1. Dep. of Horticulture Univ. of Wisconsin 1575 Linden Dr. Madison WI 53706‐1590
2. Instituto de Biotenología, Facultad de Agronomía Univ. Nacional Agraria la Molina Av. La Molina s/n, Lima 12 Lima Perú
3. Dep. of Chemistry Univ. of Wisconsin‐Platteville, 1 University Plaza Platteville WI 53818‐3099
4. USDA‐ARS, Vegetable Crops Research Unit, Dep. Horticulture Univ. of Wisconsin 1575 Linden Dr. Madison WI 53706‐1590