Guignardia citricarpa , the causal agent of citrus black spot, forms airborne ascospores on decomposing leaves and water‐spread conidia fruits, twigs. The spatial pattern diseased fruit in tree canopies was used to assess importance spot epidemics São Paulo State, Brazil. aggregation canopy quantified by binomial dispersion index ( D ) binary form Taylor's Power Law for 303 trees six groves. significantly greater than 1 251 trees. intercept regression line 0 slope not different from 1,...

The constitutive characters of plants can be structural or biochemical and play an important role in their defence against pathogens. Citrus postbloom fruit drop (PFD) caused by Colletotrichum spp. is one the most fungal diseases citrus. pathogen infects flowers, leading to premature reducing citrus production. However, flower buds smaller than 8 mm long are usually not infected Thus, this study investigated whether there mechanisms related infection. We studied that were 2, 3, 4, 8, 12 15...

Anthracnose is an important disease in vineyards south and southeast Brazil, the main grape‐producing regions country. This study aimed to identify causal agents of grapevine anthracnose Brazil through multilocus phylogenetic analyses, morphological characterization pathogenicity tests. Thirty‐nine Elsinoë ampelina 13 Colletotrichum spp. isolates were obtained from leaves, stems berries with symptoms collected 38 southern southeastern Brazil. For E. isolates, internal transcribed spacer (...

Uma escala diagramática, abrangendo os dois tipos prevalentes de sintomas mancha preta em frutos cítricos (Citrus spp.), dura e falsa melanose, foi desenvolvida para padronizar a avaliação da severidade doença. A elaborada considerando limites máximos mínimos doença observados no campo. Os valores intermediários seguiram incrementos logarítmicos do tipo (0,5; 1,7; 5,0; 11,5; 22,5 49,0%) melanose (1,1; 4,5; 15,0; 31,0; 53,0 68,0%). Para validação escala, seis avaliadores quantificaram partir...

Citrus black spot (CBS), caused by Guignardia citricarpa, is the most important fungal disease of orange trees in Brazil. The spatial pattern CBS-symptomatic was evaluated using binomial dispersion index (D), Ripley's K function (K), and a Monte Carlo test for minimum mean distance (d) to understand distribution pathogen. Disease monitored 7,790 citrus from four commercial groves. In one grove, incidence assessed 1999 2001 and, others, assessments were conducted only 2002. Infected...

Citrus postbloom fruit drop ( PFD ) is caused by C olletotrichum acutatum and . gloeosporioides These pathogens attack the flowers cause premature retention of calyces. This study was designed to characterize spatial temporal dynamics in commercial citrus‐growing areas better understand disease spread. Experiments were carried out three young orchards (500 trees each) two municipalities Sao Paulo State, B razil. Symptoms on presence persistent calyces assessed each for years. Logistic,...

Escalas diagramáticas são importantes ferramentas na avaliação da severidade de doenças. Objetivando padronizar a estimativa do cancro cítrico em folhas citros (Citrus sinensis) causada por Xanthomonas axonopodis pv. citri, foram elaboradas quatro escalas diagramáticas, considerando ocorrência lesões isoladas pequenas (LP), médias (LM) e grandes (LG) associadas com o ataque larva minadora dos (LMC). Cada escala possui oito níveis porcentagens área foliar lesionada: 0,2 16% para LP; 0,6 25%...

Abstract Anthracnose caused by Elsinoë ampelina is one of the most important table grape diseases in humid regions Brazil and Australia. The objective this study was to characterize E. isolates from Australia means phylogenetic analyses, morphological features pathogenicity tests. Phylogenetic relationships among 35 were determined based on a data set internal transcribed spacer ( ITS ), histone H3 HIS 3) elongation factor 1‐α TEF ) sequences. In tree using combined sequence alignment, all...

Abstract Over the last 10 years, global raspberry production has increased by 47.89%, based mainly on red species (Rubus idaeus). However, black occidentalis), although less consumed, is resistant to one of most important diseases for crop, late leaf rust caused Acculeastrum americanum fungus. In this context, genetic resistance sustainable way control disease, because there are no registered fungicides in Brazil. Therefore, aim was understand architecture that controls raspberries. For...

Brazilian exports of fresh citrus represent less than 1% the overall production. Phytosanitary barriers and poor appearance stand out among several reasons contributing to such low exporting/production ratio. The purpose this work was characterize postharvest injuries in 'Valencia' sweet oranges 'Murcott' tangors produced for foreign markets after different processing stages a packinghouse, as well identify critical points impact extent on packing lines. Sampling performed both pre-washing...

Postbloom fruit drop ( PFD ) is an important citrus disease that causes up to 100% yield losses during years in which conditions are favourable for the occurrence of epidemics. The conidia Colletotrichum acutatum and C. gloeosporioides , causal agents predominantly dispersed by rain splash. At beginning epidemics, distribution diseased plants random progress rate very high, unusual pathogens spread As pathogen produces abundant on petals, pollinating insects may contribute dispersal. This...

The endophyte Guignardia mangiferae is closely related to G. citricarpa, the causal agent of citrus black spot; for many years these species had been confused with each other. development molecular analytical methods has allowed differentiation pathogen citricarpa from mangiferae, but physiological traits associated pathogenicity were not described. We examined genetic and enzymatic characteristics spp strains; produces significantly greater amounts amylases, endoglucanases pectinases,...

A mancha preta dos citros (Citrus spp.), causada por Guignardia citricarpa, vem causando sérios prejuízos à citricultura paulista. O parque citrícola está alicerçado em praticamente quatro variedades de copa laranja doce sinensis): 'Hamlin', 'Pera', 'Valência' e 'Natal'. literatura cita as tardias ('Valência' 'Natal') como mais suscetíveis, razão da elevada severidade doença nos frutos dessas ocasião colheita, mas não há informações sobre o progresso temporal no campo. resistência das...

Citrus sudden death (CSD) has greatly affected sweet orange cultivars grafted on Rangpur lime in São Paulo and Minas Gerais States, Brazil. To characterize quantify CSD damage, fruit yield quality were assessed each combination of cultivar (Hamlin, Pera, Natal, Valencia), age class (3 to 5, 6 10, 11 15 years old), severity (0 = no symptom, 1 initial symptoms, 2 severe symptoms). For combination, 10 trees harvested 20 taken for analysis. Damage was characterized by reduction of: (i) total...

Raspberries (Rubus spp) are temperate climate fruits with profitable high returns and have the potential for diversification of fruit growing in mid to low-latitude regions. However, there still no cultivars adapted climatic conditions pressure diseases that occurs tropical areas. In this context, our objective was evaluate genetic diversity from a 116 raspberry genotypes panel obtained interspecific crosses testcross scheme four already introduced Brazil. The genotyped via...

O objetivo deste trabalho foi avaliar a resistência de Guignardia citricarpa aos fungicidas carbendazim e piraclostrobina, por meio avaliação do crescimento em cultura, decomposição tecido foliar produção corpos frutificação. Para isso, o fungo G. isolado lesões frutos laranja (Citrus sinensis), produzidos área com intensa aplicação fungicida. Os isolados obtidos foram avaliados quanto à sensibilidade piraclostrobina carbendazim, nas dosagens 0,5, 1 2 µg mL-1 i.a., para se verificar efeito...