RESUMO O clima é um fator limitante à expansão do cultivo de mirtileiro para novas áreas no Brasil, sendo comercialmente viável apenas nas regiões mais frias e de altitude dos estados do Sul. Objetivou-se avaliar o desempenho das cultivares de mirtilo 'Emerald' e 'Jewel', de baixa exigência em frio. Foram caracterizadas as fases de crescimento vegetativo, brotação, florescimento, frutificação e produção de frutos. A cultivar 'Emerald' apresenta dois picos de florescimento e frutificação, com a colheita principal ocorrendo de agosto a outubro, enquanto a cultivar 'Jewel' apresenta dois picos de emissão de botões florais, mas apenas um pico de florescimento e uma única colheita, que ocorre entre outubro e janeiro. Para ambas as cultivares, a produção ocorre durante o período de entressafra do mercado interno e externo, o que possibilita melhores preços para a fruta. É possível produzir ambas as cultivares em região subtropical sem a incidência de frio hibernal, demonstrando, assim, que essas cultivares apresentam menor exigência em frio do que relatado na literatura, e favorecendo a produção de frutos frescos na entressafra dos principais países produtores do hemisfério Norte.

ABSTRACT Climate is a limiting factor for cultivating blueberries in new areas in Brazil, being the commercial production restricted only to the colder and high-altitude regions of the southern states. This study aimed to evaluate the performance of low-chill requirement 'Emerald' and 'Jewel' blueberry cultivars. For that, the stages of vegetative growth, sprouting, flowering fruiting and yield were assessed. The 'Emerald' cultivar has two peaks for both flowering and fruiting, with the main harvest period occurring between August and October, while the 'Jewel' cultivar shows two peaks for budding, but only one flowering peak and only one harvest, which extends from October through January. For both cultivars, the production occurs during the off-season of the internal and external markets, resulting in higher fruit prices. Growing both cultivars is feasible in a subtropical region with no-chill incidence, thus demonstrating that these cultivars have much lower chill requirements than those referred to in the literature, and favoring, this way, the fresh fruit production during the off-season of the main producing countries in the northern hemisphere.

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.

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 Poucos modelos fenológicos têm sido formulados para abacateiros cultivados em sequeiro, em ambientes subúmidos cálidos, e em nenhum deles foram sugeridas estratégias de manejo do cultivo para melhorar o desempenho das árvores nessas condições. Avaliou-se a ocorrência e a intensidade dos principais eventos fenológicos em abacateiros 'Hass' e 'Margarida', visando a programar práticas culturais apropriadas para otimizar o manejo de pomares não irrigados, em ambiente cálido e subúmido. Foram avaliados o crescimento de brotos, densidade da raiz, número de flores abertas, frutos fixados e taxa de queda de frutos. Para ambas as cultivares, observaram-se dois fluxos de brotação em setembro-outubro (primavera) e janeiro-fevereiro (verão), enquanto o crescimento máximo das raízes de absorção ocorreu no final de agosto, coincidindo com o florescimento. Dois outros fluxos de raízes, de menor intensidade, ocorreram após o início das chuvas sazonais de verão. Ambas as cultivares apresentaram apenas um período de floração, seguido por uma queda intensa de frutos. Uma segunda queda menor de frutos ocorreu em fevereiro (meados do verão), em ambas as cultivares. Ao determinar a extensão de cada fase fenológica em ambas as cultivares, é possível programar aplicações de fertilizantes, cobertura vegetal e corretivos ao solo, durante os fluxos de crescimento das raízes, assim como pulverizações foliares durante as brotações, para manter um estado nutricional e sanitário adequado.

ABSTRACT Only a few phenological models have been formulated for rain-fed avocados in warm subhumid environments, and none of them have suggested crop management strategies for improving the trees performance in such conditions. The occurrence and intensity of major phenological events were assessed in 'Hass' and 'Margarida' avocado trees, in order to properly schedule the main crop practices for optimum management of rain-fed orchards in warm subhumid growing environments. Shoot growth, root density, number of open flowers, fruit set and fruit dropping rate were evaluated. For both cultivars, two shoot flushes were observed in September-October (spring) and January-February (summer), while a maximum feeder root growth took place in late August, coinciding with flowering. Two other minor root growth flushes occurred after the onset of summer rains. Both cultivars had only one flowering period, followed by an intense fruitlet dropping. A second minor fruit dropping wave occurred in February (mid-summer), for both cultivars. By determining the extent of each phenological phase in both avocado cultivars, it is possible to schedule applications of fertilizer, mulch and soil amendments, during the root growth flushes, as well as foliar sprays during shoot flushes, in order to maintain an adequate nutritional and sanitary status.

Este trabalho avaliou a resistência à infecção de tronco e de raízes por Phytophthora nicotianae em híbridos somáticos de citros com potencial para serem utilizados como porta-enxertos. Os híbridos somáticos avaliados foram laranja 'Hamlin' (Citrus sinensis) + toranja 'Indian Red' (Citrus grandis) (plantas 1 e 2) e laranja 'Hamlin' (C. sinensis) + toranja 'Singapura' (C. grandis). Plantas de limão 'Cravo' (Citrus limonia), laranja 'Caipira' (C. sinensis), laranja-azeda (C. aurantium) e Poncirus trifoliata 'Davis A' (Poncirus trifoliata) foram utilizadas como plantas-controle devido à reação conhecida à infecção pelo patógeno. Avaliações realizadas entre 30 e 60 dias após as inoculações com o patógeno incluíram o comprimento das lesões no tronco e a massa seca do sistema radicular nas plantas avaliadas. O híbrido somático laranja 'Hamlin' + toranja 'Indian Red' (planta 1) mostrou-se tolerante a P. nicotianae, indicando potencial para continuidade nas suas avaliações como porta-enxerto para citros.

This study aimed to evaluate the resistance to trunk and root infection by Phytophthora nicotianae in citrus somatic hybrids with potential to be utilized as rootstocks. The somatic hybrids evaluated were 'Hamlin' sweet orange (Citrus sinensis) + 'Indian Red' pummelo (Citrus grandis) (plants 1 and 2), and 'Hamlin' sweet orange (C. sinensis) + 'Singapura' pummelo (C. grandis). Plants of 'Rangpur' lime (Citrus limonia), 'Caipira' sweet orange (C. sinensis), sour orange (C. aurantium), and Poncirus trifoliata 'Davis A' (Poncirus trifoliata) were used as control due to their known reaction to the pathogen. Evaluations performed between 30 and 60 days after pathogen inoculation included the length of trunk lesions, and root dry mass of the root system of evaluated plants. The somatic hybrid 'Hamlin' sweet orange + 'Indian Red' pummelo (plant 1) was tolerant to P. nicotianae, indicating potential to be further evaluated as a rootstock.