April 2001
New chemicals offer weed control solutions for hard-to-kill perennials
The right combination of spray solutions can give you a handle on the toughest challengesby DON STONEMAN
When you've got 10,000 acres of cropland to plant, spray, harvest, and rotate, there are bound to be a few "problem weeds" in the mix. At least, Mike Dick feels that he now has a leg up on Canada thistle.Dick is the agronomist for Anthony Acres Farms, based in Limehouse, near Acton. Two years ago, he was looking at a particular farm that was infested with Canada thistle and was a good site for a new weed spray test. In 1999, that field was sprayed with a tank mix of Ultim and Distinct, a mix favoured by spray maker BASF. Test plots were left unsprayed as a check. "There was definitely lots of thistle in there," Dick says. The spray knocked down the thistle. "I don't think it (the thistle) was an issue for that corn crop."
What surprised Dick was the effect that the 1999 spray had on the crop planted the following year. "We were very surprised at how little of the thistle came back. Wherever the treatments were, it was fairly clean," he says. The unsprayed checks stood out in sharp relief.
Some of the new chemistry on the market is offering farmers relief from hard-to-kill perennials. At Ridgetown College, weed researcher Peter Sikkema sees potential for control of Canada thistle. In the last couple of years he's been looking at a couple of combinations, one an Ultim and Distinct tank mix, the other Accent and Summit. Of the two combinations, he thinks that the Ultim-Distinct mix has a slight advantage. He says there is about 80 per cent control of Canada thistle in the year that the spray is applied.
Distinct has a small amount of dicamba and something new that mimics plant hormones. The new ingredient is called diflufenzopyr. Peter Zwart, field biologist for BASF, explains that diflufenzopyr's site of action is the growing point of the plant. It makes the plant grow very fast, concentrating the dicamba in the growing point, where it kills the plant. Because the dicamba is concentrated in that key point, a lower rate of the chemical can be used, Zwart explains.
The dicamba-diflufenzopyr combination controls most tough perennial broadleafs, including Canada thistle, perennial sow thistle and prickly lettuce, and it does a reasonably good job on dandelions, he says. Zwart says the control on Canada thistle is especially good, and he is more optimistic about results than was Sikkema. In test plots, there was still a full 80 per cent control the year following the application, compared to an untreated check.
This combination is also effective against such tough perennials as sow-thistle and horse-nettle. As well, the Ultim-Distinct tank mix has what Sikkema describes as "some interesting activity" in prickly lettuce. He explains that Distinct is a BASF product while Ultim is a Dupont chemistry and Accent-Summit is a Syngenta product. The active ingredient in Accent is nicosulfuron. Summit's ingredients are primisulfuron and dicamba in one jug. As for the tough-to-handle weeds, there are spray solutions for some but not for others, Sikkema has found. For Spreading Atrplex, glyphosate applied alone as a pre-emergent in no-till corn offers only poor full season control. But all the glyphosate tank mixes that were tested did a good job of controlling weeds throughout the season. Atrazine sprayed post-emerge gives fair control. Mesotrione gave good control, as did primisulfuron and dicamba and the dicamba/diflufenzopyr mix. Swamp Smartweed remains untouched. At the four-to-six-leaf stage of corn, there is no acceptable control for this weed.
A run down on some of the other culprits:
Volunteer hemp. Atrazine, dicamba/diflufenzopyr, dicamba/atrazine, bromoxynil plus atrazine and prosulfuron plus dicamba all do the job. So do glyphosate and glufosinate.
Canada Fleabane. Glyphosate applied alone pre-emergence, or any of the glyphosate tank mixes tested, provided excellent control of Canada Fleabane in corn. Flumetsulam, clopyralid, 2,4-D, dicamba and ZA 1296 all gave excellent full season results.
Crabgrass. All the pre-emergence and post-emergence treatments that were tested provided good to excellent control of this weed in corn.
Sandbur. Hit it post-emerge with rimsulfron or nicosulfuron and rimsulfuron for good control. The effectiveness of s-metolachlor with benoxacor and atrazine isn't as clear.
Bur Cucumber. Pre-emerge treatments don't hold this weed off full season. Bromoxynil and atrazine applied post-emerge gave full season control in corn.
Field Horsetail. The jury is out on control for this weed. All of Sikkema's post-emerge tankmixes controlled Field Horsetail in one location while giving only poor to fair control at another.
Horsenettle. Just about everything worked on this weed last year.
Annual Sowthistle. All of the post-emerge corn treatments worked except for mesotrione.
Dandelion. Glyphosate plus imazethapyr is the ticket to corn control here.
Three Seeded Mercury. Hit it with pre-plant glyphosate plus imazethapyr. All of the post-emerge treatments work with the exception of flufosinate.
Proso millet. Isoxaflutole plus atrazine works as a pre-emerge. Post-emergent applications include the aforementioned nicosulfuron/rimsulfuron or either one of them alone.BF
© copyright 2001 AgMedia Co-operative Inc..
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Weighing the pros and cons of three-phase electricity
Three-phase is ideal for motors, but it can be expensive to bring to the farm. Look before you leapby RON MACDONALD
Electrical deregulation's effects are just beginning to be felt in the United States and, so far, the only thing certain is that no one knows what the long-term effects will be for American farm customers.Ontario is now in the process of deregulation as well. And, like the United States, where it will end up is anyone's guess. The old Ontario Hydro and its spun-off companies will always be a supplier available to rural Ontario. However, it is expected that a number of other retail companies will emerge, each with its own pricing structures and marketing pitches suggesting they offer the best pricing and services.
The coming electricity and energy market deregulation, plus the trend to larger farms, means you have opportunities to improve the cost and efficiency of running your farm. However, be sure to investigate thoroughly what this will mean for your farm by evaluating technologies such as three-phase power and the different electricity sellers sure to appear.
As farms continue to grow in size and electrical load, the question regarding three-phase power keeps coming up. There are a number of reasons to use three-phase power, but also times when it is impractical and expensive.
Three-phase power is ideal for motors. They are much simpler, with fewer moving parts and thus much more reliable than single phase motors. Three-phase motors are usually more efficient, meaning that they convert the electricity supplied to them to rotational motion at the motor shaft; the rest of the energy is lost in heat, friction, etc. The larger the motor, the more efficient it is in using energy. These motors are also easier to start, even under load. They reduce surges on the line (which reduces problems with voltage-sensitive electronics such as controllers) and cost less on a dollar-per-horsepower basis.
So, with all these advantages, why don't all farms convert to three-phase power right away? There are a number of barriers:
* Three-phase power is very expensive to bring into the farm. Since you have to pay from the road to the farmyard, costs can escalate to four times that of single phase
* If three-phase power is not out at the road, then new road lines must be erected, meaning higher and stronger poles, transformers and wire. This is prohibitively expensive and rarely would any business requiring three-phase power locate where it needed to be brought far down a road.
* Three-phase power is more expensive until electrical consumption rises to $1,200 or more a month.
* Three-phase power is more powerful and therefore more dangerous to work with. Many electricians choose not to work on three-phase power, and certainly many producers used to doing their own repairs and minor installations should think twice before tackling three-phase.
* On most farm operations, there may be many motors around. But often these motors are "fractional" (less than one hp). Three-phase motors are generally not as readily available for these smaller loads, so we are stuck with the regular single-phase motors even though three-phase power may be available on the farm.
* Because there are a number of single-phase loads on most farms, from block heaters to computers to power tools, a transformer from three- to single-phase power is needed. This is another expense and component that requires maintenance and replacement. It also wastes energy.
Many livestock and poultry farms may have large electrical motors, up to 25 hp, for unloading silos, manure handling and feed processing. However, it is worth evaluating if converting the entire farm to three-phase is justified for one or two motors.
First, if they only run for short time periods every day, there will be little saved in operating costs. For example, the cost of electricity to run a 10 hp motor for one hour every day to unload corn is about 80 cents. An energy-efficient three-phase would reduce this cost to 60 cents per day, saving about $73 year at current electrical rates. Second, there are other methods of reducing the problems from having one or two large motors on single phase. You can install an inverter, to change single- to three-phase for these limited loads or install a "Written Pole TM" motor on the large loads, so eliminating start-up current and voltage sags You can ensure that the motor used is correctly sized and the correct type for the application. You can use load management to ensure critical components and other larger load motors (washers, dryers, and any other non-critical loads) are not running and ensure the electrical load is balanced on both legs of the single-phase panel.
Consult with your agricultural engineer for more details on these and other techniques and technologies.BF
Ron MacDonald is an agricultural engineer with Agviro Inc., Guelph.
© copyright 2001AgMedia Co-operative Inc..
back Murray Selves' "circle of life" may finally have its day
Though his biogas experiment did not pay off in 1982, success may be just around the corner in the form a Ukrainian anaerobic digesting system. And his daughter, Joanna, is watching closelyby KEN BENNETT
Joanne Selves was in teacher's college at the University of Toronto when her father saw one of his dreams become a reality. Remembered as a consummate innovator, Murray Selves hated the idea of waste. He thought about his farm as a system and would draw encompassing pictures illustrating schemes of how it should be managed. Joanne came to know these as his "circle of life" diagrams. Whatever came out of his hog operation would circle around to be somehow used again.Selves did not see manure as waste, but as a resource to be used. It was this philosophy that made him enthusiastic about a system built on his farm in 1982 that could recycle pig manure into heat, electricity, protein and fertilizer. He was not alone. Now, there could be renewed interest as a Ridgetown group studies an anaerobic digesting system that may be imported from the Ukraine as early as this year.
Jim Morris and Ron Fleming are agriculture professors who are optimistic about a system that was seen as an alternative to increasing the capacity of the manure treatment facility at Ridgetown College. Morris resolved to lead a feasibility study that would satisfy this and a number of his research interests in one system. These include odour control, pathogen removal, greenhouse gas reduction and cost-effective energy recovery.
Fleming explains how it is different from other technologies in that it can take wastewater treatment much further, with the objective of producing a clarified, odourless, pathogen-free flush water for use in the barn. Some of it could be even be purified to the point where it would be safe for livestock to drink. He identifies water supply in Ontario as an emerging issue that people did not envision 10 years ago.
While intensive recycling does echo the past, Morris and Fleming say they are very aware that systems installed in the 1980s left people with the impression that they are not feasible. However, they have not forgotten what was learned on farms such as the Selves' and are exercising due caution.
Joanne is now president of Selves Farms Limited, having seen it grow from 375 sows to a 1,950 sow, multi-site, farrow-to-finish operation. With an MBA in Agriculture from the University of Guelph, she has a sober view of the economics of the long-since-dismantled biogas facility built in 1982. She cites high capital cost and an ongoing management and maintenance cost among the main reasons for the family decision to shut it down in the late 1980s. As well, the predicted rise in energy costs did not materialize. At the time, the buy-back rate given by Ontario Hydro for co-generated power was a fraction of the cost to produce it.
Though energy costs have risen considerably since then, she maintains a system like that would not fly today. It would have to be different. She is clear that the bottom line goal of the farm is pork production and anything that makes pork production better. What would need to change to make such a system viable again would be for environmental and economic benefits to come together as a total package. The economic payback was not evident in a 1986 review to the Ontario Government about biogas production on the Selves farm and several others.
Morris and Fleming agree that those systems were not financially sustainable without government support. They relate the high capital cost to the fact they were tailor-made for each farm. The aim this time is for a package that comes "off the back of a truck."
Still, Fleming emphasises it is not just today's high energy costs that are driving things now, but rather issues related to odour and pathogen removal from animal waste. Motivation is now coming from stronger regulatory and pollution guidelines. While Morris is still negotiating the cost of the new anaerobic system, the feasibility study is satisfied with the operational specifications. The idea is to import the technical expertise while sourcing widely available parts from the North American market. Over the long term, it is hoped the kind of environmental and economic package Joanne Selves spoke about can be met. For an anaerobic waste treatment system to succeed, it will now have to satisfy the needs of a different kind of farm.
On the farm Murray Selves began in 1956, one senses his pioneering spirit is not lost on the next generation. Though he did not live to see the report praising the effectiveness of his digester and the competence of his family and staff, he did see some of his dreams of energy self-sufficiency and waste utilization come off the drawing board and go into practice. As in his diagrams, some of those ideas may now be coming full circle again.BF
© copyright 2001AgMedia Co-operative Inc..
back The timing wasn't ripe for methane production
The experiments of the 1980s showed that the market was not there for on-farm commercialization. Rising fuel prices and a de-regulated Ontario Hydro could spur renewed interestJohn Pittens may have the only remaining methane digester still standing from the government funded renewable energy initiative in the early 1980s. Originally proposed to co-generate power at a rate of 60 kW, the system is now just a cold reminder of the fears of soaring energy prices and fuel shortages that haunted the country for more than a decade from the early 1970s.
by KEN BENNETT A dairy farmer for 38 years, Pittens is clearly the survivor, walking around equipment silenced when those fears weren't realized. Owner of a 400 Holstein dairy operation, he measures his innovations by their business worthiness. His evaluation of methane production? Not worth it. The combination of high capital cost, estimated at almost $250,000 in 1985, and a large maintenance demand began to distract him away from his core product. His business sense told him attention would best be focussed on the management of his herd.
John Ogilvie agrees. Now professor emeritus at the University of Guelph, Ogilvie was project co-ordinator in the early 1980s of the university's large Renewable Energy Applications project, which included a $750,000 methane digester for liquid swine manure. He points out that there has been a continual shift toward specialization in agriculture. With herds growing larger and milk output increasing, farmers would rather spend time concentrating on nutrition than struggling to add value to the waste stream. At the time, it was thought that the farmer could operate the system with a small amount of labour. As it turned out, it took a lot.
Methane, also the primary component of natural gas, is produced by the anaerobic digestion of animal manure. While good quality biogas contains 60-70 per cent methane, it is not as "clean" as natural gas, which is about 97 per cent pure methane. While the remaining fraction of biogas is not useful to combustion, consisting mostly of carbon dioxide, it will readily burn in natural gas devices that have been modified. According to Ogilvie, biogas can be fed directly to a diesel generator. Then the generator requires as little as 10 per cent added diesel fuel to run well.
One of the complexities of anaerobic digesters is that they must be kept warm in order to maintain an optimum production rate. This is because the digestion reaction is actually a living system. Two classifications of bacteria work together in stages to transform the volatile organic manure. One set of bacteria convert the organic solids into volatile acids while the other finishes the process, transforming those acids into methane and carbon dioxide. The whole system is notoriously sensitive and, as Pittens found, it requires constant supervision and monitoring.
While both species of bacteria are dependent on each other to produce methane, they are somewhat less than compatible. The methane-producing bacteria prefer a neutral pH and are sensitive to overproduction by the acid forming bacteria. The methane bacteria are slower growing and prefer warmer temperatures. Therefore, the system must be kept warm and the feed rate of the manure must be steady, yet optimum, so that the acid forming bacteria do not get out of step with the methane producers.
Confounding this is the seasonal temperature fluctuation. Pittens recollects the difficulty of trying to pump manure in the winter at a rate that would prevent freezing. Water heated by some of the methane was used to keep the digester warm. Ogilvie acknowledges one of the methane problems is that it is more easily produced in the summer when it is needed less.
At the time , it was thought that there would be a market hungry to buy energy. But, while Ogilvie's project yielded research gains, the market was not there for on-farm commercialization and there was little demand for selling hydro back to the grid. However, with a de-regulated Ontario Hydro, rising fuel prices and a new outlook that includes placing a value on waste treatment in addition to a value-added product, there may be renewed demand. But if anaerobic digestion is to be reconsidered, it needs to be a more efficient process, require less management, and have a product that matches market demands.
As for John Pittens, he will continue to seek quality, economical feed sources. As a truck rolls into the yard to unload brewery waste, he exhibits a huge feed trough of red liquid with a rich strawberry aroma. A waste product from a candy factory, he claims it is a great energy drink for his milkers. Asked how he finds his sources, he laughs, "When you get big enough, they find you." BF
© copyright 2001AgMedia Co-operative Inc..
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