HYBRID POPLAR IS RECOGNIZED AS A PROMISING SOURCE OF BIOMASS FOR ENERGY. TO REALIZE THIS VISION, ADVANCED MOLECULAR GENETICS TOOLS MUST BE COUPLED WITH TRADITIONAL BREEDING TECHNIQUES TO CREATE THE PIPELINE NEEDED TO PROVIDE IMPROVED HYBRID POPLAR GENOTYPES FOR THE SOUTHEAST'S. THIS PROJECT WILL CONDUCT A MORE IN-DEPTH EVALUATION OF EASTERN COTTONWOOD AND SELECT HYBRID POPLAR TAXA AND CLONES WHEN ESTABLISHED ACROSS A VARIETY OF UPLAND SITES AND SOILS IN THE SOUTHEASTERN UNITED STATES. FOUR OBJECTIVES WILL BE ADDRESSED:1) IDENTIFY GENETICALLY SUPERIOR POPLAR CLONES BASED ON VOLUME PRODUCTION AND DISEASE RESISTANCE, SECURING SELECTED MATERIAL INTO CLONE BANKS FOR DEPLOYMENT PLANTATIONS AND CONTINUED BREEDING.2) DETERMINE THE EFFECT OF FERTILIZATION ON VOLUME PRODUCTION FOR BOTH UNCUT AND COPPICE MATERIALS. EVALUATE COPPICE REGENERATION OF ALL CLONES AND ITS CORRELATION TO THE SPREAD OF SEPTORIA STEM CANKER AND MELAMPSORA LEAF RUST AND THE EFFECT OF THESE PATHOGENS ON BIOMASS YIELDS.3) DIFFERENTIATE THE PHYSIOLOGY AND RESOURCE (WATER AND NUTRIENTS) DEMANDS BETWEEN HYBRID POPLARS AND EASTERN COTTONWOOD THAT RESULT IN INCREASED BIOMASS YIELDS.4) CONSTRUCT A LIBRARY OF POPULUS CLONES, INCLUDING KEY QUALITY CHARACTERISTICS, THAT WILL ALLOW FOR THE BEST USE OF CLONES ACROSS UPLAND SITES IN THE SOUTHEASTERN UNITED STATES.THE APPS PROGRAM, BUILDING ON CONSIDERABLE PRIOR INVESTMENT, WILL SOLIDIFY THE FOUNDATION FOR CONTINUED IMPROVEMENT OF HYBRID POPLAR AS A CRUCIAL HARDWOOD RESOURCE FOR THE REGION. WHILE ADDRESSING NEAR-TERM OPPORTUNITIES TO INTRODUCE HYBRID POPLAR ONTO THE LANDSCAPE, RESEARCH WILL GENERATE FUNDAMENTAL INSIGHT INTO GENETIC CONTROL OVER KEY UTILIZATION TRAITS.