Drought tolerance combined with resistance to black sigatoka (BS) dise
ase are two desirable traits for plantains in some parts of the tropic
s. Field evaluation of leaf stomatal conductance, single leaf transpir
ation rate, photochemical efficiency, and role of stomata in BS resist
ance, was done for 18 genotypes of Musa spp., which included diploid a
nd triploid banana and plantains and tetraploid plantain hybrids, at a
sub-humid and a humid site. Conductances were significantly (P less t
han or equal to 0.01) higher for leaf abaxial than adaxial surfaces (S
), while clonal (C) differences were significant (P less than or equal
to 0.05). Interactions between sampling period (T: morning vs afterno
on) and location (L), and clone and location (C x L) were significant
for both conductance and transpiration; (C x T x L) interaction was si
gnificant for conductance. Significant interactions for (C x L) and (C
x T) suggested that conductance and transpiration of a specific clone
need to be considered for a given environment. Total variation in con
ductance was explained by the following variables: S, C, (C x L), (C x
T), and(C x L x T). In general, ABB cooking banana had higher conduct
ances than other Musa taxonomic groups (AAB, AA, AAA, and AAAB). Evalu
ation of morphological and physiological traits of leaf stomata indica
ted that the resistance to BS disease is due to non-stomatal mechanism
s.