SCIENCE TO THE GROWER: Pipe dreams and postharvest schemes
by Richard Evans
This is a story about orangeburg. With luck, it’s the only one you’ll ever encounter. The eponymous product of a manufacturing town in New York, orangeburg is a pipe material made from wood that has been ground up, compressed and impregnated with coal tar pitch. It's basically a cellulose pipe. It collapses easily because it doesn't hold up to pressure. During the housing boom after World War II, when cast iron was hard to come by, it was used for sewer lines in some towns. Towns like Davis, where I live. You might think such a material would be a poor choice for a buried pipe. I do. I've learned a lot about it (www.sewerhistory.org) because the orangeburg sewer line under my house just collapsed. More precisely, it collapsed under the concrete slab that some moron poured for an addition to my house about 30 years ago. By then the orangeburg already had surpassed its expected lifespan, so I guess I’m lucky it survived this long.
Industry veterans among you may recall that some cut flowers may be pretreated with silver thiosulfate to protect them from effects of ethylene. However, product registration issues, along with strict regulation of waste disposal because of concerns about environmental effects of silver, have limited the commercial availability of STS products. So what about the effects of nanosilver? Nanosilver materials are relatively new, so there isn’t much of a record on which to judge. Luoma (2008) and Marambio-Jones and Hoek (2011) have written reviews urging caution when introducing nanosilver into waste streams, but more testing is likely before regulatory guidelines are established. Stand by.
Richard Evans is Cooperative Extension Environmental Horticulturist, Department of Plant Sciences, UC Davis.
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