Despite the hundreds of existing stone fruit (Prunus spp.) cultivars used for fresh market, there is a continuing need to develop new stone fruit cultivars as the requirements of the industry change. Over the last 20 years there has been a shift toward private breeding as the public sector decreases its support of these long-range programs. As a result there are fewer public breeding programs and many of those still operating protect their releases and partially fund their programs with royalty payments. Other trends that are shaping the development of new stone fruit cultivars are a need for smaller or more easily managed tree architecture, a trend toward the use of fewer agricultural chemicals, the expansion of production zones into the milder winter zones to allow year-round availability of stone fruit, a general diversification of fruit types being marketed, the increased awareness of the health benefits of fruit consumption, the need for better and more consistent quality, and given the global marketing of these fruit the increased need for enhanced postharvest qualities. The breeding programs of the world are responding to these trends and working toward developing the cultivars for the world markets of the future.
David H. Byrne
Lisa Tang, Shweta Chhajed, Tripti Vashisth, Mercy A. Olmstead, James W. Olmstead, and Thomas A. Colquhoun
budbreak is critical for the onset of fruit production and the market window. For peach production in subtropic climates such as the southeastern United States, low-chill cultivars, which require less chill accumulation than those originating from temperate
Ayoub Fathi-Najafabadi, Cristina Besada, Rebeca Gil, and Alejandra Salvador
suffer chilling injury at 0 °C for up to 56 d, plus a 7-day shelf life. Fruit characteristics and postharvest behavior, mainly low chilling injury susceptibility, were corroborated during the second season. In the Mediterranean Region, the ‘Suruga
Elizabeth Conlan, Tatiana Borisova, Erick Smith, Jeffrey Williamson, and Mercy Olmstead
.S. Department of Agriculture, 2017 ). Despite early-ripening varieties being susceptible to spring frost injury ( Strik and Yarborough, 2005 ), low-chill, early harvest southern highbush blueberries [SHB ( Vaccinium corymbosum interspecific hybrids)] have been
David Campbell, Ali Sarkhosh, Jeffrey K. Brecht, Jennifer L. Gillett-Kaufman, Oscar Liburd, Juan Carlos Melgar, and Danielle Treadwell
production of organic peach in southeastern states (area not reported for South Carolina, Georgia, or Florida by the USDA NASS, 2017 ) forces resident consumers of organic peach to purchase fruit imported from other regions. In Florida, low-chill peach
Ivan dos Santos Pereira, Luciano Picolotto, Michél Aldrighi Gonçalves, Gerson Kleinick Vignolo, and Luis Eduardo Corrêa Antunes
the most common in Mexico, mainly for export to the United States. ‘Tupy’ is a low-chill, semierect, vigorous, and thorny plant which produces large fruits (8 to 10 g) with soluble solid content between 8 and 10 °Brix. ‘Xavante’ is a low-chill
M.K. Ehlenfeldt, A.D. Draper, and J.R. Clark
In the 1970s, the U.S. Department of Agriculture (USDA) began developing low-chill-adapted highbush blueberry (Vacchizium corymbosum L.) for the southern United States (lat. 29° to 32°N) by using germplasm of the native southern species, V. darrowi Camp. This breeding work resulted in the release of several low-chill southern highbush blueberry (SHB) cultivars in the mid-1980s. These cultivars have been evaluated for yield and adaptation at several locations through the southern regional blueberry germplasm evaluation trials. These trials have shown that organic mulch is required for good performance of SHB. The one-fourth V. darrowi composition of SHB cultivars presents problems of freeze damage at some locations. This problem may be resolved by breeding cultivars through several alternative approaches.
Shyi-Kuan Ou and Chia-Wei Song
The `Xiami' peach [Prunus persica SummerHoney(`Xiami')] has been released by the Taiwan Agricultural Research Institute, Council of Agriculture to provide a late maturity in the last few days of May to mid June, a large peach, high yielding, excellent quality, melting, white with red fleshed, freestone, with a very low chilling requirement of around 125 chill units. `Xiami' peach is named for its late ripening time, juicy, low acid, and sweet fruit.
Ashish Yadav, Anand Krishna Yadav, and Lila Dhar Bist
Pear growing in subtropics began with the advent of low-chill pears, but their fruit quality is inferior to high-chill European/Oriental pears. Thus, the best way to produce high-chill pears in subtropics is by topworking them on the low-chill pears. To attain this, pruned wood with spurs of `Doyenne du Comice' (DCP) and `Victoria pear' (VP) cultivars were collected in January from Hort Expt Center Chaubatia, India (6825'ASL), and tongue grafted on low-chill `Pant Pear-18' (PP18). The grafting was at different heights on trees using 25-cm and 1-m long stocks on Tatura trellis-trained PP18 trees at the Hort. Research Center, Pantnagar (760' ASL). More than 90% grafts succeeded and both DCP and VP produced high quality fruits, but DCP grafts had an edge over VP scions. Both high-chill cultivars topworked on 25-cm stocks had better grafting success (95%) than the scions topworked on 1-m stocks (92%). The increase in topworking heights on stock trees reduced the floral spur numbers in both scions grafted on 25-cm stocks, but not on the scions grafted on 1-m stocks. With the incremental height of topworking irrespective of the length of stocks, the percentage of fruit set was curtailed by 28% and 12% for the DCP and VP scions, respectively. Irrespective of the topworking heights and stock lengths, the fruit yield for DCP (12.5 lbs/tree) was markedly higher than for VP (7.9 lbs/tree). Fruit quality attributes judged by organoleptic testing, TSS, total sugars, acidity, and ascorbic acid, were better for both DCP and VP than for PP18 and other local pear cultivars. The reuse of previous year's scions topworked even after artificial chilling and/or GA3 application to supplement chilling exhibited no fruiting advantage over the grafting using fresh scions.
A highly significant correlation was observed between time of bloom of individual peach trees [Prunus persica (L.) Batsch.] and number of days required for resulting selfed seed to reach 80% germination on both local (r = 0.71) and introduced (r = 0.87) genotypes that exhibited a wide range in time of blossom. When genotypes with low chilling requirement (LCR) were pollinated with high chilling requirement (HCR) pollen sources, germination was delayed up to 16 days with respect to seeds that originated from selfing, while LCR pollen sources on late-blossoming genotypes accelerated germination 20 to 24 days.