Expansion of blueberry culture in North America has occurred during the past decade and is projected to continue into the next century. Thirty-six U.S. states and six Canadian provinces report some blueberry production. The area planted to blueberries has inreased by 19% in 10 years, with the largest increase (47%) in cultivated types and only 11% in wild blueberries. It is projected that the total area will increase by an additional 14% by the year 2000. New cultivars are proving of value and are affecting the composition of plantings. Greater interest is being given to mechanical harvesting, and new cultural and pest control innovations are being employed to enhance the economics of production. The expansion of blueberry production is being undergirded by expanded programs in problem-solving research.
James N. Moore
Ed Stover, William Castle, and Chih-Cheng T. Chao
The world market for citrus (Citrus spp.) products has undergone dramatic shifts over the last decade. These shifts are influencing development and planting of new citrus cultivars. Seedlessness and very easy peeling have become paramount in mandarin types (C. reticulata and hybrids), and new cultivars are being developed through plant breeding and selection of new sports. In both sweet orange (C. sinensis) and grapefruit (C. paradisi), essentially all important cultivars are derived from a single original hybrid of each fruit type, and plant improvement has focused on selection of sports with redder color and extended maturity. The existence of many active citrus breeding programs makes it likely that we will continue to see evolution of new citrus cultivars over the foreseeable future.
The Louisiana Agricultural Experiment Station has released a new pinkeye purple hull-type southernpea cultivar for the fresh market. The new cultivar, Quickpick, originated from a cross between breeding lines LA 88-74 and LA 88-9. `Quickpick' has a bush-type plant habit with synchronous pod set and is suitable for either machine- or hand-harvest. Pods of `Quickpick' are straight, ≈20 cm long, and about 8 mm in diameter. Fresh peas are green with a light-pink eye. Yield of `Quickpick' equaled or surpassed yield of `Texas Pinkeye Purple Hull' in machine-harvested replicated tests. In hand-harvested replicated tests, yield of `Quickpick' was comparable to `Texas Pinkeye Purple Hull', `Coronet', `Pinkeye Purple Hull-BVR', `Mississippi Pinkeye', and `Santee Early Pinkeye'. `Quickpick' is immune to a Georgia isolate of blackeye cowpea mosaic virus, a major virus of southernpea in the United States.
Andrew R. Jamieson and Katherine Sanford
Twelve clones of `Blomidon' strawberry (Fragaria xananassa) exhibiting a range of severity of June Yellows symptoms were grown in field plots to measure effects on productivity. Field plot layout was a randomized block design with four blocks. Plots were matted rows developed from five plants spaced at 45 cm inrow. Fruit samples were frozen and later analyzed for soluble solids concentration, total acidity, and pH. In the greenhouse, self-pollinated seedlings grown from these clones were rated for symptom expression as an additional measure of severity of June Yellows. Large differences in marketable yields were recorded, ranging from 1.94 t·ha–1 to 14.67 t·ha–1. Clones with severe symptoms produced smaller fruit. Small clonal differences were measured in total acidity and pH. A strong correlation was observed between the percentage of symptomless seedlings and the yield of the parental clone. This may lead to a test to predict whether a new cultivar will succumb to June Yellows.
Craig K. Chandler, T. E. Crocker, and E. E. Albregts
During the past 10 years, the Florida strawberry growers, through the Florida Strawberry Growers Association, have made a serious commitment to fund university research on strawberries. They have purchased equipment and donated monies for facilities at Dover. They have also helped support a new faculty position in breeding and genetics. During this same period, the University of Florida has made an equally strong commitment to support strawberry research and extension. These commitments are beginning to pay significant dividends for industry and the University. Cultural and pest management information has been generated that is saving the industy money, and the breeding program is developing new cultivars that will keep the industry competitive in the marketplace. The University has benefitted through the acquisition of new facilities, equipment, and faculty and graduate student support.
F. Kappel, P. Toivonen, D.-L. McKenzie, and S. Stan
Several sweet cherry (Prunus avium L.) cultivars were stored in air or modified-atmosphere packages (MAP) at 1 °C for 2 or 4 weeks, respectively. The new cultivars included `Santina', `Sumpaca Celeste', `Sumnue Cristalina', `Sumste Samba', `Sandra Rose', `Sumleta Sonata', and `Skeena', and the standards were `Lapins', `Sweetheart', and `Bing'. Fruit were rated for defects (stem browning, stem shrivel and fruit surface pitting), and fruit quality at harvest and after storage. Weight loss during storage was influenced by year, storage treatment, and cultivar. Stem shrivel, stem browning, and fruit surface pitting varied among cultivars and years. Generally, fruit stored in MAP had higher fruit firmness than at harvest or when stored in air. The respiration rate of fruit was lower in later than in earlier maturing cultivars, but respiration rate at harvest was not related to any of the quality measurements taken after storage.
James N. Moore
The blueberry cultivar situation in North America is undergoing rapid change. Attempts to grow blueberries in non-traditional areas, and increased biotic and abiotic challenges in traditional production areas, are fueling the search for superior, adapted cultivars. This survey of all blueberry-producing states/provinces in the United States and Canada provides the current status and projected trends in blueberry cultivar use in North America. Most (86%) of current hectarage is comprised of 25 northern highbush, 10 rabbiteye, and two southern highbush cultivars. `Bluecrop' is the dominant northern highbush cultivar, with 35% of the highbush area, while `Tifblue' occupies 40% of the rabbiteye area. Some historically important cultivars, such as `Jersey', `Weymouth', and `Woodard' are in decline. New cultivars of all blueberry types are beginning to have a positive impact on the blueberry industry.
Henry M. Donselman
Tissue culture labs based in countries with high labor costs are becoming more dependent on proprietary plants. This has increased the necessity of high profile plant breeding programs. Foliage and flowering plant breeding programs have evolved rapidly to take advantage of the benefits associated with tissue culture labs.
Breeding strategies and methods will be discussed on existing flowering and foliage programs for Anthuriums, Euphorbia, Aloe, Spathiphyllum, Homalomena, and Dieffenbachia. Embryo rescue in the lab has increased the survival of wide crosses from different species within a genera. Rapid multiplication of selected clones has increased the efficiency of screening for disease and insect resistance in the selection of new cultivars. Marketing, along with improved horticultural characteristics, determine the success of new releases.
James N. Moore
Blackberries have long been a popular fruit in the southern U.S., and they are widely grown there, with excellent potential for expanded production. Raspberries are also well-liked, but not widely grown, due to lack of adapted cultivars. Great progress has been made, particularly in the past four decades, in improving blackberry cultivars for the South, but little effort has been given to raspberry improvement. Germplasm exists within Rubus to provide great advances in conventional cultivar improvement in both subgenera and for creating new types of fruits through interspecific hybridization. Germplasm and breeding strategies will be discussed that would result in new cultivars to serve as the foundation on which to build much expanded blackberry and raspberry industries in the southern United States.
Duane W. Greene and Wesley R. Autio
There is a general increase in interest in planting new apple cultivars. The loss of daminozide has provided an additional stimulus for growers in New England to find an alternative to McIntosh. Promising new apple cultivars have been identified from around the world and from breeding programs in Arkansas, British Columbia, New York, New Jersey and the PRI Program. Trees were propagated and planted in a cultivar evaluation block at the University of Massachusetts Horticultural Research Center. In 1992 we evaluated over 80 new cultivars. Fruit assessment consisted of laboratory analysis and visual and sensory evaluation. All cultivar were given an overall rating, and several were identified as being worthy of further evaluation. These apple cultivars include: Arlet, BC 9P 14-32, BC 8M 15-10, BC 17-30, Ginger Gold, Honeycrisp, Kinsei, NJ 55, NY 75414-1, and Sansa.