Virosis in corn crops (Zea mays L.) in Tepechicotlán, Guerrero, Mexico.

Abstract

The sampling area is located in Tepechicotlán,
Guerrero where maize is grown. Due to the
economic importance of this crop, it was of interest
to determine the diseases that affect it as they can
affect its production. Three plots were sampled in
two stages at 45 and 90 days of maize crop
development. In each plot and stage 100 plants were
sampled in a zig-zag procedure. In the sampling
area, maize dwarf mosaic virus (MDMV),
transmitted by aphids of the genus Rhopalosiphum
maidis (Fitch), was detected. The symptoms were
foliar chlorosis, there is a reduction of growth,
decrease in stem diameter, and delay in maturity,
deformed ears. At 45 days of crop growth, 33% of
the plots were affected, with an average severity of
20%. At 90 days of development the severity
reached an average of 40%, the incidence was the
same as 33%. Symptoms were manifested in plants
at both sampling stages, to a greater degree at the
young plant stage. The affected plants had an
approximately 55% decrease in vegetative and fruit
production.