Applications Of Trifloxystrobin Research Articles

Investigating the impact of fungicides and mungbean genotypes on the management of pod rot disease caused by Fusarium equiseti and Fusarium chlamydosporum.

Mungbean is a vital pulse crop in India that can thrive in dry-land conditions and is grown in three seasons, with the added benefit of being used as green manure due to its ability to fix atmospheric nitrogen. Recently, pod rot disease has emerged as a serious threat to mungbean cultivation in India. In this study, morpho-molecular identification of associated pathogens and the bio-efficacy of systemic and non-systemic fungicides as well as genotype screening was performed during the years 2019 and 2020. The pathogens associated with this disease were confirmed on the basis of morphological and molecular characterization. For the molecular characterization, the translation elongation factor 1-alpha (tef-1) gene sequences were amplified by using primers (EF1 and EF2). Under in vitro conditions, trifloxystrobin + tebuconazole 75% WG was found to be the most effective against Fusarium equiseti (ED50 2.39 μg ml-1) and Fusarium chlamydosporum (ED50 4.23 μg ml-1) causal agents of pod rot of mungbean. Under field conditions, three applications of trifloxystrobin + tebuconazole 75% WG at 0.07% as a foliar application at fortnightly intervals starting from the last week of July proved to be the most effective against pod rot disease on mungbean cultivars, i.e., ML 2056 and SML 668. To identify the potential resistance sources, 75 interspecific derivative and mutant lines of mungbean were screened for disease reaction to pod rot under natural epiphytotic conditions for the years 2019 and 2020. Genotypic differences were observed for resistance to pod rot disease. The study revealed that among the tested genotypes, ML 2524 exhibited resistance to pod rot disease, with a disease incidence of 15.62% and disease severity of 7.69%. In addition, 41 other genotypes were found to be moderately resistant (MR) to the disease. Altogether, the identified management options will offer an immediate solution to manage this disease under recent outbreak conditions and pave a path for futuristic disease management using identified resistant sources in breeding programs.

Effect of Fungicide Mobility and Application Timing on the Management of Grape Powdery Mildew

Grape powdery mildew (GPM) fungicide programs consist of 5 to 15 applications, depending on region or market, in an attempt to achieve the high fruit quality standards demanded by the market. Understanding how fungicides redistribute and targeting redistributing fungicide to critical crop phenological stages could improve fungicide protection of grape clusters. This study evaluated fungicide redistribution in grapevines from major fungicide groups labeled for GPM control. Translaminar and xylem redistribution was examined by placing fungicide-impregnated filter disks on the adaxial or abaxial leaf surface of detached leaves for 10 min and then incubating for 48 h before inoculating the abaxial surface with conidia. Vapor redistribution used Teflon disks sprayed with fungicides and placed on the abaxial leaf surface of detached leaves 48 h before inoculation. Disease development was rated 10 days later. Translaminar movement through calyptra was tested using flowering potted vines. All fungicides tested redistributed through at least one mechanism. Fungicide timing at critical phenological stages (early, mid, and late bloom) was assessed in small plots of cultivar Pinot noir vines. The application of trifloxystrobin, quinoxyfen, or fluopyram at different bloom stages showed that applications initiated at end of bloom resulted in the lowest berry infection probabilities of 0.073, 0.097, and 0.020, respectively. The results of this study suggest that integrating two carefully timed applications of redistributing fungicides initiated at end of bloom into a fungicide program may be an effective strategy for wine grape growers in western Oregon to produce fruit with low GPM infection.

First report of QoI resistance in Cercospora beticola in sugar beet in Japan

QoI fungicides have been an important tool for controlling Cercospora leaf spot (CLS) of sugar beet in Japan. In 2013, CLS control failed at an experimental plot in Okhotsk subprefecture of Hokkaido after the application of trifloxystrobin. Among isolates of Cercospora beticola, the causal agent of CLS, collected from this field were the first QoI-resistant strains found in Japan based on bioassays, culture assays and detection of G143A mutation in the cytochrome b gene. Additionally, our surveys of commercial fields in 2014–2015 revealed the widespread QoI resistance of C. beticola in Hokkaido.

Fungicide performance on Fusarium meridionale control, grain yield and grain damage in maize

ABSTRACT Gibberella ear rot (GER) in maize, caused by Fusarium graminearum species complex, is a destructive disease in southern Brazil and worldwide. Five field-experiments were conducted to determine fungicide efficacy, grain yield and grain quality (study I), as well as response of increasing rates (study II) on GER control, grain yield (GY) and grain damage (GD) in maize during the 2014/15 and 2015/16 growing seasons. Fungicides were sprayed 48 h before (preventive action) or 48 h after (curative action) inoculation of two Fusarium meridionale isolates (PR and MG). Study I consisted in applying nine active ingredients (metconazole, pyraclostrobin, tebuconazole, trifloxystrobin, prothioconazole, thiophanate-methyl, azoxystrobin, cyproconazole and carbendazim) present in eight commercial formulations at two sowing dates. Study II consisted in applying increasing rates of three fungicides evaluated at three sowing dates using only PR isolate. In study I, no differences were observed among fungicides when the variables GER, GY and GD were analyzed together. There were interactions between time of fungicide application and F. meridionale isolates when GER severity and GY were considered. Preventive fungicide application at different sowing dates and the use of MG isolate reduced GER by 11.6% and increased GY by 5.3%, compared to curative application. In study II, there was a significant interaction between fungicides and application time for GER, GY and GD. Preventive application of trifloxystrobin + prothioconazole (0.15 + 0.17 and 0.22 + 0.26 L ha-1), pyraclostrobin + metconazole (0.19 + 0.12 and 0.29 + 0.18 L ha-1) and carbendazim (2 L ha-1) reduced GER by 41 and 50%, 47 and 54%, and 54% at the three sowing dates, respectively. There was an increment of 45.7% and 46.8% in GY when trifloxystrobin + prothioconazole (0.15 + 0.17 and 0.22 + 0.26 L ha-1), respectively, were preventively sprayed at the three sowing dates, compared to the control treatment. Trifloxystrobin + prothiocanazole, pyraclostrobin + metconazole and carbendazim (1.0 and 2.0 L ha-1) preventively sprayed at two rates reduced GD incidence by 53.5 and 48.7%, 47.7 and 57.5%, 48.1 and 50.5%, respectively, for each fungicide and rate, and could be incorporated into a disease management program.

Chemical Control of Mycosphaerella Leaf Disease on Eucalyptus dunnii in Southern Brazil

ABSTRACT Mycosphaerella leaf disease (MLD) is a dangerous disease for eucalypt plantations; however little information is available regarding its control using fungicides in South America. In this study, we evaluated MLD control, and growth in young stands of Eucalyptus dunnii clones (C18 and C25). After two applications of azoxystrobin + cyproconazole (0.3 L/ha-1 and 0.45 L/ha-1), with a spraying volume of 200 L/ha -1, and trifloxystrobin + tebuconazole (0.5 L/ha-1 and 0.75 L/ha -1), with a spraying volume of 100 L/ha-1, mean severity reduction for apical branches of C18 was 74%. For middle branches, application of trifloxystrobin + tebuconazole at 0.5 L/ha-1 reduced severity by 27% in C18. While fungicide applications did not affect growth in height or root collar diameter, our results suggest that the application of fungicide can deter disease progression throughout the plant. Therefore, the monitoring of disease outbreaks is crucial to enable effective, early application.

Strobilurins influence morphological characters and yield in chilli (Capsicum annum L.)

The present study was aimed to assess the influence of strobilurin fungicides on non-fungicidal physiological characters viz., root length, plant height, number of branches, leaf area and total dry matter accumulation in chilli (Capsicum annum). The experiment was laid out in a randomized block design and comprised of seven treatments of various concentrations of strobulin fungicides trifloxystrobin and tebuconazole. The plant height was significantly reduced in all the strobilurin fungicidal treatments as compared to the untreated control. Pyraclostrobin in combination with metiram @ 1500 g ha−1 reduced plant height by 12% over untreated control. The application of trifloxystrobin + tebuconazole @ 400 g ha−1 gave longer roots, more number of branches and higher total dry matter accumulation. Further, it gave maximum green chilli yield (20.44 t ha−1) with 13% increase over untreated control (15.26 t ha−1).

Management of tomato leaf mould caused by Cladosporium fulvum with trifloxystrobin

The protective, curative and eradicant activity of the strobilurin fungicide trifloxystrobin against Cladosporium fulvum on tomatoes was determined under growth chamber and greenhouse conditions. In growth chamber experiments chlorothalonil applied at 100 μg ml −1 was used as standard fungicide treatment. Seven-week-old tomato plants, hybrid Alma F1, were inoculated by conidial suspension. Protective treatments were carried out by spraying plants 24, 48 and 96 h before inoculation at the doses of 5, 10 and 20 μg a.i. ml −1. Curative treatments were carried out with the same doses, at the same time intervals after inoculation. Additionally, spray treatments were applied after the appearance of the symptoms to evaluate the anti-sporulant activity of the fungicides tested. Protective treatments of trifloxystrobin applied 24 and 48 h before inoculation provided disease control higher than 88% at all the application doses tested, while only the dose of 20 μg a.i. ml −1 was highly effective when applied 96 h before the inoculation of the plants (IOP). The curative treatments were less effective than the protective treatments. Post-inoculation treatments of trifloxystrobin at 10 or 20 μg ml −1 were efficacious only when applied 24 or 48 h after IOP, with limited activity when applied 96 h after inoculation. Eradicant treatments of trifloxystrobin provided satisfactory anti-sporulant activity when applied at the dose rate of 20 μg ml −1. Applications of trifloxystrobin at the rates of 5 or 7.5 g a.i. 100 l −1 of spray solution carried out during a 2-year period (2004–2005), in the greenhouse, demonstrated the validity of the above findings, providing control efficacy values higher >90%. Moreover, during both years of the study, applications of trifloxystrobin either at 5 or 7.5 g a.i. 100 l −1, reduced spore production significantly on diseased tomato leaves. The results of the study showed that trifloxystrobin may play a crucial role as part of an integrated chemical control programme for tomato leaf mould caused by C. fulvum.