Spray Calibration
When the label only gives only per/acre mixing info - in this case, 2oz/acre in minimum of 10 gal water (Aim herbicide - Carfentrazone for pigweed), how do we mix it for spot treatment using a backpack? We have directed nozzles on our boom - high volume, low pressure - and can safely run the row middles without shields. We will probably use 30 gals of water instead of 10.
But I will also need to spot treat juvenile pigweeds closer to the plants. I could shut the valve to the boom and open the one to the hose and use a shielded hand wand for closer application, but it's such a hassle dragging a hose around without tearing-up the crop. I would much rather mix 2 gals in the backpack. Can I just pump 2 gals of the main tank mix into the backpack and use it it at that strength? Or should I mix it weaker?
What worries me is applying it too strong and damaging the tomato plants - I've never found a check valve that works well with a hand wand, and it always puts much more chemical on the weed that I need or want. Some labels have separate instructions for hand application, but Aim does not - or I haven't found it in all the fine print that these labels always have.
Thanks,
Jack
Views: 16
Replies to This Discussion
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Permalink Reply by robert schuler on -
Jack, Spraying row crop herbicides with a backpack sprayer is playing with fire. You can never get an accurate application. Most labels won't permit it..... Backpack sprayers are great for non selectives like roundup and paraquat where too much or too little won't matter... "Take it from a guy who learned the hard way"...Bob.
Sunny Meadow Farm
Bridgeton, NJ.
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Permalink Reply by Jack Ellis on
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Bob, this isn't going over the top of the crop. It's just spot treating individual weeds close to the crop after we run the row middles with the calibrated sprayer. It's a broad spectrum broadleaf killer chem, though, and I'm worried it might cause damage to tomatoes if it contacts the roots in tank-mix strength. However, Aim it is labelled for tomato middles only (no contact with "foliage or green stems"). Since tomato roots run all the way out into the middles, usually pretty shallow, it should be all right.
We still use a lot of 2-1/2 ft CRW half-cages, although we have gone mostly to florida weave. and I need to get inside the cages with a broadleaf killer other than glyphosate, which kills the plants if it gets on the roots. I'd rather have paraquat (Gramoxone) but it's so highly restricted that none of our suppliers carries it - (and our tech adviser won't buy restricted chems if there is a safer alternative). We've been spot treating like that with Arrow grass killer (clethodim) for a long time, but we're rotating the tomatoes into an area where broadleaf weeds will be the problem.
Most of our volunteers are older and they have a terrible time with the string weave - all that stooping over for long periods is hard on arthritic backs. I'm under pressure to drop the weave and build more cages - and that will mean more weed problems inside those &^*% cages! And were planting 4000 toms now! We may have to cut back if we don't get some younger volunteers.
Jack
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Permalink Reply by robert schuler on
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If you must spray around the plants I would recommend a product called Scythe. Its a contact harbicide that can be safely applied around plants. I have used it and it works well on small weed seedlings and drift does little if any harm to the vegetable plant. In cages you can preplant treflan + devrinol, plant tomatoes add cages then add a 6" deep layer of shredded wheat straw in the bottom of each cage. I grew some of my best tomatoes this way... Bob.
Sunny Meadow Farm
Bridgeton, NJ.
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Permalink Reply by Jack Ellis on
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We've been using Devrinol for several years, Bob. But I don't like the 12 month rotation restriction. I like to follow the toms with mustard, collards and turnips - can't do it with Devrinol. I can't understand why heading brassicas are okay with Devrinol but not leafy brassicas! Doesn't make any sense to me - BUT, this year, just as a test patch (not for market), I planted some Alamo turnip greens right behind the toms and they didn't do well. They were stunted. It could have been nematodes, though - lots of them in that field and brassicas have no resistance. We not going to use the Devrinol this year and just fight the weeds post-emergent. I know -- "Good Luck!" LOL
I'm going to try a new tool inside the cages this year - an herbicide "wiper". Hopefully it will fit inside the 6" CRW squares. And I'm gonna run Aim (carfentrazone) in the row middles or a tank mix of Aim and Arrow (like Poast). We've never used Treflan yet. Arrow (clethodim) does a good job on the grasses and we can go over the top with it. I never use any organic mulches - I hate it - just makes a big mess for me.
I'm LUVIN' this weather - 59 low last night and 74 right now. The A/C is on!
Jack
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Permalink Reply by David Zelisse on
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Use AIM as labeled in the orchard for root suckers on apple trees. Hand apply there. Don't have the paperwork handy, but am thinking the labeled rate worked out to 1 1/4 or 1 1/2 teaspoons for 3 gallons of water plus acidifier/spreader sticker.
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Permalink Reply by Jack Ellis on
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Thanks, David. I came-up with 1/2 tspn per gal and you're confirming it. We'll use crop oil and Pinene sticker/spreader with it.
Jack
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Permalink Reply by Tom Averwater on
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I use a backpack sprayer to apply herbicides on small plantings of sweet corn .I have a pressure regulator called a cf valve on the end of the wand . I searched on the internet and found out how to calibrate the sprayer using timed distance and flat fan nozzles. it seems to work pretty good . The cf valve keeps a constant pressure and stops the flow when it is too low . I hope this helps . Tom
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