ABSTRACT It is necessary to diversify the scion/rootstock combinations for Persian lime cultivation, notably under tropical rainfed conditions. Therefore, in this work we evaluated the performance of a new cultivar, BRS EECB IAC Ponta Firme, up to six years after planting on 26 citrus rootstocks under Aw climate in northern São Paulo state, Brazil. Thirty single-tree randomized replications of each rootstock were evaluated without irrigation at 1,000 trees·ha-1. Lemon-type, followed by mandarin rootstocks induced the largest tree size and higher mean yield, probably related to the higher drought tolerance. The true dwarfing rootstocks of Flying Dragon trifoliate orange and Lindcove citrandarin were highly drought-intolerant, but, in addition to Swingle citrumelo and four other citrandarins, they did not present huanglongbing-symptomatic trees during the evaluation period under strict control of the insect vector. Overall, BRS EECB IAC Ponta Firme fruit quality was minimally influenced by the rootstock cultivar and fulfilled the requirements for both domestic and export fresh fruit markets. Due to superior production efficiency associated with high yield in relation to the canopy size, the Goutoucheng sour orange, BRS Ary, BRS Bravo and BRS Matta hybrids were selected as potential rootstocks of rainfed BRS EECB IAC Ponta Firme lime under Aw climate (tropical savannah) conditions.

Resumo: O objetivo deste trabalho foi avaliar cinco índices de seleção não paramétricos para a seleção de citros híbridos como porta-enxertos, enxertados com laranjeira 'Valência', com base em atributos horticulturais relevantes para a indústria de processamento de suco. Avaliaram-se 46 porta-enxertos em delineamento de blocos ao acaso, com três repetições e cinco plantas na parcela, no período de 2009-2015, em cultivo de sequeiro. As médias das variáveis altura de planta, produção acumulada de frutos, eficiência produtiva de frutos, concentração de sólidos solúveis totais, rendimento de suco e tolerância à seca foram utilizadas para calcular os seguintes índices: multiplicativo (IEi), soma de classificação (IMMi), distância genótipo-ideótipo (DiI) e ranqueamento (IRKi, baseado em médias simples; e IRKii, baseado em normalização linear). Os índices foram eficientes em classificar os híbridos em relação ao desempenho geral. A correlação de Spearman mostrou alta similaridade entre a maioria dos índices não paramétricos, notadamente entre IRKi e IRKii. Os índices de ranqueamento, principalmente o IRKii, fornecem uma classificação mais coerente dos híbridos, o que permite a seleção de porta-enxertos mais produtivos e tolerantes à seca, para a produção de frutas de alta qualidade para processamento.

Abstract: The objective of this work was to evaluate five nonparametric selection indices for the selection of hybrid citrus rootstocks grafted with 'Valência' sweet orange, using horticultural traits relevant for the juice processing industry. Forty-six rootstocks were evaluated in a randomized complete block design, with three replicates and five trees in the plot, in the period from 2009-2015, in a rainfed cultivation. The means of the variables plant height, accumulated fruit yield, fruit yield efficiency, total soluble solids concentration, juice yield, and drought-tolerance were used to calculate the following indices: multiplicative index (IEi), sum of classification (IMMi), genotype-ideotype distance (DiI), and ranking indices (IRKi, based on simple means; and IRKii, based on linear normalization). The indices were efficient to classify the hybrids in relation to general performance. Spearman’s correlation showed a high similarity between most nonparametric indices, notably between IRKi and IRKii. The ranking indices, mainly IRKii, provide a more coherent classification of the hybrids, which allows of the selection of more productive and drought-tolerant rootstocks to produce high-quality fruit for processing.

ABSTRACT Despite its interesting agricultural traits, Swingle citrumelo (Citrus paradisi Macfad. ‘Duncan’ × Poncirus trifoliata L. Raf.) rootstock exhibits severe incompatibility when grafted with Pera sweet orange [Citrus sinensis (L.) Osb.] scions, and this fact limits its use for propagation purposes. Nonetheless, the existence of certain Pera sweet orange clones that are compatible with Swingle citrumelo represents a substantial gain for the entire citrus industry. This study investigated the compatibility between seven Pera sweet orange clones and Swingle citrumelo rootstock, regarding the presence of a necrotic line at the graft union junction, the difference in diameter between rootstock and scion, the influence of clonal cleaning by micrografting, and the horticultural performance of the selected combinations. No trees died because of grafting incompatibility, even after twenty years (trial I), except for clone CV1, or after six years and nine months (trial II) from planting. The rootstock/scion trunk diameter ratio was not related to the presence of a necrotic line in the graft-union region. Additionally, these variables did not influence fruit yield and quality, and they were not affected by clonal cleaning or pre-immunisation of the old Pera sweet orange clones.

ABSTRACT Although Brazil is the sixth producer of mandarins in the world, fresh fruit exports are neglectable, and few cultivars are available for the domestic market. Main harvest season comprises May to November, with Ponkan mandarin and Murcott tangor representing more than 70% of the production. Therefore, there is a need for alternative early season, seedless varieties that should also be preferably resistant to Alternaria brown spot. We investigated the horticultural performance of ten selections of Satsuma mandarin in subtropical conditions in Bebedouro, northern state of São Paulo, Brazil. Clausellina, Okitsu, Unshu SRA-529, Saigon SRA-227, Panaché SRA-579, Salzara SRA-341, Miyagawa SRA-444, Kowano SRA-167, FCAV-59 and A2 60.0 selections were grafted on Swingle citrumelo and evaluated up to 7 years old. Unshu, Miyagawa and A2 60.0 presented the highest tree size. These three selections, in addition to Okitsu and Kowano mandarins, resulted in higher fruit yield for the five first harvests (mean of 31.3 kg∙tree–1∙year–1). Panaché had the smallest yield efficiency. Miyagawa and A2 60.0 selections presented lower alternate fruit bearing in the evaluated period due to their early bearing habit. These same selections had the largest fruits with the earliest maturation; similar to the Okitsu mandarin, but with lower soluble solids and higher juice content. The overall performance of the Satsuma mandarin selections grafted on Swingle citrumelo and drip irrigated was promising under subtropical climate. The Okitsu, Miyagawa and A2 60.0 mandarins were selected because of their highest productive potential and their valuable quality traits for the Brazilian domestic market.

Resumo: O objetivo deste trabalho foi selecionar porta-enxertos alternativos ao limoeiro 'Cravo' para laranjeira 'Valência', para a região Norte do Estado de São Paulo, com base na produção inicial de frutos. Foram avaliados 41 porta-enxertos em experimento realizado em março de 2007, no Município de Colômbia, SP. Avaliou-se a produção acumulada de frutos de laranjeira 'Valência' nas safras de 2009, 2010 e 2011. Os porta-enxertos tangerineira 'Sunki' x P. trifoliata 'English', tangerineira 'Malvasio SRA 115', citrange 'C-13' “S”, tangerineira 'Sunki' x P. trifoliata 'Benecke', laranjeira 'Rhode Red Valência' + limoeiro 'Volkameriano', tangerineira 'C-54-4-4 SRA 337', tangerineira 'Cleópatra' x P. trifoliata 'Rubidoux' e tangerineira 'À Peau Lisse SRA 267' apresentam potencial para substituir o limoeiro 'Cravo' na região Norte do Estado de São Paulo.

Abstract: The objective of this work was to select alternative rootstocks to 'Rangpur' lime for 'Valência' sweet orange scions in the northern region of the state of São Paulo, Brazil, based on initial fruit yield. Forty-one rootstocks were evaluated in an experiment carried out in March 2007, in the municipality of Colômbia, in the state of São Paulo. The accumulated fruit yield of 'Valência' sweet orange was assessed in the 2009, 2010, and 2011 crop seasons. The rootstocks 'Sunki' mandarin x Poncirus. trifoliata 'English', 'Malvasio SRA 115' mandarin, 'C-13' “S” citrange, 'Sunki' mandarin x P. trifoliata 'Benecke', 'Valência Rhode Red' sweet orange + 'Volkamer' lemon, 'C-54-4-4 SRA 337' mandarin, 'Cleopatra' mandarin x P. trifoliata 'Rubidoux', and 'À Peau Lisse SRA 267' have potential to replace 'Rangpur' lime in the northern region of the state of São Paulo, Brazil.

Resumo No Brasil, poucas cultivares de tangerineira (Citrus reticulata, Blanco) são exploradas atualmente, o que limita a oferta de frutas frescas no mercado. Este estudo avaliou o desempenho de 15 seleções e 3 híbridos de tangerineira Clementina, visando a buscar alternativas para produção em condições subtropicais. Quinze selecções de Clementina (‘Oroval-SRA335’, ‘Tomatera-SRA535’, ‘Reina-SRA534’, ‘Bruno-SRA531’, ‘Nules-SRA389’, ‘Ragheb-SRA386’, ‘Oroval-Y45’, ‘2-Kr-Monreal’, ‘Commune-SRA88’, ‘Commune-SRA85’, ‘Caffin-SRA385’, ‘De Nules-VCR’, ‘Commune-SRA92’, ‘Clemenules-EECB128’ e ‘Marisol-EECB126’); três híbridos (‘Clemelin-IVIA335’, ‘Caçula-1’ e ‘Caçula-3’) e duas cultivares comerciais controle (‘Ponkan’ e ‘Cravo’), enxertadas em citrumelo ‘Swingle’ [C. paradisi Mafad. cv. ‘Duncan’ x Poncirus trifoliata (L.) Raf.], foram avaliadas no município de Bebedouro-SP, Brasil, de 2001 a 2008. O pomar experimental foi plantado em 2001, com os 20 genótipos dispostos em blocos ao acaso, com três repetições de duas plantas por parcela. O controle ‘Cravo’ e o híbrido ‘Clemelin-IVIA335’ apresentaram o menor vigor das plantas. As seleções ‘Cravo’, ‘Caffin-SRA385’, ‘Clemelin-IVIA335’, ‘Marisol-EECB126’ e ‘Ragheb-SRA386’ tiveram as menores produções acumuladas. Os frutos do híbrido ‘Caçula-1’ apresentaram o maior conteúdo de sólidos solúveis, e os do ‘Caçula-3’, o maior teor de suco. As seleções ‘Bruno-SRA531’, ‘Clemenules-EECB 128’, ‘De Nules-VCR’ e ‘Reina-SRA534’ atingiram o início de produção antes das demais seleções de Clementina. Em termos de eficiência produtiva, a variedade ‘Ponkan’ igualou-se ou até ultrapassou as seleções, com frutos maiores e de maturação precoce. A seleção ‘Reina-SRA534’ destacou-se pelos frutos de tamanho médio e precocidade de produção, enquanto ‘De Nules VCR’ e ‘Tomatera-SRA535’ apresentaram rendimento elevado, apesar do maior tamanho de planta. O bom desempenho das seleções e dos híbridos de Clementina deste estudo estimula a avaliação de práticas culturais para o cultivo desse grupo em clima subtropical.

Abstract In Brazil, few mandarin (Citrus reticulata, Blanco) cultivars are being currently exploited, limiting the availability of fresh fruit in the local market. This study was aimed to investigate the performance of 15 Clementine mandarin selections and 3 hybrids, seeking for alternative varieties for production under subtropical conditions. Fifteen Clementine selections, namely: ‘Oroval-SRA335’, ‘Tomatera-SRA535’, ‘Reina-SRA534’, ‘Bruno-SRA531’, ‘Nules-SRA389’, ‘Ragheb-SRA386’, ‘Oroval-Y45’, ‘2-Kr-Monreal’, ‘Commune-SRA88’, ‘Commune-SRA85’, ‘Caffin-SRA385’, ‘De Nules-VCR’, ‘Commune-SRA92’, ‘Clemenules-EECB128’ and ‘Marisol-EECB126’; three hybrids (‘Clemelin-IVIA335’, ‘Caçula-1’ and ‘Caçula-3’) and the standard commercial varieties ‘Ponkan’ and ‘Cravo’, grafted on ‘Swingle’ citrumelo [C. paradisi Mafad. cv. ‘Duncan’ x Poncirus trifoliata (L.) Raf.], were evaluated in Bebedouro, São Paulo State, Brazil, from 2004 to 2008. The experimental plot was planted in 2001 with the 20 genotypes disposed in a randomized block design, with three replications and two plants per plot. The ‘Cravo’ variety and the ‘Clemelin-IVIA335’ hybrid presented the smallest plant size. The selections ‘Cravo’, ‘Caffin-SRA385’, ‘Clemelin-IVIA335’, ‘Marisol-EECB126’ and ‘Ragheb-SRA386’ had the smallest cumulative yield. Fruits of ‘Caçula-1’ had the highest soluble solids content and those of ‘Caçula-3’ showed the highest juice content. Among the Clementine selections, ‘Bruno-SRA531’, ‘Clemenules-EECB128’, ‘De Nules-VCR’ and ‘Reina-SRA534’ reached earlier maturity. In terms of yield efficiency, ‘Ponkan’ trees performed similarly or outperformed the other selections, with larger fruits and earlier ripening. The ‘Reina-SRA534’ selection outstood due to its high fruit yield and quality, with medium fruit size and early bearing, while ‘De Nules VCR’ and ‘Tomatera-SRA535’ had high yield, low alternate-bearing and fine fruit quality, despite of their large plant size. Good performance of Clementine selections and hybrids encourages further studies on cultural practices for growing this group of mandarins under subtropical climatic conditions.

Resumo A morte súbita dos citros (MSC) é uma doença de alto impacto destrutivo e tem levado à erradicação de milhões de plantas de laranja-doce na região Sudeste do Brasil, nos últimos 15 anos. Embora o agente causal da MSC ainda não tenha sido determinado, evidências demonstraram que esta doença pode ser transmitida por um vetor biótico. A incidência de MSC em cultivares de laranja-doce está relacionada ao porta-enxerto, sendo que a combinação com limoeiro ‘Cravo’ é a mais afetada. Por outro lado, há evidências de relação entre plantas sintomáticas para MSC e a presença de um vírus, denominado Citrus sudden death associated virus (CSDaV) e/ou com Citrus tristeza virus (CTV). Com base nessas informações, o objetivo deste estudo foi determinar a presença de CSDaV e CTV e a associação entre eles, em onze porta-enxertos para laranjeira ‘Valencia’. Os resultados apresentados aqui sugerem diferenças relacionadas à presença de CSDaV e CTV em diferentes porta-enxertos para laranja ‘Valencia’, não havendo relação entre a presença de CSDaV e CTV.

Abstract Citrus sudden death (CSD) is a highly destructive disease and has caused the eradication of millions of trees in southern Brazil within the last 15 years. In spite of the exact cause of CSD has not been determined, evidences have shown that this disease can be transmitted by biotic vectors. Disease incidence in sweet orange scions is related to the rootstock, and the combination with ‘Rangpur’ lime is the most affected. On the other hand, there are evidences of a relation between CSD affected trees and the presence of the Citrus sudden death associated virus (CSDaV) and/or Citrus tristeza virus (CTV). Based on such information, this study has been carried out to determine the presence of CSDaV and CTV, and the association between each other in eleven rootstocks for ‘Valencia’ sweet orange. The results presented herein showed differences related to the presence of CSDaV and CTV in different rootstocks for ‘Valencia’ sweet orange and no relation between the presence of CSDaV and CTV.

ABSTRACT In Brazilian regions affected by the citrus sudden death disease, sweet orange cultivation depends on the use of resistant rootstocks. Rangpur lime was mainly replaced by Swingle citrumelo and Sunki mandarin rootstocks, more drought-sensitive ones. The diversification of scion selections is also desirable aiming at the increasing demand for not from concentrate orange juice (NFC) that requires high-quality fruits. In this work, we evaluated the performance of 6 selections of Valencia (IAC, Dom João, Late Burjasot IVIA 35-2, Rhode Red SRA 360, Temprana IVIA 25 and Campbell) and Natal IAC sweet oranges grafted onto Swingle citrumelo and Sunki mandarin. The planting occurred in 2001 under rain-fed cultivation in Bebedouro, northern São Paulo state, Brazil. The outline was made through randomized blocks in a 7 × 2 factorial design (selections × rootstock), with 4 replications and 2 trees in unit. Both rootstocks performed well in the region. Sunki mandarin rootstock induced greater tree size and production per plant to the scion selections, 38 and 21%, respectively, plus higher precocity of production compared to Swingle citrumelo. The later determined a greater productive efficiency, as well as a greater percentage of juice in general, albeit with lower concentrations of soluble solids and acidity. Natal IAC, Valencia IAC and Rhode Red Valencia selections presented a higher accumulated production, on average, 218.6 kg∙plant−1 (2004 – 2008), and a higher productive efficiency (kg fruit∙m−3 of canopy) due to their smaller tree size. All assessed selections produced fruits with high soluble solids content that were suitable for juice processing.

RESUMO A podridão floral dos citros (PFC), causada por Colletotrichum acutatum Simmons e C. gloeosporioides, é a doença fúngica mais importante em limeira-ácida ‘Tahiti’, pois, leva à queda prematura de flores e frutos, acarretando a redução da produção. Avaliou-se a suscetibilidade à PFC dos clones de lima-ácida ‘Tahiti’ “IAC 5”, “IAC 5-1”, “CNPMF/EECB”, “CNPMF 2000” e “CNPMF 2001”, em Bebedouro-SP. Todos os clones são suscetíveis à doença. A maior incidência de PFC em plantas do clone “IAC 5-1” indica que este clone apresenta maior suscetibilidade. Mesmo com sintomas, plantas do clone “CNPMF/EECB” apresentam maior fixação de frutos.

ABSTRACT Citrus postbloom fruit drop (PFD), caused by Colletotrichum acutatum Simmons and C. gloeosporioides, is the most important fungal disease in ‘Tahiti’ lime, because leads to early flower and fruit drop, causing reduction in plant yield. The susceptibility to PFD was evaluated on the selections of ‘Tahiti’ lime “IAC 5”, “IAC 5-1”, “CNPMF/EECB”, “CNPMF 2000”, and “CNPMF 2001”, in Bebedouro, SP. All selections are susceptible to PFD. The highest PFD incidence in ‘IAC 5-1’ selection trees indicates that this selection is more susceptible to this disease. Even with symptoms of PFD, the “CNPMF/EECB” selection has higher fruit set.

Resumo: O objetivo deste trabalho foi avaliar a sensibilidade ao deficit hídrico de 17 seleções de laranja-doce enxertadas sobre tangerineira 'Sunki', ao longo de cinco safras. Empregou-se um modelo agrometeorológico de penalização da produtividade pelo deficit hídrico, tendo-se avaliado a relação entre os valores estimados e observados. As seleções podem ser classificadas como de alta, média e baixa sensibilidade ao deficit hídrico, classificação que é inédita para as condições brasileiras. A sensibilidade ao deficit hídrico foi classificada como alta nas seleções de laranja-doce 'Pera Milton Teixeira', 'Pera IAC', 'IAC 2000', Pera 2, 'IAC 420 Seleta Rio' e Pera 3, e baixa nas seleções 'Bidwells Bar', 'IPR Jaffa', 'Torregrosa' e 'Sanguínea'.

Abstract: The objective of this work was to evaluate the water-deficit sensitivity of 17 sweet orange selections budded on 'Sunki' mandarin along five growing seasons. An agrometeorological model related to orange yield loss caused by water deficit was used, and the relationship between the estimated and observed values was determined. Sensitivity to water deficit of selections can be classified as high, medium, and low, and this ranking is unprecedented for Brazilian conditions. Sensitivity to water deficit was ranked as high for the sweet orange selections 'Pera Milton Teixeira', 'Pera IAC', 'IAC 2000', Pera 2, 'IAC 420 Seleta Rio', and Pera 3, and as low for the selections 'Bidwells Bar', 'IPR Jaffa', 'Torregrosa', and 'Sanguínea'.

Este trabalho objetivou avaliar o crescimento vegetativo, a produção e a qualidade de frutos da tangerina 'Span Americana' em diferentes porta-enxertos, nas condições edafoclimáticas de Bebedouro-SP. O plantio foi realizado em junho de 2003, em espaçamento de 6,0 m x 3,0 m, sendo utilizada irrigação por gotejamento a partir de 2006. Os porta-enxertos avaliados foram: citranges [Citrus sinensis (L.) Osbeck × Poncirus trifoliata L. Raf] 'Carrizo' e 'Troyer', tetraploides; trifoliatas (P. trifoliata) 'Davis A' e 'Flying Dragon'; limão Volkameriano Catania 2 (C. volkameriana Tenn. et Pasq.), HRS 849 [(C. aurantium L. cv. 'Smooth Flat Seville' x P. trifoliata cv. 'Argentina')], tangelo 'Orlando' (C. reticulata Blanco × C. paradisi Macf.) e limão 'Cravo' (C. limonia Osbeck). Foram avaliadas a produção acumulada, a eficiência produtiva e a precocidade de entrada em produção, no período de 2007 a 2009. Avaliaram-se, também, as dimensões das plantas e a taxa média de crescimento das plantas no período de 2005 a 2008, além da qualidade dos frutos em 2006 e 2007. Em pomares irrigados de tangerineira 'Span Americana', os porta-enxertos trifoliata 'Davis A' e HRS 849 apresentam desempenho horticultural satisfatório. Para plantio em alta densidade, a melhor performance da tangerineira 'Span Americana' é obtida com a utilização dos porta-enxertos trifoliata 'Flying Dragon' e citranges 'Troyer' e 'Carrizo'.

This study aimed to evaluate plant growth and fruit yield and quality of 'Span Americana' mandarin on different rootstocks, under the climatic conditions of Bebedouro, state of São Paulo. The experimental orchard was planted in 2003 using 6 m x 3 m spacing, and was drip irrigated since 2006. The following rootstocks were studied: the 'Carrizo' and 'Troyer' tetraploid citranges [Citrus sinensis (L.) Osbeck × Poncirus trifoliata]; the trifoliates (P. trifoliata) 'Davis A' and 'Flying Dragon: Catania 2 Volkamer lemon (C. volkameriana Tenn. et Pasq.); HRS 849 [(C. aurantium L. cv. 'Smooth Flat Seville' x P. trifoliata cv. 'Argentina')]; 'Orlando' tangelo (C. reticulata Blanco × C. paradisi Macf.), and 'Cravo"Rangpur' lime (C. limonia Osbeck). Mean cumulative yield, productive efficiency and early-bearing yield were calculated for the 2007-2009 period. Plant size and mean plant growth rate was calculated from the annual variation in canopy volume during 2005 through 2008. Fruit quality was assessed in 2006 and 2007. Under irrigated conditions, the 'Davis A' trifoliate and the HRS 849 induced good horticultural performance to 'Span Americana' mandarin and may be used as alternative rootstocks. For high-density plantings, the rootstocks 'Flying Dragon' trifoliate and the 'Troyer' and 'Carrizo' tetraploid citranges may induce better performance to the trees.

O objetivo deste trabalho foi selecionar cultivares de laranja doce de maturação precoce, adequadas para o mercado de frutas in natura e para o processamento industrial, por meio de índices de desempenho. Índices de desempenho para citros foram estabelecidos com base em dados coletados em experimento conduzido na região sudoeste do Estado de São Paulo, envolvendo 12 cultivares de laranja doce de maturação precoce. Resultados pioneiros foram obtidos na identificação de cultivares superiores. Em comparação com a laranja 'Hamlin', cultivar padrão de maturação precoce, identificaram-se as laranjas 'Valência 2' e 'Salustiana' com potencial para o mercado de frutas in natura, e a laranja 'Westin', para o processamento industrial.

The objective of this work was to select adequate early-maturing sweet orange cultivars for the fresh fruit market and for industrial processing using performance indexes. Performance indexes for citrus were established from data collected in an experiment carried out in the southwest region of the state of São Paulo, involving 12 early-maturing sweet orange cultivars. New results were obtained by identifying cultivars with superior characteristics. In a comparison with 'Hamlin' sweet orange, a standard early-maturing cultivar, 'Valência 2' and 'Salustiana' were considered better materials for the fresh fruit market, whereas 'Westin' sweet orange was identified as a superior cultivar for orange juice processing.

O trabalho avaliou os efeitos do uso de fita fotodegradável de enxertia em mudas de laranjeira 'Valência' enxertadas em limoeiro 'Cravo' e citrumeleiro 'Swingle', em viveiro telado, em Bebedouro-SP, durante os meses de setembro a novembro de 2009. Para cada porta-enxerto, foram avaliados três tratamentos, que incluíram o uso da fita convencional de polietileno para a fixação da borbulha e a fita fotodegradável, por sua vez aplicada sob duas formas: com e sem envolvimento completo da gema. As variáveis avaliadas foram: tempo consumido na operação de amarrio da fita, porcentagem de borbulhas brotadas, comprimento e diâmetro do enxerto e porcentagem de mudas prontas para comercialização. O delineamento experimental adotado foi o de blocos ao acaso, com seis tratamentos e quatro repetições. Cada parcela foi representada por 12 plantas. Os tratamentos com a fita fotodegradável, com e sem envolvimento da gema, anteciparam a brotação do enxerto, apesar de o tempo gasto no amarrio da fita ser significativamente maior em relação ao método convencional. Quando o porta-enxerto utilizado é o citrumeleiro Swingle, menos vigoroso, recomenda-se manter a gema descoberta para evitar redução acentuada da brotação do enxerto.

The use of a photodegradable tape was evaluated on 'Valencia' sweet orange nursery trees budded both on Rangpur lime and Swingle citrumelo in a greenhouse in Bebedouro-SP, Brazil, from September to November 2009. On both rootstocks three wrapping procedures were evaluated: i) conventional polyethylene tape wrapped around the bud eye; ii) photodegradable tape wrapped around the bud eye, and iii) photodegradable tape wrapped around the graft junction without covering the bud eye. The following variables were measured: time spent for wrapping, percentage of bud sprouting, length and stem diameter of the scion shoot, and percentage of commercially valuable nursery trees. The trial was conducted following a randomized complete block design, with six treatments, four replications and 12 trees per plot. The use of photodegradable tape, with or without covering the bud eye, anticipated bud sprouting; despite of the longer time spent with wrapping when the photodegradable tape was used. Plants grafted onto the less vigorous Swingle citrumelo rootstock showed lower bud sprout percentages when the bud eye was covered with the photodegradable tape.

Citrus Variegated Chlorosis (CVC) caused by Xylella fastidiosa is one of the most important diseases for Brazilian citriculture. The CVC is a vascular disease with a long incubation period and symptoms similar to other disorders, and this factors difficult the CVC quantification in the field. Two methods of CVC assessment were compared in this study. The first method was based on a descriptive rating scale with four ratings, commonly used for the disease quantification. The second one was based on the incidence of symptomatic branches. The quantification of CVC through these two methods was carried out in a 10-year-old 'Natal' sweet orange orchard. The descriptive scale considered the symptoms of the entire plant. The disease incidence was evaluated in 36 branches in each plant. The assessments were conducted by three raters in 144 plants in July 2006 and July 2007 as well as in March and November 2008. The descriptive scale did not allow an accurate assessment and resulted in a moderate strength of agreement among the raters. On the other hand, the incidence quantification of CVC through the symptomatic branches showed high repeatability among the raters. We suggest the use of incidence of symptomatic branches as variable for CVC quantification.

A verrugose dos citros, causada pelo fungo Elsinoe fawcettii, encontra-se presente em todas as áreas citrícolas do Brasil. Dada sua importância, o comportamento de acessos e híbridos de tangerinas foi avaliado sob condições naturais de infecção. O estudo envolveu plantas não irrigadas, com 15 anos de cultivo, sendo coletados 100 frutos de três plantas por genótipo, na fase de colheita. Mediante o emprego de escala de notas que variaram de 0 (ausência de sintomas) a 6 (sintomas severos), procedeu-se a avaliação do nível de severidade da doença. Dentre genótipos que mostraram-se resistentes incluem-se Citrus deliciosa, C. tangerina, C. nobilis; um híbrido de mandarina (C. nobilis x C. deliciosa) e um híbrido de satsuma (C. unshiu x C. sinensis). Nos demais genótipos foram encontrados sintomas, cujos níveis de severidade variaram de 1 a 3, enquadrando-os como de moderada resistência.

A citrus scab disease, caused by Elsinoe fawcettii, is currently found in all citrus areas throughout Brazil. That being, given the importance of this casual agent, the behavior of tangerines and hybrids influenced by this pathogen was evaluated under natural infection conditions. This study was performed with plants around 15 years old without irrigation; 100 fruits of three plants were collected during harvest season, using a grade scale varying from 0 (absence of symptoms) to 6 (severe symptoms) the level of disease severity was determined. Among the cultivars, citrus scab resistance was observed in Citrus deliciosa, C. tangerina, C. nobilis; a mandarin hybrid (C. nobilis x C. deliciosa) and a satsuma hybrid (C. unshiu x C. sinensis ). Among the other genotypes, symptoms were observed with levels of severity ranging from 1 to 3, indicating moderate resistance.