One or more of the features that are needed to show you the maps functionality are not available in the web browser that you are using.
Please consider upgrading your browser to the latest version or installing a new browser.
More information about modern web browsers can be found at http://browsehappy.com/
Initial leaf symptoms of MMV on sweet corn are light-green to yellow long stripes along the midrib. These stripes elongate to form the distinct, even chlorotic stripes between and along the vein extending from the base of the leaf to the tip. Two kinds of striping symptoms have been recognized: fine lines and coarse lines. Stripes often appear on sheath and husk. Infected plants often show dwarfing of internodes and husks.
The symptoms on itchgrass are very similar to those on sweet corn.
MMV has the potential to cause serious crop losses and to be distributed over long distances given the optimum vector-host combination and environmental factors. Thorough understanding of the biology and ecology of Peregrinus maidis is essential in devising integrated pest management programmes, as MMV is solely dependent on P. maidis for transmission. Chemical pesticides have been tested on maize vectors, but they offer only limited control (All, 1983; Tsai et al., 1990). As no single method is completely effective in controlling any maize virus disease, pest management should be an integrated control programme.
Resistance to MMV in maize has been studied more extensively than that of all other leafhopper- and planthopper-transmitted maize viruses. The genes for resistance to MMV in maize are located on chromosomes 3, 6 and 10 (Redinbaugh et al., 2004) but the major resistance gene, designated mv1, is on chromosome 3 (Ming et al., 1997). Resistance has been introduced by direct backcrossing into more than 100 inbreds and cultivars and 150 genetic stocks (Brewbaker, 1975, 1981, 1997). In 1995, 15 tropical adapted inbred lines of maize resistant to MMV were registered and released (Brewbaker, 1997). More recently, a maize line (Hi40) which is highly resistant to MMV has been developed (Dintinger et al., 2005).
Control of Alternative Hosts
In Mauritius, it was possible to control MMV by destruction of the weed host, Sorghum arundinaceum, with the herbicide glyphosate (Autrey, 1983).
MMV causes a serious disease in the tropics and subtropics and can substantially reduce yield when conditions for disease development are optimal. In Hawaii, MMV was first recognized to cause a serious and endemic disease of maize (Kunkel, 1921). In Venezuela, it is especially prevalent during the cool months of September through January when the infection reaches 60% (Lastra, 1977). It has been speculated that MMV was a possible cause of the collapse of Mayan civilization (Brewbaker, 1979).