Western Yellow Pine Mistletoe

This bulletin gives the results of studies over a period of twelve years on the effect of mistletoe Razounzofskya cryptopoda (Engelm.) Cov. on the growth and seed production of western yellow pine. The intensive part of these studies was carried on near the San Francisco mountains in northern Arizona. The parasite is the most widely distributed and one of the most serious enemies of the western yellow pine. On southern slopes and near the lower limit of the distribution of the pine, areas occur where 75 to 90 per cent of all trees above six inches in diameter are infected