Research Highlights from the Berry Program of the University of Guelph

From a presentation at the Ontario Fruit and Vegetable Convention, Feb 16, 2006

Today, I shall be talking about highlights in berry research that have happened over the last 10-15 years. These would not have been accomplished without the help and support of many people in various research teams, the leaders of these teams are Becky Hughes, John Zandstra, John O'Sullivan, Rebecca Hallett, and John Potter (AAFC). I shall highlight eight areas and talk briefly about the future.

Varietal resistance to root lesion nematode. We came up with the concept nematode load to describe the variation between strawberry varieties. Simply put, nematode load is the number of nematodes that plant will host. It includes all the nematodes in the roots and in the surrounding soil. Our results showed that varieties closely related to Veestar and Redcoat would host about three times as many root lesion nematode as those related to the University of California germplasm, such as Annapolis and Glooscap.

Resistance to Tarnished plant bug. Tarnished plant bugs cause considerable damage to strawberry fruits, particularly dayneutral varieties. We surveyed a large number of varieties and selections to try to detect variability that we could exploit. Two years data indicated that Fragaria virginiana clones collected in Ontario were much more resistant to plant bugs than cultivated varieties. However, there was considerable variability within the cultivated varieties. Evangeline and the dayneutral, Fort Laramie, were the most tolerant.

Additional studies showed that resistance was polygenic and recessive. However, we have been able to select dayneutral clones with high resistance from progenies of Fort Laramie x Evangeline and Fort Laramie and FV4-90, a wild hybrid.

Presently, we have a graduate student, Cynthia Rougoor, investigating the mechanisms of resistance in strawberry tarnished plant bugs.

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Strawberry breeding. The program has released a number of varieties over the years. The most recent of these were: Startyme (1995), G19 (1997), Sapphire (2001) and Serenity (2002). We expect to release an early variety in 2007, and three or four more from 2009 onwards as virus-tested material becomes available.

Also, we have been selecting for winter-hardiness in New Liskeard and have one selection that has potential. This is presently being virus-tested.

Greenhouse raspberries. Since 1994, we have been working to develop systems to grow raspberries successfully year-round in the greenhouse. We have determined which varieties are suitable, worked out scheduling protocols and determined the economic feasibility.

The first thing we noticed was that the fruit quality of greenhouse-grown raspberries is vastly superior to that from field-grown plants.

The most suitable varieties that are available to us, are the summer-bearers, Tulameen and Nova, the early fall-bearers, Autumn Britten and Polana, and the yellow fall-bearer, Anne.

Fruiting can be scheduled in several ways. With summer-bearing varieties, plants can be brought into the greenhouse at 6 week intervals to give continuous cropping. With fall-bearing plants, canes can be summer-pruned and plant can be cold-stored to achieve the same effect.

Economic studies which used data from a greenhouse raspberry grower, indicated that raspberries can be grown profitably. If the greenhouse was dedicated to raspberries, an internal rate of return of 18% was achieved. If the greenhouse costs were amortized over two crops the internal rate of return was 42%

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Gyphosate resistance in strawberries. Resistance to glyphosate is found in wild strawberries in Ontario. This has been transferred by conventional means into cultivated strawberry. Our selections are not yet completely resistant, but we estimate that practical levels of resistance will be available in selections of variety quality in two more generations.

Herbicide and insecticide trials. The Simcoe Research Station is GLP certified. Consequently , over the last three years, Dual II Magnum, Spartan, Admire, Select and Sencor have been tested in residue and tolerance trials on some of the berry crops. The data from these trials are now part of applications for minor use registrations.

Dayneutral strawberries. Dayneutral strawberries will fruit in Ontario throughout the summer and can extend the fruiting season well beyond the normal strawberry season. When high tunnels are used there is potential to harvest fruit from late May into November.

This year we have started a project to assess the market feasibility and gather market intelligence, develop adapted dayneutral varieties which will enable us to compete with imports, investigate dayneutral production methods to maximize yield, and to determine how feasible it is to use high tunnels to extend the season.

Future research. Over the last year, a group of researchers has been assembled to work together on berry crops. They include production scientists, working on production and plant physiology, breeding, entomology and pathology, post-harvest physiology and food chemistry, and extension specialists. Together we hope to provide the information to maintain and expand the berry industry in the Province.

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