TROPICAL CORN (Zea mays L) GENOTYPES WITH HIGH YIELD AND TOLERANCE TO CORN STUNT DISEASE IN THE GULF OF MEXICO REGION

Abstract

In the humid tropic of México, there are planted 2.5 million hectares of corn with yield of 2.0 tons per hectare. In this area the corn stunt disease has caused damages greater than 25 % in commercial planting in Yucatán and Veracruz states and the coast region of the Gulf. The objectives of this research were to know the yield and agronomic characteristics of tropical corn genotypes and to identify those well adapted and tolerant to corn stunt disease, Thus, during the spring summer season in 2005/05, there were carried out experiments of maize genotypes, in Medellín de Bravo, Tlalixcoyan and Ignacio de la Llave in Veracruz State, under a randomized complete block design with 10 entries and two replications in plots of eight rows 10 m long and 80 cm wide, for getting 62 500 plants ha-1. The agronomic traits registered were: grain yield, percentage of damaged plants and ears for corn stunt and severity of damage. From the combined analysis for all traits registered, there were found high significant differences for genotypes (G) and locations (L). For interaction GxL, except for percentage of damaged plants, there were found high significant differences for the others traits. The genotypes that had the best yield, agronomic characteristics and tolerance to corn stunt were: H-520, H-513, H-518 and C-343.

Keywords

• Dalbulus maidis, Spiroplasma kunkelii, Phytoplasm Corn stunt Maize bushy stunt, tolerant genotypes, humid tropic