The primary goal is to better predict spear emergence and growth in asparagus. This will be accomplished by:First, evaluating the role of soil temperature (Tsoil) on asparagus bud break (growth resumption). The specific questions include: 1) what are the optimal soil temperature requirements for bud growth, and 2) once growth resumes, how does soil temperature affect spear elongation and the interval between spear initiation or harvest?Second, is there a dormancy period in asparagus, and how does it impact bud break and spear growth? Specifically to: 1) assess chilling durations on bud break? 2) evaluate chilling temperatures on bud base temperatures? and, 3) how growing temperatures impact spear elongation?Third, to use the information collected in Obj. 1 and 2 to improve existing spear growth models. The models of interest include: 1) identification of base temperature values, 2) chilling and heat unit parameters, and 3) use these to improve predictive growth models for asparagus.Fourth, to provide asparagus researchers, educators, growers, and industry representatives with the needed information to create conditions that optimize spear production. Since asparagus grows for many years, a better understanding will help them program production, schedule labor, and manage markets.