The control of annual weeds in young prune orchards increased growth. The degree of foliar expressed phytotoxicity did not result in decreased tree growth. Simazine gave long lasting weed control and the most foliar symptoms on prunes, but superior tree growth. Simazine and dichlobenil produced more foliar symptoms than diphenamid, but less indication of growth reduction.
Principal hosts of the misletoe Phoradendron flavescens (Pursh.) Nutt. that infests black and English walnut trees in California are common cottonwood and California buckeye, but it also occurs on many other trees. The mistletoe usually becomes established in new growth or roughened areas along the older stems and crotches of branches of the host trees (2).