Estimation of orange yield in citrus orchard based on digital photography

The citriculture is an activity that has relevance in the Brazilian agribusiness. Many researchers have sought to develop methods for oranges yield estimation, however few are simple and accurate. Thus, the aim of this work is to develop a practical method to estimate number of fruits and fruit´s mass per plant of sweet orange cv. “Valencia” [Citrus sinensis (L.) Osbeck] orange grafted on ‘Rangpur’ lime (Citrus limonia Osbeck) rootstocks with North-South orientation using digital camera. Were taken 2 photos per plant in orange orchard, one for each face (southeast and northeast). The photos were visually analyzed by 3 assessors. In the harvest we quantify the number of fruits (NFR), medium fruits mass (MMF, g) and fruit´s mass per plant (KFP, kg plant-1). Were tested the number of photos needed to the estimations and what face could show greater accuracy. The number of fruits per plant can be estimated with high precision using 10 photos taken of the Northeast face of the trees. The estimation of the fruit´s mass per plant it is also possible using 11 photos taken of the Northeast face of the trees.   Key words: Modeling, digital camera, Citrus, linear regression.