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/
H. glycines typically causes stunting of the host and this may be combined with chlorosis. The nematode causes 'yellow dwarf disease' of soyabean, the symptoms appearing in the field about two months subsequent to sowing. Diseased plants may be stunted with yellowed foliage and have fewer lateral roots than normal. In addition, there can be reduced Rhizobium nodulation. Yield is substantially reduced. In severe cases the plant may die.
H. glycines has a relatively limited host range and can thus be managed by appropriate crop rotation with non-hosts. A two year rotation with a non-host is usually sufficient to reduce populations to a non-damaging level. Resistant varieties of soyabean have also been developed and much screening work, both traditional and molecularly based, has been undertaken for resistance within accessions of Glycine max and in related species of the genus. The large number of races exhibited by the soyabean cyst nematode compromises resistance in the field to some extent. Chemical control may not be economically viable as soyabean is a low return crop. The best management strategy involves rotation with non-hosts and use of resistant varieties of soyabean. Schmitt and Noel (1984), Riggs and Niblack (1993), Sikora et al. (2005) and Niblack et al. (2006) provide good overviews of the nematode.
Reported yield losses on soyabean vary from 10-70% in Japan (Ichinohe, 1955; Inagaki, 1977). All soyabean growing areas in the USA are at risk and the nematode is still spreading into previously uninfested areas. Losses in the southeastern USA were estimated at US $88.4 million in 1990 (Sciumbato, 1991). Wrather et al. (1997) provided loss estimates for the top 10 soyabean producing countries and concluded that, worldwide, H. glycines was the most important constraint on yield. Wrather et al. (2003) reported on losses due to H. glycines and other diseases on soybean in the USA and Ontario, Canada from 1999-2002. They found that highest yield losses were caused by H. glycines in both the USA and Canada, the reduction in yield in the USA in 2002 amounting to US $784 million. In the USA yield losses were estimated at 4.2 million tons in 1999 and 3.6 million tons in 2001.
