A standard area diagram set (SADs) with eight severity values ranging from 0.5 to 32% was evaluated as a tool to improve the accuracy of the estimates of Phomopsis leaf blight severity on eggplant by ten inexperienced raters. A first assessment in a 50-leaf dataset of digital images was performed unaided (UN, no SAD). Two further aided (A) assessments, conducted two (A1) and four weeks after the first (A2) unaided one were performed. The precision of the estimates, as indicated by the Pearson’s correlation coefficient (r), improved significantly when using the aid (A1: r = 0.96 and A2: r = 0.96) compared to unaided (UN: r = 0.79). However, the generalized bias (Cb) was not significantly affected because the unaided estimates were already quite accurate (Cb = 0.93). The overall concordance (ρc) was significantly improved due to the large gains in precision when using the SADs. The raters’ estimates were more uniform (ρc > 0.9) when using the aid, with progressive gains in the reliability of the estimates among them, indicated by the concordance correlation coefficient statistics. The SADs proposed in this study will be useful in severity estimation during field work involving multiple raters, especially as use of the SADs results in less variable estimates, improving accuracy and reliability among raters. 相似文献
The cover image, by Oscar Fernando Santos‐Amaya et al., is based on the Research Article Fitness costs and stability of Cry1Fa resistance in Brazilian populations of Spodoptera frugiperda, DOI: 10.1002/ps.4312 . Photo Credit: Dr. Oscar Santos‐Amaya.
Soil organic matter (SOM) is a key of most nutrient cycling and its content influences labile phosphorus (P) pool. In order to promote P availability from SOM, some plant strategies could be important to increase organic P mineralization, which may change among cultivars of the same crop. This study evaluated phosphorus dynamics in the rhizosphere of two wheat cultivars in soil with high organic matter content. Experiment was established in a greenhouse using a Humic Cambisol in a randomized block design using Quartzo and Abalone as wheat cultivars and harvested 20 days after seedling. Pots with a horizontal mesh (25 µm) were used to isolate the soil from roots. At harvest, the soil under the mesh was sliced in five distances from the rhizoplane (0–3; 3–6; 6–10; 10–20; 20–30 mm). Organic P was the buffer to maintain P dynamics in the rhizosphere and there was phosphorus depletion in the first slice near the rhizoplane due to the root effect, regardless the cultivar. Quartzo showed high labile inorganic P, presumably due to the high amount of root hairs, which increased the acid phosphatase activity and consequently root P uptake. Quartzo was more efficient in changing rhizosphere regarding the P acquisition. 相似文献
It is convenient to store gas samples containing e.g. carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), in polypropylene syringes before chromatographic analysis. However, there is no study of the integrity of these samples or of what storage condition may be critical. To investigate we filled polypropylene syringes with two standard mixtures of CO2, CH4, and N2O, and stored them at ~2 °C and ~25 °C, and analyzed the contents using gas chromatography. Our results suggest that the storage of gases on the syringe at room temperature is not viable due the CO2 storage integrity when in low concentration. However, the quantitative integrity of samples is maintained when the syringe is kept refrigerated up to 19 h, period limited by CO2 and CH4, taking into account the three gases CO2, CH4, and N2O. 相似文献
