Andrzej Wójtowicz

Forecasting the influence of temperature increase on the development of the Colorado potato beetle [Leptinotarsa decemlineata (Say)] in the Wielkopolska region of Poland

Abstract The Colorado potato beetle (Leptinotarsa decemlineata) is probably the most dangerous pest species of potatoes. This study assessed the influence of expected climate warming on the number of Colorado potato beetle generations in the Wielkopolska region of Poland using two simulation models, SimLep 1 and NumoGen 1. Two types of data sets were utilised in the simulations: real meteorological data recorded in Winna Góra (52.2N; 17.4E) in the period 2002–2011 and virtual data obtained after transformation of the real data to include an increase in the recorded temperature values between 1 and 6°C. The threat to potato crops from Colorado potato beetle was found to increase in response to expected climate change. A temperature increase of 2°C above that recorded during the last few years would allow the development of two full generations of the beetle, and further temperature increases may even permit the occurrence of three generations.

Predicting the effects of climate change on the latency period of wheat leaf rust in western Poland

ABSTRACT Leaf rust caused by Puccinia recondita f. sp. tritici belongs to the most important diseases of wheat worldwide. The progress of the disease is highly dependent on meteorological conditions. One of the parameters affecting the disease progress is latency period driven mostly by temperature. Examination of the influence of predicted temperature changes on the monthly sum of the daily latency period expressed as rate (MSLPR) in western Poland was the aim of our study. Experiments in quasi-natural conditions were performed with the aim of validating models describing the influence of temperature on leaf rust latency period in two wheat varieties, Turnia and Ostroga. Both models used for assessment of latency period duration on cv. Turnia and cv. Ostroga performed well. The influence of climate changes on leaf rust latency period was then simulated using meteorological data from three weather stations located in western Poland and virtual data obtained after transformation of the recorded data to reflect a temperature changes under RCP2.6 and RCP8.5 scenarios according to giss_e2_r climate model. The study shows that without mitigation of greenhouse gas emission latency period of wheat leaf rust is going to decrease which may result in increase of wheat leaf rust incidence.

Effect of protection against pathogens on yield of two breeding types of winter oilseed rape cultivars under high level of nitrogen fertilizationWpływ ochrony przed patogenami na plonowanie dwóch typów hodowlanych odmian rzepaku ozimego w warunkach wysokiego poziomu nawożenia azotem

The carried out studies confirmed the efficacy of chemical protection in reduction of infection caused by the following pathogens; Leptosphaeria spp. – phoma stem canker, Sclerotinia sclerotiorum – stem rot, Botryotinia fuckeliana – grey mould, Alternaria spp. – dark leaf and pod spot. In all plant protection programs the treatments were applied at the growth stage BBCH 65 which, was recommended for a control of pathogens occurring at highest intensity during the studies (S. sclerotiorum and Alternaria spp.) and it resulted in similar efficiency of protection. Plant protection also significantly affected the yield. The highest seed yield was collected from the objects protected three times during a vegetation season. The seed yield was also dependent on nitrogen fertilization level. Significant higher seed yield was achieved on objects fertilized with 220 kg N/ha. Seed yield was also influenced by cultivar and sowing density. Visby cultivar produced a significantly higher yield when sown at smaller density.