Weed host-pathogen system

Weeds host pathogens and nematodes and use soil nutrients. One example is pigweed, a luxuriant extractor of soil nitrogen that causes nitrate deficiencies in the sugarcane plant. Weedy grasses serve as an alternate hosts and reservoirs for systemic viruses, and they harbor insects that carry diseases to sugarcane. Rats find shelter in weedy fields. Because stalk juice alone does not provide an adequate diet, rats are attracted to weed seeds as a source of protein. 

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