The relationship between Fusarium head blight traits, thousand-kernel weight, and yield in winter wheat

Factors influencing Fusarium head blight (FHB) occurrence and yield losses in winter wheat have extensively been studied through the years; however, reports on the relationship between FHB traits and yield are conflicting. In addition, studies neglected the relationship between FHB traits and thousand-kernel weight (TKW). This study evaluated the variability in the relationship between FHB traits, TKW, and yield under field conditions, using 40 commercial winter wheat cultivars differing in resistance/susceptibility to FHB. In general, the FHB index had greater relation to yield, while Fusarium-damaged kernels (FDK) was more related to TKW. The relationship between yield, TKW, FHB index, and FDK was also determined by resistance/susceptibility of winter wheat cultivars. Fusarium-damaged kernels influenced yield more in moderately resistant (R2 = 43 %) than in susceptible/moderately susceptible cultivars (R2 = 27 %). The influence of the FHB index on TKW was weak (R2 = 9 %) in susceptible/moderately susceptible cultivars and in moderately resistant ones (R2 = 1 %). The potential to predict TKW from yield under pathogen pressure was limited due to the moderate-to-positive correlation between yield and TKW (r = 0.349, p < 0.001). This study provides insights into factors that influence TKW under FHB pathogen pressure and gives direction to more efficient and reliable investigations on grain resistance toward FHB.(AU)

Potential use of lemongrass essential oil as fungicide against Aspergillus brasiliensis and as post-harvest protectant of wheat

Fungi are among the main responsible for damage and loss in stored grains, its control has been done through synthetic substances, which are harmful to man and the environment. Brazil, one of the leading countries in agriculture, has optimal environmental conditions for the development of mycotoxigenic fungi. Most of the synthetic chemicals used as preservatives have often been realized to be toxic to humans and also cause adverse environmental effects. Thus, it is necessary to search for alternative methods of controlling. In this study the aimed was to evaluate the efficacy of lemongrass essential oil in the control of the Aspergillus brasiliensis. In vitro and serial microdilution tests were carried out at different concentrations of essential oil and citral, which corresponds to 72% of the total oil composition. Inhibition of fungal growth on contaminated wheat grain was evaluated. The in vitro test results showed that the essential oil has fungicidal potential at concentrations from 0.6 956;L mL-1, the minimum inhibitory concentration was determined at 0.8 956;L mL-1. The tests with citral showed fungal control at concentrations from 0.6 956;L mL-1 onwards. For wheat grain, fungal growth inhibition was obtained at the concentration of 1.6 956;L mL-1. The essential oil of Cymbopogon flexuosus showed fungicidal activity against the fungus Aspergillus brasiliensis.

Potential use of lemongrass essential oil as fungicide against Aspergillus brasiliensis and as post-harvest protectant of wheat

Fungi are among the main responsible for damage and loss in stored grains, its control has been done through synthetic substances, which are harmful to man and the environment. Brazil, one of the leading countries in agriculture, has optimal environmental conditions for the development of mycotoxigenic fungi. Most of the synthetic chemicals used as preservatives have often been realized to be toxic to humans and also cause adverse environmental effects. Thus, it is necessary to search for alternative methods of controlling. In this study the aimed was to evaluate the efficacy of lemongrass essential oil in the control of the Aspergillus brasiliensis. In vitro and serial microdilution tests were carried out at different concentrations of essential oil and citral, which corresponds to 72% of the total oil composition. Inhibition of fungal growth on contaminated wheat grain was evaluated. The in vitro test results showed that the essential oil has fungicidal potential at concentrations from 0.6 956;L mL-1, the minimum inhibitory concentration was determined at 0.8 956;L mL-1. The tests with citral showed fungal control at concentrations from 0.6 956;L mL-1 onwards. For wheat grain, fungal growth inhibition was obtained at the concentration of 1.6 956;L mL-1. The essential oil of Cymbopogon flexuosus showed fungicidal activity against the fungus Aspergillus brasiliensis.(AU)

Nitrogen fertilization and leaf spraying with Azospirillum brasilense in wheat: effects on mineral nutrition and yield / Adubação nitrogenada e pulverização foliar de Azospirillum brasilense em trigo: efeitos na nutrição mineral e produtividade

The use of Azospirillum brasilense has the potential to improve plant nitrogen (N) use efficiency, while a better understanding of alternative management practices with inoculation is necessary. The aim was to examine the effects of the leaf application of A. brasilense in association with nitrogen fertilization on the wheat crop. The experiment was conducted in Lidianópolis, Paraná, Brazil, in a completely randomized block design with four replications. The treatments included four doses of A. brasilense for leaf application (0, 200, 400, and 600 ml ha-1) and four doses of N (0, 40, 80, and 120 kg N ha-1). The nutritional content, yield components, quality, and yield of the wheat crop were evaluated. There was no interaction among the factors, nor did the treatments have an isolated effect on spike length, the number of spikelets per spike, spikes per m2, thousand grain weight, and test weight. However, doses of A. brasilense increased calcium and magnesium absorption at 283 and 380 ml ha-1, respectively. Similarly, nitrogen application increased the content of calcium, magnesium, and copper in the leaf at 61, 47, and 49 kg N ha-1, respectively. Nitrogen also increased the number of grains per spike and yield at 56 and 54 kg N ha-1, respectively. Yield correlated with the number of grains per spike and the manganese and copper content in the leaf.

O uso de Azospirillum brasilense apresenta potencial em melhorar a eficiência de uso do nitrogênio (N), sendo necessário melhor compreensão de formas alternativas de inoculação, visto que o tratamento químico de sementes pode comprometer a eficiência das bactérias. O objetivo foi avaliar os efeitos do A. brasilense aplicado via foliar associado a adubação nitrogenada na cultura do trigo. O experimento foi implantado em Lidianópolis, no estado do Paraná, Brasil, em blocos completos com tratamentos ao acaso e quatro repetições, sendo os tratamentos: quatro doses de A. brasilense via foliar (0, 200, 400 e 600 ml ha-1) e quatro doses de N (0, 40, 80 e 120 kg N ha-1). Foram avaliados os teores nutricionais, componentes de rendimento, qualidade e produtividade. Não houve interação entre os fatores, tampouco efeito isolado dos tratamentos para comprimento da espiga, número de espiguetas por espiga, espigas por m², massa de mil grãos e peso de hectolitro. Todavia as doses de A. brasilense, aumentaram a absorção de Ca e Mg até a dose de 283 e 380 ml ha-1, respectivamente. De modo similar, o N aplicado aumentou os teores foliares de cálcio, magnésio, além de cobre até a dose de 61, 47 e 49 kg ha-1 de N, respectivamente. O N também incrementou o número de grãos por espiga e a produtividade até a dose 56 e 54 kg N ha-1, respectivamente, porém a eficiência de uso

Nitrogen fertilization and leaf spraying with Azospirillum brasilense in wheat: effects on mineral nutrition and yield / Adubação nitrogenada e pulverização foliar de Azospirillum brasilense em trigo: efeitos na nutrição mineral e produtividade

The use of Azospirillum brasilense has the potential to improve plant nitrogen (N) use efficiency, while a better understanding of alternative management practices with inoculation is necessary. The aim was to examine the effects of the leaf application of A. brasilense in association with nitrogen fertilization on the wheat crop. The experiment was conducted in Lidianópolis, Paraná, Brazil, in a completely randomized block design with four replications. The treatments included four doses of A. brasilense for leaf application (0, 200, 400, and 600 ml ha-1) and four doses of N (0, 40, 80, and 120 kg N ha-1). The nutritional content, yield components, quality, and yield of the wheat crop were evaluated. There was no interaction among the factors, nor did the treatments have an isolated effect on spike length, the number of spikelets per spike, spikes per m2, thousand grain weight, and test weight. However, doses of A. brasilense increased calcium and magnesium absorption at 283 and 380 ml ha-1, respectively. Similarly, nitrogen application increased the content of calcium, magnesium, and copper in the leaf at 61, 47, and 49 kg N ha-1, respectively. Nitrogen also increased the number of grains per spike and yield at 56 and 54 kg N ha-1, respectively. Yield correlated with the number of grains per spike and the manganese and copper content in the leaf.(AU)

O uso de Azospirillum brasilense apresenta potencial em melhorar a eficiência de uso do nitrogênio (N), sendo necessário melhor compreensão de formas alternativas de inoculação, visto que o tratamento químico de sementes pode comprometer a eficiência das bactérias. O objetivo foi avaliar os efeitos do A. brasilense aplicado via foliar associado a adubação nitrogenada na cultura do trigo. O experimento foi implantado em Lidianópolis, no estado do Paraná, Brasil, em blocos completos com tratamentos ao acaso e quatro repetições, sendo os tratamentos: quatro doses de A. brasilense via foliar (0, 200, 400 e 600 ml ha-1) e quatro doses de N (0, 40, 80 e 120 kg N ha-1). Foram avaliados os teores nutricionais, componentes de rendimento, qualidade e produtividade. Não houve interação entre os fatores, tampouco efeito isolado dos tratamentos para comprimento da espiga, número de espiguetas por espiga, espigas por m², massa de mil grãos e peso de hectolitro. Todavia as doses de A. brasilense, aumentaram a absorção de Ca e Mg até a dose de 283 e 380 ml ha-1, respectivamente. De modo similar, o N aplicado aumentou os teores foliares de cálcio, magnésio, além de cobre até a dose de 61, 47 e 49 kg ha-1 de N, respectivamente. O N também incrementou o número de grãos por espiga e a produtividade até a dose 56 e 54 kg N ha-1, respectivamente, porém a eficiência de uso(AU)

Productivity and the presence of mycotoxins in oats, wheat, and triticale subjected to grazing / Produtividade e presença de micotoxinas em grãos de aveia, trigo e triticale submetidos ao pastejo

This study aimed to evaluate the effects of grazing on the agronomic characteristics, grain yield, andpresence of the mycotoxins aflatoxins, fumonisins, and zearalenone in IPR 126 oat, BRS Tarumãwheat, and IPR 111 triticale. This study was performed from April 24, 2012 to November 11, 2013 atUNIOESTE’s Experimental Farm in southern Brazil. The experimental design was a randomized blockin a banded scheme, with four replications. The treatments in the A tracks were the three crops andthe B tracks, the treatments: without grazing, one grazing event, or two grazing events. One grazingreduced the productivity of oat by 42.48% and triticale by 28.09% and increased wheat productivityby 24.89%. Two grazings reduced oat productivity by 54.14%, wheat by 40.96%, and triticale by54.69%. Crops subjected to two grazings should be used for dry matter production for ground coveror partially used for silage when the plant is in the pasty or semi-hard grain stage, as grazing affectsthe agronomic characteristics and grain yield. The BRS Tarumã wheat, when used in crop-livestockintegration systems, should be grazed only once due to increased productivity, while IPR 126 oat andIPR 111 triticale should not be grazed in crop-livestock integration systems for commercial productionof grain. Oats from grazed plants should not be added to feeds of poultry in the early stage or pigs inthe early and growth stages due to the higher levels of aflatoxins, fumonisins, and zearalenone. Grazingof winter crops increases the length of the crop cycle and grain formation will occur under climaticconditions favorable to the mycotoxins. Therefore, when grains are intended for human consumption,grazing is not recommended, as it increases the possibility of aflatoxins, fumonisins, and zearalenone atlevels above the maximum tolerable levels permitted by law. These grains should be supplied to animalsonly after analysis of the mycotoxin levels present in the grains.

Objetivou-se avaliar os efeitos dos pastejos nas características agronômicas, produtividade de grãose presença das micotoxinas: aflatoxinas, fumonisinas e zearalenona em grãos de aveia IPR 126, trigoBRS Tarumã e triticale IPR 111. O trabalho foi desenvolvido no período de 24/04/2012 a 21/03/2014(24º31’56,1’’S; 54º01’10.3”O). O delineamento experimental foi em blocos ao acaso em esquema defaixas, com quatro repetições. Os tratamentos nas faixas A foram as três culturas e nas faixas B osmanejo:sem pastejo, um pastejo e dois pastejos. O manejo com apenas um pastejo reduziu a produtividadede grãos da aveia em 42,48% e do triticale em 28,09% e aumentou a produtividade do trigo em 24,89%.O manejo com dois pastejos reduziu a produtividade da aveia em 54,14%, do trigo em 40,96% e dotriticale em 54,69%. As culturas submetidas a dois pastejos devem ser diferidas para produção dematéria seca para cobertura do solo ou utilizar de forma parcial a planta no estágio de grãos pastosos ousemiduros para silagem, pois o pastejo prejudica as características agronômicas e produtividade. O trigoBRS Tarumã, quando utilizado em sistema de ILP deverá ser pastejado apenas uma vez com aumentode produtividade, enquanto a aveia IPR 126 e o triticale IPR 111 não devem ser pastejados em sistemasde integração lavoura pecuária para produção comercial de grãos. Grãos de aveia oriundos de plantasque foram submetidas a pastejo não devem ser adicionados em rações para aves na fase inicial e suínosna fase inicial e crescimento por possuírem maiores teores de aflatoxinas, fuminisinas e zearelenona.

Productivity and the presence of mycotoxins in oats, wheat, and triticale subjected to grazing / Produtividade e presença de micotoxinas em grãos de aveia, trigo e triticale submetidos ao pastejo

This study aimed to evaluate the effects of grazing on the agronomic characteristics, grain yield, andpresence of the mycotoxins aflatoxins, fumonisins, and zearalenone in IPR 126 oat, BRS Tarumãwheat, and IPR 111 triticale. This study was performed from April 24, 2012 to November 11, 2013 atUNIOESTEs Experimental Farm in southern Brazil. The experimental design was a randomized blockin a banded scheme, with four replications. The treatments in the A tracks were the three crops andthe B tracks, the treatments: without grazing, one grazing event, or two grazing events. One grazingreduced the productivity of oat by 42.48% and triticale by 28.09% and increased wheat productivityby 24.89%. Two grazings reduced oat productivity by 54.14%, wheat by 40.96%, and triticale by54.69%. Crops subjected to two grazings should be used for dry matter production for ground coveror partially used for silage when the plant is in the pasty or semi-hard grain stage, as grazing affectsthe agronomic characteristics and grain yield. The BRS Tarumã wheat, when used in crop-livestockintegration systems, should be grazed only once due to increased productivity, while IPR 126 oat andIPR 111 triticale should not be grazed in crop-livestock integration systems for commercial productionof grain. Oats from grazed plants should not be added to feeds of poultry in the early stage or pigs inthe early and growth stages due to the higher levels of aflatoxins, fumonisins, and zearalenone. Grazingof winter crops increases the length of the crop cycle and grain formation will occur under climaticconditions favorable to the mycotoxins. Therefore, when grains are intended for human consumption,grazing is not recommended, as it increases the possibility of aflatoxins, fumonisins, and zearalenone atlevels above the maximum tolerable levels permitted by law. These grains should be supplied to animalsonly after analysis of the mycotoxin levels present in the grains.(AU)

Objetivou-se avaliar os efeitos dos pastejos nas características agronômicas, produtividade de grãose presença das micotoxinas: aflatoxinas, fumonisinas e zearalenona em grãos de aveia IPR 126, trigoBRS Tarumã e triticale IPR 111. O trabalho foi desenvolvido no período de 24/04/2012 a 21/03/2014(24º3156,1S; 54º0110.3”O). O delineamento experimental foi em blocos ao acaso em esquema defaixas, com quatro repetições. Os tratamentos nas faixas A foram as três culturas e nas faixas B osmanejo:sem pastejo, um pastejo e dois pastejos. O manejo com apenas um pastejo reduziu a produtividadede grãos da aveia em 42,48% e do triticale em 28,09% e aumentou a produtividade do trigo em 24,89%.O manejo com dois pastejos reduziu a produtividade da aveia em 54,14%, do trigo em 40,96% e dotriticale em 54,69%. As culturas submetidas a dois pastejos devem ser diferidas para produção dematéria seca para cobertura do solo ou utilizar de forma parcial a planta no estágio de grãos pastosos ousemiduros para silagem, pois o pastejo prejudica as características agronômicas e produtividade. O trigoBRS Tarumã, quando utilizado em sistema de ILP deverá ser pastejado apenas uma vez com aumentode produtividade, enquanto a aveia IPR 126 e o triticale IPR 111 não devem ser pastejados em sistemasde integração lavoura pecuária para produção comercial de grãos. Grãos de aveia oriundos de plantasque foram submetidas a pastejo não devem ser adicionados em rações para aves na fase inicial e suínosna fase inicial e crescimento por possuírem maiores teores de aflatoxinas, fuminisinas e zearelenona.(AU)

Alleviation of salt stress by halotolerant and halophilic plant growth-promoting bacteria in wheat (Triticum aestivum)

In the current study, 18 halotolerant and halophilic bacteria have been investigated for their plant growth promoting abilities in vitro and in a hydroponic culture. The bacterial strains have been investigated for ammonia, indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate-deaminase production, phosphate solubilisation and nitrogen fixation activities. Of the tested bacteria, eight were inoculated with Triticum aestivum in a hydroponic culture. The investigated bacterial strains were found to have different plant-growth promoting activities in vitro. Under salt stress (200 mM NaCl), the investigated bacterial strains significantly increased the root and shoot length and total fresh weight of the plants. The growth rates of the plants inoculated with bacterial strains ranged from 62.2% to 78.1%.Identifying of novel halophilic and halotolerant bacteria that promote plant growth can be used as alternatives for salt sensitive plants. Extensive research has been conducted on several halophilic and halotolerant bacterial strains to investigate their plant growth promoting activities. However, to the best of my knowledge, this is the first study to inoculate these bacterial strains with wheat.(AU)

Dose and application rate of fungicide to control leaf rust (Puccinia triticina) and yellow spot (Pyrenophora tritici repentis) of wheat / Dose e taxa de aplicação de fungicida no controle da ferrugem da folha (Puccinia triticina) e da mancha amarela (Pyrenophora tritici repentis) do trigo

The aim of this paper was to study the role of dose and rate of application, and the effect of concentration of fungicide in the spray solution resulted from the interaction of these factors, in the control of leaf rust and yellow spot of wheat. It was conducted two experiments, the first used the CD 104 cultivar (susceptible to lead rust and yellow spot). The experimental design was an factorial 3 x 3 + untreated control, that involve the factors dose (0,25, 0,30 and 0,35 L.ha-1) and application rate (143, 286 and 429 L.ha-1). The second experiment used the BRS 208 cultivar (resistant to leaf rust and moderately resistant to yellow spot). The experimental design was an factorial 2 x 2 + untreated control, consisting the factors dose (0,2 and 0,3 L.ha-1) and application rate (143 and 286 L.ha-1). The applications were made with a coastal sprayer by CO2, pressure of 250 kPa, XR 110-02 nozzle, which generated an application rate of 143 L.ha-1. The respective rates of each treatment were changed by the number of sprayers per area. It was also used a spore trap denominated Siga, associated with meteorological data and weather forecast, which detected spores of rust and yellow spot before the symptoms in the plants, helping in the identification of disease and in the timing of application. There wasn´t any interaction between dose and rate of application for any of the experiments, therefore, there wasn´t effect of concentration of fungicide in control. The dose and rate of application just influenced in the control of the yellow spot. Higher doses and rates were more effective. However, no difference was observed for yield and hectolitre weight among treatments, except untreated control.(AU)

O objetivo deste trabalho foi estudar a associação entre a dose e a taxa de aplicação e o efeito desta interação na concentração de fungicida da calda de pulverização para o controle da ferrugem da folha e mancha amarela do trigo. Realizaram-se dois experimentos, sendo que no primeiro utilizou-se a cultivar CD 104 (suscetível a ferrugem e mancha amarela), tendo como delineamento experimental o fatorial 3 x 3 + testemunha sem controle. Os fatores foram dose (0,25, 0,30 e 0,35 L.ha-1) e taxa de aplicação (143, 286 e 429 L.ha-1). Para o segundo experimento usou-se a cultivar BRS 208 (resistente a ferrugem e moderadamente resistente a mancha amarela), tendo como delineamento experimental o fatorial 2 x 2 + testemunha sem controle. Os fatores foram dose (0,2 e 0,3 L.ha-1) e taxa de aplicação (143 e 286 L.ha- 1). As aplicações foram realizadas com um pulverizador costal pressurizado via CO2, sob pressão de trabalho de 250 kPa, ponta de pulverização XR 110-02, gerando uma taxa de aplicação de 143 L.ha-1. As respectivas taxas de cada tratamento foram alteradas pelo número de vezes que a área foi pulverizada. Utilizou-se ainda o coletor de esporos SIGA associado a dados meteorológicos e de previsão de tempo, que detectou esporos da ferrugem e da mancha amarela antes da efetiva manifestação dos sintomas nas plantas, auxiliando assim na identificação das doenças e na tomada de decisão para a aplicação. Não foi evidenciada nenhuma interação entre dose e taxa de aplicação para nenhum dos experimentos, não havendo, portanto, efeito da concentração de fungicida no controle. A dose e a taxa de aplicação somente exerceram influência no controle da mancha amarela, cujo uso de maiores doses e taxas mostraram-se mais eficientes. Contudo, não foram verificadas diferenças para produtividade e peso hectolitro entre os tratamentos com fungicidas, exceto à testemunha sem aplicação.(AU)

Efficiency of treatments for controlling Trichoderma spp during spawning in cultivation of lignicolous mushrooms

Trichoderma spp is the cause of the green mold disease in mushroom cultivation production. Many disinfection treatments are commonly applied to lignocellulose substrates to prevent contamination. Mushroom growers are usually worried about the contaminations that may occur after these treatments during handling or spawning. The aim of this paper is to estimate the growth of the green mold Trichoderma sp on lignocellulose substrates after different disinfection treatments to know which of them is more effective to avoid contamination during spawning phase. Three different treatments were assayed: sterilization (121 ºC), immersion in hot water (60 and 80 ºC), and immersion in alkalinized water. Wheat straw, wheat seeds and Eucalyptus or Populus sawdust were used separately as substrates. After the disinfection treatments, bagged substrates were sprayed with 3 mL of suspension of conidia of Trichoderma sp (10(5) conidia/mL) and then separately spawned with Pleurotus ostreatus or Gymnopilus pampeanus. The growth of Trichoderma sp was evaluated based on a qualitative scale. Trichoderma sp could not grow on non-sterilized substrates. Immersions in hot water treatments and immersion in alkalinized water were also unfavorable treatments for its growth. Co- cultivation with mushrooms favored Trichoderma sp growth. Mushroom cultivation disinfection treatments of lignocellulose substrates influence on the growth of Trichoderma sp when contaminations occur during spawning phase. The immersion in hot water at 60 ºC for 30 min or in alkalinized water for 36 h, are treatments which better reduced the contaminations with Trichoderma sp during spawning phase for the cultivation of lignicolous species.

A procedure to evaluate the efficiency of surface sterilization methods in culture-independent fungal endophyte studies

Extraneous DNA interferes with PCR studies of endophytic fungi. A procedure was developed with which to evaluate the removal of extraneous DNA. Wheat (Triticum aestivum) leaves were sprayed with Saccharomyces cerevisiae and then subjected to physical and chemical surface treatments. The fungal ITS1 products were amplified from whole tissue DNA extractions. ANOVA was performed on the DNA bands representing S. cerevisiae on the agarose gel. Band profile comparisons using permutational multivariate ANOVA (PERMANOVA) and non-metric multidimensional scaling (NMDS) were performed on DGGE gel data, and band numbers were compared between treatments. Leaf surfaces were viewed under variable pressure scanning electron microscopy (VPSEM). Yeast band analysis of the agarose gel showed that there was no significant difference in the mean band DNA quantity after physical and chemical treatments, but they both differed significantly (p < 0.05) from the untreated control. PERMANOVA revealed a significant difference between all treatments (p < 0.05). The mean similarity matrix showed that the physical treatment results were more reproducible than those from the chemical treatment results. The NMDS showed that the physical treatment was the most consistent. VPSEM indicated that the physical treatment was the most effective treatment to remove surface microbes and debris. The use of molecular and microscopy methods for the post-treatment detection of yeast inoculated onto wheat leaf surfaces demonstrated the effectiveness of the surface treatment employed, and this can assist researchers in optimizing their surface sterilization techniques in DNA-based fungal endophyte studies.

Improvement of yield of the edible and medicinal mushroom Lentinula edodes on wheat straw by use of supplemented spawn

The research evaluated the interactions of two main factors (strain / types of spawn) on various parameters with the purpose to assess its effect on yield and biochemical composition of Lentinula edodes fruiting bodies cultivated on pasteurized wheat straw. The evaluation was made with four strains (IE-40, IE-105, IE-124 and IE-256). Different types of spawns were prepared: Control (C) (millet seed, 100%), F1 (millet seed, 88.5%; wheat bran, 8.8%; peat moss, 1.3%; and CaS0(4), 1.3%) and F2 (the same formula as F1, but substituting the wheat bran with powdered wheat straw). Wheat straw was pasteurized by soaking it for 1 h in water heated to 65 °C. After this the substrate (2 kg wet weight) was placed in polypropylene bags. The bags were inoculated with each spawn (5% w/w) and incubated in a dark room at 25 °C. A proximate analysis of mature fruiting bodies was conducted. The mean Biological Efficiency (BE) varied between 66.0% (C-IE-256) and 320.1% (F1-IE-124), with an average per strain of 125.6%. The highest mean BE was observed on spawn F1 (188.3%), significantly different from C and F2. The protein content of fruiting bodies was high, particularly in strain IE-40-F1 (17.7%). The amount of fat varied from 1.1 (F1-IE-40) to 2.1% (F2-IE-105) on dry matter. Carbohydrates ranged from 58.8% (F1-IE-40) to 66.1% (F1-IE-256). The energy value determined ranged from 302.9 kcal (F1-IE-40) to 332.0 kcal (F1-IE-256). The variability on BE observed in this study was significantly influenced by the spawn's formulation and genetic factors of the different strains.

Dose and application rate of fungicide to control leaf rust (Puccinia triticina) and yellow spot (Pyrenophora tritici repentis) of wheat / Dose e taxa de aplicação de fungicida no controle da ferrugem da folha (Puccinia triticina) e da mancha amarela (Pyrenophora tritici repentis) do trigo

The aim of this paper was to study the role of dose and rate of application, and the effect of concentration of fungicide in the spray solution resulted from the interaction of these factors, in the control of leaf rust and yellow spot of wheat. It was conducted two experiments, the first used the CD 104 cultivar (susceptible to lead rust and yellow spot). The experimental design was an factorial 3 x 3 + untreated control, that involve the factors dose (0,25, 0,30 and 0,35 L.ha-1) and application rate (143, 286 and 429 L.ha-1). The second experiment used the BRS 208 cultivar (resistant to leaf rust and moderately resistant to yellow spot). The experimental design was an factorial 2 x 2 + untreated control, consisting the factors dose (0,2 and 0,3 L.ha-1) and application rate (143 and 286 L.ha-1). The applications were made with a coastal sprayer by CO2, pressure of 250 kPa, XR 110-02 nozzle, which generated an application rate of 143 L.ha-1. The respective rates of each treatment were changed by the number of sprayers per area. It was also used a spore trap denominated Siga, associated with meteorological data and weather forecast, which detected spores of rust and yellow spot before the symptoms in the plants, helping in the identification of disease and in the timing of application. There wasn´t any interaction between dose and rate of application for any of the experiments, therefore, there wasn´t effect of concentration of fungicide in control. The dose and rate of application just influenced in the control of the yellow spot. Higher doses and rates were more effective. However, no difference was observed for yield and hectolitre weight among treatments, except untreated control.

O objetivo deste trabalho foi estudar a associação entre a dose e a taxa de aplicação e o efeito desta interação na concentração de fungicida da calda de pulverização para o controle da ferrugem da folha e mancha amarela do trigo. Realizaram-se dois experimentos, sendo que no primeiro utilizou-se a cultivar CD 104 (suscetível a ferrugem e mancha amarela), tendo como delineamento experimental o fatorial 3 x 3 + testemunha sem controle. Os fatores foram dose (0,25, 0,30 e 0,35 L.ha-1) e taxa de aplicação (143, 286 e 429 L.ha-1). Para o segundo experimento usou-se a cultivar BRS 208 (resistente a ferrugem e moderadamente resistente a mancha amarela), tendo como delineamento experimental o fatorial 2 x 2 + testemunha sem controle. Os fatores foram dose (0,2 e 0,3 L.ha-1) e taxa de aplicação (143 e 286 L.ha- 1). As aplicações foram realizadas com um pulverizador costal pressurizado via CO2, sob pressão de trabalho de 250 kPa, ponta de pulverização XR 110-02, gerando uma taxa de aplicação de 143 L.ha-1. As respectivas taxas de cada tratamento foram alteradas pelo número de vezes que a área foi pulverizada. Utilizou-se ainda o coletor de esporos SIGA associado a dados meteorológicos e de previsão de tempo, que detectou esporos da ferrugem e da mancha amarela antes da efetiva manifestação dos sintomas nas plantas, auxiliando assim na identificação das doenças e na tomada de decisão para a aplicação. Não foi evidenciada nenhuma interação entre dose e taxa de aplicação para nenhum dos experimentos, não havendo, portanto, efeito da concentração de fungicida no controle. A dose e a taxa de aplicação somente exerceram influência no controle da mancha amarela, cujo uso de maiores doses e taxas mostraram-se mais eficientes. Contudo, não foram verificadas diferenças para produtividade e peso hectolitro entre os tratamentos com fungicidas, exceto à testemunha sem aplicação.