Published online by Cambridge University Press: 31 May 2012
Sterility of grasses caused by a constricted brown region, usually in the upper internode, is commonly described as silver top because of the bleached appearance of the inflorescence. Hodgkiss (1908) reported that silver top was caused by the mite, Siteroptes graminum (Reuter), in conjunction with the fungus, Fusarium poae (Pk.) Wr. Brown et al. (1952) found that in the greenhouse several chlorinated hydrocarbons controlled S. graminum. Hardison et al. (1957) reported that S. graminum in combination with F. poae was of little importance in causing silver top of cultivated grasses in western Oregon. They suggested that two thrips of the genus Aptinothrips might be the primary cause. They recommended DDT or heptachlor applied in late April or early May. They also found that post-harvest burning reduced silver top.