ABSTRACT. The cabbage aphid, Brevicoryne brassicae L. (Hemiptera:Aphididae), is a perennial pest that specializes on plants of the Brassicaceae family, attacking winter canola (Brassica napus L.) mainly during and after flowering. Under field conditions, cabbage aphid colonizes the upper flowering canopy. Population dynamics of aphids in the flowering canopy could be regulated by differences in either plant quality (bottom-up) or predatory (top-down) forces. The goal of our study was to determine the effect of feeding location on cabbage aphid demography.

Abstract Ramularia collo-cygni is the biotic factor responsible for the disease Ramularia leaf spot (RLS) of barley (Hordeum vulgare). Despite having been described over 100 years ago and being considered a minor disease in some countries, the fungus is attracting interest in the scientific community as a result of the increasing number of recorded economically damaging disease epidemics. New reports of disease spread and fungal identification using molecular diagnostics have helped redefine RLS as a global disease.

Abstract Ramularia collo-cygni is the biotic factor responsible for the disease Ramularia leaf spot (RLS) of barley (Hordeum vulgare). Despite having been described over 100 years ago and being considered a minor disease in some countries, the fungus is attracting interest in the scientific community as a result of the increasing number of recorded economically damaging disease epidemics. New reports of disease spread and fungal identification using molecular diagnostics have helped redefine RLS as a global disease.

ABSTRACT. The aim of the experiment was to study diurnal variation in water-soluble carbohydrate (WSC) concentrations in leaf and stem of tall fescue and lucerne in autumn and to determine the impact of these changes on the rate and the extent of in vitro fermentation. Vegetative herbage of lucerne and tall fescue were sampled at 0900, 1300 and 1700 h, following three consecutive regrowths between April and May. Whole plants, leaf and stem were analysed for chemical composition and in vitro gas production.

ABSTRACT. The aim of this study was to evaluate the toxicity of Stryphnodendron fissuratum pods in guinea pigs (Cavia porcellus) and test the hypothesis that this plant has teratogenic effects. Thus, sixteen guinea pigs were randomly divided into four groups of four animals each. Groups 10, 20 and 40 consisted of guinea pigs that received commercial food that contained crushed pods of S. fissuratum at concentrations of 10, 20 and 40 g/kg, respectively, during the period of organogenesis.

ABSTRACT. The reduced pool of the abscisic acid (ABA) precursors, ?-? carotenoids, in roots does not account for the substantial increase of ABA content in response to water stress (WS) conditions, suggesting that ABA could be transported from other organs. Basipetal transport was interrupted by stem-girdling and ABA levels were determined in roots after two cycles of WS induced by transplanting plants to dry perlite.

ABSTRACT. Phytophthora root and stem rot caused by Phytophthora sojae is an economically important disease of soybean throughout the Midwestern United States. This disease has been successfully managed with resistance (Rps) genes, however, pathogen populations throughout the Midwest have developed virulence to many (Rps genes including those that have not been deployed. To gain a better understanding of the processes that influence P.

ABSTRACT. The sensitivity of Venturia inaequalis to trifloxystrobin and difenoconazole was studied in Uruguay. Populations of V. inaequalis were collected from apple orchards with different histories of trifloxystrobin use. Sensitivity of populations to trifloxystrobin was analysed using a method for testing spore germination published by FRAC, using a discriminatory concentration of 2.0 mg a.i./l. Resistance to trifloxystrobin was widespread in the region of commercial apple production with resistance detected in all orchards examined, the incidences ranging from 3% to 95%.

SUMMARY. Togninia minima (anamorph Phaeoacremonium aleophilum) is one of the main fungi responsible for trunk diseases of grapevines and other woody hosts worldwide. Sequences of protein-coding genes of isolates from countries in different continents have been published, presenting a useful resource for examination of the diversity and spatial distribution of T. minima genotypes.