Organic Trials

By Dan Woolley
August 27, 2007

The Organic Agriculture Centre of Canada’s Brookside trials site this summer has proven difficult at time for researchers.

Dr. Derek Lynch, a senior OACC researcher, commented carrots are a challenging crop, "particularly this year with all the rain."

Raised beds are a big part of the weed management strategy for organic carrot production, along with flame weeding, but with the wet weather the carrot beds sank and weed control became even more difficult because researchers could not get onto the carrot site early due to the wet weather, Lynch said. Just one year into the carrot rotation, weed numbers were high in the trials plot which uses a green manure of oats, peas and vetch, he said, adding that potatoes are also a part of this rotation which ties in well with other research the OACC is doing on greenhouse gas emission and soil amendments.

Emily Clegg, a graduate student, is doing research on greenhouse gas emissions from organic potato plots by examining the effects of organic matter in the soil on emission rates in plots that have been under seeded with different forage crops such as timothy or clover.

Dr. Andrew Hammermeister, OACC research scientist, observed that wireworm is found in a lot of former pasture fields which can cause a lot of damage to carrot and potato crops.

Consumers will not buy produce whose appearance has been marred by wireworm, he said, noting organic producers have no real control measure for wireworm. OACC researchers are, therefore, looking at cover crops as, "a push-pull strategy," to lure the pests away from carrots and potatoes to a nearby attractive alternative such as wheat.

On the adult beetles, Hammermeister said researchers are using four different crop treatments: mustard, buckwheat barley and flax to provide food and habitat for the beetles.

There is anecdotal evidence from farmers that buckwheat will depress wireworm numbers in the soil, he said. Mustard also excretes a natural compound, glucosalinate, into the soil which might also depress wireworm populations and alfalfa may also dessicate the soil making conditions inhospitable for wireworm.

Barley, under seeded with clover could be a control as could brown mustard ploughed down into the soil, said Hammermeister.

In conjunction with these treatments, he mentioned they are also looking planting pheromone traps in the soil to reduce beetle numbers.

Roxanne Beavers, a graduate student, is conducting carrot trials at six sites across the Maritimes with cooperating farmers, comparing two conventional varieties commonly grown in the region, Napoli and Neptune against 12 different hybrid organic varieties.

The OACC also has trials on eight broccoli varieties, including several newly-introduced organic hybrids.

Ms. Beavers also has trials on pumpkins that produce oil in their seed. She wants to see if the oil pumpkin varieties will grow in the Maritime climate and what quality of oil they will produce.

Pumpkin oil is very high in zinc, which is good for prostate gland health, and it is also a salad oil ingredient, she said.

The OACC also has Polish canola on trial, but it has presented a management challenge because finger weeding it has been very difficult this year, Hammermeister said.

This is the first year the OACC has attempted a trial on navy beans; but weed control has also been an issue as had "mud tagging," he said.

The OACC is also conducting mixed cropping trials for organic grain producers.

Hammermeister reported in a low fertility field peas did very well compensating for the low yield in grains.

He saw the advantage of mixed cropping in providing that yield compensation; but it was also important to prevent lodging as peas will pull down grain. He also conceded: "The downside is processors may not want grains mixed with other crops."

The OACC also has trials on four different wheats: Red Fife, Helen, Barrie and Walton. Besides the Brookside site, the wheat trials are also replicated in New Brunswick and Prince Edward Island. Speerville Mills in NB will then mill the grain for flour to be tested by bakers.

Hammermeister said OACC barley trials are testing seven different seed treatments, including the stimulant Nanogro to address seed quality issues.

He noted there are only a limited number of barley seed cultivars available and there is a reluctance to get into seed production for organic barley.

The OACC also has trials on white lupins; but Hammermeister sees no point in continuing them if producers do not adopt the crop or there is no local supply of seeds.

This year the OACC also had a 75-percent stand loss in lupins. One of the big challenges in lupins is weed control and so Hammermeister said the OACC is looking at pest and weed control.

Lupins have a high protein content and are used as an animal feed and silage in Europe. Although it is a more aggressive crop than soybeans; it is a late crop and so the OACC will look at Nanogro to stimulate the lupin’s immune response to see if anthracnnose can be controlled.

OACC researchers have trials on nine different soybean varieties, comparing them to see how they perform under different row spacings.

Hammermeister remarked: "It is a difficult year to manage soybeans as you can’t easily finger weed."

 

OACC wishes to gratefully acknowledge the author, Dan Woolley for permission to post this article on our website.

 

Posted December 2007