Prediction of the commencement and duration of the flowering period of citrus

Lomas, J.; Burd, P.

doi:10.1016/0002-1571(83)90014-6

Cited by 14 publications

(14 citation statements)

References 2 publications

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“…Climatic conditions of the pre-flowering period affect fruit set, since they determine the time of flowering (early or late) and its duration (extended or concentrated) (Ben Mechlia & Carrol, 1989). Therefore, the occurrence of stress conditions due to water deficit, high temperatures and high evaporative demands during those months (much earlier than the normal flowering period, in October/November), probably leads to the anticipation of flowering to a period when meteorological conditions are less adequate for pollination and fruit set (Lomas & Burd, 1983).…”

Section: Influence Of Meteorological Variables On the Crop Cyclementioning

confidence: 99%

Agrometeorological models for 'Valencia' and 'Hamlin' sweet oranges to estimate the number of fruits per plant

Paulino

Filho

Maia

et al. 2007

Sci. agric. (Piracicaba, Braz.)

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The development of models that allow forecasting yield tendencies is important to all sectors of the citrus industry. This work evaluated the influence of meteorological variables in different phases of the crop cycle in order to propose empirical models to estimate the number of fruits per plant (NFP) of 'Valencia' and 'Hamlin' sweet oranges. NFP sampling data from the citrus juice industry of the State of São Paulo, on the total of 15 harvests (1990/91 to 2004/05), classified into three age classes, and meteorological data of maximum and minimum air temperature and rainfall of Limeira, SP, Brazil, were utilized. Correlation coefficients were initially computed between the number of fruits per plant and each meteorological variable used for water balance and variables related to air temperature, in different periods. Linear multiple regression models were fit to describe the empirical relationship between NFP and the subsets of agrometeorological predictors that presented higher correlations in different phases of the crop cycle. The meteorological conditions during the phases of vegetative summer flush, preflowering, flowering and beginning of fruit growth influenced the number of fruits per plant. The proposed models presented adequate goodness-of-fit with determination coefficients varying from 0.72 to 0.87. Key words: citrus, harvest, modeling, yield MODELOS AGROMETEOROLÓGICOS PARA ESTIMAÇÃO DO NÚMERO DE FRUTOS POR PLANTA EM LARANJEIRAS 'VALÊNCIA' E 'HAMLIN'RESUMO: O desenvolvimento de modelos para previsões de tendências de produtividade é de grande importância para todos os elos da cadeia produtiva de citros. Buscou-se avaliar a influência de variáveis meteorológicas, em diferentes fases do ciclo da cultura, para propor modelos empíricos para estimação do número de frutos por planta em laranjeira 'Valência' e laranjeira 'Hamlin'. Utilizaram-se dados amostrais, provenientes da indústria de suco paulista, de número de frutos por planta (NFP), em três classes de idade, referentes aos valores estimados anuais de produtividade, no total de 15 safras (1990/91 a 2004/ 05), e dados meteorológicos (temperatura do ar e precipitação pluvial) para o município de Limeira, SP, Brasil. Foram determinados os coeficientes de correlação linear entre NFP e variáveis meteorológicas componentes do balanço hídrico e temperatura, em diferentes períodos. Modelos de regressão linear múltipla foram ajustados para os subconjuntos de variáveis meteorológicas que apresentaram as maiores correlações significativas com o NFP em diferentes fases do ciclo da cultura. As condições meteorológicas durante as fases de crescimento vegetativo de verão, pré-florescimento, florescimento e início de crescimento dos frutos influenciaram a produção de frutos por planta. Os modelos apresentaram boa qualidade de ajuste, com coeficiente de determinação variando de 0,72 a 0,87.

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Section: Influence Of Meteorological Variables On the Crop Cyclementioning

confidence: 99%

Agrometeorological models for 'Valencia' and 'Hamlin' sweet oranges to estimate the number of fruits per plant

Paulino

Filho

Maia

et al. 2007

Sci. agric. (Piracicaba, Braz.)

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“…An important point is the flowering evaluation method, which is not standardized and thus forces comparisons to previous literature. Regarding flowering evaluation, some authors have considered only branches or shoots of the plant canopy (Lomas & Burd, 1983;Rocha et al, 1990;Nuñez et al, 1992;Koshita et al, 1999;Tonietto & Tonietto, 2005), while others have used a visual scale or taken measurements with frames (hollow squares with varying areas) positioned at single or multiple regions around the plant canopy (Holguín et al, 1992;Nuñez et al, 1992;Araújo et al, 1999;Koller et al, 2000;Sanches et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

'Valencia' sweet orange tree flowering evaluation under field conditions

Ribeiro¹,

Rolim²,

Azevedo³

et al. 2008

Sci. agric. (Piracicaba, Braz.)

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Since citrus flowering is a key process in citriculture and its evaluation is often difficult due to the canopy structure and field sampling, the aim of this research was to give some directions regarding the evaluation of flowering in field-grown sweet orange plants. This study was conducted in a citrus orchard of sweet orange plants cv. 'Valencia' [Citrus sinensis (L.) Osbeck] grafted on 'Cleopatra' mandarin (Citrus reshni hort. ex Tanaka) or 'Rangpur' lime (Citrus limonia Osbeck) rootstocks, with North-South orientation. Generative structures [buds, flowers and fruitlets (diameter < 3 cm)] were quantified weekly between August and November 2005, by using a 1 m 2 frame positioned at the middle third of plant canopy, sampling a volume of about 1 m 3 . Frames were divided in two parts so that two people could take measurements, and were positioned at Southeast, Southwest, Northeast and Northwest orientations, using seven plants. The following flowering parameters were: (i) number of plants necessary for a representative evaluation of flowering; (ii) plant canopy position to be sampled, and (iii) volume to be evaluated. When considering practical aspects of crop production, a rapid, simple and representative method for flowering evaluation is necessary, especially for growers that frequently have to make strategic decisions about the management of citrus groves. The flowering of fieldgrown 'Valencia' sweet orange plants can be rapidly assessed by considering at least five plants and sampling canopy volumes of 0.5 m 3 in at least one canopy position on each side of the plant row. Key words: Citrus spp., bloom, method, sampling AVALIAÇÃO DO FLORESCIMENTO DE LARANJEIRAS VALÊNCIA EM CONDIÇÃO DE CAMPORESUMO: O florescimento dos citros é um processo chave na citricultura e sua avaliação é dificultada devido à estrutura da copa e amostragem em campo. O objetivo desse artigo foi fornecer algumas indicações de como avaliar o florescimento de laranjeiras em condição de campo. Esse estudo foi conduzido em um pomar de laranjeiras 'Valência' [Citrus sinensis (L.) Osbeck] enxertadas em tangerineira 'Cleópatra' (Citrus reshni hort. ex Tanaka) ou limoeiro 'Cravo' (Citrus limonia Osbeck), com orientação Norte-Sul. As estruturas reprodutivas [botões florais, flores e frutos (diâmetro < 3 cm)] foram quantificadas semanalmente entre agosto e novembro de 2005, utilizando guias de 1 m 2 posicionadas no terço médio da copa das plantas, amostrando aproximadamente um volume de 1 m 3 . As guias foram divididas em duas partes para que duas pessoas pudessem realizar as avaliações, e posicionadas nas orientações sudeste, sudoeste, nordeste e noroeste, em sete plantas. Alguns aspectos do florescimento dos citros foram avaliados: (i) quantas plantas são necessárias para uma amostragem representativa do florescimento; (ii) em qual orientação deve ser feita a medida e (iii) qual volume da copa das plantas que deve ser amostrado. Ao se considerar os aspectos práticos da produção dos citros, um método rápido, simples e representativo é n...

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“…Ambient temperature not only has a direct effect on induction and differentiation but also affects fl owering date and intensity (Cassin et al, 1969;García-Luis et al, 1992). Sustained periods of low temperature in winter will produce a later anthesis by delaying initiation of differentiation and reducing the subsequent growth rate of the bud (Lomas and Burd, 1983). High daytime temperatures during fl oral differentiation shorten development time and advance date of anthesis (Moss, 1973a;Valiente and Albrigo, 2002).…”

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confidence: 99%

Flower Bud Induction of Sweet Orange Trees [Citrus sinensis (L.) Osbeck]: Effect of Low Temperatures, Crop Load, and Bud Age

Valiente¹,

Albrigo²

2004

jashs

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Citrus flowering is a complex phenological process influenced by a number of interacting factors. Low winter temperatures are recognized as an important factor, but the flowering response has not been quantified under Variable natural conditions. A study was conducted to monitor the flower bud induction response of `Valencia' and `Hamlin' sweet orange trees [Citrus sinensis (L.) Osbeck] to naturally occurring winter weather conditions during the 1999 and 2000 seasons. The flowering response was quantified and related to shoot age, bud position along the shoot, local weather information, and crop load status. Results indicate that buds on previous summer shoots developed 2.52 and 3.59 to 1 flower on spring shoots, for `Hamlin' and `Valencia', respectively. In addition, buds at apical positions produced more flowers than buds located far from the apex. These basal positions buds required higher induction levels. Under Florida conditions, greater accumulation of hours of temperatures 11 to 15 °C increased floral intensity by the combined effect on the number of sprouting buds with reproductive growth and the number of flowers per flowering bud. Some statistical analyses indicated that high winter temperatures reduced flowering in `Valencia' and `Hamlin' oranges. The presence of fruit consistently reduced reproductive response for both cultivars. Crop load reduced flowering by an average of 41.5% compared to no crop and varied by cultivar. A discussion on the different induction requirements as well as on the differential effect of crop load on flowering by cultivar is presented.

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Prediction of the commencement and duration of the flowering period of citrus

Cited by 14 publications

References 2 publications

Agrometeorological models for 'Valencia' and 'Hamlin' sweet oranges to estimate the number of fruits per plant

Agrometeorological models for 'Valencia' and 'Hamlin' sweet oranges to estimate the number of fruits per plant

'Valencia' sweet orange tree flowering evaluation under field conditions

Flower Bud Induction of Sweet Orange Trees [Citrus sinensis (L.) Osbeck]: Effect of Low Temperatures, Crop Load, and Bud Age

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