Fungicide Active Ingredients Research Articles

Early Detection of Fungicide Resistance Through Sensitivity Testing of Various Fungicide Active Ingredients and Genetic Variation of Downy Mildew-Causing Peronosclerospora maydis from Maize (Corn) Production Centers in Java, Indonesia

Early Detection of Fungicide Resistance Through Sensitivity Testing of Various Fungicide Active Ingredients and Genetic Variation of Downy Mildew-Causing Peronosclerospora maydis from Maize (Corn) Production Centers in Java, Indonesia

Sensitivity of dominant UKPhytophthora infestans genotypes to a range of fungicide active ingredients

AbstractLate blight, caused by Phytophthora infestans, is a serious disease of potatoes worldwide and is predominantly controlled by repeated prophylactic use of fungicides throughout the growing season. Effective blight management and integrated pest management strategies rely on knowledge of the efficacy of available fungicides to control contemporary genotypes of P. infestans. Between 2019 and 2022, representative isolates of the newer dominant genotypes EU36, EU37 and the older dominant genotype EU6 were sampled from GB crops and tested for sensitivity to seven commonly used fungicide active ingredients (cyazofamid, fluopicolide, mandipropamid, propamocarb, oxathiapiprolin, amisulbrom and mancozeb) used preventatively in detached leaf tests and zoospore motility assays where appropriate. Dose–response curves based on lesion area (mm2) were constructed, and EC50 values calculated. Isolates of P. infestans genotype EU37 were insensitive to fluazinam as previously reported. No insensitivity, or progression towards resistance over time, to any of the other fungicides was observed in any isolates of the genotypes tested, and EC50 values were generally in line with previous testing. Zoospore motility tests with fluopicolide revealed significantly higher MIC values for isolates of genotype EU36 compared with EU37 and EU6, which, whilst not indicative of resistance at the low concentrations of active ingredient tested, may be a factor contributing to the overall dominance of that genotype in the wider population of P. infestans. The evidence suggests that the fungicides tested, with the exception of fluazinam and EU37, are effective for the control of P. infestans genotypes dominant in the GB population up until 2022.

Efficacy of Several Fungicides Against Root Rot Disease (Phytophthora capsici Leonian) on Pepper

Root rot disease caused by the fungus Phytophthora capsici can cause up to 60% yield loss of pepper in West Kalimantan, which is spread across Singkawang, Bengkayang, Pontianak, Sintang, and Sekadau Regencies. Control of BPB chemically with fungicide is considered to be effective enough to suppress BPB both in vitro and in the field. This study aims to examine the effectiveness of several fungicide active ingredients that are widely used in BPB control, namely Chlorotalonil, Azoxystrobin, Mankozeb, and Phosphoric Acid. Efficacy tests were carried out on sample plant plots consisting of 25 sample trees for each treatment of the active ingredient of the fungicide. Fungicide application was carried out 3 times (2-week intervals) within 3 months. BPB attack intensity was calculated to obtain the Efficacy Level (TE) category of the active ingredients used. The fungicide with the active ingredient phosphite acid showed the highest efficacy level of 30.06%, while the active ingredients Azoxystrobin and Mankozeb had TE values of 29.01% and 28.23%, respectively. The lowest result was the function with the active ingredient Chlorotalonil with a TE percentage of only 4.13%.

Application of Pyraclostrobin Fungicide at Miniature Floral Head Development Growth Stage Is Efficacious Against Phomopsis Stem Canker Fungi in Sunflower (Helianthus annuus)

Phomopsis stem canker, caused by multiple species of Diaporthe, is a yield-limiting disease of sunflower ( Helianthus annuus L.) in the U.S. Northern Great Plains. To develop fungicide recommendations, we performed meta-analyses on data collected from 56 foliar fungicide efficacy trials conducted in Minnesota, Nebraska, North Dakota, and South Dakota between 2009 and 2021. The specific objectives were to compare the fungicide application timings and active ingredients with a nontreated control (NTC) and determine their impact on the disease severity index (DSI) and yield. Effect sizes, Cohen's f or Hedges’ g, were calculated as the difference in DSI or yield between the fungicide treatment and NTC. We observed that fungicide application timings (DSI [ f = 0.43] and yield [ f = 0.26]) and active ingredients (DSI [ f = 0.51] and yield [ f = 0.39]) had a significant effect on DSI and yield ( P < 0.0001). In addition, application of pyraclostrobin (DSI [ g = −0.65] and yield [ g = 0.43]), pyraclostrobin + fluxapyroxad (DSI [ g = −0.55] and yield [ g = 0.36]), and mefentrifluconazole + pyraclostrobin + fluxapyroxad (DSI [ g = −2.23] and yield [ g = 0.85]) at the R1 (miniature floral head formation) growth stage outperformed NTC. This study suggests that farmers can rely on a single application of pyraclostrobin at R1 for Phomopsis stem canker management. Future studies on the economic benefits from fungicide use are important to help enhance farmer decisions.

Management of Pythium myriotylum in burley tobacco transplants and its effect on field productivity

Pythium root rot (PRR) is a significant disease of tobacco transplants produced in the greenhouse floatbed system, but little is known about its influence once PRR-infected plants are transplanted in the field. Tobacco producers have limited chemical options to manage PRR, and additional data are needed on the efficacy of the fungicide active ingredients etridiazole, mefenoxam, and hydrogen peroxide-peroxyacetic acid. With the support of a pictorial, ordinal root ball quality (RBQ) rating scale, etridiazole and mefenoxam improved RBQ in tobacco transplants inoculated with Pythium myriotylum in greenhouse trials. In multi-year, generalized linear mixed model analyses, higher average RBQ in transplants significantly increased plant establishment, survival to season-end, and cured yield in research farm trials. To further apply the pictorial scale, a potential threshold of average RBQ >3.0 would be expected to result in 201 kg/ha more cured yield, over transplants with average RBQ ≤3.0. These results document for the first time the influence of transplant PRR on cured tobacco yield, in addition to its interim effects on tobacco establishment and survival. While additional data are needed to support a critical RBQ value, estimated effects of transplant quality on cured tobacco yield may assist growers in post-transplant farm management decisions, such as labor planning.

Short communication: Effect of combined fungicide treatments on fatty acid content in Eisenia fetida earthworms

Aim of study: To study the toxic effects of a combined fungicide in Eisenia fetida earthworms and in its lipid fatty acid composition. Material and methods: We investigated the acute toxicity (LC50, 14 days) of a combined fungicide (active ingredients: carbendazim + cyproconazole) in Eisenia fetida using artificial substrate. The quantitative content of fatty acids (FAs) of body lipids was determined by the method of high-sensitivity gas chromatography. Main results: Moderate toxicity of the combined fungicide was determined for Eisenia fetida earthworms. Changes in behavioral response, biomass loss, and mortality of test objects were detected. A decrease in the content of saturated FAs was found. At the same time, an increase of long-chain polyunsaturated FAs content of ω6 and ω3 families, which are involved in the regulation of a wide range of physiological processes, was revealed. Modulation of the lipid FAs profile in Eisenia fetida worms is explained by the participation of the FAs in the restructuring of the organism reactivity system under fungicidal load. Research highlights: The reorganization of the FA profile can be considered as an early criterion of metabolic perturbations in earthworms under the action of fungicides. Understanding the toxic potential of fungicides to organisms in soil ecosystems is essential for practical risk assessment in response to pesticide application.

Reduction of Pythium Damping-Off in Soybean by Biocontrol Seed Treatment.

Pythium spp. is one of the major groups of pathogens that cause seedling diseases on soybean, leading to both preemergence and postemergence damping-off and root rot. More than 100 species have been identified within this genus, with Pythium irregulare, P. sylvaticum, P. ultimum var ultimum, and P. torulosum being particularly important for soybean production given their aggressiveness, prevalence, and abundance in production fields. This study investigated the antagonistic activity of potential biological control agents (BCAs) native to the U.S. Midwest against Pythium spp. First, invitro screening identified BCAs that inhibit P. ultimum var. ultimum growth. Scanning electron microscopy demonstrated evidence of mycoparasitism of all potential biocontrol isolates against P. ultimum var. ultimum and P. torulosum, with the formation of appressorium-like structures, short hyphal branches around host hyphae, hook-shaped structures, coiling, and parallel growth of the mycoparasite along the host hyphae. Based on these promising results, selected BCAs were tested under field conditions against six different Pythium spp. Trichoderma afroharzianum 26 used alone and a mix of T. hamatum 16 + T. afroharzianum 19 used as seed treatments protected soybean seedlings from Pythium spp. infection, as BCA-treated plots had on average 15 to 20% greater plant stand and vigor than control plots. Our results also indicate that some of these potential BCAs could be added with a fungicide seed treatment with minimum inhibition occurring, depending on the fungicide active ingredient. This research highlights the need to develop tools incorporating biological control as a facet of soybean seedling disease management programs. The harnessing of native BCAs could be integrated with other management strategies to provide efficient control of seedling diseases.

Reduced Sensitivity of Pseudoperonospora cubensis Clades 1 and 2 to Oxathiapiprolin in South Carolina

Oxathiapiprolin has been the most effective fungicide active ingredient to manage cucurbit downy mildew, caused by Pseudoperonospora cubensis, since its introduction in 2015. However, oxathiapiprolin was not always the most effective treatment on cucumber in field plot experiments in 2020 and 2021. Potted cucumber, butternut squash, and watermelon treated with 0.13× or 0.25×, 0.5×, 1×, and 2× the maximum field rate of 17.5 g/ha of oxathiapiprolin were exposed to naturally occurring P. cubensis in the field in Charleston, South Carolina, in fall 2020, spring 2021, and fall 2021. On cucumber, mean severity was 18% at 0.25× in fall 2020 and 21% at 0.13× in fall 2021. On butternut squash, mean severity was 8.4% at 0.25× in fall 2020. The 1× field rate reduced severity compared to the nontreated control on all hosts. With cucumber and butternut squash, the slopes of the linear regression lines relating relative disease severity (disease severity on oxathiapiprolin-treated leaves divided by disease severity on water-treated control leaves) to log-10 concentration of oxathiapiprolin were greater than 0 (P ≤ 0.02). On watermelon, the slope was slightly greater than 0 (P = 0.085). Disease was more severe on cucumber infected with P. cubensis clade 2 than on squash infected with clade 1. EC50 values on cucumber were 4.5 and 13.9 ppm in spring and fall 2021, respectively. To slow development of resistance to oxathiapiprolin, cucurbit growers should increase the number of applications of other fungicides applied in rotation with oxathiapiprolin.

Pollen Treated with a Combination of Agrochemicals Commonly Applied During Almond Bloom Reduces the Emergence Rate and Longevity of Honey Bee (Hymenoptera: Apidae) Queens.

Honey bee (Apis mellifera L.) colonies that pollinate California’s almond orchards are often exposed to mixtures of agrochemicals. Although agrochemicals applied during almond bloom are typically considered bee-safe when applied alone, their combined effects to honey bees are largely untested. In recent years, beekeepers providing pollination services to California’s almond orchards have reported reductions in queen quality during and immediately after bloom, raising concerns that pesticide exposure may be involved. Previous research identified a synergistic effect between the insecticide active ingredient chlorantraniliprole and the fungicide active ingredient propiconazole to lab-reared worker brood, but their effects to developing queens are unknown. To test the individual and combined effects of these pesticides on the survival and emergence of developing queens, we fed worker honey bees in closed queen rearing boxes with pollen artificially contaminated with formulated pesticides containing these active ingredients as well as the spray adjuvant Dyne-Amic, which contains both organosilicone and alkyphenol ethoxylate. The translocation of pesticides from pesticide-treated pollen into the royal jelly secretions of nurse bees was also measured. Despite consistently low levels of all pesticide active ingredients in royal jelly, the survival of queens from pupation to 7 d post-emergence were reduced in queens reared by worker bees fed pollen containing a combination of formulated chlorantraniliprole (Altacor), propiconazole (Tilt), and Dyne-Amic, as well as the toxic standard, diflubenzuron (Dimilin 2L), applied in isolation. These results support recommendations to protect honey bee health by avoiding application of pesticide tank-mixes containing insecticides and adjuvants during almond bloom.

Comparative assessment of spray nozzles efficacy in the control of fusarium head blight in the barley crops using developed quantitative PCR assay

Fusarium species infect cereal spikes during anthesis and cause Fusarium head blight (FHB), a destructive disease of cereal crops with worldwide economic relevance. The necessity for these phytopathogenic fungi effective control becomes increasingly important for the production of both cultivated plants and those plants seeds. Fungicide application is a key methodology for controlling the disease development and mycotoxin contamination in cereals. Polymerase chain reaction (PCR) is currently the most commonly admitted DNA-based technology for specific, rapid and precise Fusarium detection. We have developed and patented the method for detection and quantitative determination of phytopathogenic fungi F. avenaceum and F. graminearum in plant seeds using Real-Time PCR with a pair of primers, designed to amplify sequences of the internal transcribed spacer at the ribosomal RNA gene cluster of those phytopathogenic fungi. This study was aimed to perform a comparative assessment of the efficacy of different spray nozzles for antifungal treatment to control F. avenaceum and F. graminearum infection of barley grains using a developed qPCR diagnostic system. A single application of a fungicide (active ingredient's content: 250 g/l propiconazole, 80 g/l cyproconazole) at BBCH 65 (middle of flowering) was carried out. For this purpose, four spray nozzles with different technical characteristics were used: Flat Fan 030, Amistar 030, Defy 3D 030 and Vegetable 060 (Pentair, USA). DNA-based fungi detection and identification was performed using conventional PCR and developed qPCR. The level of mycotoxins in barley grain was determined using enzyme-linked immunosorbent assay (ELISA). Grain count in the ear of barley and thousand seed weight (TSW) were also examined.
 A single application of the fungicide inhibited the development of FHB and is accompanied by the slight increase of TSW values in treated plants. It was found, that the most effective fungicide was against F. avenaceum and F. graminearum. The inhibitory effect depended on sprayer type. According to qPCR results, the best performance was achieved when using Amistar 030 and Flat Fan (FF) 030 sprayers. The average concentration of deoxynivalenol (DON) content in all barley grain samples were up to 4 times higher than the permissible level. Overall, because of the high contamination levels, found in tested samples, it is possible to state that a single application of the fungicide at the flowering phase was not able to effectively reduce DON contamination in barley samples.
 The developed test-system for qPCR provides new important information in the study of the effectiveness of fungicides and development of strategies to control FHB in cereals, not achievable with conventional PCR.

Fungicide Management of Pasmo Disease of Flax and Sensitivity of Septoria linicola to Pyraclostrobin and Fluxapyroxad.

Among the diseases that have the potential to cause damage to flax (Linum usitatissimum L.) every year, the fungal disease pasmo, caused by Septoria linicola, is the most important. Fungicide application and a diverse crop rotation are the most important strategies to control this disease because there is little variation in resistance among flax cultivars. However, few fungicide products are available to flax growers. Field studies were conducted at four locations in Western Canada in 2014, 2015, and 2016 to determine the effect of two fungicide active ingredients applied singly and in combination: pyraclostrobin, fluxapyroxad, and fluxapyroxad + pyraclostrobin; and two application timings (early-flower, mid-flower, and at both stages) on pasmo disease severity, seed yield, and quality of flaxseed. The results indicated that among the three fungicide treatments, both pyraclostrobin and fluxapyroxad + pyraclostrobin controlled pasmo effectively; however, fluxapyroxad + pyraclostrobin was the most beneficial to improve the quality and quantity of the seed for most of the site-years. Disease severity in the fungicide-free control was 70%, and application of fluxapyroxad + pyraclostrobin decreased disease severity to 18%, followed by pyraclostrobin (23%) and fluxapyroxad (48%). Application of fluxapyroxad + pyraclostrobin also improved seed yield to 2,562 kg ha-1 compared with 1,874 kg ha-1 for the fungicide-free control, followed by pyraclostrobin (2,391 kg ha-1) and fluxapyroxad (2,340 kg ha-1). Fungicide application at early and mid-flowering stage had the same effects on disease severity and seed yield; however, seed quality was improved more when fungicide was applied at mid-flowering stage. Continuous use of the same fungicide may result in the development of fungicide insensitivity in the pathogen population. Thus, sensitivity of S. linicola isolates to pyraclostrobin and fluxapyroxad fungicides was determined by the spore germination and microtiter assay methods. Fungicide insensitivity was not detected among the 73 isolates of S. linicola tested against either of these fungicides.

Effect of pydiflumetofen onGibberella ear rot andFusarium mycotoxin accumulation in maize grain

In Ontario, Canada,Fusarium graminearum Schwabe causesGibberella ear rot (GER) in maize, resulting in the accumulation of mycotoxins, mainly deoxynivalenol (DON), DON-3-glucoside (DON-3G) and zearalenone (ZEN) in infected kernels. Fungicides can be an important tool for managing GER and DON and otherFusarium mycotoxins in maize. Until recently, all fungicides available to growers were triazoles, thus no resistance management strategy through fungicide use was possible. In this study, a novel carboxamide fungicide active ingredient (pydiflumetofen) was evaluated against conventional triazole fungicides and mixtures for: (1) effectiveness on mycotoxins (2) optimal application timing; and (3) efficacy of application, with and without an insecticide, under natural and inoculated-misted conditions. The best timing for fungicide application was at full silk, resulting in the highest reduction of GER symptoms and lowest accumulation ofF. graminearum mycotoxins in harvested grain. DON and DON-3G concentrations were reduced by at least 50% with a fungicide application at full silk. Fungicide treatments did not affect fumonisin concentrations in grain. Pydiflumetofen (94 g active ingredients (AI)/ha) and fungicides containing pydiflumetofen (75-94 g AI/ha) were similar to standard triazole fungicides (prothioconazole at 200 g AI/ha and metconazole at 90 g AI/ha) for reducing GER andF. graminearum mycotoxins under misted-inoculated plots and commercial field conditions; as a result, we expect pydiflumetofen to be competitive with triazole-only chemistries in the marketplace, which should delay the onset of fungicide resistance.

Development and Spread of Diseases in Spring Camelina (Camelina sativa (L.) Grantz) when using Various Treatments

Spring camelina is a promising oilseed crop for the dry steppe zone of Northern Kazakhstan. However, the expansion of its sowing areas is constrained by the lack of scientific research, especially on the phytosanitary state. The article presents the results of the study of fungi of the Alternaria and Fusarium genus isolated from the affected organs of spring camelina plants and provides measures to control them in the field conditions of the region. The research aimed to identify common diseases and determine their development and distribution under different backgrounds when treated with fungicides. To identify fungal strains, the method of determination of the direct nucleotide sequence of the intergenic transcribed region was used, followed by the determination of nucleotide identity with the sequences deposited in the Gene Bank international database, as well as the construction of phylogenetic trees with nucleotide sequences. As a result of the analysis, phytopathogenic strains belonging to Alternaria alternata, Alternaria tenuissima and Fusarium acuminatum were identified. During field studies, the development and spread of diseases under different background conditions of fungicide treatment versus control were analyzed. Of the products used, the Pictor fungicide (active ingredients: Boscalid 200 g/l + dimoxystrobin 200 g/l) showed high efficiency, compared with the Extrasolbiofungicide (Bacillus subtilis, strain H-13). The results of the study can serve as a basis for the development of chemical and biological control methods aimed at specific pathogens.

Potensi Fungisida Perlakuan Benih terhadap Perenosclerospora sp. penyebab Penyakit Bulai Jagung

Jamur patogen Perenosclerospora sp. merupakan penyakit penting pada tanaman jagung. Dampak yang ditimbulkan dapat menimbulkan kerugian hingga 100%. Penelitian ini bertujuan untuk mengetahui pengaruh bahan aktif fungisida sebagai perlakuan benih dalam mengendalikan penyakit bulai (Perenosclerospora sp.) pada tanaman jagung. Penelitian dilaksanakan dengan diawali menanam tanaman jagung yang diinokulasi bulai sebagai tanaman spreader (sumber inokulum alami) dan pembatas antar perlakuan. Selanjutnya saat tanaman border sudah terinfeksi bulai baru ditanam benih perlakuan yang sudah dicampur dengan bahan aktif fungisida. Penelitian disusun dalam rancangan acak lengkap dengan delapan perlakuan dengan tiga ulangan. Perlakuan terdiri atas kontrol tanpa fungisida (P0), dimetomorf (P1), dimetomorf + piraklostrobin (P2), fenamidon (P3), fenamidon dan propamokarb hodroklorida (P4), metalaksil (P5), mefenoksam (P6), dan fluopikolid+propineb (P7). Hasil penelitian menunjukkan perlakuan kontrol lebih bagus dalam meningkatkan daya kecambah dibandingkan dengan menggunakan fungisida. Benih jagung yang diberikan perlakukan bahan aktif dimetomorf + piraklostrobin memiliki potensi yang paling tinggi dalam menekan keterjadian penyakit bulai pada jagung manis dan mampu meningkatkan pertumbuhan tinggi tanaman jagung yang dibandingkan perlakuan lainnya.

Silent effect of the fungicide pyraclostrobin on the larval exposure of the non-target organism Africanized Apis mellifera and its interaction with the pathogen Nosema ceranae in adulthood

The frequent exposure of bees to a wide variety of fungicides, on crops where they forage, can be considered a stressor factor for these pollinators. The organisms are exposed both to the fungicide active ingredients and to the adjuvants of commercial formulations. All these ingredients are brought to the hive by bee foragers through contaminated pollen and nectar, thus exposing also immature individuals during larval phase. This work aimed to compare the effects of larval exposure to the fungicide pyraclostrobin (active ingredient and commercial formulation) and its influence on the cytotoxicity to midguts in adults, which were inoculated with the Nosema ceranae spores in the post-emergence stage. Under laboratory conditions, Apis mellifera larvae received an artificial diet containing fungicide solution from the third to the sixth day of the feeding phase. One-day-old adult workers ingested 100,000 infectious N. ceranae spores mixed in sucrose solution. Effects on midgut were evaluated through cellular biomarkers of stress and cell death. The exposure to the fungicide (active ingredient and commercial formulation) did not affect the larval post-embryonic development and survival of adult bees. However, this exposure induced cytotoxicity in the cells of the midgut, showed by the increase in DNA fragmentation and alteration in the HSP70 immunolabeling pattern. Without the pathogen, the midgut cytotoxic effects and HSP70 immunolabeling of the organisms exposed to the commercial formulation were lower when compared to the exposure to its active ingredient. However, in the presence of the pathogen, the cytotoxic effects of the commercial formulation to the adult bees’ midgut were potentialized. The pathogen N. ceranae increased the damage to the intestinal epithelium of adult bees. Thus, realistic doses of pyraclostrobin present in beebread consumed by larvae can affect the health and induce physiological implications to the midgut functions of the adult bees.

Role of Fungicide Applications on the Integrated Management of Wheat Stripe Rust.

First described in Europe in 1777, stripe rust (SR) caused by Puccinia striiformis Westend. f. sp. tritici Erikss (Pst) is one of the most important and destructive diseases of wheat worldwide. Until 2000, SR was mainly endemic to cooler regions, but since then, new aggressive strains have emerged, spread intercontinentally, and caused severe epidemics in warmer regions across the world. This has put SR as a disease that poses a threat to the world food security. At present, the preferred strategy for control of SR is the access to wheat cultivars with adequate levels of SR resistance. However, wheat breeding programs are not sufficiently advanced to cope with the recently emerged Pst strains. Under this scenario, foliar fungicide applications have become an important component of SR management, but information on the effects of fungicide applications on SR control and wheat cultivar yield response is scarce. This review seeks to provide an overview of the impact and role of fungicides on SR management. With focus on wheat management in the major wheat-growing regions of the world, the review addresses: (a) the efficacy of different fungicide active ingredients, optimal fungicide timing and number of applications in controlling SR, and (b) the impact of fungicide on wheat grain yield response. Inclusion of fungicides in an integrated crop management approach is discussed.

Effectiveness of the Concord fungicide in the treatment of vegetative rice plants

The results of research into rice sown for grain (2017–2018) are presented. The effectiveness of Concord fungicide (active ingredients tebuconazole, 125 g/l; triadimefon, 100 g/l) against rice Pyricularia was studied. The experiment was conducted in the conditions of the greenhouse experiment in the Primorsky Territory. Artificial inoculation of plants was carried out in the phase of 4–5 leaves with a suspension of conidia of the fungus Pyricularia oryzae Broomeet Cavara (concentration of 100 thousand in 1 ml). The test results were compared with the action of the preparation Favorit (active ingredients tebuconazole, 125 g/l; triadimefon, 100 g/l). Concord fungicide was used once on the next day after inoculation at a normal rate of 0.75; 1.0 and 1.25 l/ha. Under the influence of the preparation, the damage to rice plants decreased by 57.5% (0.75 l/ ha); 70.0 (1.0) and 69.5% (1.25 l/ ha) compared to the control. The use of fungicide contributed to an increase in plant growth by 7.6– 13.3 cm, and panicle length by 1.4–2.9 cm, and had a positive effect on the number of grains and the weight of grains in an ear. With the action of Concord, the mass of 1000 grains increased by 1.38 (0.75 l/ha); 2.14 (1.0) and 3.03 g (1.25 l/ha) compared to the control. The positive effect of fungicidal treatments of rice crops led to obtaining an additional grain yield. Concord does not show a phytotoxic effect and does not have a retardant effect on rice plants. The maximum indicators of biological efficiency were obtained with the use of the preparation at a flow rate of 1.0 and 1.25 l/ha. In agro-climatic conditions of the south of the Far East, Concord fungicide proved to be effective for protecting rice vegetating plants from Pyricularia.

Revisiting Sustainability of Fungicide Seed Treatments for Field Crops

The use of fungicide seed treatment (FST) is a very common practice worldwide. The purported effectiveness of many fungicides in providing broad-spectrum and systemic control of important diseases and the perception that FST reduces overall pesticide use, hence lowering environmental impacts, have greatly promoted the use of FST in the last five decades. Since there have been rapid advancements in the types, formulations, and application methods for seed treatments, there is a need to re-evaluate the benefits versus the risks of FST as a practice. While the use of seeds treated with neonicotinoid insecticides has come under scrutiny due to concern over potential nontarget effects, there are knowledge gaps on potential negative impacts of FST on operators' (those who apply, handle, and use treated seeds) health and nontarget soil organisms (both macro- and microorganisms). Here we review existing knowledge on key fungicides used for seed treatments, benefits and risks related to FST, and propose recommendations to increase benefits and limit risks related to the use of FST. We found FST is applied to almost 100% of sown seeds for the most important arable crops worldwide. Fungicides belonging to 10 chemical families and with one or several types of mobility (contact, locally systemic, and xylem mobile) are used for seed treatment, although the majority are xylem mobile. Seed treatments are applied by the seed distributor, the seed company, and the farmer, although the proportion of seed lots treated by these three groups vary from one crop to another. The average quantity of fungicide active ingredient (a.i.) applied via seed treatment depends on the crop species, environment(s) into which seed is planted, and regional or local regulations. Cost-effectiveness, protection of the seed and seedlings from pathogens up to 4-5 weeks from sowing, user friendliness, and lower impact on human health and nontarget soil organisms compared with foliar spray and broadcast application techniques, are among the most claimed benefits attributed to FST. In contrast, inconsistent economic benefits, development of resistance by soilborne pathogens to many fungicides, exposure risks to operators, and negative impacts on nontarget soil organisms are the key identified risks related to FST. We propose eight recommendations to reduce risks related to FST and to increase their benefits.

KAJIAN JENIS FUNGISIDA DAN INTERVAL APLIKASI TERHADAP PERKEMBANGAN PENYAKIT ANTRAKNOSA PADA KEDELAI

Soybean is an important commodity after rice and corn. The attack of plant pest organisms in cultivation decreased soybean productivity. Anthracnose is a disease that can reduce soybean production to 95%. The use of excessive synthetic chemical fungicides causes resistance to plant disturbing organisms and leaves chemical residues. The solution to overcome this problem is pay attention using types of fungicide active ingredients and span application time. This study aims to determine the effect of several types of fungicides and span application time on the development of anthracnose and yields. This research was carried out from February to April 2018 on Agroteknopark Jubung land of Jember University. This study used a Factorial Randomized Group Design model with 9 combinations of treatments and 4 replications. The first factor of the type of fungicide consisted of three levels, namely Triadimefon, T. harzianum and betel leaf. The second factor is the span application time of 3.5 and 7 days. The research data were analyzed using variance analysis, if there were significant differences Duncan's Multiple Range Test (DMRT) test was carried out at the level of 5%. Observation parameters included the disease incidence, diseases severity, rate of infection, and weight of pods. The results of the study showed that the combination treatment of PT3 (vegetable fungicide with betel leaves with span application time of 7 days) was the most efficient than the other treatments and gave the results of the rate of disease infection (0.84 units per day).Keywords: anthracnose, fungicide, infection rate, soybeans

Penampilan Penyakit Bulai yang disebabkan spesies Peronosclerospora philippinensis pada Kombinasi Perlakuan Varietas dan Fungisida Bahan aktif Metalaksil

Maize Downy Mildew caused by pathogenic fungus of Peronosclerospora philippinensis is an important disease in centers of maize crops outside Java Island. Research on “The Appearance of Maize Downy Mildew Caused by Pathogenic Peronosclerospora philippinensis in Combination Treatment of Resistant Varieties and Metalaxyl Fungicide ” aimed to determine the effectiveness of a combination of fungicide treatment of active ingredients of metalaxyl with varieties that have resistance to Maize Downy Mildew which was caused by P.philippinensis species. This research was conducted at KP Bajeng (endemic area of Maize Downy Mildew of P. Philippinensis species), which was compiled in Separate Plot Design with 3 replications. The main plot contained 5 varieties of maize, namely: (1) Bima-3 Bantimurung, (2) Bima-20 URI, (3) Lagaligo, (4) Bima-15 Sayang, and (5) Anoman. On the other hand, the sub plot contained 5 levels of seeds treatment dose with Metalaxyl Fungicide Active Ingredient (0 g/kg, 2 g/kg, 3 g/kg, 5 g/kg, and 7 g/kg of maize seed). The results showed that the combination of resistant and susceptible varieties with Metalaxyl Active Ingredient at doses of 2g, 3g, 5g and 7g/kg of maize seed controlled the Maize Downy Mildew which was caused by the Peronosclerospora philippinensis species effectively. It was shown by the low reaction of Maize Downy Mildew infection, at the percentage of 0% -1,86%, respectively. Under the circumstances of susceptible varieties without Metalaxyl Active Ingredient treatment, the intensity of Maize Downy Mildew reached the percentage of 100%. The lower intensity was also followed by the production, cob length and weight of 1000 seeds that were higher than those of control treatment.