ʻWhite rings ̓have been reported to occur within trembling aspen (Populus tremuloides Michx.) during years of intense early defoliation by the forest tent caterpillar (Malacosoma disstria Hbn.). This study was undertaken to 1) assess the distribution of white rings within trembling aspen stems and 2) to quantify the anatomical differences between white rings and the ʻnormal ̓rings formed in the p...

The mechanisms linking C/N balance to N uptake and assimilation are central to plant responses to changing soil nutrient levels. Defoliation and subsequent regrowth of grasses both impact C partitioning, thereby creating a significant point of interaction with soil N availability. Using defoliation as an experimental treatment, we investigated the dynamic relationships between plant carbohydrat...

Background and Aims Nebbiolo grapes are used to produce Sfursat wine, following partial dehydration. This research aimed clarify the influence of fruit exposure light postharvest water loss on concentration green leaf volatiles (GLVs) lipoxygenase (LOX) alcohol dehydrogenase (ADH) activity grapes. Methods Results from Control vines (no defoliation) (ND) defoliated at fruitset (DFS) or post-vera...

Climate and weather fluctuations changes are the most important environmental drivers of tree canopy defoliation, an indicator forest health. We examined relationship between defoliation Basal Area Increment (BAI), a dimension growth related to wood biomass increment carbon sequestration therefore climate change mitigation potential forests. analysed data from mostly even-aged, single-species p...

Short-term greenhouse studies with soybean (Glycine max cv. Bragg) were used to examine interactions between the soybean cyst nematode (Heterodera glycines) and two other common pests of soybean, the stem canker fungus (Diaporthe phaseolorum var. caulivora) and the soybean looper (Pseudoplusia includens), a lepidopterous defoliator. Numbers of cyst nematode juveniles in roots and numbers of cys...

The genus Calosoma (Coleoptera: Carabidae) is a group of large, sometimes ornate beetles, which often voraciously attack caterpillars. Many studies have reported Calosoma beetles being highly conspicuous during defoliator outbreaks. Based on observations of individual beetle behavior, patterns of activity density and phenology we provide a hypothesis on how environmental cues may synchronize Ca...

This RPC experiment assesses the potential of VIIRS (Visible/Infrared Imager/ Radiometer Suite) and MODIS (Moderate Resolution Imaging Spectroradiometer) data for contribution to the EWS. In doing so, the RPC project employed multitemporal simulated VIIRS and MODIS data for detecting and monitoring forest defoliation from the non-native Eurasian gypsy moth (Lymantria despar). Gypsy moth is an i...

Background The defoliation of oaks is an urgent problem for forestry in Central Europe. During the last outbreak of the green oak leaf roller(Tortrix viridana) in 2003-2005, we observed fundamental differences in the defoliation level of individual Quercus robur trees in Germany. Some of the trees seem to be somehow “tolerant” (T oaks) against the insects grub while some seem to be conspicuousl...

This work quantifies two important epidemiological features of the bean (Phaseolus vulgaris)/Phaeoisariopsis griseola pathosystem. The first is the effect of the number of nights of leaf wetness on infection efficiency. Infection efficiency was below 10% when inoculated leaflets were exposed to less than two nights of leaf wetness. Optimum infection efficiencies were obtained after three to fou...