Volume 37, Number 17 | November 7, 2011
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PRACTICAL PRODUCTION TIPS FOR THE PRAIRIE FARMER
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Six steps to better tank cleanout Is that sprayer really clean? Certain products can cling to tanks, filters and screens, only to be released later and harm susceptible crops BY ANGELA LOVELL (WITH THANKS TO TOM WOLF)
I
mproper or inadequate cleaning of sprayers following the application of Group 2 herbicides can cause significant damage to canola and other susceptible crops. If not cleaned out thoroughly, residue can hang around in the sprayer tank, nozzles or screens. Tom Wolf, a research scientist at Agriculture and Agri-Food Canada at Saskatoon, Sask., has done extensive research into sprayer cleanout procedures, and says that it’s not only important to be thorough when cleaning out the sprayer, but it’s also important to know when it’s necessary to be especially careful. “You need to know what’s in the tank,” says Wolf. “And you need to know what kinds of products may cause you problems and which ones won’t.” There are hundreds of herbicides on the market, says Wolf, and because of the proliferation of different brand names containing the same active ingredients, it’s not always easy for farmers to know what the active ingredient is. With tank mixing now deregulated by the Pest Management Regulatory Agency applicators could also encounter some incompatible mixes. “Producers have to educate themselves and know when to be careful,” says Wolf. “Once you have identified a possible problem then you have to take the appropriate action.” Not all products are going to cause problems in subsequent spray operations, even if some residue remains. “I think most farmers know that there are some products are not an issue, where a tank clean out problem has never been reported,” says Wolf. “Like glyphosate — it’s watersoluble, it washes out very readily with plain water and it tends to lose its effectiveness when diluted a reasonable amount. So even if you have some residue,
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PHOTO : DARWIN KELLS
Group 2 damage to canola in a field near Elfros, Sask. The crop on the left shows significant delayed growth. and it gets diluted, it will be at a concentration where its effect is not noticeable.” Other products, like Group 2s can be more problematic because they are highly effective at very low doses. “You can apply them at one thousandth of the recom-
fall you get essentially a double whammy in terms of the exposure of the crop,” says Wolf, “so that contributes to the potency.” Older formulations of Group 2 products had clay-based carriers that tended to adhere to tank walls, plastic parts and build up
Not all products cause problems, but some can even in tiny amounts mended rate and they can cause damage to a very susceptible crop,” says Wolf. Group 2s are also absorbed by plants through the leaves and the soil, so they may have some degree of persistence in soil. “The persistence may be just days or weeks but if you get an inopportune rain-
on nozzles and screens, then slowly release themselves over successive applications. Recently DuPont, the primary manufacturer of Group 2 herbicides, has changed the formulations to make them easier to clean out. Wolf feels that many of the problems associated with Group
2 products may be alleviated by this change in formulation, he recommends following the steps below to effectively clean out the sprayer, regardless of the products being used.
RINSE IN THE FIELD FIRST Accurately measuring the amount of product necessary for the spray operation and accurately dispensing it in the field is important to minimize leftover spray solution. Once spraying is done, spray any remaining product out in the field. Over-spraying what has just been sprayed is fine because the registration process requires that the active ingredient in the herbicide be safe at twice the label rate, so it’s designed to accommodate overlap. Wolf suggests speeding up a little bit so as to under-apply the remaining product if there is any concern.
In This Issue
Have clean water available in the field and add 10 times the sump’s remnant of clean water to the sprayer, circulate it and then spray that out (also in the field). Then repeat the process again. Having a clean water tank on the sprayer and a wash-down nozzle makes this job easier. You have now completed the first rinse operation before you fold up the booms and head back to wherever you plan to do a more thorough cleaning.
CHECK THE SCREENS Now, take all the screens out of the sprayer and inspect them. If there is residue on them clean them thoroughly. There are screens in the nozzle bodies and this is often where residues accumulate and can reintroduce themselves into the
» CONTINUED ON PAGE 4
Wheat & Chaff ..................
2
Features ............................
5
Farmer Panel ....................
8
Crop Advisor’s Casebook .. 10 Columns ........................... 15 Machinery & Shop ............ 29
Fine tune your fertilizer rates by field JASON CASSELMAN
PAGE 5
When are land prices too high? MARIANNE STAMM PAGE 23
Cattleman’s Corner .......... 37 FarmLife ............................ 43