Cuticular wax load and surface wettability of leaves and fruits collected from sweet cherry (Prunus avium) trees grown under field conditions or inside a polytunnel

Abstract

In this work, the effect of microclimate at the tree level inside a polytunnel and in an uncovered orchard of Prunus avium was studied through the observation of leaf and fruit micromorphology and the accumulation of cuticular waxes. Records of environmental parameters showed a significantly higher daytime temperature in the polytunnel (on an average 4°C), whereas the night temperature did not differ between treatments. Furthermore, photosynthetic active radiation and UV-B radiation inside the polytunnel were 43 and 97% lower, respectively, than the radiation measured outside. Leaves grown in the polytunnel had lower contact angles and higher load of cuticular wax per unit area, irrespective of cultivar. The impact of the microclimate was observed at the first sampling and did not increase with exposure time of leaves. Fruits of the cultivars 'Souvenir' and 'Prime Giant' grown outside had significantly less cuticular wax despite their delayed harvest time of 11 and 5 days, respectively. The relationship of higher cuticular wax load and lower contact angles of protected leaves might have practical importance for plant protection activities and the retention and uptake of leaf-applied agrochemicals.

Research on the changes in wettability of rice (Oryza sativa.) leaf surfaces at different development stages using the OWRK method

“…Previous studies found that the cuticular wax in rice leaf has a total amount of 8.35 µg/cm 2 and consists of 34.3% fatty acids (mainly C24–C32), 31.2% aldehydes (mainly C30–C34), 23.9% primary alcohols (mainly C30), 6.9% alkanes and 8.35% esters, dominated by relative non‐polar components . In addition to chemical effects, microstructure and nanostructure on the leaf surface, which is generally agreed as the key for the hydrophobicity of surfaces, has been reported as having a clear relationship with the chemical composition of the cuticular waxes . Former studies of the morphology of rice leaf surface have shown that the surface is covered with smaller convex sculptures (insert) and wax platelets, causing superhydrophobicity .…”

“…Except for the influence of plant development, environment factors were also reported to influence the wettability of leaf surfaces such as environmental pollutant, the infestation of pests, and changes in temperature and humidity . So some measurements should be taken so as to adjust the pesticide formulation to adapt the plants surface wettability changes with growth process of crops.…”

“…As is well known, apparent disparity in chemical wax compositions and morphology properties of leaf surfaces between different plants leads to distinct wettability differences, and has been given some attention in researches and applications for better wetting behavior. Extrinsic factors such as environmental influences are also of wide concern, the factors reported already containing the effects of acid‐rain, sulfur‐dioxide and ozone, industrial pollutions, and also temperature and humidity conditions in different places . While the wettability changes during plant's growth and development impacting changes in active ingredient deposition is almost neglected.…”

Adsorption of Strontium onto Adaxial and Abaxial Cuticle of Photinia serrulata Leaf

“…However, there remain some differences in structure between the adaxial and abaxial foliar cuticles of most plants, especially angiosperms, the stomas of which are typically located in the abaxial epidermis [9]. The adaxial and abaxial cuticular topographies are distinct from each other resulting in different pollutant uptake behaviors [16,17]. Stomata located in abaxial cuticle was suggested to contribute importantly in the uptake of chemicals by plants, as the pore structures would offer a rapid access of toxicants to the deeper cuticle parts [18].…”

Wettability of pear leaves from three regions characterized at different stages after flowering using the OWRK method

“…The presence of a cuticle surrounded by a waxy layer can control moisture transpiration, enhance mechanical properties, prevent invasive bacteria and reduce the adhesion of insects . The chemical composition, morphology and quantity of the waxy layer change with plant species and environmental factors such as temperature, humidity, drought stress, atmospheric pollutants and other non‐biological factors . Chemical composition, microstructure geometry and epiphytic surface material are major factors that influence leaf surface wettability .…”