Sunki mandarin and Swingle citrumelo as rootstocks for rain-fed cultivation of late-season sweet orange selections in northern São Paulo state, Brazil.

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

Caracterização tecnológica e aptidão mercadológica de clones de lima ácida 'Tahiti'.

A produção nacional de lima ácida Tahiti (Citrus latifolia Tanaka) possui três mercados bastante distintos: mercado interno, processamento industrial e a exportação de frutos in natura. Embora o mercado interno seja o principal destino da produção, merece destaque o aumento das exportações brasileiras da fruta que setuplicaram no período 2000-2006 alcançando US$ 32 milhões (SILVA; ALMEIDA; FERRAZ, 2008). No mercado interno, os preços praticados acompanham a disponibilidade da fruta, atingindo valores máximos nos meses de entressafra, quando a oferta é restrita. No período de safra, quando a oferta da fruta é maior, o produtor tem como alternativa a exportação de frutos, cujos preços são superiores aos praticados pelo mercado interno. De forma geral, o processamento industrial é o destino dos frutos que não atendem as exigências do mercado interno e externo.pdf 159

Avaliação horticultural de doze portaenxertos para laranjeira 'Folha Murcha', limeira ácida 'Tahiti' e tangerineira Satsuma 'Okitsu'.

A citricultura paulista destaca-se pela sua notável evolução em importância econômica. No entanto, a baixa diversidade genética do atual pool varietal aumenta sua vulnerabilidade à ocorrência de novas epidemias, com importantes conseqüências para a sustentabilidade deste agronegócio. Neste contexto, o uso de novas cultivares de copas e portaenxertos, complementares ou substitutos aos atuais, dará maior competitividade à citricultura brasileira, pelo aumento na produtividade e na qualidade final dos produtos.pdf 212

Current situation, management and economic impact of citrus variegated chlorosis in Brazil.

Citrus variegated chlorosis (CVC), caused by Xylella fastidiosa, affects all commercial sweet orange cultivars and is widely spread in São Paulo State, the most important citrus producer region in Brazil. CVC used to be the most important disease to the Brazilian citrus industry until the advent of huanglongbing (ex-greening). The disease is graft-transmissible and has twelve sharpshooters species identified as vectors. A survey performed in 2005 indicated that 43.8% of sweet orange trees in São Paulo and Minas Gerais States were affected by CVC. Recently, yield reduction caused by CVC has been estimated between 10 and 14% of the total production, with larger impact observed on orchards located in the North and Northwestern regions of the São Paulo State. In those regions, where water deficiency and high temperature frequently occur, low leaf transpiration and sap flow rates on CVC-affected plants are caused by reduced stomatal conductance, which may be associated with the blockage of xylem vessels due to X. fastidiosa colonization that increases the resistance to water movement toward the leaves. The CVC management is based on the use of healthy nursery trees, chemical control of vectors, removal of affected young trees and pruning of branches with initial symptoms. Those measures may allow a good control of CVC, but they are time-consuming and very expensive. The utilization of resistant cultivars is compulsory for a long-term coexistence with the disease. Since 1990 a great effort to determine the reaction of citrus genotypes to CVC has been made at the Citrus Experimental Station of Bebedouro. Among the existing and imported germplasm, about 600 citrus genotypes have been evaluated. From these, 503 tested sweet orange varieties and clones were symptomatic, but large differences on cultivar reaction to CVC were observed among them. A Navelina sweet orange selection showed mild symptoms only when topworked on severe CVC affected trees. Studies are in progress to confirm its tolerance to the diseas

Desempenho da Tangerineira SPAN Americana em diferentes porta-enxertos.

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'.201