D6-Lancastar Firming Saturday, May 11,1991 Understand Host/Pest Triangle To Manage Crops DEKALB, 111. Insects and disease are problems that always nag com growers and cause yield and profit loss. But farmers can better manage this problem by understanding the host/pest triangle. “This term refers to the condi tions necessary for a disease or insect problem to fully develop,” said Larry Martin, regional agro nomist for DEKALB Plant Gene tics. “These involve a susceptible plant, a causal agent such as a fun gus or virus, and a favorable environment.” Martin said that all three condi tions must be met for crop damage to occur. Even then, timing plays a big role in actual problem P. L ROHRER & BRO.. INC. I Smoketown, PA PH. 717-299-2571 ■ Agr, Pro ,s a registered trademark of ABI PO -Jox 2955 Shawnee V,ss«>n KS 56201 01990A81 jfc— *»— 31* as «/* j. - Western P® Robert Smote 412-942-0129 development The DEKALB agronomist also said that understanding the triangle makes it easier for growers to defuse yield-threatening agents such as insects and disease. He said susceptibility depends on the genetic constitution of plants, their stage of development, and their overall health and vigor. In addition, plants that ate well fed and watered, vigorous and well managed will fare better against pest attacks. Soil fertility and pH, drainage and moisture condition also can indirectly affect pest development, said Martin. Presence of causal agents depends on previous crops, nearby vegetation, wind and air move- FARM Livestock • Storage • Utility HORSE Barns • Riding Arenas • Open-Sided Shelters COMMERCIAL Office • Warehouse • Retail Over 35 years of design-build experience and expertise in providing turnkey solutions, competitively priced with a variety of financing options For more information contact AGWAY BULOmGS -- t . Jf•i. "**- y. Penn-Atlantlc Region 1 *■ P.O. Box 43 Elizabethtown, Pa. 17022 717/367-1178 Southeast