Fungicide efficacy on tar spot and yield of corn in the Midwestern United States

Tar spot of corn caused by Phyllachora maydis has recently led to significant yield losses in the eastern corn belt of the Midwestern United States. Foliar fungicides containing quinone outside inhibitors(QoI), demethylation inhibitors(DMI), and succinate dehydrogenase inhibitors(SDHI) are commonly used to manage foliar diseases in corn. To mitigate the losses from tar spot thirteen foliar fungicides containing single or multiple modes of action (MOA/FRAC groups) were applied at their recommended rates in a single application at the standard tassel/silk growth stage timing to evaluate their efficacy against tar spot in a total of eight field trials in Illinois, Indiana, Michigan, and Wisconsin during 2019 and 2020. The single MOA fungicides included either a QoI or DMI. The dual MOA fungicides included a DMI with either a QoI or SDHI, and fungicides containing three MOAs included a QoI, DMI, and SDHI. Tar spot severity estimated as the percentage of leaf area covered by P. maydis stroma of the non-treated control at dent growth stage ranged from 1.6 to 23.3% on the ear leaf. Averaged across eight field trials all foliar fungicide treatments reduced tar spot severity, but only prothioconazole+trifloxystrobin, mefentrifluconazole+pyraclostrobin+fluxapyroxad, and mefentrifluconazole+pyraclostrobin significantly increased yield over the non-treated control. When comparing fungicide treatments by the number of MOAs foliar fungicide products that had two or three MOAs decreased tar spot severity over not treating and products with one MOA. The fungicide group that contained all three MOAs significantly increased yield over not treating with a fungicide or using a single MOA.

Biochar Phosphate Fertilizer Loaded with Urea Preserves Available Nitrogen Longer than Conventional Urea

Biochar, a carbon-rich material obtained by pyrolysis of organic wastes, is an attractive matrix for loading nutrients and producing enhanced efficiency fertilizers. In this study, poultry litter (PL) was enriched with phosphoric acid (H3PO4) and MgO to produce a biochar-based fertilizer (PLB), which was loaded with urea in a 4:5 ratio (PLB:urea, w/w) to generate a 15–15% N–P slow-release fertilizer (PLB–N) to be used in a single application to soil. A greenhouse experiment was carried out in which a common bean was cultivated followed by maize to evaluate the agronomic efficiency and the residual effect of fertilization with PLB–N in Ultisol. Six treatments were tested, including four doses of N (100, 150, 200, and 250 mg kg−1) via PLB–N in a single application, a control with triple superphosphate (TSP—applied once) and urea (split three times), and a control without N-P fertilization. The greatest effect of PLB–N was the residual effect of fertilization, in which maize showed a linear response to the N doses applied via PLB–N but showed no response to conventional TSP + urea fertilization. Biochar has the potential as a loading matrix to preserve N availability and increase residual effects and N-use efficiency by plants.

Evaluation of a Peroxide-Based Algaecide for Cyanobacteria Control: A Mesocosm Trial in Lake Okeechobee, FL, USA

A 72 h small-scale trial was conducted in enclosed mesocosms in the Lake Okeechobee waterway to evaluate the effectiveness of a USEPA-registered peroxide-based algaecide (formulated as sodium carbonate peroxyhydrate) for controlling a natural cyanobacteria population. Mesocosms were initially subjected to either no algaecide or the maximum label rate of 10 mg H2O2·L−1. A subset of mesocosms were then subjected to a sequential application of 5 mg H2O2·L−1 at 48 h after initial treatment. Following application, peroxide concentrations rapidly decreased and were undetectable by 48 h. At 24 h after treatment, significant decreases in all biomass indicators were observed (compared to untreated mesocosms), including extracted chlorophyll a, microscopic counts (total phytoplankton and total cyanobacteria), and cyanobacteria-specific 16S rRNA gene copies by over 71%. Although peroxide treatment reduced cyanobacteria biomass, there was no change in overall community structure and the remaining population was still dominated by cyanobacteria (>90%). After 48 h exposure, some biomass recovered in single application mesocosms resulting in only a 32–45% reduction in biomass. Repeated peroxide dosing resulted in the greatest efficacy, which had a sustained (60–91%) decrease in all biomass indicators for the entire study. While a single application of the peroxide was effective in the first 24 h, a sequential treatment is likely necessary to sustain efficacy when using this approach to manage cyanobacteria in the field. Results of this study support that this peroxide-based algaecide is a strong candidate to continue with scalable field trials to assess its potential future utility for operational management programs in the Lake Okeechobee waterway.

Does foliar nicotinamide application affect second crop corn (Zea mays)?

The largest corn yeld in Brazil is currently in the second harvest, which is the most susceptible period to climatic adversities occurring during the cycle. Thus, introducing beneficial elements for maintaining the adequate development of the plant can help producers in obtaining greater kernel yields. Among studied elements, nicotinamide has potential use since it is associated with accumulating secondary metabolites and manifesting defence metabolism in plants. The objective of this work was to evaluate the influence of nicotinamide applied in different doses (only once or in instalments) on the biometric and productive characteristics of corn. The treatments were composed by the number of nicotinamide applications (one or two) and five doses (0, 50, 100, 150 and 200 mg L-1). Plant diameter, plant height, ear insertion height, leaf area and dry matter, yield and 100-kernel mass were evaluated. It was found that doses close to 100 mg L-1 resulted in increases in vegetative and reproductive development, regardless of the number of applications. In this way, foliar nicotinamide application positively influences the biometric and productive characteristics of second crop corn. Highlights The use of nicotinamide in corn plants improves its growth, yield components and grain yield. A single application of nicotinamide during vegetative stage V3 at a dose of 100 mg L-1 is sufficient to increase the leaf area of corn plants. Corn grain yield can be increased by 12.6% with a single application of nicotinamide. There was no need for two applications of nicotinamide in corn crop.

Chemformer: A Pre-Trained Transformer for Computational Chemistry

Transformer models coupled with Simplified Molecular Line Entry System (SMILES) have recently proven to be a powerful combination for solving challenges in cheminformatics. These models, however, are often developed specifically for a single application and can be very resource-intensive to train. In this work we present Chemformer model – a Transformerbased model which can be quickly applied to both sequence-to-sequence and discriminative cheminformatics tasks. Additionally, we show that self-supervised pre-training can improve performance and significantly speed up convergence on downstream tasks. On direct synthesis and retrosynthesis prediction benchmark datasets we publish state-of-the-art results for top- 1 accuracy. We also improve on existing approaches for a molecular optimisation task and show that Chemformer can optimise on multiple discriminative tasks simultaneously. Models, datasets and code will be made available after publication.

Handheld Devices for Food Authentication and Their Applications: A Review

This review summarises miniaturised technologies, commercially available devices, and device applications for food authentication or measurement of features that could potentially be used for authentication. We first focus on the handheld technologies and their generic characteristics: (1) technology types available, (2) their design and mode of operation, and (3) data handling and output systems. Subsequently, applications are reviewed according to commodity type for products of animal and plant origin. The 150 applications of commercial, handheld devices involve a large variety of technologies, such as various types of spectroscopy, imaging, and sensor arrays. The majority of applications, ~60%, aim at food products of plant origin. The technologies are not specifically aimed at certain commodities or product features, and no single technology can be applied for authentication of all commodities. Nevertheless, many useful applications have been developed for many food commodities. However, the use of these applications in practice is still in its infancy. This is largely because for each single application, new spectral databases need to be built and maintained. Therefore, apart from developing applications, a focus on sharing and re-use of data and calibration transfers is pivotal to remove this bottleneck and to increase the implementation of these technologies in practice.

Chlorfenapyr and Methomyl Deterioration on Spinach Plants and Their Residual Effects in Vitro on Egyptian cotton Leafworm (Spodoptera littoralis)

Field trials conducted to determine the degradation of chlorfenapyr and methomyl insecticides in/on spinach leaves. Spinach plants sprayed with chlorfenapyr (Challenger Super™ 24% SC) and methomyl (Neomyl™ 90% SP) at the rates of 50 cm3/100 L water and 715 g/ ha, respectively. The QuEChERS method used for the extraction and clean-up of the samples. Residue amounts determined at 2 h, 2, 4, 6, 9, 13 and 16 days after application by UHPLC-UV. The mean of recovery percentages was 98.78 and 99.05 % for chlorfenapyr and methomyl, respectively. The initial deposits of chlorfenapyr and methomyl on/in spinach leaves, two hours after a single application of the insecticides were 23.17 and 235.37 mg/kg, respectively. The percentages of dissipation of chlorfenapyr were 37.68, 55.29, 69.45, 84.45 and 96.83% for 2, 4, 6, 9 and 16 days after application. The corresponding dissipation percentages of methomyl were 38.27, 56.01, 71.44, 84.34 and 97.81%. The rates of degradation (k values) were 0.212 and 0.223, while the corresponding half-life times (t0.5) were 3.27 and 3.11 days with chlorfenapyr and methomyl, respectively. It could be recommended that single application of chlorfenapyr on Spinach plants at the early ages followed by single application of methomyl at least 17 days before harvest.

Aplikasi Pestisida Nabati Maja - Gadung dan Metabolit Sekunder Beauveria Bassiana Bals. Untuk Mengendalikan Hama Thrips Sp. Pada Tanaman Cabai Rawit

Pest attacks on chili plants are the main limiting factor in cultivation activities. The research aims to determine the effect of single application of botanical pesticide maja-gadung (PMG), single application of secondary metabolite Beauveria bassiana BIO (BIO B10), combined application of PMG and BIO B10 on pest populations, predator populations and plant growth and production of chili. The reesearh used a factorial Completely Randomized Block Design (RAKL) with 3 replications, so there were 9 treatment combinations (0 ml/l PMG, 4 ml/l PMG, 8 ml/l BIO B10, 0 ml/l PMG, 2 ml/l BIO B10, 4 ml/l BIO B10, 4 ml PMG+2 ml/l BIO B10, 4 ml/ml PMG+4 ml BIO B10, 8 ml/l PMG+2ml/l BIO B10, 8 ml/l PMG+4 ml/l BIO B10). The variables observed were Thrips sp population, predator population, plant height, number of leaves, and fruit weight per plant. The results showed that the single application treatment of PMG with a concentration of 4 ml/l and 8 ml/l was able to suppress the population of Thrips sp. by 21.6% and 41.4% compared to the control. The single application treatment of BIO B10 with concentrations of 2 ml/l and 4 ml/l was able to suppress the population of Thrips sp. by 66.5% and 65.5% compared to the control. The best combination application is PMG and BIO B10with a concentration of 8 ml/l + 4 ml/l which is able to suppress the population of Thrips sp. by 76.9% compared to the control. The application treatment of PMG andBIO B10 did not affect plant height, number of leaves, and fruit weight per plant.

Evaluation of chemical resistance inducers in maradol papaya against Phytophthora nicotianae var. parasitica

Objective: To test the efficiency of four chemical resistance inducers on Maradol papaya to reduce Phytopthora nicotianae var. parasitica infections in rainfed crops at Chontalpa, Tabasco, Mexico. Design/methodology/approach: Three doses of four resistance inducers were tested on 60-day-old papaya plants in a greenhouse with a randomized design, with four replications and 10 plants as experimental plots. Three days after the inducers' application inoculations with mycelium discs were made, there were negative and positive control treatments to evaluating their efficiency by applying Abbott's formula. Results: The four chemical inducers for resistance (sodium silicate (SS), potassium silicate (PS), potassium phosphite (PF) and acibenzolar-s-methyl (ASM)) were statistically different from the control (P < 0.0001**). The inducers SS 1 %, PS 1 %, FP 0.35 % and ASM 0.1 mM showed higher effectiveness (81.2, 75.9, 74.7 and 74.0 %). Study limitations/implications: The retained effective concentrations were tested in a single application, and their durability is unknown, so this point should be broadened. however, it may be an alternative for repeated use after transplanting. Findings/conclusions: Optimal concentrations of SS, PS, FP, and AMS, that respond against P. nicotianae var. parasitica infections can reduce damages in rainfed crops.