The objective of this research was to determine if canopy reflectance measured by an Unmanned Aerial Vehicle (UAV) equipped with a 5-band multi-spectral camera can differentiate between water and nitrogen (N) deficiency in irrigated maize. Crop reflectance was used to generate a Normalized Difference Red Edge (NDRE), Green Leaf Index (GLI), and a Blue Reflectance Index (BRI). These indices were then used in combination to categorize N and water stressed experimental units into a Combined Index (CI) indicating water-stressed, N-stressed, or non-stressed crops. The CI generated at blister (R2) successfully identified 90% of experimental treatments to the correct group but only identified 60% of treatments when generated at the 14th leaf stage (V14). The CI methodology was subsequently applied to two independent site-years where only N deficiency gradients were imposed. The CI was not successful at separating treatments at the validation sites, incorrectly identifying water stress where there was none. Among individual indices investigated, NDRE had the strongest relationship to grain yields (r² = 0.62, p < 0.001) but a weaker linear relationship compared to the CI (r² = 0.68, p < 0.005) where deficit irrigation treatments were imposed. At sites where irrigation was sufficient to meet crop water demand, NDRE (r² = 0.63, p < 0.05) had a stronger relationship to grain yield compared to the CI (r² = 0.41, p = 0.31). This study found that, under narrow cropping system circumstances, N and irrigation-induced differences in maize productivity can be differentiated in-season by a combination of reflectance indices, but that NDRE alone provides superior information under broader contexts.

Antibiotic resistant bacteria are an increasing and serious health concern worldwide and emergence of multi-drug resistant pathogens is increasing in patients across the United States of America. Researchers are increasingly exploring sources of traditional medicines, including mushrooms, to find new antibiotic compounds. In this study, the antibiotic activities of seventy-five mushrooms collected in the area surrounding Oxford, Ohio (USA) were assayed for antibiotic activity against six bacterial strains (Pseudomonas aeruginosa reference strain PAO1, P. aeruginosa reference strain PA14, P. fluorescens, Bacillus subtilis, Staphylococcus epidermidis, and Micrococcus luteus). Mushroom samples were identified using DNA ribotyping. Methanol and water extracts of mushrooms were used in agar diffusion assays to screen for antibiotic activity toward each bacterial strain. Twenty-five mushroom species had antibacterial activity against at least one bacterium. Water extracts of Polyporus squamosus, Ganoderma applanatum, Lentinellus subaustralis, Laetiporus sulphureus, Ganoderma lucidum, and Trametes versicolor exhibited strong antibiotic activity against all bacterial strains tested. Water and methanol extracts from 25 mushroom species had significant activity against the majority of bacteria tested. A minimum inhibitory concentration was determined against S. epidermidis for all samples that exhibited antibiotic activity in the disk assay. The G. lucidum and L. sulphureus extracts displayed the strongest inhibition with MIC values of 0.1 mg/mL.