Brief Summary of Minutes of Annual Meeting

Minutes were approved from 2009. We discussed the chair for next year. John Masiunas agreed to chair next year. Charlene, Robin, Chuck, and others agreed to contribute. There are no annual reports on record for 2007, 2008, and 2009. John is asking that the chairpersons for those years send him an annual report because these will need to be submitted prior to writing a renewal. John will set up a conference call this spring/summer to think about the rewrite and have that started prior to the December meeting in Portland, OR. Tom Lanini, Bill Curran, Robin Bellinder will be conducting natural product work in 2010. They will coordinate protocols. John, Dan, Tom B. Bill C. and others have a grant to make summer cover crops standard practice on organic vegetable farms in this region. Tom B. also has a SARE grant with seven extension field staff in four states with on farm research and cover crops. They will be coordinating protocols for summer cover crop research. No work is planned on mineral nutrition effects on weeds. Robin Bellinder is going to continue working with the new cultivator tools.

Objective 1. Natural product herbicides were evaluated in New York, Michigan, Pennsylvania, and California. In New York, 200 grain vinegar (75 gpa) was applied as a banded in-row application, directed to the base of transplanted broccoli and bell pepper. Two organic paints, a linseed oil and a clay-based paint, were applied to crop stems before transplanting. The paints create a physical barrier between vinegar and the crop stem. In-row weed survival was reduced by more than 90%, at 1 day after vinegar application. There was an 80% reduction in new weed germination at 2 weeks after vinegar was applied in-row, compared to 2 weeks after in-row hoeing and handweeding. With vinegar, minimal soil was disturbed, and the potential to stimulate latent weed seed was reduced. Neither stem paint prevented crop injury; the clay paint flaked off within 2 weeks while the linseed oil was phytotoxic. Despite pepper foliar injury of less than 5%, stem injury by 2 weeks post-application measurably reduced yields. Broccoli injury with vinegar applications was limited to instances where overspray contacted the crop canopy. Per-plant broccoli yields were not reduced, although per-plot yields were marginally reduced. In Pennsylvania, the target is to control hairy vetch as a weed. They are evaluating mechanical control, flaming, and Greenmatch (de-liminine 55%) applications to control hairy vetch. Greenmatch may have better activity under cooler temperatures. In Michigan, carrots (Sugarsnax) and barley (windbreak) were sown in muck soil in mid-May, and either covered or left uncovered with floating row cover. Nine days after sowing carrots (before carrot emergence), row covers were removed and Matran (10% 35 GPA) (50% clove oil), Greenmatch (10% 35 GPA), and vinegar (10% acetic acid; 20 GPA) were applied to emerged , Powell amaranth, common lambsquarters, large crabgrass, and ladysthumb. A conventional herbicide control treatment of Lorox/Dual was also included. Immediately after application, row covers were replaced on plots to achieve all factor combinations of pre and post-row covers. Post row covers were left on for 2 days following herbicide application and then removed. At 2 WAT, visual weed control ratings were taken. Severe flooding resulted in complete loss of the trial shortly after the 2 WAT ratings, so no yield or final weed data were taken. Row covers had no significant effect on the number of weeds emerging or the efficacy of any of the natural product herbicides. In contrast to previous studies, temperature and soil moisture were not elevated under row covers compared to uncovered treatments due perhaps to heavy rainfall and consistent cloud cover during the period of row-cover use. None of the natural product herbicides sufficiently controlled weeds to be effective for stale seed bed use. There was no effect of row cover on the efficacy of these products. Cloudy and wet conditions resulted in the row covers probably having limited effect on air temperatures. In California, Greenmatch, Greenmatch EX (lemon grass oil 50%), Weedzap (clove oil and cinnamon oil each 45%), Seaside (20% citric acid) and Matran are approved for food use. WeedPharm will probably be approved in one year. Coverage and volume with organic sprays is essential. The two Greenmatch materials require 15% concentration; Weedzap 10% concentration. This is a lot of herbicide when spray volumes are greater than 60 gpa. Weeds vary in their sensitivity to natural product herbicides with brown mustard easiest to control, jungle rice most difficult to control, and pigweed intermediate. In orchards, less weed control occurs in heavy shade. Also, warmer temperatures resulted in better weed control. Humidity is not an issue in California because of the dry climate. Organic silicone surfactants improve activity and may allow lowering spray volumes to 10 gpa instead of 70 gpa while still using a 10% concentration of the natural product. This would result in a much lower price because the amount of herbicide would be reduced significantly.

Objective 2. Cover crop research was conducted in Florida, New York, Michigan, and Illinois. Florida has completed buckwheat research. Spring planting dates in year 1 were March 15 through May 22 and in year 2, February through May 8. In the fall, buckwheat was planted September 20 through November 29 in both years. Planting was at weekly intervals. Planting buckwheat during a two week period, late April through early May, resulted in optimum growth of the cover crop and the best suppression of weeds. Later planting dates had less weed suppression by buckwheat. In Florida it is recommended to plant buckwheat at the beginning of May. In the fall the best planting date was mid-October. Termination practices were evaluated including rolling, mowing, light tillage, and flailing. All four methods gave 90% kill or greater if conducted prior to the buckwheat seeding out. But many weeds in buckwheat were not controlled by rolling. In New York rolling did not control buckwheat and in Illinois mowing only partly controlled buckwheat. In New York, establishment dates (June through August) for buckwheat cover crops were evaluated. The best buckwheat planting windows were mid-June and mid-August. Buckwheat does well in highly tilled silt loam soils and does not do well in light sandy soils because of not enough water. In Illinois, had two different timings for killing the buckwheat and planting pickling cucumbers. Either buckwheat planting date gave over 2 MT of biomass. If they planted the crop after three days of killing the buckwheat, there was no crop injury. Pickle growth improved in the buckwheat cover crop treatments.

Mustard genotypes differ in when they bolt, their winter hardiness, biomass production, and glucosinolates content. In a greenhouse study, shoot mass of mustards at flowering ranged from 2.97 (PI263866) to 27.51 (Florida Broadleaf) g/plant. Generally, total glucosinolates levels were similar among accessions. Ida Gold and Red Giant mustards had higher total glucosinolate levels than accessions such as Jupiter rapeseed. Ida Gold is sold as a high-glucosinolate containing cultivator for biofumigation while Jupiter is an older European rapeseed cultivar. Gluconapin and sinigrin are the predominant glucosinolates in most of the accessions, with Ida Gold containing the most gluconapin and Red Giant containing the most sinigrin. Progoitrin and glucoalysin were the other two common aliphatic glucosinolates. Shoots of Red Giant mustard and Jupiter rapeseed contained the largest amount of the aromatic glucosinolate, gluconastrutiin. Ida Gold, Jupiter, and Red Giant shoot mass were approximately 12 g/ plant. Field studies evaluated planting and tilling dates for mustard. Pacific Gold and Tilney mustards were studied in New York. Successful mustard establishment from mid March (last frost) to April planting were dependent on good climatic conditions. If mustard is planted later it bolts and provides limited weed suppression. The mustards must be incorporated (mowed, flail mowed, and light disking) in June. Increased soil moisture, relative to trials conducted in 2008, decreased weed suppression. One weed that mustard suppressed was common purslane, a host for Phytopthera. Yellow mustard Tilney was seeded in mid-April and mid-May (2009) at two separate sites, allowed to grow for at least 4 weeks, and then mowed and incorporated. At 2 weeks after incorporation of the first seeding, and 1 day after incorporation of the second seeding, broccoli and lettuce were transplanted, and pea and snap bean seeded, into each site area. There was no crop injury when mustard was incorporated 2 weeks before planting the crop. However, germination and growth of all four crops was reduced when the mustard was incorporated 1 day before planting. Of the four crops, transplanted lettuce was the least impacted by mustard. Is this allelopathy, a burst of fungal pathogens, nitrogen immobilization, or another cause? Mustard was seeded as a fall cover crop, in early August and early September (2008), at two separate sites. The mustard was grown for at least 5 weeks before incorporation. Jensen wheat was seeded two weeks after incorporation of the August seeding, and one day after incorporation of the September seeding. The following summer (2009), wheat was harvested. Wheat yield and quality were not influenced by the timing of mustard incorporation. Wichita, a public winter canola, also can be planted at the end of August and survive the winter. Growers are interested in mustards more for soil borne disease suppression than weed management.

Objective 3. No research was done on the effect of mineral nutrition on weeds.

Objective 4. At New York, trials were conducted at two different sites to evaluate transplanted Lady Bell bell pepper and Premium Crop broccoli tolerance to a stirrup cultivator and a block cultivator relative to the traditional s-tine sweep, when used for inter-row cultivation. Each tool was adjusted to leave either a 15 or 24 cm-wide uncultivated band, centered over the transplants. In-row areas were hand-weeded as necessary. Pepper and broccoli yields were similar in treatments cultivated with the new tools or S-tines. Close cultivation was possible with all three tools. However, there was often greater crop injury and variation in yield with close cultivation as compared to distanced cultivation. In Michigan research is timing rotary hoeing based on growing degrees days in field corn and black beans. In Maine, Weed Master, an innovative set of cultivation and flame-weeding equipment, designed and built by a team of Finnish small-scale organic farmers. The Weed Master incorporates two wheels, a tool bar, and lightweight cultivator attachments, some of which have a parallel-linkage design. This collection of tools is the first transfer of physical weed control technologies, including sweeps, rolling disks, finger and torsion weeders, from the tractor tool bars of larger farms, to a hand tool appropriate for a farmer of 4 acres or less. The innovations include using two wheels and a scaled-down toolbar to provide lateral stability and adjustment flexibility along with lightweight parallelograms that offer precise depth control, optimizing soil movement (weed control) and effort required to push the implement. The Weed Master was evaluated or demonstrated on three diversified organic vegetable farms, at the Maine Agricultural Trades Show, a University of Maine Cooperative Extension field day in southern Maine, and the Maine Organic Farmers and Growers Association Apprentice Summer Meeting Field Days at the Peacemeal Farm in Dixmont, and the Common Ground Country Fair. The results were shared through a research blog (see: gallandt.wordpress.com) and a YouTube Channel, "Zeroseedrain" (http://www.youtube.com/user/zeroseedrain). The efficacy of weed control with the Weed Master is equal to hand weeding, hoeing or using a wheel hoe, but required less working time.

A greenhouse experiment studied effect of burial on the survival of seedlings of barnyardgrass, giant foxtail, lambsquarters, and velvetleaf. Variables were size of seedling, and watering after burial. Seedlings of giant foxtail, lambsquarters, and velvetleaf were grown to two different sizes and then buried. Barnyardgrass was only buried in the seedleaf stage. Survival of lambsquarter and velvetleaf was negligible. Only two out of 1,573 lambsquarters and 1 out of 1,596 velvetleaf seedlings buried with 2 cm of soil survived. The giant foxtail and barnyardgrass had slightly higher survival rates particularly when the soil was not settled by watering than lambsquarters or velvetleaf. More cotyledon stage seedlings survived than seedlings with a first true leaf. There was slightly less seedling reemergence when the soil is settled by watering after burial. In California, redroot pigweed, mustard, and jungle rice were completely killed when buried with 1 to 2 cm of soil. If the least bit of green was still visible, the weedy plants recovered. There was more survival of grasses if cutting/scalping occurred ahead of burial. Yellow nutsedge survives burial

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