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

Silvia Elisandra Pasqua Paulino,Durval Dourado Neto,Tatiana Eugenia Cantuarias Avilés,Francisco De Assis Alves Mourão Filho,Aline De Holanda Nunes Maia

doi:10.1590/s0103-90162007000100001

Silvia Elisandra Pasqua Paulino, Durval Dourado Neto + Show 3 more

Open Access

https://doi.org/10.1590/s0103-90162007000100001

Copy DOI

Journal: Scientia Agricola	Publication Date: Feb 1, 2007
Citations: 8	License type: cc-by

Affiliation: Methodist University of Piracicaba

Abstract

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, pre-flowering, 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.

Highlights

Brazil is the current major world citrus producer, which is mainly commercialized for industrial processing of frozen concentrated orange juice for export
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
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

Summary

Introduction

Brazil is the current major world citrus producer, which is mainly commercialized for industrial processing of frozen concentrated orange juice for export. Significant correlations between NFP and agrometeorological predictors were observed for ‘Valencia’ (Table 1) and for ‘Hamlin’ sweet oranges (Table 2) along the flowering year before harvest and at the beginning of the harvest year, at four stages, in the three age classes: during the summer months (January and February), in the pre-flowering period (April to September), during the flowering (October to No-Table 1 - Correlation coefficients (r) between the number of fruits per plant and meteorological variables corresponding to different periods during harvest seasons from 1990 to 2004.

Results

Conclusion