Pythium spp. cause seed decay, damping-off, and root rot in soybean and corn; however, their diversity and importance as pathogens in Minnesota are unknown. Our objectives were to identify the Pythium spp. present in Minnesota soybean fields, determine their aggressiveness on corn and soybean, and investigate their sensitivity to seed treatment fungicides. For identification, sequences obtained using internal transcribed space ITS4 and ITS1 primers were compared with reference sequences in the National Center for Biotechnology Information database. Seedling and soil samples yielded over 30 oomycete species. Aggressiveness was determined using two methods; a seed assay, which also examined temperature effects on aggressiveness, and a seedling assay. Of 21 species evaluated, seven Pythium spp. were pathogenic on both soybean and corn, reducing root growth by 20% or more while two Pythium and one Phytopythium spp. were pathogenic only on soybean. Aggressiveness of many isolates increased as temperature increased from 15°C to 25°C. The sensitivity of 10 pathogenic species to azoxystrobin, ethaboxam, mefenoxam, pyraclostrobin, or trifloxystrobin was tested. EC50 values for mefenoxam and ethaboxam were 10−2 of those to strobilurin fungicides. Pythium spp. in Minnesota are diverse and a significant cause of seedling disease on soybean and corn. Most Pythium spp. isolated in this study were more sensitive to mefenoxam and ethaboxam than to strobilurin fungicides.

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From data collected over the course of a year in a commercial broiler hatchery it was possible to infer the positions in the boxes that had been occupied during transit from farm to hatchery by 25,179 eggs subsequently downgraded upon candling. Two thousand seven hundred eggs were sampled from each of 168 consignments; the total number of eggs sampled was nearly half a million. They came from flocks of two strains and were candled by four candlers. Analysis of variance showed the downgrading rate to depend on (a) identity of the candler, (b) strain, (c) sample, which was confounded with flock and season, and (d) position of the egg in the box. Positional variation occurred in all three dimensions. Vertically (between trays) the downgrading showed a linear increase from top to bottom. Horizontally (within trays) the variation was such that eggs near the corners were at greatest risk, followed by those in the middle of the sides. Those in the centre of the tray were at least risk. The horizontal variation is believed to be due to damage caused by unidentified external objects (at the corners) and by the string with which the boxes were tied (at the middle of the sides). Within-box variation accounted for the downgrading of 1 egg in 200. There is a need for further work on the design of egg trays and boxes.

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