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quiet
11-16-2004, 09:20 PM
Summaries from Iowa State's Research on CGM:

1999 Corn Gluten Meal/Urea Crabgrass Control Study - Year 2

The 2000 growing season was quite warm and dry with above-average temperatures and below-average rainfall from April through September. Supplemental irrigation was required throughout the season to keep the bluegrass in good condition.
In early May, bluegrass quality was improved on grass treated with urea. Response to CGM treatment was slower but the quality of urea and CGM treated turf was similar through June and better than the untreated control. As expected, quality improved following the sequential treatments of CGM and urea in July and August. By September, the high temperatures and below-normal rainfall caused the bluegrass to enter dormancy. Rainfall and moderate temperatures in October caused a late season greenup and on October 27, grass treated with CGM or urea on September 5 (Treatments 2 and 4) had significantly better quality than grass not receiving treatments on that date. Mean data for the entire season show that all CGM and urea-treated grass had better quality than untreated.
There were no statistically significant differences in weed populations between the treated and untreated bluegrass. Crabgrass populations were low in all plots (Table 2). There were fewer crabgrass plants in untreated bluegrass than in treated because of increased competition from broadleaf weeds in the untreated grass. Dandelion populations were similar in treated and untreated bluegrass (Table 3). There were slight numerical differences but none were statistically different. Percentage clover cover also was similar in the treated and untreated bluegrass (Table 4). Through August 29, clover cover was numerically greater in bluegrass treated with CGM and urea in split applications of 2 lb/1000 ft2 than in the untreated controls.

1991 Corn Gluten Meal Crabgrass Control Study - Year 10
Spring 2000 was quite warm and dry with above-average temperatures and below-average rainfall. At spring greenup in April, there were slight quality differences between treated and untreated turf but by mid-May, the differences were quite distinct (Table 1). Quality differences between CGM-treated turf and untreated turf were significantly different for the entire season but on some dates, the quality of turf treated at various CGM levels was not different from the untreated control. By mid- to late-July, the quality of all treated and untreated turf began to deteriorate because of the lack of rainfall. Some rainfall improved turf quality by late August. Late season data from October 27 show a definite CGM effect in turf treated with CGM at 60 lb/1000 ft2 and above.

Treatment with CGM resulted in numeric reductions in crabgrass populations for the entire season but the differences were not statistically significant (Table 2). Mean crabgrass reductions for the entire season were „ 98% for all CGM rates except 20 lb/1000 ft2 (Table 2). In 1997 through 1999, crabgrass counts were higher in turf treated with 20 lb/1000 ft2 than in untreated turf. In 2000, crabgrass counts were higher in untreated turf and CGM at 20 lb/1000 ft2 provided a 63.3% reduction in crabgrass (Table 5). Reductions in crabgrass counts for 2000 were higher than in 1997, 1998, and 1999 at all other CGM levels.


Another study worth reading in it's entirety was done by UC-Davis.
http://ucce.ucdavis.edu/freeform/slosson/documents/1999-20002063.pdf

timturf
11-17-2004, 07:50 PM
Don't think it's all that healthy to apply 20lbs/m cgm to control crabgrass on cool season turf, proably ok for warm season turf, but way too much spring nitrogen on cool season turf, unless maybe your in upper usa!

trying 2b organic
11-29-2004, 02:37 AM
Corn gluten meal doesnt work correct? This is what real life testing has shown us. Or at least you have to use a whole lot of it, at great expence, to get minimal results. CGM would be a very important part of my business if one app in the spring would provide noticeably less weeds.

Btw I have bought it, I have used it, I have tested it. Untill I hear something new I will focus on using Best Management Practices to help thick turf crowd out weeds naturally. (to the extent this works)

Also, given my experience with it, and the experience of others, I am suprised they actually got it registered as a herbicide in the U.S.. Turfmaize is working on getting it registered as such in Canada so it can be sold here as organic weed and feed.

Dchall_San_Antonio
11-30-2004, 03:46 PM
Just for the record, I agree with trying 2b organic.

timturf
11-30-2004, 04:10 PM
Just for the record, I agree with trying 2b organic.

Trying 2b organic is stating in real life cgm isn't very effective and expensive, and mr moderator, I thought you pushed cgm!!!!!!!!!

quiet
11-30-2004, 11:15 PM
This data leads to some conclusions from a commercial business standpoint. For commercial applications, selling CGM apps as a preemergent would seem to be unethical since there is no data to back up it's specific pre-m qualities.

Selling it as a beneficial organic fertilizer that enhances turf quality and density, and thus reduces weed germination . . . well, that's a tough sell based on it's cost/MSF.

trying 2b organic
12-02-2004, 03:04 PM
quiet, i agree with you. But what I posted is that in fact it HAS been university tested and registered as a pre-em. I read the original test results that lead to this. Unless something has changed in the U.S. this was the situation with cgm.

So my suprise and dissapointment is in that we in the real world dont seem to be getting very good results from it. It is supposed to supress the germination of annual weeds and lessen the amount of new perennials. It does not kill existing weeds or prevent existing perrennials from comming up again in spring. If it did what it claimed to do quite well with one spring app. I would be all over it and hard selling it as well.

I was hopping to do achieve weed control by using an app of cgm in the spring and spot treating perrenials by wiping them with a weed stick full of horticultural vinegar. This was to be my groundbreaking organic lawn care prgm. (in addition to fert apps using organics also of course) The major coup would have been -weed control-- without synth. It didnt pan out in testing and now my organic prgms are just fert apps, aerating and overseeding. giving the best lawn possible without synthetics. These lawns have some weeds which means I can only sell this prgm to my niche market and not everyone who wants a perfect lawn.

Ok i went on a bit but know from emails i get that some out there will benifit from that info. I know I would have a yr ago.