The usefulness of Maleic Hydrazide (MH) as a grass growth retardant when applied to urban, suburban and rural roadsides was evaluated from 1961 through 1964. The material was also tested on "hard-to-maintain" areas such as fence lines. MH was applied at various rates, in the spring and fall with and without an herbicide (weed killer). The areas on which the material was applied are normally mowed from 2 to 11 times a year, depending on the areas.
The application of MH at six pounds active material per acre in the spring generally retarded the height of grass. Lower rates and fall applications were generally ineffective. Depending on the area (rural or urban) and the effectiveness of the application, between zero and five mowings per year were saved.
When the turf was of other than excellent quality and the MH application was effective, annual weeds such as crabgrass, foxtail and ragweed tended to become very evident. When MH was used without an herbicide the roadside generally appeared more ragged than when not treated. When MH was applied with an herbicide and annual weed invasion, did not occur, a satisfactory appearing roadside was obtained. The period of time in the spring during which MH can be effectively applied is short, about two weeks. Rains, winds and springtime maintenance activities make proper timing of the application work very difficult under Minnesota conditions.
Herewith is a copy of the interim report covering a portion of the work performed on this research project in 1963, 1964 and 1965.
The report includes further observations regarding some of the materials covered in the 1962 Report, "Experiments on Seeding and Mulching for Roadside Erosion Control". A section on erosion basics is included to provide background knowledge on this important, and often costly natural process.
The mulch experiment, reported herein has resulted in the addition of another material (green wood excelsior) to the specifications. This new material is supplied in bales and applied like straw, but it does not require an asphalt tack.
Seeding trials, species trials and some soil sterilant studies are also reported. The species work has resulted in the inclusion of birdsfoot trefoil in most of the seeding mixtures in the new specification book and in a wider use of crownvetch on specific sites.
This study was concerned primarily with a laboratory evaluation of the effectiveness of several chemical inhibitors in reducing corrosion of autobody steel by deicing salts. Under the controlled exposure conditions imposed in the laboratory tests, the treated salts appear to be quite effective in reducing corrosion. It was therefore deemed necessary to further evaluate the effectiveness of anticorrosive salt under natural conditions of exposure more typical of that experienced by vehicles in normal use.
A separate field evaluation was conducted beginning in the fall of 1965 and continuing through the 1966-67 winter. The results of this study, in comparison with the results of the laboratory study indicate a much reduced effectiveness. Because of the difference in the findings of the two studies, a summary of the final report of the field evaluation is given in Appendix C of this publication.
The degree of corrosion to autobody steel by anticorrosive salt was evaluated when compared to the corrosive effects of nontreated salt. The evaluation extended from the winter of 1995-96 through the the winter of 1966-67. Evaluation were primarily made primarily through the corrosion product weight loss method, however, a visual evaluation method was also used during the 1966-67 winter. Comparisons were made in metropolitan areas as well as semi-rural communities. Corrosion losses of autobody steel subjected only to the natural atmospheric environmental conditions in different portions of the state were also studied.
