor Hanna's program prior to his retirement from the University of California in 1971 with his release of VF-90, VF-92, VF-105J and VF-134. The VF-134 was the best and most adaptable of these varieties released and out of this one variety were a number of selections made in various areas of the world. Varieties such as VF-134-1-2 and Petomech II for California and South America and CAL-J (R) Petomech and Euromech for the Mediterranean countries. All of the forementioned varieties were selected out of VF-134. The background of the VF-134 was Florida 1346 a line out of J. Strobel's program at the University of Florida, and VF-65 a long fruited, crack tolerant variety from Professor Hanna's program at the University of California. VF-134 contributed many important characters, such as a high level of crack tolerance, excellent color, high viscosity, vine storage, well adapted for mechanical harvesting, and firm enough to withstand cracked and broken fruits in bulk trailers, as well as maintaining a favourable pH level. It is obvious why this variety, or its offspring, is presently the most widely used world wide, not only as a processing variety, but also as a source of breeding material. VF-134-1-2 has been used extensively in the Peto Seed research and variety development program. The most consistent characteristic of the more progressive producers of processing tomatoes world wide has been changed. The history of the life cycle of tomato varieties in California since 1938 has been approximately ten years with the possible exception of VF-145, which has lasted about 20 years. The same can be said for the major tomato producing regions of the world in the midwestern United States, South America and the Mediterranean countries. The causes responsible for these changes has been the ever changing needs of the industry. These changes are brought about by political changes, labor availability and efficiency, diseases, changes in product requirements, and methods of harvesting and handling of the fruit. When Professor Hanna retired from the University of California in 1970 and became associated with Peto Seed Company he was made responsible for the breeding of processing tomatoes. His mahor emphasis was placed in developing varieties with higher soluble solids, while maintaining firmness, high viscosity compact plant with concentration of fruit set and maintaining a suitable pH level. In the early 1970's an outbreak of a new race of fusarium wilt, which is reffered to as a race II, accured in Northern California. Resistance to this new race of fusarium wilt came out of a Florida fresh market variety and was incorporated into all Professor Hanna's breeding lines. In 1975 Professor Hanna released the first fusarium race II resistant processing variety, Petogro. In 1976 he released Peto 76, in 1977 Peto 77, Peto 80 and Peto 81 and Petopride II, an F1 hybrid, and in 1978 Peto 86 was released, all carrying resistance to fusarium wilt race II. At the present time practically all new varieties released by Petoseed will be resistant to fusarium wilt race II, as well as verticillium wilt race I and alternaria crown rot. This program of incorporating resistance to fusarium wilt race II temporarily slowed down on the high soluble solids program. Along with the interruption of this program with the fusarium wilt race II problem, governmental restrictions on certain chemicals for nematode control, along with the high costs of recommended controls has necessitated the incorporation of nematode resistance into this program. All of these programs require compromise on the part of the breeder. With the breeding material presently available lower yields and softer fruit are associated with higher soluble solids. The nematode resistance has been associated by some research workers with lower yields, larger stem scars and tighter stems. I dont't necessarily agree with those assumption. However, by the proper combination of the material we now have on hand the above problems should be solved in the near future. During the past 30 years I have been involved with tomato breeding I have seen many changes in the industry. We have gone from large plant types with large fruit sizes, hand harvest types with little to no disease resistance, to highly resistant, compact plant types with firm fruits, smaller fruit sizes adaptable to mechanical harvesting. All of these changes have been forced on the industry primarily because of new need of the industry and a reluctance of people to change. It appears that all too often the pressures put on the plant breeders by the industry are too great as there are many areas where changes within processing plants, as well as cultural practices by growers, could have a very positive effect on the industry. By proper irrigation and fertilizer management we could automatically increase the soluble solids and maintain firmer fruits with less cracked and broken problems. In many processing plants, the processor is not able to take full advantage of the higher viscosity levels, nor are they capable of properly peeling the firm fruited varieties. There are still requests being made for large fruit sizes because, for many, large fruit sizes has been traditional - the idea that they are easier and cheaper to hand harvest. We do know that smaller fruit sizes (2–3 ounces or 60–90 grams) with concentrated fruit set results in easy, quick harvest with high tonnage in a single harvest, whether by mechanical harvest or by hand harvest with a lot less mechanical damage and loss. The biggest problem today in plant breeding is attempting to anticipate the needs of the industry 10 to 20 years from now. We cannot be as concerned about today's problems as we are already too late to correct them. Many excellent varieties have been released which are 10 years too late. An example of this was VFN8, one of the best hand harvest varieties developed by Professor Hanna while at the University of California, which was released at the time of the industry's change to mechanization. At Petoseed we attempt to anticipate the needs brought about by population shifts, government policies, new product developments, new races of diseases, new potential growing areas and labor requirements in the world. This is not easy to do and in many instances is at best an educated guess. It is a matter of accumulating germ plasm from whatever source we can find that will give to us new sources of disease resistance and fruit and plant characteristic necessary to assist us in breeding for this ever changing industry. We have seen tremendous strides in the industry primarily through the advent of mechanical harvesting and the incorporation of many new sources of disease resistance and the one thing I can promise you here, today, is we will continue to see these changes occur with newer and better varieties for the future.
Thomas, P. (1980). BREEDING PROCESSING TOMATOES FOR THE WORLD FROM PETOSEED. Acta Hortic. 100, 395-398
DOI: 10.17660/ActaHortic.1980.100.42
https://doi.org/10.17660/ActaHortic.1980.100.42

Acta Horticulturae