Flowering estimation in apple orchards by image analysis

Tree-specific management practice related to individual tree physiological condition is necessary for higher quality and quantity in apple fruit production. Detection of apple flowering abundance based on analysis of HSL (hue, saturation, luminance) images was used to estimate the number of flower clusters (FC) of individual trees in a high density apple orchard. The image acquisition was performed with a still camera and an industrial color camera during the day and night. The FC estimation algorithm included HSL thresholding with parameter optimization. Three hypothetical, tree-specific management practices (sprayings) were assumed, using >25, >50 and >100 FC thresholds to carry out the practice. When an industrial camera was used for image acquisition during the daytime and hypothetical spraying was done by on/off criterion >100 FC per tree, 10 % incorrect executions were identified. Comparable FC counting performance was achieved by using a still camera or an industrial camera.

[1]  D. Bochtis,et al.  Yield prediction in apple orchards based on image processing , 2011, Precision Agriculture.

[2]  D. Stajnko,et al.  Modelling apple fruit yield using image analysis for fruit colour, shape and texture. , 2009 .

[3]  H. Jeon,et al.  Original paper: Evaluation of ultrasonic sensor for variable-rate spray applications , 2011 .

[4]  A. Escolà,et al.  Variable rate dosing in precision viticulture: use of electronic devices to improve application efficiency. , 2010 .

[5]  Anatoly A. Gitelson,et al.  Monitoring Maize (Zea mays L.) Phenology with Remote Sensing , 2004 .

[6]  Arnon Karnieli,et al.  A spectral index to monitor the head-emergence of wheat in semi-arid conditions , 2009 .

[7]  L. C. Grappadelli,et al.  Spatial Analysis of the Effect of Fruit Thinning on Apple Crop Load , 2009 .

[8]  A. Escolà,et al.  Variable rate application of plant protection products in vineyard using ultrasonic sensors , 2007 .

[9]  Yael Edan,et al.  Computer vision for fruit harvesting robots - state of the art and challenges ahead , 2012, Int. J. Comput. Vis. Robotics.

[10]  Raphael Linker,et al.  Determination of the number of green apples in RGB images recorded in orchards , 2012 .

[11]  J. Tromp.  lower-bud formation in pome fruits as affected by fruit thinning , 2000, Plant Growth Regulation.

[12]  Kelly R. Thorp,et al.  Analysis of hyperspectral reflectance data for monitoring growth and development of lesquerella , 2011 .

[13]  Edward M. Barnes,et al.  Method for Using Images from a Color Digital Camera to Estimate Flower Number , 2000 .

[14]  M. J. Bukovac,et al.  A Long-term Study on Native Variation of Flowering and Fruiting in Spur-type 'Delicious' Apple , 2010 .

[15]  Q. Zaman,et al.  Software development for real-time ultrasonic mapping of tree canopy size , 2005 .

[16]  G. Doruchowski,et al.  Environmentally friendly spray techniques for tree crops , 2000 .

[17]  H. Tukey.  ALTERNATE BEARING OF FRUIT TREES. , 1922, Science.

[18]  T. Godeša,et al.  Design and testing of an automated system for targeted spraying in orchards , 2010 .

[19]  T. A. Gemtos,et al.  Spatial variation in yield and quality in a small apple orchard , 2010, Precision Agriculture.

[20]  F. G. Jr. Dennis,et al.  The history of fruit thinning , 2000, Plant Growth Regulation.

[21]  M. J. Delwiche,et al.  Sprayer control by sensing orchard crop characteristics: Orchard architecture and spray liquid savings , 1989 .

[22]  Brane Širok,et al.  Design and Testing of an Ultrasound System for Targeted Spraying in Orchards , 2011 .

[23]  Kelly R. Thorp,et al.  Color image segmentation approach to monitor flowering in lesquerella , 2011 .

[24]  E. Goldschmidt,et al.  Alternate Bearing in Fruit Trees , 1982 .