Presence of leaves and use of IBA in adventitious rooting, chlorophyll fluorescence, and root ontogeny of 'Fepagro C 13' and 'Trifoliata' cuttings / Presença de folhas e uso de AIB no enraizamento adventício, fluorescência da clorofila e ontogenia radicular em estacas de 'Fepagro C 13' e 'Trifoliata'

Cutting is proposed as an alternative method for the propagation of citrus rootstocks to obtain clonal material especially in varieties with a low rate of polyembryony and possibly reduce the seedling formation period. The aim of this study was to examine the influence of leaves and the application of indolebutyric acid (IBA) on adventitious rooting and chlorophyll fluorescence as well as to characterize root ontogeny in 'Fepagro C 13' and 'Trifoliata' citrus rootstock cuttings. Semi-hardwood cuttings were collected in December 2018 and subjected to the following treatments: presence or absence of leaves, with or without application of IBA (4000 mg L-1). Over 92 days in a greenhouse environment, leaf abscission percentage, cutting mortality, rooting percentage, and number of roots per cutting were evaluated. Additionally, initial (Fo), maximum (Fm), and variable (Fv) chlorophyll fluorescence, photochemical efficiency (Fv/Fm), and Fv/Fo ratio were analyzed. Tissue samples from the base of the cutting were collected for the anatomical study. The presence of leaves on 'Fepagro C 13' and 'Trifoliata' cuttings is essential for adventitious rooting. The use of auxin influences the photochemical efficiency of leaves on the cuttings. In 'Trifoliata' cuttings, adventitious roots originate from the vascular cambium.(AU)

A estaquia é proposta como método alternativo para a propagação de porta-enxertos de citros, visando a garantia de obtenção de material clonal, especialmente em variedades com baixa taxa poliembriônica, e uma possível redução no período para a obtenção das mudas. O objetivo deste estudo foi avaliar a influência das folhas e da aplicação de ácido indolbutírico (AIB) sobre o enraizamento adventício, fluorescência da clorofila e caracterizar a ontogenia radicular em estacas dos porta-enxertos citrangeiro 'Fepagro C 13', e 'Trifoliata'. Estacas semilenhosas foram coletadas em dezembro de 2018 e submetidas aos tratamentos: presença ou ausência de folhas com aplicação ou não de AIB (4000 mg L-1). Ao longo de 92 dias em casa de vegetação foram avaliados os percentuais de abscisão foliar, mortalidade de estacas, percentual de enraizamento e número de raízes por estaca. Também os dados da fluorescência inicial (Fo), máxima (Fm) e variável (Fv) da clorofila, a eficiência fotoquímica (Fv/Fm) e a razão Fv/Fo foram avaliados. Amostras de tecido da base da estaca foram coletadas para a realização do estudo anatômico. A presença das folhas nas estacas de 'Fepagro C 13' e 'Trifoliata' é essencial para o enraizamento adventício. O uso de auxina influencia a eficiência fotoquímica nas folhas das estacas. Em estacas de 'Trifoliata' as raízes adventícias originam-se a partir do câmbio vascular.(AU)

Chemical and microbiological changes in the soil mediated by different vegetative coverings in a Natal orange orchard / Alterações químicas e microbiológicas do solo mediada por diferentes coberturas vegetais em pomar de laranjeira 'Natal'

Proper soil cover management for citrus cultivation can contribute to increased productivity and improved soil quality. This study examined five different vegetative coverings [Urochloa brizantha; U. decumbens, U. ruziziensis, spontaneous vegetation, and herbicide application (glyphosate) in the total area] in the inter rows of a Natal orange orchard [Citrus sinensis (L.) Osbeck] grafted on the Swingle citrumelo (C. paradisi × Poncirus trifoliata). Their effects on the microbiological and chemical attributes of the soil and the vegetative development in the orchard were examined. Chemical (Ca2+, Mg2+, K+, P, pH, H+Al, CECpH7, base saturation, and OM) and microbiological (carbon and nitrogen of microbial biomass, basal respiration, and metabolic quotient) soil attributes in the rows and inter-rows were evaluated for the orchard in 2018 and 2019. There was a significant difference for most variables in the 2 years studied, emphasizing 2019 for microbiological parameters and OM, with the latter being 14.8% lower in the treatment with glyphosate in the total area compared to the treatment with spontaneous vegetation. The results showed the benefits of vegetation cover with brachiaria in inter-rows of the Natal sweet orange orchard in the chemical and microbiological attributes of the soil, especially in carbon and nitrogen of the microbial biomass.(AU)

O manejo adequado da cobertura do solo para o cultivo de citros pode contribuir com o aumento da produtividade e melhoria da qualidade do solo. Esse trabalho estudou cinco diferentes coberturas vegetais (Urochloa brizantha; U. decumbens, U. ruziziensis, vegetação espontânea e aplicação de herbicida (glifosato) em área total) na entrelinha do pomar de laranjeira 'Natal' [Citrus sinensis (L.) Osbeck] enxertada em citrumeleiro 'Swingle' (C. paradisi × Poncirus trifoliata) nos atributos microbiológicos e químicos do solo, bem como a influência desse manejo no desenvolvimento vegetativo do pomar. Foram avaliados os atributos químicos (Ca2+, Mg2+, K+, P, pH, H+Al, CTCpH7 saturação por bases e MO) e microbiológicos (carbono e nitrogênio da biomassa microbiana, respiração basal e quociente metabólico) do solo na linha e na entrelinha do pomar, nos anos de 2018 e 2019. Houve diferença significativa para a maioria das variáveis nos dois anos estudados, com destaque no ano de 2019 para as variáveis microbiológicas e na MO, sendo esse último, 14,8% menor no tratamento com glifosato em área total em relação ao tratamento com vegetação espontânea. Os resultados permitiram evidenciar os benefícios da cobertura vegetal com as braquiárias na entrelinha do pomar de laranjeira doce 'Natal' nos atributos químicos e microbiológicos do solo, sobretudo no carbono e nitrogênio da biomassa microbiana.(AU)

Nursery performance of potentially promising rootstocks for citriculture in the south of Brazil / Desempenho em viveiro de porta-enxertos potencialmente promissores para a citricultura do sul do Brasil

ABSTRACT: Diversification of rootstock varieties, with consequent reduction in phytosanitary risks, has great importance to the sustainability of citrus cultivation in the south of Brazil. This study evaluated the performance of 42 rootstocks in the nursery phase to generate 'Valencia Late' sweet orange seedlings. Therefore, nucellar seedlings from the rootstocks under study were analyzed in relation to plant height, stem diameter, mortality rate and percentage of bud set after grafting. The experimental design was completely randomized with four replications of 20 sample units. Not adapted genotypes had high mortality rates, and the ones of both hybrids LCR x CTSW - 009 and LVK x LCR - 038 were 100% and 90%, respectively. Other 13 genotypes had mortality rates above 30%, and 'Sunki' mandarin was the female genitor of ten of them. 'Swingle' citrumelo was the rootstock with the highest development (plant height and stem diameter), associated with low mortality rate. In relation to the other rootstocks, the best results were the fast grafting diameter, associated with low mortality rate obtained by hybrids HTR - 053, LRF x (LCR x TR) - 005, CLEO x TRBN - 245, CLEO x TRSW - 287, and citrandarins 'Indio', 'Riverside' and 'San Diego', as well as Trifoliate orange and 'Rangpur' lime. In addition to Trifoliate orange, which is widely used in Rio Grande do Sul, these rootstocks have great potential in citriculture in the south of Brazil.

RESUMO: A diversificação do uso de variedades porta-enxerto, com a consequente redução de riscos fitossanitários, é de fundamental importância para a sustentabilidade da citricultura do Sul do Brasil. O objetivo deste trabalho foi avaliar o comportamento de 42 porta-enxertos na formação de mudas de laranjeira 'Valência Late' em fase de viveiro. Nesse sentido, seedlings (plantas oriundas da germinação de sementes) nucelares dos porta-enxertos estudados foram avaliados relativamente aos caracteres altura da planta, diâmetro do caule, taxa de mortalidade e percentagem de pegamento de borbulhas após a enxertia. O delineamento experimental foi inteiramente casualizado, com quatro repetições de 20 unidades amostrais. Genótipos não adaptados tiveram altas taxas de mortalidade, os híbridos LCR x CTSW - 009 e LVK x LCR - 038 apresentaram 100% e 90% de mortalidade, respectivamente. Mais 13 genótipos apresentaram mortalidade superior a 30%, destes, dez têm como parental feminino a tangerineira 'Sunki'. O citrumelo 'Swingle' foi o porta-enxerto que apresentou maior desenvolvimento (altura da planta e diâmetro do caule), associado a uma baixa taxa de mortalidade. Quanto aos demais porta-enxertos, destacaram-se por atingir rapidamente o diâmetro de enxertia, associado a baixa taxa de mortalidade, os híbridos HTR - 053, LRF x (LCR x TR) - 005, CLEO x TRBN - 245, CLEO x TRSW - 287, citrandarins 'Indio', 'Riverside' e 'San Diego', assim como o limoeiro 'Cravo' e o Trifoliata. Além do Trifoliata, amplamente utilizado no Rio Grande do Sul, estes porta-enxertos são promissores para a citricultura do Sul do Brasil.

Nursery performance of potentially promising rootstocks for citriculture in the south of Brazil / Desempenho em viveiro de porta-enxertos potencialmente promissores para a citricultura do sul do Brasil

Diversification of rootstock varieties, with consequent reduction in phytosanitary risks, has great importance to the sustainability of citrus cultivation in the south of Brazil. This study evaluated the performance of 42 rootstocks in the nursery phase to generate 'Valencia Late' sweet orange seedlings. Therefore, nucellar seedlings from the rootstocks under study were analyzed in relation to plant height, stem diameter, mortality rate and percentage of bud set after grafting. The experimental design was completely randomized with four replications of 20 sample units. Not adapted genotypes had high mortality rates, and the ones of both hybrids LCR x CTSW - 009 and LVK x LCR - 038 were 100% and 90%, respectively. Other 13 genotypes had mortality rates above 30%, and 'Sunki' mandarin was the female genitor of ten of them. 'Swingle' citrumelo was the rootstock with the highest development (plant height and stem diameter), associated with low mortality rate. In relation to the other rootstocks, the best results were the fast grafting diameter, associated with low mortality rate obtained by hybrids HTR - 053, LRF x (LCR x TR) - 005, CLEO x TRBN - 245, CLEO x TRSW - 287, and citrandarins ‘Indio’, ‘Riverside’ and ‘San Diego’, as well as Trifoliate orange and ‘Rangpur’ lime. In addition to Trifoliate orange, which is widely used in Rio Grande do Sul, these rootstocks have great potential in citriculture in the south of Brazil.

A diversificação do uso de variedades porta-enxerto, com a consequente redução de riscos fitossanitários, é de fundamental importância para a sustentabilidade da citricultura do Sul do Brasil. O objetivo deste trabalho foi avaliar o comportamento de 42 porta-enxertos na formação de mudas de laranjeira 'Valência Late' em fase de viveiro. Nesse sentido, seedlings (plantas oriundas da germinação de sementes) nucelares dos porta-enxertos estudados foram avaliados relativamente aos caracteres altura da planta, diâmetro do caule, taxa de mortalidade e percentagem de pegamento de borbulhas após a enxertia. O delineamento experimental foi inteiramente casualizado, com quatro repetições de 20 unidades amostrais. Genótipos não adaptados tiveram altas taxas de mortalidade, os híbridos LCR x CTSW - 009 e LVK x LCR - 038 apresentaram 100% e 90% de mortalidade, respectivamente. Mais 13 genótipos apresentaram mortalidade superior a 30%, destes, dez têm como parental feminino a tangerineira 'Sunki'. O citrumelo 'Swingle' foi o porta-enxerto que apresentou maior desenvolvimento (altura da planta e diâmetro do caule), associado a uma baixa taxa de mortalidade. Quanto aos demais porta-enxertos, destacaram-se por atingir rapidamente o diâmetro de enxertia, associado a baixa taxa de mortalidade, os híbridos HTR - 053, LRF x (LCR x TR) - 005, CLEO x TRBN - 245, CLEO x TRSW - 287, citrandarins 'Indio', ‘Riverside’ e ‘San Diego’, assim como o limoeiro 'Cravo' e o Trifoliata. Além do Trifoliata, amplamente utilizado no Rio Grande do Sul, estes porta-enxertos são promissores para a citricultura do Sul do Brasil.

Nursery performance of potentially promising rootstocks for citriculture in the south of Brazil / Desempenho em viveiro de porta-enxertos potencialmente promissores para a citricultura do sul do Brasil

Diversification of rootstock varieties, with consequent reduction in phytosanitary risks, has great importance to the sustainability of citrus cultivation in the south of Brazil. This study evaluated the performance of 42 rootstocks in the nursery phase to generate 'Valencia Late' sweet orange seedlings. Therefore, nucellar seedlings from the rootstocks under study were analyzed in relation to plant height, stem diameter, mortality rate and percentage of bud set after grafting. The experimental design was completely randomized with four replications of 20 sample units. Not adapted genotypes had high mortality rates, and the ones of both hybrids LCR x CTSW - 009 and LVK x LCR - 038 were 100% and 90%, respectively. Other 13 genotypes had mortality rates above 30%, and 'Sunki' mandarin was the female genitor of ten of them. 'Swingle' citrumelo was the rootstock with the highest development (plant height and stem diameter), associated with low mortality rate. In relation to the other rootstocks, the best results were the fast grafting diameter, associated with low mortality rate obtained by hybrids HTR - 053, LRF x (LCR x TR) - 005, CLEO x TRBN - 245, CLEO x TRSW - 287, and citrandarins ‘Indio, ‘Riverside and ‘San Diego, as well as Trifoliate orange and ‘Rangpur lime. In addition to Trifoliate orange, which is widely used in Rio Grande do Sul, these rootstocks have great potential in citriculture in the south of Brazil.(AU)

A diversificação do uso de variedades porta-enxerto, com a consequente redução de riscos fitossanitários, é de fundamental importância para a sustentabilidade da citricultura do Sul do Brasil. O objetivo deste trabalho foi avaliar o comportamento de 42 porta-enxertos na formação de mudas de laranjeira 'Valência Late' em fase de viveiro. Nesse sentido, seedlings (plantas oriundas da germinação de sementes) nucelares dos porta-enxertos estudados foram avaliados relativamente aos caracteres altura da planta, diâmetro do caule, taxa de mortalidade e percentagem de pegamento de borbulhas após a enxertia. O delineamento experimental foi inteiramente casualizado, com quatro repetições de 20 unidades amostrais. Genótipos não adaptados tiveram altas taxas de mortalidade, os híbridos LCR x CTSW - 009 e LVK x LCR - 038 apresentaram 100% e 90% de mortalidade, respectivamente. Mais 13 genótipos apresentaram mortalidade superior a 30%, destes, dez têm como parental feminino a tangerineira 'Sunki'. O citrumelo 'Swingle' foi o porta-enxerto que apresentou maior desenvolvimento (altura da planta e diâmetro do caule), associado a uma baixa taxa de mortalidade. Quanto aos demais porta-enxertos, destacaram-se por atingir rapidamente o diâmetro de enxertia, associado a baixa taxa de mortalidade, os híbridos HTR - 053, LRF x (LCR x TR) - 005, CLEO x TRBN - 245, CLEO x TRSW - 287, citrandarins 'Indio', ‘Riverside e ‘San Diego, assim como o limoeiro 'Cravo' e o Trifoliata. Além do Trifoliata, amplamente utilizado no Rio Grande do Sul, estes porta-enxertos são promissores para a citricultura do Sul do Brasil.(AU)

Overcoming dormancy in citrus rootstock seeds / Superação de dormência em sementes de porta-enxertos de citros

Citrus is a fruit of great importance in Brazil, mainly in the socio-economic issue as it generates employment and income due to the production and export of concentrated orange juice, as well as other products. In view of the above, this work aimed to evaluate the dormancy overcoming of citrus seeds of the cultivars: Flying Dragon, San Diego, Índio, Cravo Santa Cruz, Riverside, BRS Sunki Tropical, Volkamerian, as well as the species Poncirus trifoliata. The seeds from Embrapa (Brazilian Agricultural Research Corporation) Clima Temperado, located in Pelotas-RS, as well as from Embrapa Cassava e Fruticultura, located in Cruz das Almas-BA, were submitted to the germination test as written in the Seed Analysis Rules and a germination test in which a small cut was made in the seed coat on the side of the embryo, around 0.1 mm with the help of a stylet, which was used 200 seeds (4 samples of50 seeds per repetition) on germitest® paper, moistened with distilled water in an amount equivalent to 2.5 times its weight and kept inside a germinator at a constant temperature of 25 °C, photoperiod of 12 hours. The evaluations were carried out at the end of the 21 days after the installation of the test, providing data that were expressed in percentage of normal and abnormal seedlings and non-germinated seeds (hard, dormant or dead). of citrus seedlings at the end of the tests and the data obtained were submitted to analysis of variance and the means were compared by the Tukey test at a 5% significance level (p≤0.05), with the aid of the R-bio. It is concluded that, when evaluating germination and shoot and root length of seedlings cultivars Flying Dragon, Índio, Cravo Santa Cruz, BRS Sunki Tropical, Riverside and Volkameriano, San Diego and the species P. trifoliata, were satisfactory when submitted in the dormancy breaking process, but further studies are needed.

Os citros é uma frutífera de grande importância no Brasil, principalmente na questão sócio econômico, pois gera emprego e renda por conta da produção e exportação de suco concentrado de laranja, bem como outros produtos. Diante do exposto este trabalho teve como objetivo avaliar a superação de dormência de sementes de citros das cultivares: Flying Dragon, San Diego, Índio, Cravo Santa Cruz, Riverside, BRS Sunki Tropical, Volkameriano, bem como a espécie Poncirus trifoliata. As sementes oriundas Embrapa (Empresa Brasileira de Pesquisa Agropecuária) Clima Temperado, localizada em Pelotas-RS, bem como da Embrapa Mandioca e Fruticultura, localizada em Cruz das Almas-BA, foram submetidas ao teste de germinação como escrito nas Regras de Análise de Sementes e a um teste de germinação na qual foi feito um pequeno corte no tegumento da semente do lado do embrião, em torno de 0,1 mm com ajuda de um estilete, a qual foi utilizada 200 sementes (4 amostras de 50 sementes por repetição) em papel germitest®, umedecido com água destilada em quantidade equivalente a 2,5 vezes o seu peso e mantidos no interior de um germinador à temperatura constante de 25°C, fotoperíodo de 12 horas. As avaliações foram realizadas ao final dos 21 dias após a instalação do teste, fornecendo dados que foram expressos em porcentagem de plântulas normais, anormais e sementes não germinadas (duras, dormentes ou mortas). Além de ser realizado o comprimento da parte aérea e raiz das plântulas de citros no final dos testes e os dados obtidos foram submetidos à análise de variância e as médias, comparadas pelo teste Tukey ao nível de 5% de significância (p≤0,05), com o auxílio do pacote estatístico R-bio. Conclui-se, que ao avaliar a germinação e o comprimento da parte aérea e raiz das plântulas cultivares Flying Dragon, Índio, Cravo Santa Cruz, BRS Sunki Tropical, Riverside e Volkameriano, San Diego e a espécie P. trifoliata, foram satisfatórios, quando submetidos no processo de quebra de dormência, porém se faz necessário mais estudos a respeito.

Establishment and optimization of a hydroponic system for root morphological and nutritional analysis of citrus

The hydroponic growth system is a convenient platform for studying whole plant physiology, especially for root morphological and nutritional analysis. However, we found that most hydroponic systems described in the literature are not suitable for citrus plants. In this study, a hydroponic system for citrus was designed, comprising three principal components: power and time switch, aeration and hydroponic culture. Herein, details of the protocol were described, including equipment setup, seed pregermination and cultivation, together with preparation and transfer of nutrient solution into hydroponics. In order to demonstrate the adaptability of the trifoliate orange plant to our hydroponic system, comparative tests between soil- and hydroponically-grown plants were carried out. The results showed that the plants grew normally and there were no obvious differences between soil- and hydroponically-grown plants. In addition, nutrient deficiency and transcriptional analysis were carried out to test the efficiency, functionality and suitability of our hydroponic system for the application of physiological and molecular analysis. The results, compared with previous studies, showed that our hydroponic system delivered superior performance as regards the physiological and molecular analysis. Taken together, we established the culture system which is best suited for the growth of trifoliate oranges under hydroponic conditions. The hydroponic system described in this paper is easily constructed and controlled at a low cost. It may serve a wide gamut of experimental purposes, especially root morphological and nutritional analysis of trifoliate oranges and the system is also adaptable to other citrus plants by varying the device size.

Establishment and optimization of a hydroponic system for root morphological and nutritional analysis of citrus

The hydroponic growth system is a convenient platform for studying whole plant physiology, especially for root morphological and nutritional analysis. However, we found that most hydroponic systems described in the literature are not suitable for citrus plants. In this study, a hydroponic system for citrus was designed, comprising three principal components: power and time switch, aeration and hydroponic culture. Herein, details of the protocol were described, including equipment setup, seed pregermination and cultivation, together with preparation and transfer of nutrient solution into hydroponics. In order to demonstrate the adaptability of the trifoliate orange plant to our hydroponic system, comparative tests between soil- and hydroponically-grown plants were carried out. The results showed that the plants grew normally and there were no obvious differences between soil- and hydroponically-grown plants. In addition, nutrient deficiency and transcriptional analysis were carried out to test the efficiency, functionality and suitability of our hydroponic system for the application of physiological and molecular analysis. The results, compared with previous studies, showed that our hydroponic system delivered superior performance as regards the physiological and molecular analysis. Taken together, we established the culture system which is best suited for the growth of trifoliate oranges under hydroponic conditions. The hydroponic system described in this paper is easily constructed and controlled at a low cost. It may serve a wide gamut of experimental purposes, especially root morphological and nutritional analysis of trifoliate oranges and the system is also adaptable to other citrus plants by varying the device size.(AU)

Vigor and mortality of citrus progenies with potential use as rootstocks / 10.1590/1678-992x-2016-0455

Rootstocks influence certain characteristics of the scion, such as vigor, fruit yield and quality, and tolerance to biotic and abiotic factors. In conventional citrus breeding programs, hybridization is the main method used for obtaining rootstock varieties. Between Sept and Oct 2006, controlled pollinations were carried out resulting in nine progenies, totaling 461 hybrid seedlings. The female parents were the ‘Santa Cruz Rangpur’ lime (SCRL) and the ‘Sunki of Florida’ mandarin (SFM), while the male parents, in addition to this mandarin, were the ‘Indio’ and ‘Riverside’ citrandarins, the ‘Thomasville’ citrangequat (THOM), the ‘Swingle’ citrumelo, the ‘Argentina’ citrange (AGC) and the ‘Benecke’ trifoliate orange (BKTO). Fruit setting rates of these crosses were measured and the hybrids generated were planted in the field in 2008 and evaluated from 2010 to 2014, for the variables of plant mortality, visual vigor, plant height and trunk diameter. The descriptive statistics mean, variation range, coefficient of variation and Pearson skewness coefficient were calculated. Data were submitted to analysis of variance and the means of the treatments were grouped by the Scott-Knott test, both at 5 % significance. The progenies, having the ‘Sunki’ mandarin as the female parent, presented higher fruit setting rates and lower plant mortality rates than those obtained from the female parent ‘Rangpur’ lime, while zero plant mortality was observed in the SFM × BKTO cross. The crosses SCRL × SFM, SFM × BKTO, SFM × AGC and SFM × THOM have the potential to generate vigorous hybrids, resulting in rootstock varieties adapted to the landscape unit of Coastal Tableland.

Vigor and mortality of citrus progenies with potential use as rootstocks / 10.1590/1678-992x-2016-0455

Rootstocks influence certain characteristics of the scion, such as vigor, fruit yield and quality, and tolerance to biotic and abiotic factors. In conventional citrus breeding programs, hybridization is the main method used for obtaining rootstock varieties. Between Sept and Oct 2006, controlled pollinations were carried out resulting in nine progenies, totaling 461 hybrid seedlings. The female parents were the ‘Santa Cruz Rangpur lime (SCRL) and the ‘Sunki of Florida mandarin (SFM), while the male parents, in addition to this mandarin, were the ‘Indio and ‘Riverside citrandarins, the ‘Thomasville citrangequat (THOM), the ‘Swingle citrumelo, the ‘Argentina citrange (AGC) and the ‘Benecke trifoliate orange (BKTO). Fruit setting rates of these crosses were measured and the hybrids generated were planted in the field in 2008 and evaluated from 2010 to 2014, for the variables of plant mortality, visual vigor, plant height and trunk diameter. The descriptive statistics mean, variation range, coefficient of variation and Pearson skewness coefficient were calculated. Data were submitted to analysis of variance and the means of the treatments were grouped by the Scott-Knott test, both at 5 % significance. The progenies, having the ‘Sunki mandarin as the female parent, presented higher fruit setting rates and lower plant mortality rates than those obtained from the female parent ‘Rangpur lime, while zero plant mortality was observed in the SFM × BKTO cross. The crosses SCRL × SFM, SFM × BKTO, SFM × AGC and SFM × THOM have the potential to generate vigorous hybrids, resulting in rootstock varieties adapted to the landscape unit of Coastal Tableland.(AU)

Vigor and mortality of citrus progenies with potential use as rootstocks

ABSTRACT: Rootstocks influence certain characteristics of the scion, such as vigor, fruit yield and quality, and tolerance to biotic and abiotic factors. In conventional citrus breeding programs, hybridization is the main method used for obtaining rootstock varieties. Between Sept and Oct 2006, controlled pollinations were carried out resulting in nine progenies, totaling 461 hybrid seedlings. The female parents were the Santa Cruz Rangpur lime (SCRL) and the Sunki of Florida mandarin (SFM), while the male parents, in addition to this mandarin, were the Indio and Riverside citrandarins, the Thomasville citrangequat (THOM), the Swingle citrumelo, the Argentina citrange (AGC) and the Benecke trifoliate orange (BKTO). Fruit setting rates of these crosses were measured and the hybrids generated were planted in the field in 2008 and evaluated from 2010 to 2014, for the variables of plant mortality, visual vigor, plant height and trunk diameter. The descriptive statistics mean, variation range, coefficient of variation and Pearson skewness coefficient were calculated. Data were submitted to analysis of variance and the means of the treatments were grouped by the Scott-Knott test, both at 5 % significance. The progenies, having the Sunki mandarin as the female parent, presented higher fruit setting rates and lower plant mortality rates than those obtained from the female parent Rangpur lime, while zero plant mortality was observed in the SFM × BKTO cross. The crosses SCRL × SFM, SFM × BKTO, SFM × AGC and SFM × THOM have the potential to generate vigorous hybrids, resulting in rootstock varieties adapted to the landscape unit of Coastal Tableland.

Initial horticultural performance of nine Persian lime selections grafted onto Swingle citrumelo

Persian lime (PL) [Citrus latifolia (Yu. Tanaka) Tanaka] is an important species both for domestic fresh fruit consumption in Brazil as well as the export market, since the country is one of the largest producers in the world despite the fact that, in commercial plantations, it is still not uncommon to find trees with low productivity and high plant vigor of unknown origin. Selections of Persian lime CNPMF2000, CNPMF2001, CNPMF01, CNPMF02, IAC5, IAC5.1, Bearss, Persian58, and 5059, were therefore grafted onto Swingle citrumelo [C. paradisi Macfad. cv. Duncan × Poncirus trifoliata (L.) Raf.] rootstocks and evaluated in Cruz das Almas, Bahia, Brazil in a field experiment conducted in a completely randomized block design with five replications and two trees per plot. The biometric attributes (canopy height, diameter and volume), yield parameters (yield during the off-season harvest period, yield per plant, production efficiency), and fruit quality traits, were evaluated. The CNPMF2001, CNPMF01, CNPMF02, IAC5, and Bearss selections had 5-11 % shorter trees than the other cultivars. CNPMF01, CNPMF02, Persian58, and 5059 presented higher yield efficiency values, between 3.1-3.4 kg m3, and higher yield levels during the off-season harvest periods. The Bearss, Persian58, CNPMF2000, IAC5.1 and 5059 selections had more acid fruits and the latter three, smaller fruits. Based on their horticultural performance up to eight years of age, CNPMF01, CNPMF02, Persian58 and 5059 selections were the most promising varieties of Persian lime.

Initial horticultural performance of nine Persian lime selections grafted onto Swingle citrumelo

Persian lime (PL) [Citrus latifolia (Yu. Tanaka) Tanaka] is an important species both for domestic fresh fruit consumption in Brazil as well as the export market, since the country is one of the largest producers in the world despite the fact that, in commercial plantations, it is still not uncommon to find trees with low productivity and high plant vigor of unknown origin. Selections of Persian lime CNPMF2000, CNPMF2001, CNPMF01, CNPMF02, IAC5, IAC5.1, Bearss, Persian58, and 5059, were therefore grafted onto Swingle citrumelo [C. paradisi Macfad. cv. Duncan × Poncirus trifoliata (L.) Raf.] rootstocks and evaluated in Cruz das Almas, Bahia, Brazil in a field experiment conducted in a completely randomized block design with five replications and two trees per plot. The biometric attributes (canopy height, diameter and volume), yield parameters (yield during the off-season harvest period, yield per plant, production efficiency), and fruit quality traits, were evaluated. The CNPMF2001, CNPMF01, CNPMF02, IAC5, and Bearss selections had 5-11 % shorter trees than the other cultivars. CNPMF01, CNPMF02, Persian58, and 5059 presented higher yield efficiency values, between 3.1-3.4 kg m3, and higher yield levels during the off-season harvest periods. The Bearss, Persian58, CNPMF2000, IAC5.1 and 5059 selections had more acid fruits and the latter three, smaller fruits. Based on their horticultural performance up to eight years of age, CNPMF01, CNPMF02, Persian58 and 5059 selections were the most promising varieties of Persian lime.(AU)

Substratos e recipientes para a produção de porta-enxertos de citros irrigados por subcapilaridade / Substrates and containers for the citrus rootstocks' production irrigated by capillarity

O conhecimento do porta-enxerto, do substrato e do recipiente são fundamentais para a definição do período necessário para produzir mudas cítricas de qualidade. O objetivo deste trabalho foi avaliar a emergência de plântulas e o desenvolvimento vegetativo de seis porta-enxertos cítricos, cultivados em dois substratos e mantidos em diferentes recipientes, em sementeira, irrigados por subcapilaridade. Foram testados dois substratos comerciais e a semeadura foi realizada em tubetes com 50cm³, tubetes com 120cm³ e bandejas de isopor contendo 72 células com volume de 120cm³. Os seis porta-enxertos cítricos avaliados foram: Trifoliata [Poncirus trifoliata [L.] Raf.]; Flying Dragon [Poncirus trifoliata (L.) Raf. var. monstrosa]; limoeiro Volkameriano (Citrus volkameriana Pasq.), citrangeiro Fepagro C37 [P. trifoliata x Citrus sinensis [L.] Osbeck.], tangerineira Sunki (C. sunki hort. ex Tan.) e citrumeleiro Swingle (P. trifoliata x C. paradisi). Avaliou-se emergência, altura e diâmetro das plantas ao longo do cultivo em casa de vegetação. Em laboratório, avaliou-se massa fresca e seca da parte aérea e raiz, número de folhas, área foliar por folha e área foliar por planta. Nas avaliações de emergência de plântulas, a tangerineira Sunki, o limoeiro Volkameriano e o citrumeleiro Swingle apresentaram maiores taxas em relação ao Trifoliata, ao citrangeiro Fepagro C 37 e ao Flying Dragon. Ao empregar-se o sistema de irrigação por subcapilaridade, o substrato comercial 1 é recomendado para todos recipientes. O substrato comercial 2 somente deve ser empregado em bandejas alveoladas de 120 cm³.(AU)

In the production of citrus seedling, the knowledge of rootstock substrate and container is essential to define the entire substantial period to produce quality seedling. The objective of this research was to evaluate seedling emergence and vegetative development of six citrus rootstocks grown on two substrates and kept in different containers at the stage of sowing irrigated by capillarity. Two commercial substrates were tested and seeding was performed in three containers: stiff plastic tubes with 50cm³, stiff plastic tubes with 120cm³ and polystyrene trays containing 72 cells with a volume of 120cm³. The six rootstocks citrus evaluated were: Trifoliata [Poncirus trifoliata [L.] Raf.]; Flying Dragon [Poncirus trifoliata (L.) Raf. var. monstrosa]; Volkameriano lemon (Citrus volkameriana Pasq.), Fepagro C37 citrange [P. trifoliata x Citrus sinensis [L.] Osbeck.], Sunki tangerine (C. sunki hort. ex Tan.) and Swingle citrumelo (P. trifoliata x C. paradisi). The emergence, height and diameter of plants in the greenhouse were evaluated. Fresh weight, root and shoot dry weight, leaf number, leaf area per plant and leaf area per leaf were evaluated in the laboratory. In the evaluations of emergence of seedlings, the Sunki tangerine, Volkameriano lemon and Swingle citrumelo had higher rates compared to Trifoliata, Fepagro C37 citrange and Flying Dragon. When the system in a floating irrigation system, commercial substrate 1 is recommended for all containers. The commercial substrate 2 should be only used in alveolate trays of 120cm³.(AU)

Produção de mudas de laranjeira Pêra por meio do método de interenxertia / Production of nursery trees of Pera sweet orange by the interstock method

A interenxertia é uma prática que é usada, quando se deseja unir duas plantas que, sabidamente, são incompatíveis, ou quando se pretende diminuir o vigor da cultivar copa. Neste trabalho, avaliou-se uma metodologia alternativa para a produção de mudas de laranjeira Pêra interenxertadas, usando a subenxertia como técnica auxiliar na formação de um interenxerto de limoeiro Cravo. Foram avaliados os seguintes tratamentos: T1 - porta-enxerto trifoliata Flying Dragon (FD) e interenxerto de laranjeira Bahia; T2 - porta-enxerto Citrumeleiro Swingle (CS) e interenxerto de laranjeira Bahia; T3 - porta-enxerto limoeiro Cravo (LC); T4 - porta-enxerto FD e interenxerto de LC; T5 - Porta-enxerto CS e interenxerto de LC. As mudas produzidas no tratamento 4 (Pêra / LC / FD) se aproximaram em vigor das mudas produzidas sem filtro (Pêra / LC). A produção de mudas de laranjeira Pêra interenxertadas pelo sistema tradicional, tendo como porta-enxerto CS ou FD e interenxerto de laranjeira Bahia, não foi possível, em virtude da baixa viabilidade e vigor das brotações.

The interstock is a practice used when to merge two plants that are known to be incompatible or when it is intended to low vigor of the scion. In this study we evaluated an alternative method for the production of Pêra sweet orange nursery trees interstocked, using the technique as inarching assist in forming a interstock of Rangpur Lime (RL). The treatments were: T1 - rootstock trifoliate Flying Dragon (FD) and interstock of sweet orange Bahia, T2 - rootstock Citrumelo Swingle (CS) and interstock of sweet orange Bahia, T3 - rootstock Rangpur Lime (RL); T4 - rootstock FD and interstock RL; T5 - rootstock CS and interstock RL. The sweet orange nursery trees produced in treatment 4 (Pêra / RL / FD) had vigor nearest sweet orange nursery trees produced with interstock (Pêra / RL). The production Pera sweet orange nursery trees interstocked for traditional system, with the rootstock CS or FD and interstock sweet orange Bahia was not possible because of the low viability and vigor of the shoots.

Produção de mudas de laranjeira Pêra por meio do método de interenxertia / Production of nursery trees of Pera sweet orange by the interstock method

A interenxertia é uma prática que é usada, quando se deseja unir duas plantas que, sabidamente, são incompatíveis, ou quando se pretende diminuir o vigor da cultivar copa. Neste trabalho, avaliou-se uma metodologia alternativa para a produção de mudas de laranjeira Pêra interenxertadas, usando a subenxertia como técnica auxiliar na formação de um interenxerto de limoeiro Cravo. Foram avaliados os seguintes tratamentos: T1 - porta-enxerto trifoliata Flying Dragon (FD) e interenxerto de laranjeira Bahia; T2 - porta-enxerto Citrumeleiro Swingle (CS) e interenxerto de laranjeira Bahia; T3 - porta-enxerto limoeiro Cravo (LC); T4 - porta-enxerto FD e interenxerto de LC; T5 - Porta-enxerto CS e interenxerto de LC. As mudas produzidas no tratamento 4 (Pêra / LC / FD) se aproximaram em vigor das mudas produzidas sem filtro (Pêra / LC). A produção de mudas de laranjeira Pêra interenxertadas pelo sistema tradicional, tendo como porta-enxerto CS ou FD e interenxerto de laranjeira Bahia, não foi possível, em virtude da baixa viabilidade e vigor das brotações.(AU)

The interstock is a practice used when to merge two plants that are known to be incompatible or when it is intended to low vigor of the scion. In this study we evaluated an alternative method for the production of Pêra sweet orange nursery trees interstocked, using the technique as inarching assist in forming a interstock of Rangpur Lime (RL). The treatments were: T1 - rootstock trifoliate Flying Dragon (FD) and interstock of sweet orange Bahia, T2 - rootstock Citrumelo Swingle (CS) and interstock of sweet orange Bahia, T3 - rootstock Rangpur Lime (RL); T4 - rootstock FD and interstock RL; T5 - rootstock CS and interstock RL. The sweet orange nursery trees produced in treatment 4 (Pêra / RL / FD) had vigor nearest sweet orange nursery trees produced with interstock (Pêra / RL). The production Pera sweet orange nursery trees interstocked for traditional system, with the rootstock CS or FD and interstock sweet orange Bahia was not possible because of the low viability and vigor of the shoots.(AU)

Performance of ‘Okitsu satsuma mandarin trees on different rootstocks in Northwestern Paraná State / Comportamento de tangerineira satsuma ‘Okitsu sobre diferentes porta-enxertos no Noroeste do Paraná

O limoeiro ‘Cravo é o principal porta-enxerto utilizado para citros no estado do Paraná e temapresentado bom desempenho para as diferentes cultivares de copa. Porém, são necessários estudos paradiversificar os porta-enxertos utilizados no Estado e também para serem utilizados em cultivares aindapouco exploradas comercialmente. O objetivo deste estudo foi avaliar o desenvolvimento vegetativo, aprodução e a qualidade de frutos da tangerineira satsuma ‘Okitsu (Citrus unshiu Marc.) enxertada sobrediferentes porta-enxertos. O pomar foi implantado na Estação Experimental de Paranavaí do InstitutoAgronômico do Paraná IAPAR, em Paranavaí, PR, em janeiro de 2001. O delineamento experimentalfoi de blocos ao acaso, com nove tratamentos, três repetições e duas plantas úteis por parcela. Osporta=enxertos utilizados foram limoeiro ‘Cravo (Citrus limonia Osb.), tangerineira ‘Cleópatra(Citrus reshni hort. ex Tanaka), citrangeiro ‘C-13 [Citrus sinensis x Poncirus trifoliata (L.) Raf.],limoeiro ‘Volkameriano (Citrus volkameriana V. Ten. e Pasq.), citrangeiro ‘Carrizo [C. sinensis x P.trifoliata (L.) Raf.], tangerineira ‘Sunki (Citrus sunki hort. ex Tanaka), trifoliata [P. trifoliata (L.) Raf.],citrumeleiro ‘Swingle [Citrus paradisi Macfad. cv. Duncan x P. trifoliata (L.) Raf.] e laranjeira ‘CaipiraDAC [C. sinensis (L.) Osb.]. O maior volume de copa das plantas de satsuma ‘Okitsu foi induzidopela tangerineira ‘Cleópatra com 37,1 m3, e o menor foi para as plantas enxertadas em ‘Trifoliata,com 9,9 m3. O citrumeleiro ‘Swingle proporcionou maior relação entre diâmetro do tronco abaixoe acima do ponto de enxertia. As maiores produções acumuladas em oito safras foram induzidas porlimoeiros ‘Volkameriano e ‘Cravo, laranjeira ‘Caipira DAC, tangerineira ‘Cleópatra e citrangeiro‘Carrizo, com valores entre 867,3 kg e 989,6 kg...(AU)

In the state of Paraná, ‘Rangpur lime is the main citrus rootstock, which has provided good performancefor trees of different cultivars planted in the State. However, rootstock diversification is needed as wellas to identify the best ones for citrus cultivars less explored commercially yet. The objective of thisstudy was to evaluate the vegetative growth, yield and fruit quality of ‘Okitsu satsuma mandarin trees(Citrus unshiu Marc.) grafted on nine rootstocks in the Northwest region of the state of Paraná, Brazil.The orchard was established in the Paranavaí Experimental Station of the Agronomic Institute of Paraná,Paranavaí, PR, on January 2001. The experimental design was randomized blocks with nine treatments,three replications, and two trees per plot. The rootstocks included in this study were ‘Rangpur lime(Citrus limonia Osb.), ‘Cleópatra mandarin (Citrus reshni hort. ex Tanaka), ‘C-13 citrange [Citrussinensis × Poncirus trifoliata orange (L.) Raf.], ‘Volkamer lemon (Citrus volkameriana V. Ten. ePasq.), ‘Carrizo citrange [C. sinensis × P. trifoliata (L.) Raf.], ‘Sunki mandarin (Citrus sunki hort.ex Tanaka), ‘Trifoliate orange [P. trifoliata (L.) Raf. ], ‘Swingle citrumelo [Citrus paradisi Macfad.cv. Duncan × P. trifoliata (L.) Raf.], and ‘Caipira DAC sweet orange [C. sinensis (L.) Osb.]. Thelargest tree canopy was induced by ‘Cleópatra mandarin and the lowest by ‘Trifoliate orange, with37.1 m3 and 9.9 m3 of tree canopy, respectively. The highest relationship between scion and rootstocktrunk diameter was observed for trees grafted on ‘Swingle citrumelo. The largest cumulative yieldsover eight seasons were induced by ‘Volkamer lemon, ‘Rangpur lime, ‘Caipira DAC sweet orange,‘Cleópatra mandarin, and ‘Carrizo citrange, ranging from 867.3 to 989.6 kg per tree. These rootstocksalso induced the largest fruit mass, along with ‘Sunki, ranging from 173.3 to 188.0 g. ‘Trifoliateorange...(AU)

Performance of 'Okitsu' Satsuma Mandarin on nine rootstocks

Mandarins have become increasingly valued as citrus fruits for the fresh market due to the easy peeling, attractive flavor, and health and nutritional properties. Plant growth and yield, and characteristics of fruits of 'Okitsu' Satsuma mandarin (Citrus unshiu Marc.) trees grafted on nine rootstocks were evaluated in Londrina, northern Paraná, Brazil. The rootstocks were: 'Rangpur' lime (Citrus limonia Osb.); 'Cleopatra' (Citrus reshni hort. ex Tanaka) and 'Sunki' mandarins (Citrus sunki hort. ex Tanaka); 'C-13' [Citrus sinensis × Poncirus trifoliata (L.) Raf.] and 'Carrizo' citranges [C. sinensis × P. trifoliata (L.) Raf.]; 'Volkamer' lemon (Citrus volkameriana V. Ten. & Pasq.); trifoliate orange [P. trifoliata (L.) Raf.; 'Caipira DAC' sweet orange [C. sinensis (L.) Osb.] and 'Swingle' citrumelo [Citrus paradisi Macfad. cv. Duncan × P. trifoliata (L.) Raf.]. The highest plant growth was for the trees on 'Cleopatra' mandarin and 'Caipira DAC' sweet orange. In contrast, the smallest size was for the trees on 'Volkamer' lemon and trifoliate orange. The largest difference between the trunk diameter below and above the grafting point was induced by 'Swingle' citrumelo. Trees of 'Okitsu' Satsuma mandarin on 'Swingle' citrumelo presented the highest yield, while 'C-13', 'Carrizo', 'Sunki', and 'Swingle' induced the largest fruit masses. With regard to fruit characteristics, 'Carrizo' and trifoliate orange induced the best ratio and juice content. Based on theoretical values, 'Rangpur' lime and 'Volkamer' lemon induced the lowest yields

Performance of 'Okitsu' Satsuma Mandarin on nine rootstocks

Mandarins have become increasingly valued as citrus fruits for the fresh market due to the easy peeling, attractive flavor, and health and nutritional properties. Plant growth and yield, and characteristics of fruits of 'Okitsu' Satsuma mandarin (Citrus unshiu Marc.) trees grafted on nine rootstocks were evaluated in Londrina, northern Paraná, Brazil. The rootstocks were: 'Rangpur' lime (Citrus limonia Osb.); 'Cleopatra' (Citrus reshni hort. ex Tanaka) and 'Sunki' mandarins (Citrus sunki hort. ex Tanaka); 'C-13' [Citrus sinensis × Poncirus trifoliata (L.) Raf.] and 'Carrizo' citranges [C. sinensis × P. trifoliata (L.) Raf.]; 'Volkamer' lemon (Citrus volkameriana V. Ten. & Pasq.); trifoliate orange [P. trifoliata (L.) Raf.; 'Caipira DAC' sweet orange [C. sinensis (L.) Osb.] and 'Swingle' citrumelo [Citrus paradisi Macfad. cv. Duncan × P. trifoliata (L.) Raf.]. The highest plant growth was for the trees on 'Cleopatra' mandarin and 'Caipira DAC' sweet orange. In contrast, the smallest size was for the trees on 'Volkamer' lemon and trifoliate orange. The largest difference between the trunk diameter below and above the grafting point was induced by 'Swingle' citrumelo. Trees of 'Okitsu' Satsuma mandarin on 'Swingle' citrumelo presented the highest yield, while 'C-13', 'Carrizo', 'Sunki', and 'Swingle' induced the largest fruit masses. With regard to fruit characteristics, 'Carrizo' and trifoliate orange induced the best ratio and juice content. Based on theoretical values, 'Rangpur' lime and 'Volkamer' lemon induced the lowest yields

Trifoliata hybrids rootstocks for 'Lane Late' navel orange in Spain

Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.] and Cleopatra mandarin (C. reshni Hort. ex Tan.) are the most important rootstocks used in Spain, but they are problematic and it is necessary to search for new rootstocks with better all-round performance. The performance of 'Lane Late' navel orange [Citrus sinensis (L.) Osb] on ten rootstocks was determined in the South of the province of Alicante (Spain). They are Carrizo citrange, Cleopatra mandarin and eight new hybrids obtained at the Instituto Valenciano de Investigaciones Agrarias in Valencia (Spain): 020324 [Troyer citrange (C. sinensis × P. trifoliata) × Cleopatra mandarin], Forner-Alcaide 418 (F&A 418) [Troyer citrange × common mandarin (C. deliciosa Ten.)], Forner-Alcaide 13 (F&A 13), 030118, 030127 and 030131 (Cleopatra mandarin × P. trifoliata) and 030212 and 030230 (Cleopatra mandarin × Troyer citrange). Soil is clay loam, with pH 8.5 and electric conductivity in the saturation extract at 25ºC of 5.79 mS cm-1. Yield was weighed during the first nine harvests, fruit quality was determined in the last three. Pre-harvest fruit-drop was controlled for the 4th until 9th harvests. The trees of 'Lane Late' navel budded on Cleopatra mandarin were the tallest (2.5 m) and F&A 418 (1.6 m) the shortest of all rootstocks tested. Trees on 030131 hybrid and Carrizo citrange rootstocks had the highest mean yield (81.2 and 80.3 kg per tree per year respectively), while trees on F&A 418 produced the lowest mean yield (22.3 kg per tree per year). Trees on 030131, 020324 and 030212 had the highest yield efficiency as total cumulative yield per cubic meter of canopy volume (62.1, 58.7 and 55.9 kg m-3 respectively) whereas trees on 030127, F&A 418 and Cleopatra mandarin had lower yield efficiencies (45.0, 44.4 and 38.6 kg m-3, respectively). Pre-harvest fruit-drop was lower in trees grafted on Cleopatra mandarin (24.62 %) and on 030212 (26.61 %), and was also low on F&A 418 (27.76 %), 020324 (28.14 %) and 030230 (29.18 %) rootstocks. Trees on Carrizo citrange and 030127 experienced important fruit-drop (40.24 % and 38.27 % respectively). Trees on F&A 418 had the highest fruit weight and fruit size whereas trees on 030118 induced the lowest ones. The ripeness index was the highest on F&A 13 (18.3) and lowest on F&A 418 (15.3), 030212 (15.3).