I did some research on nutgrass/nutsedge last year, and was fascinated to find what a huge problem it is around the world. In agricultural settings it can be devastating when it completes with commercial cotton and various grain-growing operations. I've just reproduced that search, and here are a few examples:
Manitoba, Canada: http://www.gov.mb.ca/agriculture/crops/ ... 62s00.html
British Columbia, Canada: http://www.agf.gov.bc.ca/cropprot/nutsedge.htm
California: The University of California calls this ozone-hardy plant "the botanical equivalent of the cockroach": http://ucanr.org/spotlight/nutsedge.shtml
American Vegetable Grower (through some intermediate search site, I don't know if this is a durable link) http://www.findarticles.com/p/articles/ ... i_n9343662
Indiana, Florida, et al: It's chemical warfare out there. Purdue in Indiana, the University of Florida, all of these agriculture departments are talking big guns and nasty stuff to try to control it, even though they all admit it is not completely effective. For example: http://edis.ifas.ufl.edu/FW015
Australia has a Cyperus that arrived from Africa: http://www.weeds.crc.org.au/documents/wmg_cyperus.pdf
In the midst of this I found a rather bizarre page from Mississippi State U that in a quick first reading apparently considers almost anything
to be a "weed." http://msucares.com/crops/weeds/
This one is kind of scary, as if Dr. Strangelove took up farming.
I'll conclude my enumeration of nutsedge sites with this link to an interesting article: http://www.fftc.agnet.org/library/article/bc45017.html
I have skimmed this so far, but it sounds very interesting. This work is coming out of something called the Food and Fertilizer Technology Center. What caught my eye in particular was this line:
Strategies include minimum use of chemical pesticides to maintain pests below economic thresholds, use of biological control agents for specific pests, use of resistant crop cultivars, modification of cultural practices to prevent or reduce pest infestations, and the use of any input to prevent the deleterious impact of pests on crops.
and the following paragraph:
Integrated weed management is a viable component of integrated pest management (Shaw 1982, 1984; Smith 1982). The weed management system combines use of multiple-pest-resistant, high-yield, well-adapted crop cultivars, that also resist weed competition, with precise placement and timing of fertilizers to give the crop a competitive advantage. Optimum crop plant population, the use of crop cultivars that form a canopy for shading early-season weed growth, and seedbed tillage and seeding methods that enhance crop growth while minimizing weed growth, are viable components of the system. Such systems also include the use of judicious irrigation practices; timely and appropriate cultivation; carefully planned crop rotations; field sanitation; harvesting methods that do not spread weed seeds; use of biological control agents and strategies, such as pathogens, insects, nematodes, animals, and allelopathy; and employment of effective chemical weed control methods. Also, preventive weed control practices to reduce the number of weed seeds and other propagules in the soil are a component of the system.
Further down in the same article it says:
The rust fungus Puccinia canaliculata (Schw.) Lagerh. has the potential of controlling yellow nutsedge (Cyperus esculentus L.). Release of the pathogen early in the spring on seedling yellow nutsedge reduced plant populations, tuber formation, and flowering (Phatak et al. 1987). This mycoherbicide is being developed and commercialized in the United States for control of yellow nutsedge (Phatak 1992). Research is needed to determine the potential of P. canaliculata as a mycoherbicide in rice. A valid approach would be to integrate P. canaliculata with registered chemical herbicides, including bentazon and bensulfuron methyl.
It would be nice if they'd consider the biological control without the chemical cocktail, but at least it appears progress is being made. After all of this, though, I think I'll just live with the nutsedge and keep up the mechanical removal and low watering.