Nitrogen and potassium fertilization on the yield and intensity of the maize white spot.

ABSTRACT - A plant’s nutritional balance can influence its resistance to diseases. In order to evaluate the effect of increasing doses of N and K on the yield and severity of the maize white spot, two experiments were installed in the field, one in the city of Ijaci, Minas Gerais, and the other in the city of Sete Lagoas, Minas Gerais. The experimental delimitation was in randomized blocks with 5 x 5 factorial analysis of variance, and four repetitions. The treatments consisted of five doses of N (20; 40; 80; 150; 190 Kg ha-1 of N in the experiments 1 and 2) and five doses of K (15; 30; 60; 120; 180 Kg ha-1 of K in experiment 1 and 8.75; 17.5; 35; 50; 100 Kg ha-1 of K in experiment 2). The susceptible cultivar 30P70 was planted in both experiments. The plot consisted of four rows 5 meters long, with a useful area consisting of two central rows 3 meters each. Evaluations began 43 days after emergence (DAE) in the first experiment and 56 DAE in the second one. There was no significant interaction between doses of N and K and the disease progress. The effect was only observed for N. The K did not influence the yield and the severity of the disease in these experiments. Bigger areas below the severity progress curve of the white spot and better yield were observed with increasing doses of N. Thus, with increasing doses of N, the white spot increased and also did the yield. RESUMO - O equilíbrio nutricional de plantas pode influenciar a resistência a doenças. Com o objetivo de avaliar o efeito de doses crescentes de N e de K na produtividade e na severidade da mancha branca do milho, foram instalados em campo, dois experimentos, um em Ijaci, MG e o outro em Sete Lagoas, MG. O delineamento experimental foi em blocos casualizados com esquema de análise de variância fatorial 5 x 5 e quatro repetições. Os tratamentos consistiram de 5 doses de N (20; 40; 80; 150; 190 Kg ha-1 de N nos experimentos 1 e 2) e de 5 doses de K (15; 30; 60; 120; 180 Kg ha-1 de K no experimento 1 e 8,75; 17,5; 35; 50; 100 Kg ha-1 de K no experimento 2). Foi plantado nos dois experimentos o cultivar suscetível 30P70. As parcelas foram constituídas de quatro fileiras de 5 m de comprimento, sendo a área útil composta por duas linhas centrais com 3 m cada. As avaliações iniciaram-se aos 43 dias após emergência (DAE) no primeiro e aos 56 DAE, no segundo experimento. Não houve interação significativa entre as doses de N e de K e o progresso da doença. O efeito foi observado apenas para o N. O K não influenciou a produtividade e a severidade da doença nesses experimentos. Observaram-se maiores áreas abaixo da curva de progresso da severidade da mancha branca e maior produtividade com o aumento das doses de N. Sendo assim, com o aumento das doses de N houve aumento da mancha branca do milho e também da produtividade

Cercosporin production by Cercospora coffeicola isolates: spectrophotometry and HPLC quantification and image analysis

Cercosporin has excellent properties of photosensitization that have been widely used in organophotocatalyst and photodynamic therapy as well as an antimicrobial agent. Therefore, there is a need to quantify it accurately with accessible methods. A comparative analysis of cercosporin quantification obtained by spectrophotometry (SPEC) and high-performance liquid chromatography (HPLC) was performed for nineteen Cercospora coffeicola isolates from different coffee-producing municipalities in Brazil. Image analysis of cercosporin crystals was performed in isolates with either high or low production of the toxin. Our results show that SPEC and HPLC are equally valid for the cercosporin evaluation of C. coffeicola cultures grown in vitro. The isolates with high cercosporin production had a higher crystal number and size when compared to the one with low cercosporin productioninfo:eu-repo/semantics/publishedVersio

Characterization of \u3cem\u3eGlomerella\u3c/em\u3e Strains Recovered from Anthracnose Lesions on Common Bean Plants in Brazil

Anthracnose caused by Colletotrichum lindemuthianum is an important disease of common bean, resulting in major economic losses worldwide. Genetic diversity of the C. lindemuthianum population contributes to its ability to adapt rapidly to new sources of host resistance. The origin of this diversity is unknown, but sexual recombination, via the Glomerella teleomorph, is one possibility. This study tested the hypothesis that Glomerella strains that are frequently recovered from bean anthracnose lesions represent the teleomorph of C. lindemuthianum. A large collection of Glomerella isolates could be separated into two groups based on phylogenetic analysis, morphology, and pathogenicity to beans. Both groups were unrelated to C. lindemuthianum. One group clustered with the C. gloeosporioides species complex and produced mild symptoms on bean tissues. The other group, which belonged to a clade that included the cucurbit anthracnose pathogen C. magna, caused no symptoms. Individual ascospores recovered from Glomerella perithecia gave rise to either fertile (perithecial) or infertile (conidial) colonies. Some pairings of perithecial and conidial strains resulted in induced homothallism in the conidial partner, while others led to apparent heterothallic matings. Pairings involving two perithecial, or two conidial, colonies produced neither outcome. Conidia efficiently formed conidial anastomosis tubes (CATs), but ascospores never formed CATs. The Glomerella strains formed appressoria and hyphae on the plant surface, but did not penetrate or form infection structures within the tissues. Their behavior was similar whether the beans were susceptible or resistant to anthracnose. These same Glomerella strains produced thick intracellular hyphae, and eventually acervuli, if host cell death was induced. When Glomerella was co-inoculated with C. lindemuthianum, it readily invaded anthracnose lesions. Thus, the hypothesis was not supported: Glomerella strains from anthracnose lesions do not represent the teleomorphic phase of C. lindemuthianum, and instead appear to be bean epiphytes that opportunistically invade and sporulate in the lesions

Inventarisasi Penyakit Tanaman Pisang Koleksi Kebun Plasma Nutfah, Cibinong Science Center-BG

Kebun Plasma Nutfah Pisang Cibinong Science Center (CSC) merupakan koleksi pisang ha-sil dari eksplorasi ke seluruh wilayah Indonesia. Koleksi ini kemudian diperbanyak untuk pe-nelitian lebih lanjut. Dalam proses pengelolaannya monitoring kesehatan tanaman pisang per-lu dilakukan untuk meningkatkan kualitas koleksi tersebut. Untuk keperluan tersebut dilaku-kan inventarisasi terhadap jenis-jenis penyakit yang menyerang tanaman koleksi, dengan ha-rapan untuk mempertahankan kualitasnya sebagai bahan dasar penelitian lebih lanjut. Pe-nelitian diawali dengan (1) Identifikasi kerusakan tanaman pisang dengan menggunakan hasil modifikasi metode Forest Health Monitoring (FHM), kemudian dilanjutkan dengan (2) me-ngukur intensitas serangan dan luas serangan pada tanaman pisang. Hasil penelitian menun-jukkan bahwa koleksi pisang di kebun plasma nutfah CSC terserang penyakit Layu Fusarium (2,9%), penyakit bercak Cordana (2%), penyakit Black Sigatoka (5,62%) dan penyakit Yel-low Sigatoka (4,68%). Luas serangan terjadinya penyakit sebesar 30,89%

Produção de tomateiro orgânico irrigado por aspersão e gotejamento, em cultivo solteiro e consorciado com coentro.

O uso eficiente da água e a diversificação ambiental são fundamentais para o equilíbrio e a sustentabilidade dos sistemas orgânicos de produção de tomate. O presente estudo teve por objetivo avaliar a produção de tomate de mesa em cultivo solteiro e consorciado com coentro com irrigação por aspersão e gotejamento, em sistema orgânico. O experimento foi conduzido em área de produção orgânica no Distrito Federal. O delineamento foi blocos ao acaso, com tratamentos dispostos num arranjo fatorial 2 x 2 (dois sistemas de irrigação x dois sistemas de cultivo). Não houve interação significativa entre os fatores avaliados, assim como não houve efeito do sistema de cultivo sobre as variáveis avaliadas. Embora o ciclo do tomateiro irrigado por gotejamento tenha diminuído, a produtividade de frutos não foi afetada pelos sistemas de irrigação. A maior redução de estande verificada na aspersão foi compensada por um aumento no número de frutos por planta, sem variação na massa por fruto. O menor volume de solo explorado pelas raízes do tomateiro associado à maior incidência de traça-o-tomateiro (Tuta absoluta) e principalmente de oídio (Leveillula taurica) pode ter limitado a produtividade do tomateiro irrigado por gotejamento. A taxa de frutos podres na aspersão foi o dobro da verificada no sistema por gotejamento

Foliar fortification of Copper (Cu) in Glycine max L. for the protection against Asian Soybean Rust (Phakopsora pachyrhizi Syd. & P.Syd.)

The Asian Soybean Rust caused by the fungus Phakopsora pachyrhizi is one of the serious phytosanitary problems faced by soybean [Glycine max (L.) Merrill], which cause up to 80% yield loss. An alternative for the integrated management of the disease is the use of mineral nutrition together with phytosanitary treatments. Thus, the objective of this study is to understand the effect of foliar fortification with copper (Cu) along with phytosanitary treatments in the soybean reaction to Rust by lignin content variation in leaf tissues, and how it reflects the yield. The experimental design was a randomized block with four replicates. Four concentrations Cu (30, 60, 90, 120 g Cu ha-1) were tested in two distinct sources (cuprous oxide and copper carbonate) together with phytosanitary treatments. Evaluations were made to determine the progression of Asian Rust severity, micronutrient content in leaves and grains, as well as lignin content in leaves. The grain yield components and productivity were also evaluated. The Cu contents in the soybean leaves and grains were influenced by foliar spraying. Foliar spray with Cu retarded the disease progression, reducing the severity of Asian Rust and positively impacting grain yield. The amount of lignin present in the leaves was altered considerably with the application of the Cu associated with phytosanitary treatments. The results suggest that the leaf nutrition with copper together with phytosanitary treatments, may reduce the rust severity and improvement the plant performance. Future research with Cu application and analysis of specific enzymes, secondary metabolites and cell wall thickness may further contribute to the understanding of the role of Cu in defence against Asian Soybean Rust

Adubação nitrogenada e potássica na severidade da antracnose em dois cultivares de milho.

O equilíbrio nutricional pode contribuir para a resistência das plantas às doenças. Com o objetivo de avaliar o efeito da interação entre as adubações nitrogenada e potássica na severidade das lesões da antracnose foliar e na nutrição mineral da cultura do milho, foram instalados dois experimentos, em casa de vegetação com dois cultivares, o DAS 2B71O (moderadamente resistente à doença) e o BRS 1010 (susceptível), cinco doses de N (75,150,300,600 e 1200 mg dm') e cinco doses de K 63,125,250,500 e 1000 mg dm'). O delineamento experimental para cada cultivar foi em blocos inteiramente ao acaso, em esquema fatorial5 x 5, com 25 tratamentos e quatro repetições. Cada vaso com quatro plantas constituiu uma parcela experimental. As doses de N e K foram divididas em quatro parcelas, com intervalos de dez dias a partir da semeadura, para os dois cultivares. Aos 21 dias após a semeadura, as plantas foram inoculadas e levadas para câmara úmida, com fotoperíodo de 16 horas, no escuro durante três dias consecutivos. Avaliou-se a severidade das lesões diariamente, até 11 dias após a inoculação. Aos 43 dias após a semeadura, a parte aérea das plantas foi colhida, secada e moída para determinar os teores de N e de K. A quantidade de área foliar lesionada dependeu da interação entre os nutrientes. Em ambos os cultivares, os menores valores de severidade foram observados na menor dose de N, combinada com a maior dose de K. A severidade das lesões observada no cultivar moderadamente resistente foi 41 % menor que a observada no cultivar susceptível. A adubação nitrogenada influenciou de forma negativa o teor de K da parte aérea

Manganese phosphite in Coffee defence against Hemileia vastatrix, the coffee rust fungus: biochemical and molecular analyses.

Phosphites (Phi) are inorganic salts of phosphorous acid that have been used as resistance elicitors to activate mechanisms underlying plant defence. This study assessed the effectiveness of manganese phosphite (MnPhi) for the management of rust (Hemileia vastatrix) on coffee seedlings. The effect of this compound on the induction of resistance was also measured by the expression of defence-related genes such as POX (peroxidase), CAT (catalase), GLU (b-1.3-glucanase) and PAL (phenylalanine ammonia-lyase) and by the activity of defence enzymes such as ascorbate peroxidase (APX), superoxide dismutase (SOD) and polyphenol oxidase (PPO). Foliar sprayings of MnPhi on coffee seedlings provided 63% control of rust severity. This compound induced defence responses in seedlings with increased transcription of genes POX, CAT, GLU and PAL in non-inoculated plants and increased activity of APX, SOD and PPO enzymes in plants inoculated with H. vastatrix and in non-inoculated plants. It is suggested that MnPhi can induce resistance in coffee seedlings

Severidade do oídio em feijão-caupi sob diferentes temperaturas.

Suplemento. Edição dos Anais do 52 Congresso Brasileiro de Olericultura, Salvador, jul. 2012

The Inferto-Sex Syndrome (ISS): sexual dysfunction in fertility care setting and assisted reproduction

Purpose Infertility represents a peculiar social burden affecting more than 15% of couples, provoking it a real threat to the general quality of life and to the sexual health. The medicalization (diagnosis, therapy and follow up) of the lack of fertility is frequently a challenge in term of personal and couple's involvement. In particular, while the Assisted Reproductive Technology (ART) has allowed many infertile couples to achieve pregnancy, the therapeutic process faced by the couple bears a strong psychological stress that can affect the couple's quality of life, relationship and sexuality. Despite infertility affects both female and male sexual health, only recently the interest in the effects of ART on the couple's sexuality has grown, especially for women. Methods A literature research on the sexual dysfunction in fertility care and particularly in ART setting was performed. Results Literature largely found that intimacy and sexuality appear specifically impaired by intrusiveness of treatments and medical prescriptions. Moreover, there is a close relationship between emotional, psychological and sexual aspects, which can be integrated in the new concept of Inferto-Sex Syndrome (ISS) that can impair the ART treatment outcomes. Evidence demonstrates that the assessment of sexual function is necessary in couples undergoing diagnosis of infertility and ART. Conclusion A close relationship between infertility and sexuality, both in the female and male partners, was detected. ART treatments may heavily impact on the couple's psychosexual health. A couple-centred program for the integrated management of psychological and sexual dysfunction should be considered in the context of ART programs