Municipal Tree Survey and Urban Tree Inventory

Abstract

Fretz, T. A. and E. M. Smith. 1975. Why herbicides fail. Am. Nurseryman 141(1): 12, 116-124. Most herbicide failures reported are not really herbicide failures. When one considers all the external forces that can ultimately affect herbicidal action, it's amiracle they work at all. Not only are there numerous environmental factors that are involved in herbicidal action, but the chances for human error are present from the initial steps of selection of the herbicide, its application and crop management. This paper calls attention to the fact that herbicides are not perfect. The variety of weather, soil texture, temperature, weed spectrum, soil organic matter, crop and the many other factors alone and in combination influence herbicide performance year after year. There may be seasons when, because of these factors, individual herbicide performance varies. But cultural control also varies year to year, so one bad experience with the use of herbicides should not result in relinquishing an herbicide program. Lee, C. I , B. C. MoserandC. E. Hess. 1974. Root regeneration of transplanted pin and scarlet oak. New Horizons, p. 10-13. Hort. Research Inst., Washington, D. C. The research described in this report was undertaken in an effort to shed some light on the oak transplant problem. For experimental purposes, it was decided to investigate factors affecting root regenerating potential (RRP) of the difficult to transplant scarlet oak as compared to the easily transplanted pin oak. Because of the large number of plants needed, all experiments were conducted with oneand two-year-old seedlings. In all cases, bare root field grown seedlings were transplanted into one gallon pots and held under greenhouse conditions for six weeks at which time the media was washed from the roots and RRP observed. Root regenerating potential was determined by counting the number of new roots formed. The above experiments lead to the following conclusions concerning the oaks studied: 1) Scarlet oak has a lower RRP than pin oak, which is a major factor in ease of transplanting. 2) There is a seasonal pattern to RRP for both oaks with a maximum in the spring. 3) Auxin treatment to the roots enhances RRP of both oaks but does not alter its seasonal pattern. 4) Pruning of shoots enhances RRP of scarlet oak but has a negative effect on RRP of pin oak. 5) Disbudding experiments suggest that RRP in scarlet oak is limited by its aerial shoots while RRP in pin oak is promoted by its shoots. 6) Antitranspirants applied to dormant shoots enhance RRP in scarlet oak but have no consistent effect on pin oak. 7) Reciprocal grafting experiments support the hypothesis that limitations to RRP in scarlet and pin oaks are imposed on them by factors in the aerial portion of the plant.