-5- 



The cut stump treatment is for trees two to three inches and up, which are more 

 easily cut Yfhen green. As soon as the tree is cut, the cut surface and bark are 

 thoroughly wetted with the herbicides. This may be done by painting or spraying. 



For the latter two methods a small power sprayer, or a hand outfit such as a 

 knapsack or compressed air sprayer is ordinarily used. Very low pressure is desirable, 

 A weed nozzle with a narrow flat fan saves material. 



Not all species of brush are equally sensitive to herbicidal sprays. The root 

 sprouting species such as chokecherry and poplar sprout from live sections of root 

 and vri.ll almost certainly need retreatment. Other species, such as red maple, v/'hich 

 are very resistant, will not be eliminated by a single spray. Even though respraying 

 is necessary the amount of time and material required will be greatly reduced. 



A word of caution, 2, U-D and 2,U,5-T are very difficult to wash from spraying 

 equipment. Even after thorough washing there may be enough herbicidals left in the 

 sprayer to injure such sensitive plants as grapes. An advantage of these dormant 

 season treatments is that inexpensive equipment can be purchased and used for tliis 

 kind of spraying only. 



— John S, Bailey 



S TOf]Y PIT DISEASE OF BOSC PEARS 



A deformity and pitting of Bosc pears has come to our attention. YiTith the help 

 of Dr. John L» Dunegan, United States Department of Agriculture, the diseasa has been 

 identified as Stony Pit, a serious transmissable virus disease. It has the 

 appearance of injury caused by tarnished plant bug and even curculio. The disease 

 has been \<jiavm only in the Pacific Coast States since 192^. The fruit becomes 

 gnarled and pitted and is considered worthless. It has been reported that from 10- 

 80^ of the Bosc culls at the packing houses there are due to stony pit, and surveys 

 in the Hood River Valley have shown almost every Bosc orchard to contain from a few 

 to as many as T0% of trees affected, The variety Anjou is also seriously affected. 



The disease was observed in a Bosc pear orchard in Ashland, It has been 

 recognized here by the grower for several years, first on a single tree and more 

 recently on other trees which confirms report from the Pacific Northwest that there 

 is a slow spread of virus from tree to tree by means other than budding and grafting. 

 We also have confirmed the occurrence of the disease in a Bosc pear orchard in 

 Hamden, Connecticut. The occurrence of the disease far remote from its knovm range 

 of distribution would indicate that the trees or scion vrood used in making the trees 

 originated in the far west, although we have no definite information from the growers 

 involved , 



In addition to fruit pitting, pimples appear on young tvfigs vfliich crack to 

 form target canker effects. Older branches show rough bark like the bark of an oak 

 tree and much different from natural bark cracking of healthy Bosc, Trees with this 

 advanced stage of disease are not considered profitable, A leaf symptom consisting 

 of a veinlet chlorosis is associated with pitted fruits, but this occurs only on 

 occasional leaves and may become masked as the season progresses. 



The Bartlett variety is not affected and Bartletts top-worked on diseased Bosc 

 trees have always produced healthy fruit. Therefore to reduce losses from stony pit. 

 Brown, Oregon Sta, Bui, h38, 19U6, advocated placing buds or grafts throughout the 

 framework of infected Bosc trees. By this method the Bartlett variety is tolerant 

 of the virus. Buds or grafts from Bartlett on diseased Bosc put back into healthy 

 Bosc will transmit the disease. 



~ E. F. Guba 



