2010 Annual Report
Objective 2: Integrate new and existing small fruit cultivars into efficient, environmentally acceptable production systems. Sub-objectives: a. Determine the physiological response of small fruit genotypes to different environmental constraints (e.g., soil water limitations, nutrient deficiency, extreme temperatures, and plant diseases) and identify key determinants of resistance, tolerance, and susceptibility to these constraints. b. Develop cultural practices and crop management systems including better irrigation and fertilizer management practices for new and existing small fruit cultivars that mitigate environmental constraints on their horticultural performance and optimize their genetic yield potential.
To develop a better understanding of inheritance of aphid resistance in black raspberry, we established a new seedling field using plants screened for aphid resistance and developed a group of aphid-resistant selections that will serve as the foundation for producing cultivars resistant to aphid-borne black raspberry necrosis virus.
To support breeding programs throughout the U.S., we assembled strawberry germplasm and organized the distribution of 900 strawberry clones to breeding programs in California, Florida, Michigan, New Hampshire, and Oregon, as well as The Netherlands, France, and the United Kingdom. We also made 58 strawberry selections; planted three dozen thornless blackberry selections in replicated trial; and made 28 new blueberry crosses for our new breeding efforts in blueberry.
To increase production and reduce losses of natural resources, we determined the water requirements for irrigation of blueberry and raspberry by drip and identified the best location in each crop to position the drip emitters. We discovered that drip reduced irrigation needs by 20-25% of conventional sprinkler systems and that the actual crop water requirements were less than half the rate currently recommended by USBR and FAO. We are developing irrigation strategies, such as deficit irrigation and evaporative cooling, for enhancing fruit quality of these crops.
We found in young blueberries that N fertigation, or injection of N fertilizer through the drip lines, produced more growth and less salt injury than conventional fertilizers but required much more N fertilizer. Thus, a new study was initiated with six blueberry genotypes to identify cultural practices and inherent plant traits for improving N use efficiency with fertigation.
In cooperation with scientists at Oregon State University, we completed the first 3 years of a long-term project to develop organic production systems for highbush blueberry that maximize plant growth, yield, and fruit quality; facilitate weed, water, and nutrient management; and provide economic benefit to growers. We also continued work to produce a custom compost for blueberry and began a new project to identify practices for organic production and processing of blackberry.
5.Significant Activities that Support Special Target Populations
The blackberry, raspberry, blueberry and strawberry cultivars we have released have been valuable for large and small farmers. Finn, C.E., Clark, J.R., Sleezer, S. 2010. Blackberry. HortScience. 45:720-721.
Du, X., Kurnianta, A., Mcdaniel, M., Finn, C.E., Qian, M.C. 2010. Flavour profiling of 'Marion' and thornless blackberries by instrumental and sensory analysis. Food Chemistry. 121:1080-1088.
Du, X., Finn, C.E., Qian, M. 2010. Bound volatile precursors in genotypes in the pedigree of 'Marion' Blackberry (Rubus Sp.). Journal of Agricultural and Food Chemistry. 58:3694-3699.
Du, X., Finn, C.E., Qian, M. 2010. Distribution of volatile composition in 'Marion' (Rubus Species Hyb) blackberry pedigree. Journal of Agricultural and Food Chemistry. 1860-1869.
Du, X., Finn, C.E., Qian, M. 2010. Volatile composition and odour-activity value of thornless 'Black Diamond' and 'Marion' blackberries. Food Chemistry. 119:1127-1134.
Thompson, E., Strik, B., Finn, C.E., Zhao, Y., Clark, J.R. 2009. High tunnel versus open field: management of primocane-fruiting blackberry using pruning and tipping to increase yield and extend the fruiting season. HortScience. 44(6):1581-1587.