Utah Science Vol. 46 No. 1, Spring 1985

1 POISON-IVY IN UTAH R. J. Shaw and M. C. Williams Conditions seem to favor the spread of this plant, now found in 17 of the state\u27s 29 counties. 7 TRICHOMES: A POTENTIAL DEFENSE AGAINST GRASS BUGS W. F. Campbell and Y. H. Ling Insect-resistant grasses may be a practical method of controlling range pests and serve as the foundation for an integrated system of pest control. 10 INTEGRATED PEST MANAGEMENT FOR POTATOES T. W. Helms and J. L. Bushnell Better irrigation scheduling and disease control have markedly cut production costs and improved yields. 14 LIMITING EROSION ON FROZEN GROUND IN NORTHERN UTAH C. A. Lacey and A. R. Southard Terraces alone won\u27t prevent erosion on frozen ground and should be used with other soil conservation practices. 16 CONSERVATION TILLAGE IN UTAH Less Tillage Often Means More Management USU researchers studying conservation tillage techniques are optimistic, but say farmers should temper their enthusiasm, and not start on too large a scale. 24 INTEGRATED PEST MANAGEMENT: NEW WAYS TO MANAGE APHIDS AND OTHER ALFALFA PESTS D. W. Davis IPM programs for alfalfa employ a variety of tactics and can often reduce insecticide use. 28 PARADOXES AND PROBLEMS IN THE HORSE INDUSTRY J. McArthur Expensive programs to protect wild horses may mean more of these horses are available for adoption at a time when trends indicate that there\u27s less interest in raising grade horses. 32 ADOLESCENT PREGNANCY AND CHILDBEARING IN UTAH AND THE UNITED STATES B. C. Miller Teen fertility rates in Utah are among the highest in the nation, a trend which is related to a variety of problems and social concerns. 36 THE SEARCH FOR SALT-TOLERANT ALFALFA/ Rhizobium R. M. Mohammad and W. F. Campbell Salt-tolerant alfalfas and bacteria could convert more atmospheric nitrogen into a form usable by plants and make more productive use of millions of acres of saline land