Photo by Ronda Payne
Eric Gerbrandt
A berry researcher recognizes the need to look to the integration of methods to sustain the future of a much loved berry.
Growers and farmers differ. They have different land, different practices, different points of view; but there’s one thing raspberry farmers have in common – the struggle against declining crop yields. It’s something Eric Gerbrandt, berry scientist and owner of Sky Blue Horticulture, wants to help change. He believes the key is to bring multiple methodologies together for the berry’s benefit.
“The future sustainability of raspberry production in the Fraser Valley requires integrated solutions to soil-borne disease and pest issues that contribute to a yield decline complex,” he says.
The scary truth is that raspberry plantings don’t last for as long as they once did. Their yields and vigour have been impacted and the preferred methods of dealing with soil-borne issues have been altered by regulatory controls,.
Together with other researchers, Gerbrandt has been involved in a number of studies to look at solutions to help raspberries return to their former productivity levels. It’s a complex issue and one that requires complex trials. A number of these studies are happening in Clearbrook (at the Agriculture and Agri-Food Canada Clearbrook Substation) in tandem with the BC berry breeding program.
“We’ve taken the first stab at integrated solutions…obviously there’s more to look at. One step that we have worked on recently is to integrate bed fumigation with organic amendments and the use of tissue culture plugs with plastic mulches,” Gerbrandt notes. “In addition to this, we are using germ plasm from the BC berry breeding program to understand the genetics of resistance to pest and soil-borne disease pressures.”
With so many inputs, the latest experiments involving Meeker variety tissue culture plugs and bare-root plants from commercial nurseries have required multiple plots and replication to look at all the potential aspects, and provide growers with sound results. The final results of one study are being compiled and new areas of study are now underway.
One of those new studies includes looking at applying bed fumigation via the drip line. Others involve reviews of alternative fertility management options in raspberries as well as in blueberries.
The approach to address overall raspberry yield declines is three-pronged. As Gerbrandt explains, the first step is looking at improved establishment practices.
“To give the plants a better, healthier start,” he notes. “This includes things like plastic mulch, tissue culture and organic amendments.”
The second prong is what Gerbrandt describes as “directly waging war against the causal agents, pests and diseases we know are going to be a problem in the future.”
This involves tools like bed fumigation and application post-plant nematicidal products applied in a unique way (through a drip line, which is not a common practice). Studies have shown that fumigation is still the best known method for control of nematodes.
“We are looking at fumigation alternatives in a more restricted regulatory environment,” says Gerbrandt. “We’re primarily targeting parasitic nematodes using pre-plant fumigation. We’re also evaluating post-plant options in the context of tissue culture plugs planted under plastic mulch.”
Novel activities like the post-plant dripline application of nematicides are being evaluated and may help to accelerate the application for new product registrations for the industry.
The third prong is, “utilizing all fertilization practices to foster a healthy soil environment and stimulate better plant growth,” he notes. “For example, the use of organic acids to alter nutrient availability. This work is in the early stages for both raspberries and blueberries. We are building on work by other researches in the Pacific Northwest.”
When asked just why the raspberry industry is experiencing a decline in yield, Gerbrandt pointed to a variety of reasons, one being the longevity of the industry in the Fraser Valley.
“It’s because the raspberry industry has been growing on the same land for three or four decades,” he says.
Rising land prices, limited ability to rotate crops, soil-borne pests and a range of diseases have had the opportunity to accumulate and work against the industry in limiting production.
That reduced productivity has been a double-edged sword for the raspberry industry as it was one of the elements that led to the decline in raspberry acreages. Not only were berry growers achieving smaller yields, some were removing their raspberries in favour of other crops as a result of those declined yields, causing an overall reduction in the tonnage of berries in the market from BC
All is not doom and gloom however. Gerbrandt sees his work, and that of other berry researchers, as having a positive impact on keeping the industry growing and sustainable for generations to come.
“The raspberry industry is very supportive of both plant breeding and finding ways to combat yield declines,” he notes.
Raspberry yield decline is a serious issue of concern to growers and those who value the berry. Fortunately researchers like Gerbrandt are looking at new possibilities, with multiple options, to keep the industry alive and growing. ■
