Chapters authored
The Role of Irrigation and Nitrogen Fertilization on the Feeding Behavior of European Corn Borer
European corn borer (ECB) creates tunnels inside the plant stalks, causing damage, which could significantly decrease yield loss. This study aimed to determine the relationship between damage caused by ECB larval feeding and different irrigation and nitrogen fertilization rates on different maize genotypes. We conducted a field experiment in Croatia from 2012 to 2014. Increased plant nitrogen adsorption was observed under irrigation only in drought years, and it was decreased in optimal or extremely wet years. We found a weak or a moderate relationship between ECB damage and nitrogen concentration, but the greatest ECB damage was in all years recorded in treatments with the highest fertilization rates. However, the highest plant nitrogen concentration was observed in the hybrid with the lowest damage from ECB larvae. The maize damage caused by ECB larval feeding was negatively affected by high plant nitrogen concentrations only when plants were under drought stress. Nitrogen uptake was increased in irrigated plots. We did not find a strong relationship between the C/N ratio or irrigation and intensity of ECB damage. In 2012, when the narrowest C/N ratio was calculated, the greatest damage by ECB was measured. Further studies are needed since we detected the significant impact of drought on intensive ECB larval feeding.
Part of the book: Pests, Weeds and Diseases in Agricultural Crop and Animal Husbandry Production
Effects of Irrigation and Bioproducts of Microbial Origin on Nematode Community and Mycorrhizal Root Colonization in Soybean
Soybean (Glycine max L. Merr) is the most important legume and threaten by diverse pests and diseases. Complex interactions among rhizosphere organisms are found in all agro-ecosystems. Results of these interactions can be positive and/or negative in terms of plant production. Soil nematode community consists of different trophic groups of nematodes. Nematodes are the most abundant soil invertebrates. Several nematode species penetrate soybean roots as parasites, and can cause loss in yields. Arbuscular mycorrhiza fungi are obligate plant symbionts that colonize soybean roots naturally. The aim of the study was to evaluate effects of irrigation and amendments of bioproducts containing beneficial soil microorganisms (ABM) on nematode community and mycorrhizal root colonization in soybean. Field experiments were conducted in soybean in 2013 in Osijek, Croatia. The plots were either rain fed or irrigated to 60-100% field water capacity (FWC). We tested soil amendments and soil + foliar amendments of three commercial products containing beneficial organisms. Average number of nematodes per soil sample varied from 186,67 (soil ABM in non-irrigated plots) to 297,57 (soil+foliar ABM in plots with 60-100% FWC), and there were no significant differences between the treatments. Bacterial feeding nematodes were the most abundant, while plant parasitic genus Pratylenchus was the most abundant among other plant parasitic nematodes. There was no clear influence of any of the treatments on soil nematode community. Amendments of the bioproducts increased mycorrhizal root colonization in rain fed plots, while it decreased the mycorrhizal root colonization when soybeans were irrigated. Irrigation increased mycorrhizal root colonization in plots without amendments of the bioproducts, and mycorrhizal colonization differed significantly between the sampling dates. Further research is needed to determine if irrigation alters the potential of mycorrhiza to colonize the roots.
Part of the book: Nematodes