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The identification of promising commercial varieties for irrigated crops in semiarid conditions based on characters of interest to sugarcane agro-industries is important, considering the search for high sugarcane yields to obtain sustainable crops. Thus, the objective of this work was to evaluate production components of agroindustrial interest of different sugarcane varieties grown under subsurface drip irrigation in the Semiarid region of Brazil, during two crop cycles. A randomized block experimental design was used, in an 8×2 factorial arrangement (varieties and cycles) with three replications. The sugarcane juice quality, sugar yield, and culm yield were evaluated in each cycle. Gross sugar percentage, sugarcane culm yield, juice apparent sucrose content, and juice purity were affected by the crop cycles. Soluble solids content presented strong significant correlation with most variables of agroindustrial interest. The path coefficient analysis showed that juice apparent sucrose content was the explanatory character with higher direct effect on soluble solids and that this variable presented high indirect effects on most explanatory variables. The sugarcane varieties RB72454 and Q124 are recommended for production managements with drip irrigation under semiarid conditions. Soluble solids content can be used as an alternative for direct selection of varieties with higher sugar yields in different cycles.(AU)

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Somatic embryogenesis is the process by which embryos are formed from a single or small group of somatic cells in response to specific stimuli. Somatic embryogenesis has been applied to achieve mass clonal propagation on an industrial scale and to increase the agronomic performance of species of economic interest, including sugarcane. The use of somatic embryogenesis in sugarcane stands out as a biotechnological tool with a high potential for application in the clonal propagation of disease-free elite varieties, as an essential part of genetic transformation protocols, and in the production of synthetic seeds. A better understanding of each phase of somatic embryogenesis can help to optimize the process to enhance yields and produce high-quality emblings. In this chapter, we describe a detailed protocol for somatic embryogenesis in sugarcane (Saccharum sp.) to be used in research projects for small-scale production. This protocol comprises all steps from explant preparation to the establishment of sugarcane emblings.

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Beneficial plant-microbe interactions lead to physiological and biochemical changes that may result in plant-growth promotion. This study evaluated the effect of the interaction between sugarcane and endophytic bacterial strains on plant physiological and biochemical responses under two levels of nitrogen (N) fertilization. Six strains of endophytic bacteria, previously selected as plant growth-promoting bacteria (PGPB), were used to inoculate sugarcane mini stalks, with and without N fertilization. After 45 days, biomass production; shoot nutrient concentrations; foliar polyamine and free amino acid profiles; activities of nitrate reductase and glutamine synthase; and the relative transcript levels of the GS1, GS2, and SHR5 genes in sugarcane leaves were determined. All six endophytic strains promoted sugarcane growth, increasing shoot and root biomass, plant nutritional status, and the use efficiency of most nutrients. The inoculation-induced changes at the biochemical level altered the foliar free amino acid and polyamine profiles, mainly regarding the relative concentrations of citrulline, putrescine, glycine, alanine, glutamate, glutamine, proline, and aspartate. The transcription of GS1, GS2, and SHR5 was higher in the N fertilized seedlings, and almost not altered by endophytic bacterial strains. The endophytic strains promoted sugarcane seedlings growth mainly by improving nutrient efficiency. This improvement could not be explained by their ability to induce the production of amino acid and polyamine composts, or GS1, GS2, and SHR5, showing that complex interactions may be associated with enhancement of the sugarcane seedlings' performance by endophytic bacteria. The strains demonstrated biotechnological potential for sugarcane seedling production.

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Little is known about the interaction between the inoculation of diazotrophic bacteria, the variety, and the substrate used in inoculated sugarcane seedling production. Bearing this in mind, the aim of this study was to evaluate the effects of diazotrophic bacteria inoculation, four sugarcane varieties and four different substrates on the growth and nitrogen accumulation of sugarcane seedlings. Parameters related to sprouting, height, and root growth, as well as nitrogen accumulation, were evaluated. The results indicate that inoculating sugarcane seedlings belonging to the following varieties: RB867515, RB92579, RB966928 and RB975932 with bacteria may increase sprouting speed index, height, root length, fresh and dry matter weight, as well as nitrogen accumulation, which has resulted in a more uniform stem diameter. However, the responses to inoculation differ from variety to variety and are also dependent on the substrate used with better results observed in the commercial substrate and the substrate mixtures containing a higher proportion of organic compost. Understanding the interaction between the variety and the substrate with the bacterial inoculation is essential to the success of the production of inoculated sugarcane seedlings.(AU)

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Little is known about the interaction between the inoculation of diazotrophic bacteria, the variety, and the substrate used in inoculated sugarcane seedling production. Bearing this in mind, the aim of this study was to evaluate the effects of diazotrophic bacteria inoculation, four sugarcane varieties and four different substrates on the growth and nitrogen accumulation of sugarcane seedlings. Parameters related to sprouting, height, and root growth, as well as nitrogen accumulation, were evaluated. The results indicate that inoculating sugarcane seedlings belonging to the following varieties: RB867515, RB92579, RB966928 and RB975932 with bacteria may increase sprouting speed index, height, root length, fresh and dry matter weight, as well as nitrogen accumulation, which has resulted in a more uniform stem diameter. However, the responses to inoculation differ from variety to variety and are also dependent on the substrate used with better results observed in the commercial substrate and the substrate mixtures containing a higher proportion of organic compost. Understanding the interaction between the variety and the substrate with the bacterial inoculation is essential to the success of the production of inoculated sugarcane seedlings.

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The sugarcane agro-industry is a major producer of organic waste, which could be used as substrates for production of pre-sprouted sugarcane seedlings aiming at reducing production costs and the sustainability of the sugar and alcohol industry. This study aimed to identify the best position of origin of the bud chip (little portion of stem with one bud) for the production of pre-sprouted seedlings (PSS) of sugarcane and the effects of commercial and alternative substrates containing by-products of the sugarcane industry on the production of sugarcane PSS. For this, a 4x2 factorial experiment was performed with four substrates: two commercial (TRIMIX® and BIOPLANT®) and two substrates formulated from sugarcane bagasse and filter cake (SABAFI and SUSBAFI) combined with bud chip from the basal and apical regions. The chemical and physical-hydric properties of the substrates and the development of PSS were evaluated. The substrates evaluated provided contrasting environments for root growth in relation to the physical-hydric and chemical properties. The use of by-products from the sugarcane industry can be added to the formulation of substrates for the production of pre-sprouted sugarcane seedlings, although the commercial substrate TRIMIX® provides superior performance to the seedlings, regardless of the origin position of the bud chip.(AU)

A agroindústria canavieira é grande produtora de resíduos orgânicos, que poderiam ser utilizados como substratos na produção de mudas pré-brotadas de cana-de-açúcar visando a redução de custos de produção e a sustentabilidade do setor sucroalcooleiro. Assim, objetivou-se identificar a melhor posição de origem do minirrebolo para a produção de mudas pré-brotadas de cana-de-açúcar (MPB) e os efeitos de substratos comerciais e alternativos com subprodutos da indústria canavieira na produção de MPB de cana-de-açúcar. Para tanto, realizou-se um experimento fatorial 4x2, sendo quatro substratos: dois comerciais (TRIMIX® e BIOPLANT®) e dois substratos formulados a partir do bagaço da cana e da torta de filtro (SABAFI e SUSBAFI) combinados com minirebolos provenientes da região basal e apical. Avaliaram-se as propriedades químicas e físico-hídricas dos substratos e o desenvolvimento das MPB. Os substratos proporcionaram ambientes de crescimento radicular contrastante em relação às propriedades físicas e químicas. O uso de subprodutos na formulação de substratos para produção de mudas pré-brotadas de cana-de-açúcar pode ser utilizado, embora o substrato comercial TRIMIX® tenha condicionado desempenho superior às mudas, independentemente da posição de origem do minirrebolo.(AU)

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Few studies have evaluated endophytic bacteria in relation to plant growth promotion, nitrogen uptake and biological control. The aim of this study was to molecularly and physiologically characterize thirteen endophytic bacteria strains, evaluate their biological control properties and their ability to promote plant growth and plant N nutrition. All the strains produced indole acetic acid and promoted increase of plant biomass, N accumulative amount and N-use efficiency index. None of the strains carries the nifH gene. Four strains stimulated plant nitrate reductase activity, four solubilized phosphate, nine produced siderophores and none produced HCN. Seven strains inhibited Bipolaris sacchari growth and one was antagonistic to Ceratocystis paradoxa. The pathogens were inhibited by the production of diffusible and volatile metabolites by the bacterial strains. Moreover, this is the first study to demonstrate the effect of Delftia acidovorans on sugarcane plant growth, nitrogen metabolism improvement and antagonism to B. sacchari. The most efficient strains in promoting plant growth and exhibiting antagonistic activities towards fungal pathogens were Herbaspirillum frinsingense (IAC-BECa-152) and three Pantoea dispersa strains (IAC-BECa-128, IAC-BECa-129, and IAC-BECa-132). These bacteria show potential to be used as inoculants for sustainable agricultural management, mainly at the seedling production phase.

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The sugarcane agro-industry is a major producer of organic waste, which could be used as substrates for production of pre-sprouted sugarcane seedlings aiming at reducing production costs and the sustainability of the sugar and alcohol industry. This study aimed to identify the best position of origin of the bud chip (little portion of stem with one bud) for the production of pre-sprouted seedlings (PSS) of sugarcane and the effects of commercial and alternative substrates containing by-products of the sugarcane industry on the production of sugarcane PSS. For this, a 4x2 factorial experiment was performed with four substrates: two commercial (TRIMIX® and BIOPLANT®) and two substrates formulated from sugarcane bagasse and filter cake (SABAFI and SUSBAFI) combined with bud chip from the basal and apical regions. The chemical and physical-hydric properties of the substrates and the development of PSS were evaluated. The substrates evaluated provided contrasting environments for root growth in relation to the physical-hydric and chemical properties. The use of by-products from the sugarcane industry can be added to the formulation of substrates for the production of pre-sprouted sugarcane seedlings, although the commercial substrate TRIMIX® provides superior performance to the seedlings, regardless of the origin position of the bud chip.

A agroindústria canavieira é grande produtora de resíduos orgânicos, que poderiam ser utilizados como substratos na produção de mudas pré-brotadas de cana-de-açúcar visando a redução de custos de produção e a sustentabilidade do setor sucroalcooleiro. Assim, objetivou-se identificar a melhor posição de origem do minirrebolo para a produção de mudas pré-brotadas de cana-de-açúcar (MPB) e os efeitos de substratos comerciais e alternativos com subprodutos da indústria canavieira na produção de MPB de cana-de-açúcar. Para tanto, realizou-se um experimento fatorial 4x2, sendo quatro substratos: dois comerciais (TRIMIX® e BIOPLANT®) e dois substratos formulados a partir do bagaço da cana e da torta de filtro (SABAFI e SUSBAFI) combinados com minirebolos provenientes da região basal e apical. Avaliaram-se as propriedades químicas e físico-hídricas dos substratos e o desenvolvimento das MPB. Os substratos proporcionaram ambientes de crescimento radicular contrastante em relação às propriedades físicas e químicas. O uso de subprodutos na formulação de substratos para produção de mudas pré-brotadas de cana-de-açúcar pode ser utilizado, embora o substrato comercial TRIMIX® tenha condicionado desempenho superior às mudas, independentemente da posição de origem do minirrebolo.

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In this study, we investigated resistance traits to the sugarcane borer Diatraea saccharalis Fab. (Lepidoptera: Crambidae) in the leaves and stalks of six sugarcane cultivars in a series of greenhouse and laboratory assays. Investigation of plant factors and infestation rates to better discriminate stalk damage by the sugarcane borer indicated that infestation of 7-month-old, single plants with 20 larvae at the third or fourth instar per plant was suitable to assess tunneling length. Three cultivars (i.e. SP803280, RB928064, and RB835486) had lower stalk damage (i.e. tunnel length) than cultivar SP891115, which exhibited relatively greater susceptibility to tunneling by the borer. The time required for the larvae to enter the sugarcane stalk was longer for cultivar SP803280, indicating resistance traits on the stalk surface, which correlated with lower stalk damage. Larvae feeding on SP813250 stalks had the lowest weight gain, indicating that this cultivar has resistance traits to larval development within its stalks. Cultivars RB867515 and SP891115 resulted in the highest mortality of early-stage larvae feeding on leaves, indicating the presence of resistance factors in their leaves. Multi-trait cluster and principal component analyses placed the cultivars into three and four clusters, respectively. The cultivars placed in different groups that exhibited resistance to leaf feeding, stalk entrance, and tunneling by the sugarcane borer could be used for crossings in sugarcane breeding programs with the goal of obtaining higher levels of resistance to D. saccharalis.

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Understanding how host-crop genotypes affect the life history of insect pests is important for developing and using varietal resistance as a pest control measure. Here we determined how wild and cultivated sugarcane genotypes affect key life-history traits and the demographic performance of the root spittlebug, Mahanarva fimbriolata (Stål; Hemiptera: Cercopidae), a major pest of sugarcane, which produces most of the world's sugar and bioethanol. In the greenhouse, plants of four sugarcane genotypes (two wild and two cultivated) were infested with newly-ecloded spittlebug nymphs. A longitudinal life-table experiment was conducted recording developmental time, survival, reproductive output, and longevity of the released spittlebug nymphs. One of the promising sugarcane genotypes was the accession IM76-229 (Saccharum robustum Brandes & Jesw. ex Grassl), which allowed only 20% of nymph survival to adulthood and reduced the spittlebug longevity by 10 d. Such effects on these life-history traits led to a negative intrinsic rate of population growth (rm = -0.002) of the insects, indicating that the test population would eventually go extinct on this sugarcane genotype. An opposite trend (i.e., population growth) was obtained for the insects raised on Saccharum spp. (SP81-3250 and SP80-1816 cultivars) and Erianthus arundinaceus (Retz) Jeswiet (Kawandang genotype). These results show that S. robustum IM76-229 genotype has resistance traits that drastically reduce spittlebug population growth and indicate that it can be used in breeding programs aiming to develop sugarcane cultivars with resistance to spittlebugs.

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Diazotrophs are able to stimulate plant growth. This study aimed at evaluating the effect of inoculation of five diazotrophic strains on growth promotion and nitrate reductase (NR, EC 1.7.1.1) activity in sugarcane. An experiment was carried out from three stages of cultivation: sprouting, tubes, and in hydroponics. On the first two stages, seven treatments were adopted: uninoculated control; mixed inoculation with five strains; and individual inoculation with Gluconacetobacter diazotrophicus (Gd), Herbaspirillum rubrisubalbicans (Hr), Herbaspirillum seropedicae (Hs), Nitrospirillum amazonense (Na), and Paraburkholderia tropica (Pt). The four treatments showing the best performance were transferred to the hydroponic system for analysis of NR activity. Hs, Pt, and the mixture of all strains led to the highest seedling biomass in tubes, followed by Hr. In hydroponics, the mixture and the strain Hr had the highest growth-promoting effect. NR activity was influenced by inoculation only under low N supply conditions, with positive effect of Hr, Pt, and the mixture.

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BACKGROUND: Molecular markers associated with relevant agronomic traits could significantly reduce the time and cost involved in developing new sugarcane varieties. Previous sugarcane genome-wide association analyses (GWAS) have found few molecular markers associated with relevant traits at plant-cane stage. The aim of this study was to establish an appropriate GWAS to find molecular markers associated with yield related traits consistent across harvesting seasons in a breeding population. Sugarcane clones were genotyped with DArT (Diversity Array Technology) and TRAP (Target Region Amplified Polymorphism) markers, and evaluated for cane yield (CY) and sugar content (SC) at two locations during three successive crop cycles. GWAS mapping was applied within a novel mixed-model framework accounting for population structure with Principal Component Analysis scores as random component. RESULTS: A total of 43 markers significantly associated with CY in plant-cane, 42 in first ratoon, and 41 in second ratoon were detected. Out of these markers, 20 were associated with CY in 2 years. Additionally, 38 significant associations for SC were detected in plant-cane, 34 in first ratoon, and 47 in second ratoon. For SC, one marker-trait association was found significant for the 3 years of the study, while twelve markers presented association for 2 years. In the multi-QTL model several markers with large allelic substitution effect were found. Sequences of four DArT markers showed high similitude and e-value with coding sequences of Sorghum bicolor, confirming the high gene microlinearity between sorghum and sugarcane. CONCLUSIONS: In contrast with other sugarcane GWAS studies reported earlier, the novel methodology to analyze multi-QTLs through successive crop cycles used in the present study allowed us to find several markers associated with relevant traits. Combining existing phenotypic trial data and genotypic DArT and TRAP marker characterizations within a GWAS approach including population structure as random covariates may prove to be highly successful. Moreover, sequences of DArT marker associated with the traits of interest were aligned in chromosomal regions where sorghum QTLs has previously been reported. This approach could be a valuable tool to assist the improvement of sugarcane and better supply sugarcane demand that has been projected for the upcoming decades.

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A cana-de-açúcar apresenta ampla área cultivada no estado de São Paulo. Em decorrência das precipitações desuniformes e heterogêneas ao longo do ano, torna-se importante o estudo da irrigação afim de definir um correto manejo hídrico da cultura. A definição da demanda hídrica nas diferentes fases de desenvolvimento da cultura, favorece o desenvolvimento morfofisiológico. O objetivo do presente trabalho foi avaliar parâmetros morfogênicos da cana-de-açúcar RB 86 7515 irrigada durante o desenvolvimento inicial. O experimento foi conduzido em vasos de PVC no campus II da UNOESTE, durante a fase inicial de desenvolvimento vegetativo da cana-de-açúcar. Os tratamentos foram compostos por diferentes lâminas de irrigação (50, 75, 100, 125 e 150% da evapotranspiração da cultura – ETc). As lâminas de irrigação foram calculadas pelo método de Penmam-Monteith recomendado pela FAO. O delineamento experimental se deu em blocos ao acaso,sendo 5 lâminas de irrigação e 5 blocos. Avaliou-se: altura quinzenal das plantas (AP), número de folhas quinzenal (NF), massa seca de parte aérea (MSPA), eficiência da água (EUA), comprimento de raiz (CR) e matéria seca de raiz (MSR). Os parâmetros obtidos foram submetidos a ANOVA e posteriormente ao Teste de Scott-Knott ao nível de probabilidade 5% para comparação de médias. Para os parâmetros biométricos não houve diferença entre as médias obtidas. A lâmina de 50% ETc foi a que apresentou maior eficiência do uso da água. Considerando os parâmetros morfogênico não houve diferenças estatísticas para as lâminas de irrigação estudadas. No entanto, avaliando a relação entre massa seca e lâmina de irrigação aplicada, concluiu-se que 50% ETc resultou na maior eficiência do uso da água.

The sugar cane presents extensive acreage in the State of São Paulo in Brazil. Due to the desuniform and heterogeneous rainfall throughout the year, it is important to the study of irrigation in order to set a correct water management culture. The definition of water demand in the different stages of development of culture, promotes the development morphophisiological. The purpose of this study was to evaluate parameters of morphogenesis of sugar cane RB 86 7515 irrigated during the initial development. The experiment was conducted in PVC pots on campus II UNOESTE, during the initial phase of vegetative development of sugarcane. The treatments were composed of different irrigation blades (50, 75, 100, 125 and 150% of evapotranspiration of culture – ETc). The depths of irrigation were calculated by the method of Penmam-Monteith recommended by FAO. The experimental design in randomized blocks, with 5 depths of irrigation and 5 blocks. Assessed: biweekly height plants (AP), sheet number bi-weekly (NC), dry mass of the shoot (MSPA), water efficiency (USA), length of root (CR) and root dry matter (MSR). The parameters obtained were submitted to ANOVA and later by Scott-Knott test at 5 probability level for comparison of averages. For the biometric parameters there were no differences between the means obtained. The depth of irrigation of 50% ETc was presented the greater efficiency of water use. Considering the parameters morfogênico there was no statistical differences for studied irrigation. However, assessing the relationship between blade and dry mass of irrigation applied, it was concluded that 50% ETc resulted in greater efficiency of water use.

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A cana-de-açúcar apresenta ampla área cultivada no estado de São Paulo. Em decorrência das precipitações desuniformes e heterogêneas ao longo do ano, torna-se importante o estudo da irrigação afim de definir um correto manejo hídrico da cultura. A definição da demanda hídrica nas diferentes fases de desenvolvimento da cultura, favorece o desenvolvimento morfofisiológico. O objetivo do presente trabalho foi avaliar parâmetros morfogênicos da cana-de-açúcar RB 86 7515 irrigada durante o desenvolvimento inicial. O experimento foi conduzido em vasos de PVC no campus II da UNOESTE, durante a fase inicial de desenvolvimento vegetativo da cana-de-açúcar. Os tratamentos foram compostos por diferentes lâminas de irrigação (50, 75, 100, 125 e 150% da evapotranspiração da cultura ETc). As lâminas de irrigação foram calculadas pelo método de Penmam-Monteith recomendado pela FAO. O delineamento experimental se deu em blocos ao acaso,sendo 5 lâminas de irrigação e 5 blocos. Avaliou-se: altura quinzenal das plantas (AP), número de folhas quinzenal (NF), massa seca de parte aérea (MSPA), eficiência da água (EUA), comprimento de raiz (CR) e matéria seca de raiz (MSR). Os parâmetros obtidos foram submetidos a ANOVA e posteriormente ao Teste de Scott-Knott ao nível de probabilidade 5% para comparação de médias. Para os parâmetros biométricos não houve diferença entre as médias obtidas. A lâmina de 50% ETc foi a que apresentou maior eficiência do uso da água. Considerando os parâmetros morfogênico não houve diferenças estatísticas para as lâminas de irrigação estudadas. No entanto, avaliando a relação entre massa seca e lâmina de irrigação aplicada, concluiu-se que 50% ETc resultou na maior eficiência do uso da água.(AU)

The sugar cane presents extensive acreage in the State of São Paulo in Brazil. Due to the desuniform and heterogeneous rainfall throughout the year, it is important to the study of irrigation in order to set a correct water management culture. The definition of water demand in the different stages of development of culture, promotes the development morphophisiological. The purpose of this study was to evaluate parameters of morphogenesis of sugar cane RB 86 7515 irrigated during the initial development. The experiment was conducted in PVC pots on campus II UNOESTE, during the initial phase of vegetative development of sugarcane. The treatments were composed of different irrigation blades (50, 75, 100, 125 and 150% of evapotranspiration of culture ETc). The depths of irrigation were calculated by the method of Penmam-Monteith recommended by FAO. The experimental design in randomized blocks, with 5 depths of irrigation and 5 blocks. Assessed: biweekly height plants (AP), sheet number bi-weekly (NC), dry mass of the shoot (MSPA), water efficiency (USA), length of root (CR) and root dry matter (MSR). The parameters obtained were submitted to ANOVA and later by Scott-Knott test at 5 probability level for comparison of averages. For the biometric parameters there were no differences between the means obtained. The depth of irrigation of 50% ETc was presented the greater efficiency of water use. Considering the parameters morfogênico there was no statistical differences for studied irrigation. However, assessing the relationship between blade and dry mass of irrigation applied, it was concluded that 50% ETc resulted in greater efficiency of water use.(AU)

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En Cuba, entre los esfuerzos por lograr la sostenibilidad en la agricultura se han empleado biopreparados a gran escala, los cuales han tenido un gran impacto económico, ecológico y social. La caña de azúcar constituye uno de los principales cultivos agrícolas para nuestro país y tiene gran importancia desde los puntos de vista económico y ecológico a nivel mundial. En el presente trabajo se demostró el efecto de diferentes fuentes de carbono y nitrógeno en el crecimiento de 5 cepas endófitas de caña de azúcar, 3 de Gluconacetobacter diazotrophicus, una de Bacillus licheniformis y una de Enterobacter agglomerans. De igual forma, se estudió la influencia de jugos provenientes de cinco variedades, así como diferentes concentraciones de las fitohormonas ácido 3 indolacético (AIA) y ácido giberélico (GA) en el crecimiento. Se demostró que la asparagina y el sulfato de amonio como fuentes de nitrógeno adicionadas al medio LGI posibilitan un mayor crecimiento de las bacterias endófitas estudiadas. El medio LGI suplementado con jugo de caña de azúcar favorece significativamente (p≤0,05) el crecimiento de los microorganismos endófitos y no existe relación directa entre el origen varietal del jugo y de las cepas. Por otra parte las fitohormonas en bajas concentraciones favorecieron el crecimiento, no ocurriendo así cuando se encuentran a elevadas concentraciones en el medio de cultivo. Es necesario estudiar todos los factores que pueden influir en la interacción entre la planta y los endófitos para poder utilizar sus potencialidades como promotores del crecimiento vegetal.

Among the efforts done in Cuba to the sustainability in the agricultural system, one of them is the use of bioproducts, which have a relevant economic, ecological and social impact. The sugarcane is one of main crops in our country and it has a great importance at world level. In the present work is demonstrated the effect of different carbon and nitrogen sources in the growth of 5 entophytic bacteria (three of Gluconacetobacter diazotrophicus, one of Bacillus licheniformis and one of Enterobacter agglomerans) were demonstrated. As the same form are studied the influence of juices from five varieties, as well as, different concentrations of fitohormones indole3acetic acid and giberelic acid on the growth. Was demonstrated that asparagine and ammonium sulfate as nitrogen sources added to LGI medium enhance the growth a major growth of the studied endophytic bacteria. The LGI medium supplied with juices of sugarcane enhance the growth of microorganisms (p≤0,05) and don't exist any relationships among the origin of the juice and the strains. On the other hand, the fitohormones at low concentrations don't affect the growth but at high levels of these hormones inhibit the growth. It's necessary to study the factors that have influence on the interaction between the plant and endophytes to use their potentialities as plant growth promoters.

RESUMO

O Brasil se destaca como o maior produtor mundial de cana-de-açúcar e sua produtividade está intimamente relacionada à disponibilidade de água e nitrogênio durante seu desenvolvimento e também à incidência de insetos-praga. Dentre as espécies mais nocivas à cana-de-açúcar no Brasil, destaca-se Mahanarva fimbriolata, a qual tem comprometido seriamente sua produtividade. Nesse contexto, o presente trabalho teve como objetivo avaliar o efeito da fertirrigação nitrogenada sobre a incidência e os danos ocasionados por M. fimbriolata em cana-de-açúcar. O experimento foi composto por cinco tratamentos e quatro repetições em delineamento de blocos casualizados (DBC). Os tratamentos foram constituídos por quatro doses de N-fertilizante e controle (0, 50, 100, 150 e 200 kg.ha-1) em sistema de irrigação por gotejamento. Os parâmetros avaliados foram: número de ninfas nas raízes, produtividade de colmos (TCH), produtividade de açúcar (TPH), açúcar total recuperável (ATR), pol de cana corrigido (PCC) e margem de contribuição agrícola. Foi observado que a produtividade de colmos e de açúcar aumentou com a adubação nitrogenada por meio da irrigação. O uso de 200 kg.ha-1 de N-fertilizante elevou a incidência de M. fimbriolata até os níveis de controle e dano econômico. O maior rendimento financeiro foi obtido com a dose de 150 kg.ha-1 de N-fertilizante.(AU)

Brazil stands out as the world's largest producer of sugarcane and its productivity is closely related to the availability of water and nitrogen during its development and also to the incidence of pest insects. Among the species most harmful to the sugarcane in Brazil, Mahanarva fimbriolata stands out, which has seriously endangered the yields. In this context, the present study aimed to evaluate the effect of the nitrogen fertirrigation on the incidence and damage caused by M. fimbriolata in sugarcane. The experiment was composed of five treatments and four replications in a randomized block design (RBD). The treatments were composed of four doses of N-fertilizer and control (0, 50, 100, 150, 200 kg.ha-1) in drip irrigation system. The parameters evaluated were: number of nymphs in the roots, stalk productivity, sugar content, percentage of sugar, total recoverable sugar and the agricultural contribution margin. It was observed that the fertirrigation increases the productivity of stalks and sugar with the increase of nitrogen fertilization by irrigation. The use of 200 kg.ha-1 of N-fertilizer increased the incidence of M. fimbriolata up to the control and economic damage levels. The biggest financial yield was obtained with the dose of 150 kg.ha-1 of N-fertilizer.(AU)

Assuntos

RESUMO

Brazil stands out as the worlds largest producer of sugarcane and its productivity is closely related to the availability of water and nitrogen during its development and also to the incidence of pest insects. Among the species most harmful to the sugarcane in Brazil, Mahanarva fimbriolata stands out, which has seriously endangered the yields. In this context, the present study aimed to evaluate the effect of the nitrogen fertirrigation on the incidence and damage caused by M. fimbriolata in sugarcane. The experiment was composed of five treatments and four replications in a randomized block design (RBD). The treatments were composed of four doses of N-fertilizer and control (0, 50, 100, 150, 200 kg.ha-1) in drip irrigation system. The parameters evaluated were: number of nymphs in the roots, stalk productivity, sugar content, percentage of sugar, total recoverable sugar and the agricultural contribution margin. It was observed that the fertirrigation increases the productivity of stalks and sugar with the increase of nitrogen fertilization by irrigation. The use of 200 kg.ha-1 of N-fertilizer increased the incidence of M. fimbriolata up to the control and economic damage levels. The biggest financial yield was obtained with the dose of 150 kg.ha-1 of N-fertilizer.

O Brasil se destaca como o maior produtor mundial de cana-de-açúcar e sua produtividade está intimamente relacionada à disponibilidade de água e nitrogênio durante seu desenvolvimento e também à incidência de insetos-praga. Dentre as espécies mais nocivas à cana-de-açúcar no Brasil, destaca-se Mahanarva fimbriolata, a qual tem comprometido seriamente sua produtividade. Nesse contexto, o presente trabalho teve como objetivo avaliar o efeito da fertirrigação nitrogenada sobre a incidência e os danos ocasionados por M. fimbriolata em cana-de-açúcar. O experimento foi composto por cinco tratamentos e quatro repetições em delineamento de blocos casualizados (DBC). Os tratamentos foram constituídos por quatro doses de N-fertilizante e controle (0, 50, 100, 150 e 200 kg.ha-1) em sistema de irrigação por gotejamento. Os parâmetros avaliados foram: número de ninfas nas raízes, produtividade de colmos (TCH), produtividade de açúcar (TPH), açúcar total recuperável (ATR), pol de cana corrigido (PCC) e margem de contribuição agrícola. Foi observado que a produtividade de colmos e de açúcar aumentou com a adubação nitrogenada por meio da irrigação. O uso de 200 kg.ha-1 de N-fertilizante elevou a incidência de M. fimbriolata até os níveis de controle e dano econômico. O maior rendimento financeiro foi obtido com a dose de 150 kg.ha-1 de N-fertilizante.

Assuntos

RESUMO

Brazil stands out as the world's largest producer of sugarcane and its productivity is closely related to the availability of water and nitrogen during its development and also to the incidence of pest insects. Among the species most harmful to the sugarcane in Brazil, Mahanarva fimbriolata stands out, which has seriously endangered the yields. In this context, the present study aimed to evaluate the effect of the nitrogen fertirrigation on the incidence and damage caused by M. fimbriolata in sugarcane. The experiment was composed of five treatments and four replications in a randomized block design (RBD). The treatments were composed of four doses of N-fertilizer and control (0, 50, 100, 150, 200 kg.ha-1) in drip irrigation system. The parameters evaluated were: number of nymphs in the roots, stalk productivity, sugar content, percentage of sugar, total recoverable sugar and the agricultural contribution margin. It was observed that the fertirrigation increases the productivity of stalks and sugar with the increase of nitrogen fertilization by irrigation. The use of 200 kg.ha-1 of N-fertilizer increased the incidence of M. fimbriolata up to the control and economic damage levels. The biggest financial yield was obtained with the dose of 150 kg.ha-1 of N-fertilizer.

O Brasil se destaca como o maior produtor mundial de cana-de-açúcar e sua produtividade está intimamente relacionada à disponibilidade de água e nitrogênio durante seu desenvolvimento e também à incidência de insetos-praga. Dentre as espécies mais nocivas à cana-de-açúcar no Brasil, destaca-se Mahanarva fimbriolata, a qual tem comprometido seriamente sua produtividade. Nesse contexto, o presente trabalho teve como objetivo avaliar o efeito da fertirrigação nitrogenada sobre a incidência e os danos ocasionados por M. fimbriolata em cana-de-açúcar. O experimento foi composto por cinco tratamentos e quatro repetições em delineamento de blocos casualizados (DBC). Os tratamentos foram constituídos por quatro doses de N-fertilizante e controle (0, 50, 100, 150 e 200 kg.ha-1) em sistema de irrigação por gotejamento. Os parâmetros avaliados foram: número de ninfas nas raízes, produtividade de colmos (TCH), produtividade de açúcar (TPH), açúcar total recuperável (ATR), pol de cana corrigido (PCC) e margem de contribuição agrícola. Foi observado que a produtividade de colmos e de açúcar aumentou com a adubação nitrogenada por meio da irrigação. O uso de 200 kg.ha-1 de N-fertilizante elevou a incidência de M. fimbriolata até os níveis de controle e dano econômico. O maior rendimento financeiro foi obtido com a dose de 150 kg.ha-1 de N-fertilizante.

RESUMO

Brazil stands out as the worlds largest producer of sugarcane and its productivity is closely related to the availability of water and nitrogen during its development and also to the incidence of pest insects. Among the species most harmful to the sugarcane in Brazil, Mahanarva fimbriolata stands out, which has seriously endangered the yields. In this context, the present study aimed to evaluate the effect of the nitrogen fertirrigation on the incidence and damage caused by M. fimbriolata in sugarcane. The experiment was composed of five treatments and four replications in a randomized block design (RBD). The treatments were composed of four doses of N-fertilizer and control (0, 50, 100, 150, 200 kg.ha-1) in drip irrigation system. The parameters evaluated were: number of nymphs in the roots, stalk productivity, sugar content, percentage of sugar, total recoverable sugar and the agricultural contribution margin. It was observed that the fertirrigation increases the productivity of stalks and sugar with the increase of nitrogen fertilization by irrigation. The use of 200 kg.ha-1 of N-fertilizer increased the incidence of M. fimbriolata up to the control and economic damage levels. The biggest financial yield was obtained with the dose of 150 kg.ha-1 of N-fertilizer.(AU)

O Brasil se destaca como o maior produtor mundial de cana-de-açúcar e sua produtividade está intimamente relacionada à disponibilidade de água e nitrogênio durante seu desenvolvimento e também à incidência de insetos-praga. Dentre as espécies mais nocivas à cana-de-açúcar no Brasil, destaca-se Mahanarva fimbriolata, a qual tem comprometido seriamente sua produtividade. Nesse contexto, o presente trabalho teve como objetivo avaliar o efeito da fertirrigação nitrogenada sobre a incidência e os danos ocasionados por M. fimbriolata em cana-de-açúcar. O experimento foi composto por cinco tratamentos e quatro repetições em delineamento de blocos casualizados (DBC). Os tratamentos foram constituídos por quatro doses de N-fertilizante e controle (0, 50, 100, 150 e 200 kg.ha-1) em sistema de irrigação por gotejamento. Os parâmetros avaliados foram: número de ninfas nas raízes, produtividade de colmos (TCH), produtividade de açúcar (TPH), açúcar total recuperável (ATR), pol de cana corrigido (PCC) e margem de contribuição agrícola. Foi observado que a produtividade de colmos e de açúcar aumentou com a adubação nitrogenada por meio da irrigação. O uso de 200 kg.ha-1 de N-fertilizante elevou a incidência de M. fimbriolata até os níveis de controle e dano econômico. O maior rendimento financeiro foi obtido com a dose de 150 kg.ha-1 de N-fertilizante.(AU)

Assuntos

RESUMO

Brazil stands out as the world's largest producer of sugarcane and its productivity is closely related to the availability of water and nitrogen during its development and also to the incidence of pest insects. Among the species most harmful to the sugarcane in Brazil, Mahanarva fimbriolata stands out, which has seriously endangered the yields. In this context, the present study aimed to evaluate the effect of the nitrogen fertirrigation on the incidence and damage caused by M. fimbriolata in sugarcane. The experiment was composed of five treatments and four replications in a randomized block design (RBD). The treatments were composed of four doses of N-fertilizer and control (0, 50, 100, 150, 200 kg.ha-1) in drip irrigation system. The parameters evaluated were: number of nymphs in the roots, stalk productivity, sugar content, percentage of sugar, total recoverable sugar and the agricultural contribution margin. It was observed that the fertirrigation increases the productivity of stalks and sugar with the increase of nitrogen fertilization by irrigation. The use of 200 kg.ha-1 of N-fertilizer increased the incidence of M. fimbriolata up to the control and economic damage levels. The biggest financial yield was obtained with the dose of 150 kg.ha-1 of N-fertilizer.

O Brasil se destaca como o maior produtor mundial de cana-de-açúcar e sua produtividade está intimamente relacionada à disponibilidade de água e nitrogênio durante seu desenvolvimento e também à incidência de insetos-praga. Dentre as espécies mais nocivas à cana-de-açúcar no Brasil, destaca-se Mahanarva fimbriolata, a qual tem comprometido seriamente sua produtividade. Nesse contexto, o presente trabalho teve como objetivo avaliar o efeito da fertirrigação nitrogenada sobre a incidência e os danos ocasionados por M. fimbriolata em cana-de-açúcar. O experimento foi composto por cinco tratamentos e quatro repetições em delineamento de blocos casualizados (DBC). Os tratamentos foram constituídos por quatro doses de N-fertilizante e controle (0, 50, 100, 150 e 200 kg.ha-1) em sistema de irrigação por gotejamento. Os parâmetros avaliados foram: número de ninfas nas raízes, produtividade de colmos (TCH), produtividade de açúcar (TPH), açúcar total recuperável (ATR), pol de cana corrigido (PCC) e margem de contribuição agrícola. Foi observado que a produtividade de colmos e de açúcar aumentou com a adubação nitrogenada por meio da irrigação. O uso de 200 kg.ha-1 de N-fertilizante elevou a incidência de M. fimbriolata até os níveis de controle e dano econômico. O maior rendimento financeiro foi obtido com a dose de 150 kg.ha-1 de N-fertilizante.