104 research outputs found
Adaptabilidade de linhagens de Botrytis squamosa resistentes a fungicidas do grupo dos benzimidazois e dicarboximidas.
A adaptabilidade de linhagens resistentes a benomyl, iprodione, duplo-resistentes e sensĂveis de Botrytis squamosa, causador da Queima das Pontas da cebola, foi estudada atravĂ©s do crescimento micelial, produção de conĂdios, patogenicidade e competição in vitro e in vivo. As linhagens de B. squamosa resistentes a benomyl podem ser tĂŁo adaptadas quanto as sensĂveis, ao passo que as resistentes a iprodione apresentaram-se menos adaptadas. As resistĂȘncias a benomyl e a benomyl + iprodione mostraram-se instĂĄveis, visto que permaneceram inalteradas apĂłs cinco geraçÔes de transferĂȘncias monospĂłricas na ausĂȘncia dos fungicidas. Isolados tanto sensĂveis quanto resistentes aos fungicidas benomyl e iprodione se anastomosaram livremente, exceto o isolado Pd 64, resisten-te a benomyl. O nĂșmero de nĂșcleos/conĂdio em duas linhagens (uma sensĂvel e a outra resistente a benomyl) foi determinado, nĂŁo tendo sido constatadas diferenças; ambas apresentaram ate 20 nĂșcleos/conĂdio
Organic and conventional tomato cropping systems.
Among several alternative agricultural systems have been developed, organic agriculture has deserved increasing interest from. The objective of this paper was comparing both organic (OS) and conventional (CS) tomato cropping systems for varieties DĂ©bora and Santa Clara, through an interdisciplinary study. The experiment was set up in a randomized blocks design with six replicates, in a dystrophic Ultisol plots measuring 25 ÂŽ 17 m. Cropping procedures followed by either local conventional or organic growers practices recommendations. Fertilization in the OS was done with organic compost, single superphosphate, dolomitic limes (5L, 60 g, and 60 g per pit), and sprayed twice a week with biofertilizer. Fertilization in the CS was done with 200 g 4-14-8 (NPK) per pit and, after planting, 30 g N, 33 g K and 10.5 g P per pit; from 52 days after planting forth, plants were sprayed once a week with foliar fertilizer. In the CS, a blend of insecticides, fungicides and miticides was sprayed twice a week, after planting. In the OS, extracts of black pepper, garlic, and Eucalyptus; Bordeaux mixture, and biofertilizer, were applied twice a week to control diseases and pests. Tomato spotted wilt was the most important disease in the OS, resulting in smaller plant development, number of flower clusters and yield. In the CS, the disease was kept under control, and the population of thrips, the virus vector, occurred at lower levels than in the OS. Variety Santa Clara presented greater incidence of the viral disease, and for this reason had a poorer performance than 'DĂ©bora', especially in the OS. Occurrence of Liriomyza spp. was significantly smaller in the OS, possibly because of the greater frequency of Chrysoperla. The CS had smaller incidence of leaf spots caused by Septoria lycopersici and Xanthomonas vesicatoria. However, early blight and fruit rot caused by Alternaria solani occurred in larger numbers. No differences were observed with regard to the communities of fungi and bacteria in the phylloplane, and to the occurrence of weeds
Ensaio sobre o controle de "damping-off' do cafeeiro
Testes de 3 fungicidas-Vapam, PCNB e Cupravit - foram conduzidos em 2 tipos de substrato, visando controlar "damping-off" do cafeeiro. Os substratos se comportaram de maneira diferente quanto ao nĂșmero de plantas sadias obtidas. Os fungicidas agiram de maneira diferente em diferentes substratos. No substrato A os fungicidas diferiram na sua ação protetora enquanto que no solo B, nĂŁo. No resultado finai, alguns tratamentos se mostraram superiores que outros
EFEITO DE DIFERENTES FUNGICIDAS E DOSES NO CONTROLE DA ANTRACNOSE DA VIDEIRA (ELSINOE AMPELINA)
Mycobiota evolution during storage of paddy, brown and milled rice in different genotypes
Intensidade de doenças foliares, produtividade, massa de mil grĂŁos e grĂŁos manchados em resposta ao nĂșmero de aplicaçÔes de fungicida no cultivar de arroz irrigado SCS 116 Satoru
Intensidade de ataque de tripes, de alternaria e da queima-das-pontas em cultivares de cebola
Seleção de porta-enxertos resistentes ao cancro da haste e seus efeitos na produtividade de melĂŁo 'BĂŽnus nÂș 2'
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