hagis, an R Package Resource for Pathotype Analysis of Phytophthora sojae Populations Causing Stem and Root Rot of Soybean

Phytophthora sojae is a significant pathogen of soybean worldwide. Pathotype surveys for Phytophthora sojae are conducted to monitor resistance gene efficacy and determine if new resistance genes are needed. Valuable measurements for pathotype analysis include the distribution of susceptible reactions, pathotype complexity, pathotype frequency, and diversity indices for pathotype distributions. Previously the Habgood-Gilmour Spreadsheet (HaGiS), written in Microsoft Excel, was used for data analysis. However, the growing popularity of the R programming language in plant pathology and desire for reproducible research made HaGiS a prime candidate for conversion into an R package. Here we report on the development and use of an R package, hagis, that can be used to produce all outputs from the HaGiS Excel sheet for P. sojae or other gene-for-gene pathosystem studies

Will Jets Identify the Progenitors of Type Ia Supernovae?

We use the fact that a Type Ia supernova has been serendipitously discovered near the jet of the active galaxy 3C 78 to examine the question of whether jets can enhance accretion onto white dwarfs. One interesting outcome of such a jet-induced accretion process is an enhanced rate of novae in the vicinity of jets. We present results of observations of the jet in M87 which appear to have indeed discovered 11 novae in close proximity to the jet. We show that a confirmation of the relation between jets and novae and Type Ia supernovae can finally identify the elusive progenitors of Type Ia supernovae.Comment: 10 pages, 3 figure

ThetaProbe

ThetaProbe 1.0.3 (2017-11-8) Bug fixes Fix bugs where the complete CSV data file was not generated after fetching data from the server due to incorrect handling of only one probe loggin

GRDC Field Crop Diseases Community of Practice

Summer crop paddocks across northern New South Wales, southern Queensland and central Queensland, were surveyed to monitor the fungal and bacterial diseases present in the 2017-2018 summer cropping season. The season was unusually hot and dry, which in most cases, led to reduced fungal and bacterial diseases, but did not eliminate all of them. In some cases, these conditions actually favoured the development of disease, for example charcoal rot in sorghum. Observations for maize, mungbean, peanut, sorghum, soybean and sun]ower are given below

Linear modelling of soil temperature effects on root lesion nematode population densities in R [Blog post]

Pratylenchus thornei, the root-lesion nematode, is widely distributed in wheat (Triticum aestivum) growing areas of many countries and is of particular concern in sub-tropical environments (Thompson 2015). These nematodes penetrate roots to feed and reproduce in the root cortex leading to loss of root function, which affects nutrient and water uptake of nutrients and water causing nutrient deficiency and water stress (Thompson 2015). In the original paper the population response of P. thornei in Queensland, Australia wheat to temperature is modelled using a linear and quadratic equations. The study aimed to investigate the effects of soil profile temperatures after different sowing dates on reproduction of the nematodes in susceptible and moderately resistant wheat cultivars in the subtropical grain region of eastern Australia. This document recreates the models for population densities of P. thornei as described in the original paper