Potato Grower

WWW.POTATOGROWER.COM 27 suspended metabolic activity called cryptobiosis. This ability to survive in an almost inanimate state is one reason some nematode species can survive in soil for many years and resume activity only once favorable conditions return. Some plant parasitic nematodes also evade hostile environments and predators by living most of their lives inside plant roots and have only short periods of time in the soil. By using multiple survival strategies, nematodes withstand seemingly extreme environments. Nematodes are aquatic, but can swim only short distances to reach their hosts. They use the moisture in spaces between soil particles to move through the water. Nematodes can be dispersed over long distances on nematode-infested soil clinging to farm equipment, muddy shoes or in plant material such as tubers, bulbs or roots. Nematodes can easily be transported across borders in infested plant material or in soil. Essentially, any process that moves soil or plants is a pathway for introduction of these potentially invasive species. Invasion of agricultural lands by nematodes has come about though inadvertent movement in trade of infested agricultural products such as bulbs, nursery stock, seeds, tubers, or on contaminated equipment. Once introduced, apparent damage from nematodes has often gone unnoticed and has been attributed to other factors such as nutritional deficiency. As more has become known about nematodes and their damaging impact on crops, governments have increasingly placed nematodes in plant health legislation to prevent their introduction or spread. In the U.S., phytosanitary action specifically addressing plant parasitic nematodes was first implemented in 1909 against root knot nematode-infested cherry trees from Japan. Soon after, in 1912, U.S. Congress approved the first Plant Quarantine Act to minimize the threat posed from that nematode. A number of years later, the damaging impact of the potato cyst nematode— Globodera rostochiensis or the golden nematode—was recognized. The Golden Nematode Act was passed by Congress in 1948 to protect the U.S. potato industry from the spread of this damaging nematode. Europe's first phytosanitary legislation, the Beet Eelworm Order, was adopted in 1943 to manage spread and levels of infestations of the sugarbeet cyst nematode in Britain. Phytosanitary measures to minimize invasive nematodes Nematodes can be dispersed over long distances on nematode-infested soil clinging to farm equipment, muddy shoes or in plant material such as tubers, bulbs or roots. LEFT: Nematode cysts can be seen on potato roots.

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