Fernando Juliatti

By Fernando Cezar Juliatti, Fernanda Cristina Juliatti, Breno Cezar Marinho Juliatti and David S. Jaccoud-Filho

Part of the book: Fungicides

By Fernando Cezar Juliatti, Luís Antônio Siqueira de Azevedo and Fernanda Cristina Juliatti

Asian soybean rust (Phakopsora pachyrhizi) is an aggressive and destructive disease that undermines the current 34 million hectares of soybean production system in Brazil. The disease is present throughout the entire cultivated area. The disease control has required a combination of several practices in order to avoid losses. In the last 15 harvests, the application of fungicides has been shown as an effective alternative for the producer in the control of this aggressive disease. Since the first fungicides emergency recommended for the 2002/03 season (azoxystrobin, difenoconazole, fluconazole, pyraclostrobin + epoxiconazole, and tebuconazole), a large number of new formulations were added to the arsenal to control rust. There are today recorded in MAPA (Ministry of Agriculture and Supply) about 45 active ingredients (alone or in combination are about 120), trademarks, and formulations for the rational use against rust. Among fungicides, there are differences in efficacy, residual period, metabolic stability, and translocation rate, requiring care from the producer and technical assistance in the choice of the product to be used in each situation. In this review, the chemical control of rust is analyzed in Brazil from 2001/02 to 2013/14; its economic importance, strategic variables for the rational fungicides practice, factors that complicate the chemical control and the risk of resistance to the main chemical groups.

Part of the book: Soybean

By Fernando C. Juliatti, Anakely A. Rezende, Breno Cezar Marinho Juliatti and Tâmara P. Morais

Biological control agents are alternatives to chemical pesticides in the management of plant diseases. Currently, hundreds of bioproducts are commercially available in international market varying mainly in antagonistic microorganisms and formulation. We screened four Trichoderma-based products as to their efficacy in controlling Sclerotinia stem rot (SSR) under protected and field environments and their effect on soybean seeds’ sanity and physiological qualities. We also tested application technologies through seed microbiolization and foliar spraying to deliver the microorganisms, and their compatibility with chemical fungicides. In vitro assays showed that all Trichoderma strains were antagonistic to S. sclerotiorum evidencing hyperparasitic activity. Moreover, the bioproducts reduced fungi incidence on soybean seeds, promoted faster seedling emergence and did not hamper seeds’ vigor. Increases of 14 and 37% were registered for root length and shoot fresh weight over that of the untreated control indicating potential application of the bioproducts as soybean growth promoters. Thiophanate-methyl and procymidone were the most compatible, without drastically affecting spore germination or mycelium growth. Under field conditions, all Trichoderma strains reduced SSR incidence and increased soybean grain yield. Formulation interferes on bioproducts’ viability and efficacy deserving special attention upon development.

Part of the book: Trichoderma

By Fernando Cezar Juliatti and Laércio Zambolim

Brazil is the first soybean producer in the world, and the largest exporter. In the 2019/20 harvest, the country produced about 124.85 million tons, representing 30% of world production. Global soy production for 2019/20 reached 337.9 million tons. Asian soybean rust (ASR) is the most pathogen on soybean in Brazil in nowadays. Target spot and Septoria leaf spot plus white mold complete these scenarios. ASR emerged in Brazil in 1979. The use of fungicides in the soybean crop in Brazil intensified after the master of 2002 with the resurgence of soybean rust, where the use of triazoles intensified. The massive sprays to pathogen control reached 3.5 sprays per season. In 2006, the first reports of loss of sensitivity of the fungus to the group appeared, notably for the fungicide flutriafol and tebuconazole used in many situations in a curative way or to eradicate the fungus. From that moment on, the productive system sought to use triazoles and strobilurins. In 2011 came the first reports of loss of sensitivity of the fungus in the group of strobilurins. This fact was due to the use of pyraclostrobin in the vegetative phase of soybeans without protection by multisite. That same year, the introduction of the active ingredients in copper oxychloride, mancozeb and chlorothalonil took place in Brazil. In 2015, the first carboxamides ((benzovindiflupyr) (solatenol and fluxpyroxade) associated in triple mode with triazoles and strobilurins were launched on the Brazilian market. Due to the specific mode of action in the metabolism of the fungus (biosynthesis of ergosterol (triazoles), mitochondrial respiration in the cytochrome oxidase enzyme complex - QOIs (strobilurins) and succin dehydrogenase - SDHIs (carboxamides), the need for their association in the sprayings was seen. To multisite (cuprics, dithiocarbamates and nitriles). For the sustainable management of the disease in Brazil, control strategies are recommended, such as the use of systemic fungicides, with a specific biochemical mechanism of action with the adoption of tank mix with multisite, adoption of cultural practices (sanitary emptiness) and sowing schedule and the use of varieties with quantitative resistance (partial or horizontal resistance). These measures will guarantee the sustainability of the culture and the useful life of systemic fungicides or specific sites.

Part of the book: Cereal Grains