IRON CHLOROSIS TOLERANCE OF DRY BEAN GENOTYPES IN CALCAREOUS SOILS

Abstract

The Fe-ehlorosis in plants growing in calcareous soils of regions with scare precipitation can reduce the grain yield up to 100 % of Fesusceptible varieties of dried bean (Phaseolus vulgaris L.). The use of resistant varieties, is one the available methods to decrease the symptoms Fe-deficiency. Assuming that among the mexican dried bean
germplasm could exist varieties that may be able to absorb Fe in soils with low Fe-availability, the present study was carried on to evaluate the Fe-chlorosis tolerance in selected dried bean varieties in calcareous soil. The experiment was established at the Agricultural Experimental Station of the Universidad Autónoma de Nuevo León.
Two soil types with different HCO₃ contents, which caused Fechlorosis in the previous season, and 38 dried bean genotypes were evaluated. A complete randomized design with two replications was used. The mean differences were calculated using Tukey (0.05) test. Chlorosis symptoms were recorded at blooming, based in the scale
proposed by Hernández et al. (1996). There were different degree of Fe-chlorosis between the soils among the varieties. The most severe symptoms were observed on the clay loam soil, which presented 2.3 ppm of Fe-available, compared with 3.8 ppm of Fe-avariable the silt clay loam soil. The tolerant varieties (Fe-efficient) were Pinto Villa,
AN-22, Durango 222, Pinto Mex. 80, Navidad 1165 and Bco. 370 (3). The susceptible varieties (Fe-inefficient) were: LEF-IRB, Pinto 114, Selección 4, Anzalduaz 91, Negro Jamapa, Flor de Mayo RMC, PC148-93-38, Pinto Narro 1, LEF-25-RB, Manzano, Peruano, Negro Durango, Pinto Norteño, Bco. 370 (1), Bco. 370 (7), Canario 101, Negro Huasteco 81, II-952-M-26-1M-72, and Pinto Laguna 87.