BACKGROUND: Leaf wettability considerably defines the degree of retention of water and agrochemical sprays on crop and non-target plant surfaces. Plant surface structure varies with development therefore the goal was to characterise the wettability of @entity1460 leaf surfaces as a function of @entity851 ( @entity851 ). RESULTS: Adaxial surfaces of leaves developed at @entity851 16 (BBCH) were 10 times more wettable with water than leaves at the lower canopy ( @entity851 13). By measuring contact angles of a liquid having an intermediate surface tension on different leaf patches, an illustrative wetting profile was elucidated, showing to what degree wetting varies (from > 120   to < 20  ) depending on leaf patch and @entity851 . While the critical surface tension of leaf surfaces at different GSs did not correlate with the observed changes, the slope of the Zisman plot accurately represented the increase in wettability of leaves at the upper canopy and lateral shoots (GSs 17 to 19, 21 and 24). The discrimination given by the slopes was even better than that by water contact angles. SEM observations revealed that the low wettability observed at early GSs is mainly due to a dense layer of epicuticular wax crystals. The Zisman plot slope does not represent the changes in leaf roughness (i.e. epicuticular wax deposition), but provides an insight into chemical and compositional surface characteristics at the droplet-leaf interface. CONCLUSIONS: The results with different wettability measurement methods demonstrated that wetting is a feature that characterises each developmental stage of @entity1460 leaves. Positional wettability differences among leaves at the same plant and within the same leaf are relevant for performance, selectivity and plant compatibility of agrochemicals. Implications are discussed.

Wettability of XXXX ( @entity1460 L.) leaves by foliar sprays with respect to developmental changes.

@entity851 :: ('MESH:D006130', 'Disease') :: ['GS', 'growth stage'] @entity1460 :: ('3847', 'Species') :: ['soybean']
@entity1460 :: (3847,Species) :: ['soybean']
