In our work we used noninvasive point reflectance spectroscopy in the range from 400 to 2100 nm coupled with machine learning to study scales on the brown and golden iridescent areas on the dorsal side of the forewing of Diachrysia chrysitis and D. stenochrysis. We used our approach to distinguish between these species of moths. The basis for the study was a statistically significant collection of 95 specimens identified based on morphological feature and gathered during 23 years in Poland. The numerical part of an experiment included two independent discriminant analyses: stochastic and deterministic. The more sensitive stochastic approach achieved average compliance with the species identification made by entomologists at the level of 99–100%. It demonstrated high stability against the different configurations of training and validation sets, hence strong predictors of Diachrysia siblings distinctiveness. Both methods resulted in the same small set of relevant features, where minimal fully discriminating subsets of wavelengths were three for glass scales on the golden area and four for the brown. The differences between species in scales primarily concern their major components and ultrastructure. In melanin-absent glass scales, this is mainly chitin configuration, while in melanin-present brown scales, melanin reveals as an additional factor.
22 December 2017 in Acta Scientiarum Polonorum Hortorum Cultus
In two vegetative seasons 2005-2006 azoxystrobin (Amistar 250 SC at the dose of 0.7 dm 3 /ha) was applied as a spraying treatment at the beginning of plant flowering against stem canker (Leptosphaeria maculans and L. biglobosa) in winter oilseed rape crops. The effect of the following spray application parameters: water volume (200 and 400 l/ha), adjuvant type (Break Thru S 240 - 0.1% and Atpolan 80 EC - 0.5%), and nozzle type (XR11002 - fine droplet size and DB11002 - coarse droplets at 0.4 MPa pressure) on the fungi- cide efficacy was studied. The results of presented studies indicated that azoxystrobin (Amistar 250 SC) caused a significant decrease of rape infection by stem canker. Addition of adjuvants did not significantly increase the fungicide effectiveness, and sometimes low- ered its action (especially after the application of Atpolan 80 EC). The applied spray volumes of water and nozzle type provided an effective protection of oilseed rape against stem canker, however, in some cases the results of field experiments were not significantly different. The best results of the disease casual agent (L. biglobosa) control, statistically proved were shown at the higher spray volume (400 l/ha), regardless of nozzle type (droplet size) and adjuvant application.
1 January 2009 in Journal of Plant Protection Research