Effect of Saline Environment on Yield and Smut Disease Severity of Different Corn Genotypes (Zea mays L.)

Abstract

AbstractThe effects of saline irrigation water on growth, yield, smut index and leaf CI content were investigated under field conditions. The plants were grown in 1994 and 1995 and artificially infected with U. maydis‐ spore‐suspension at V6 and V10 leaf stages. The severity was rated on a 1–9 scale, whenever the symptotns appeared. The results showed that superior growth, greater yield performance, associated with lower smut incidence and leaf Cl contents were generally observed on Taba than its counterparts. Increasing salinity exhibited significant increases in leaf CI and induced marked inhibition on growth, yield and SI data. The salt sensitivity of corn genotypes, as revealed from the comparison of the slope of linear regression equations, was related to 1.00: 1.19;1.42 for cvs Taba, 310 and 320, respectively. The differential yield response with respect to SI data proved that smut susceptibility was inversely related to salt tolerance concept. The data of Cl‐disease interaction showed that smut reactions of highly susceptible and resistant genotypes (cvs 320 and Taba) were hardly monitored by plant Cl content, revealing that disease resistance is genetically controlled. Conversely, the progressive modifications of smut reaction, accompanied by CI accumulation in the moderately susceptible genotype 310 proved that disease resistance was environmentally conditioned by salt stress.