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Stephen Reiners and Olga Wickerhauser

The possibility of using annual grain rye (Secale cereale L.) as a living mulch between rows of black plastic mulch was investigated. Rye was seeded immediately after plastic was laid and ≈30 days before transplanting bell pepper (Capsicum annuum L.) seedlings. Rye growth was controlled by postemergence herbicides and mowing or was left unmowed. These treatments were compared to a weedy control, cultivation, and standard preemergence herbicides for their effect on weed control and bell pepper yield. Within the rye treatments, the unmowed rye provided the best weed control and significantly decreased the number and size of weeds between crop rows. The rye cover crop also significantly reduced the yield of peppers. In both the mowed and unmowed rye treatments, total marketable yield was reduced 50% compared to clean cultivated and herbicide-treated plots. Further work is needed to minimize the competition between the living mulch and the crop.

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John Masiunas, Elizabeth Wahle, Laurel Barmore and Albert Morgan

A foam mulch system was developed that can be applied as an aqueous mixture of cotton and cellulose fibers, gums, starches, surfactants and saponins and dries to an one inch thick mat. This mulch may overcome the difficulty in applying and lack of persistence with natural mulches. Foam mulch also has the advantage of being able to be incorporated into the soil without requiring disposal like some plastic mulches. The objective of our study was to determine the effect of foam mulch and its color on weed control within the crop row and on yields of basil (Ocimum basilicum) and tomatoes (Lycopersicon esculentum). The foam mulch maintained its integrity for the entire growing season and provided weed control within the crop row comparable to black plastic mulch. The only weeds that emerged in the crop row were through holes in either the black or foam mulch. Foam mulch color did not affect weed control because regardless of color it did not allow light penetration andserved as a physical barrier impeding weed emergence. Basil shoot biomass was not affected by mulch treatment. Mulch color affected early, ripe fruit, and total yield of tomato. Tomato yields in the blue foam were greater than other treatments. Yields in the black foam mulch were similar to those in black plastic mulch. Further research is needed to characterize the effects of foam mulch on crop microenvironment. Currently foam mulch is being commercialized for use in the home landscape and other highvalue situations.

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S. Gurusiddaiah and M. Ahmedullah

For the control of Reeds Canary grass (Phalaris arundinaceae) and yellow nutsedge (Cyperus esculentus) in blueberry fields, no satisfactory control measures are available. We tried microbially derived aerobic fermentation extracts of Pseudomonas syringae strain 3366 (P. S. 3366) as pre- and -post-emergence applications for the control of Reeds Canary grass and yellow nutsedge. In greenhouse studies using “conetainers,” 2 mg of extract per g of soil applied as preemergence completely inhibited seed germination and aerial growth of Canary grass, but had no effect on nutsedge. In addition, the same level of concentration of P. S. 3366 (2 mg of extract/g of soil) under field conditions also showed 99% inhibition of germination and growth of Canary grass, but had no effect on germination of nutsedge. However, 4-fold increase in concentration of P. S. 3366 extract completely inhibited the sprouting of yellow nutsedge in greenhouse studies. These studies indicate microbially derived extract of P.S. 3366 can be used and has potential for the control of these weeds. Post-emergence foliar sprays of P. S. 3366 extract in blueberry fields failed to inhibit the aerial growth of Reeds canary grass and yellow nutsedge.

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Dennis N. Portz and Gail R. Nonnecke

Continuous strawberry production on the same site causes proliferation of weeds and accumulation of pathogens in the soil and subsequently decreases strawberry yield ( LaMondia et al., 2002 ; Pritts and Handley, 1998 ). Continuous tillage to remove

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Brian Caldwell and Charles L. Mohler

Effects of several stale seedbed procedures on weed density and biomass were evaluated on a silt loam soil in central New York. After an initial rotary tillage, weeds were allowed to emerge and either single or multiple applications of glyphosate, propane flame, spring tine weeder, springtooth harrow, or rotary tiller were used to kill the weeds over a 4-week period. The last (or only) application occurred immediately prior to simulated seeding of a crop performed by passing an empty seeder through the plots. These stale seedbed treatments were compared with a control consisting of a single rotary tillage just before simulated planting. Flaming or glyphosate stale seedbed techniques significantly reduced density and biomass of the principal broadleaf species, common purslane (Portulaca oleracea L.) and common chickweed [Stellaria media (L.) Cyrillo], in most cases. A single delayed flame or glyphosate stale seedbed treatment was usually as effective as multiple treatments. None of the stale seedbed techniques was effective against yellow nutsedge (Cyperus esculentus L.). A flexible tine weeder was not effective as a stale seedbed weed-killing treatment in this study because of poor penetration of crusted soil. Penetration was better with a springtooth harrow, but this failed to reduce weed density. None of the stale seedbed treatments fully controlled weeds. However, glyphosate or flaming a stale seedbed could be incorporated into integrated weed management programs to improve control and reduce the need for herbicides. Broadleaf weed density within 3.8 cm of the center of the seeder wheel track was greater than elsewhere in the plot. Chemical name used: N-(phosphonomethyl)glycine (glyphosate).

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Lisa W. DeVetter, Huan Zhang, Shuresh Ghimire, Sean Watkinson and Carol A. Miles

exploring plasticulture production using day-neutral cultivars targeting the fresh market. Black PE mulch is extensively used in plasticulture because of its low cost and ability to manage weeds, conserve soil moisture, modify soil temperatures, increase

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Susan L.F. Meyer, Inga A. Zasada, Shannon M. Rupprecht, Mark J. VanGessel, Cerruti R.R. Hooks, Matthew J. Morra and Kathryne L. Everts

field soil was then spread over the section. The black plastic was laid back in place and the edges sealed with duct tape. At the time of tomato planting, the 1-ft 2 section of black plastic was removed. Weeds were counted by species on 2 and 16 Aug

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Yushan Duan, Thomas W. Walters and Timothy W. Miller

plot (0% control = no weed injury from the herbicide treatment and 100% = no weeds present) as compared with nontreated plots (by definition 0% control) at about 2-week intervals during the raspberry growing season (May through September) for 3 years

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Nanik Setyowati and Leslie A. Weston

Dithiopyr (Dimension, Monsanto) is a turfgrass herbicide currently under evaluation for use in ornamentals. Granular herbicide depth and seed placement were evaluated in greenhouse studies with tolerant or susceptible weeds. Dithiopyr was applied preemergence to weeds at the rate of 2.24 kg/ha to Maury silt loam soil. Weed seeds were planted routinely at 0.64 cm depth. Dithiopyr placed at the soil surface or 0.64 cm in depth caused the greatest injury to seedlings, followed by dithiopyr at 1.28 cm depth. Dithiopyr at 2.54 and 3.81 cm below the surface had no effect upon seedling growth. When seeding depth was investigated, seed placed at 0.64, 1.28 or 1.91 cm below the surface showed greatest seedling injury when dithiopyr was routinely applied at 0.64 cm depth. Seed placement on the soil surface resulted in the least injury to weeds.

Peat moss was added to Maury silt loam soil and to sand to investigate the influence of organic matter upon activity. Soil with 2% peat resulted in the least injury to selected weed seedlings while sand, and sand plus up to 3% peat showed greatest injury. Sand amended with 5 and 6% peat also resulted in less injury to weed seedlings. Ivy leaf morningglory and KY 31 fescue were most tolerant of dithiopyr while barnyardgrass and large crabgrass were most sensitive. Dithiopyr uptake, translocation and metabolism studies will be conducted with susceptible and tolerant weed and woody ornamental species.

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Emily R. Vollmer, Nancy Creamer, Chris Reberg-Horton and Greg Hoyt

al., 1993 ). Cover crop mixtures suppressed weeds as effectively as a herbicide-controlled treatment for no-till tomatoes 4 weeks after transplanting ( Herrero et al., 2001 ). Creamer et al. (1996a) reported season-long weed suppression using cover