Abstract

George, Wayne. 1979. Protect Our Elm Trees Society. American Forests 85(1): 27-29, 51-52.

Scientists have tested an improved form of Benlate called Lignasan BLP. This water-soluble fungicide was developed by the DuPont Corporation and was approved by the EPA for general use in May 1976. It is administered to elms by injection through the three’s trunk. Following DuPont’s lead, Merck and Company recently introduced another EPA-sanctioned fungicide patented under the name Arbotect 20. The availability of these fungicides has given hope to towns like Riverside, Illinois, one of many communities that have thrown down the gauntlet in the perhaps quixotic struggle against Dutch elm disease. Riverside, for certain unique aesthetic and historical reasons, has a very special interest in preserving its remaining elms. Riverside’s elms, many as old as the town, represent a significant part of its charm and beauty; they are an intrinsic and historical element of it. In the fall of 1976 the residents of Riverside became acutely aware of the accelerated loss of elms, and a citizen’s committee calling itself POETS (Protect Our Elm Trees Society) was formed. The people of Riverside, satisfied that their efforts during the 1977 season were of value, continued Lignasan inoculation treatment in the spring of 1978.

Kemmerer, Harleigh. 1979. Managing mulches. Grounds Maintenance 14(1): 62, 64, 66.

Forests and other areas of natural vegetation have layers of leaves, sticks and other organic debris that continuously cover the soil surface. This growth-promoting layer can be duplicated by applying mulch to the soil surface at the base of plants. Mulch helps to keep soil in good physical condition because water absorption is increased, and absorbed water penetrates to the root zone. The layer also reduces erosion by preventing raindrop impact on bare soil. The organic matter adds some nutrients to the soil. Artificial mulches break capillary action and reduce moisture loss by evaporation. Increasing the thickness of the layer of mulch generally increases the amount of weed control. Experiments with mulches on north and south-facing slopes have shown that mulches do reduce temperature. Frost penetration is less and alternate freezing and thawing is reduced. Organic matter mulches have a beneficial effect on the potassium content of the soil and its availability for plant growth. Root injury that frequently occurs with surface cultivation is eliminated. Winter injury is reduced. Texture and color is added to the landscape.

• © 1980, International Society of Arboriculture. All rights reserved.