NATURAL INCIDENCE OF PHYTOPHTHORA PHASEOLIIN DRY BEAN GROWN IN THE HIGHLANDS OF MEXICO

摘要

Downy mildew is induced by Phytophthora phaseoli or Phytophthora parasitica var. nicotianae; a disease that occurs in Central and South America and the West Indies, infecting lima bean (Phaseolus lunatus) (3) and has been classified as sporadic. The first notice of the disease in Mexico was in 1968, with posterior reports in 1973, 1975, 1978 and 1980, mainly at the central-western states of Jalisco, Michoacan and State of Mexico (the Neovolcanic axes region), a region of sub-humid temperate climate.In this region it has been observed infecting different cultivars of P. vulgaris and P. coccineus (1). In 1980 the damage rated on the cv. Bayomex (a type I) in the State of Mexico was 50% (1).