At the Texas A&M University Stone Fruit Breeding Program we evaluate germplasm from throughout the world and combine traits from various sources with advanced breeding selections in the program to develop superior early-ripening genotypes for low and medium-chill regions throughout the world.A primary program goal is to develop and isolate genotypes that exhibit consistent and superior performance under harsh conditions such as mild winters, spring freezes, and hot, humid summers (see Physiological Disorders of Stone Fruit).


The fruit breeding process is a never-ending, year-round cycle beginning in the winter as we combine and analyze evaluation data from previous years. Careful consideration must be placed on the effects of climatic conditions on cultivar performance. In the southeastern U.S., cultivar performance can be severely affected by the typically unpredictable climate (see: Chill Accumulation, its Importance and Estimation).

Once cultivar performance has been analyzed, parents for the upcoming season are chosen and as soon as bloom begins (usually January), the process of collecting and processing pollen begins. Pollen can be stored until next year, or used in the current season.

Each peach, apricot, and nectarine cross is a laborious process of hand pollinations on whole trees, either in container or in the orchard. Plum trees can be crossed with the use of whole-tree screen frames where a bouquet of the pollen source is placed within the tree and a small hive of bees to disperse the pollen.

Once pollinations are complete, the valuable crosses must be protected from spring freezes (see: Frost Probabilities in Texas). During bloom (usually from mid-January until April) weather forecasts are carefully monitored and if temperatures begin to fall below freezing, sprinklers are turned on to protect the tender blooms and developing fruit. Whole seedling blocks are protected by moveable sprinkler sets (as in the picture) while trees in our orchards are protected by individual microsprinklers mounted above each tree.

Our breeding program specializes in development of cultivars for the early market. Fruiting commences as early as April in Texas and we are continuously in the field throughout the season, evaluating fruit quality in our own orchards, in our hybrid seedling blocks, and in grower-cooperator orchards throughout the State. When an exceptional genotype is found in our hybrid seedling blocks, we select the tree to undergo further trials. A selection is often propagated and planted into our own evaluation orchards. If it becomes an advanced selection, we plant it out into cooperator orchard trials and may be later named as a commercial cultivar.

We are in constant communication with commercial growers, some of which are testing our advanced selections. We evaluate commercial cultivar performance for that year and compare performance of our own selections, and genotypes from other breeding programs, to see what is performing best during that part of the season of that particular year.

Throughout the growing season fruit must be harvested from crosses and seeds extracted from the pits before they can be germinated. We process 4000-8000 hybrid seeds for germination each year. Early-ripening genotypes have immature embryos that must be cultured in test tubes before they will germinate and grow properly (.pdf). When ready to grow, they are planted into containers and placed under lights in the lab for about two weeks, then they are moved to a mist bench in a greenhouse for two weeks.

We then transplant them again into another container where they remain in the greenhouse all winter until February when we plant seedlings into the field. By this time, we have gone full-circle and we are busy making new crosses to produce a new population of seedlings!

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