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Pyrethrum yield estimation by digital image analysis


Scott, JB and Pethybridge, SJ and Hay, FS, Pyrethrum yield estimation by digital image analysis, 2011 APS-IPPC Joint Meeting Abstracts of Presentations, 6-10 August, Honolulu, Hawaii, pp. S162. (2011) [Conference Extract]

PDF (Scott, J. B., Pethybridge, S. J., and Hay, F. 2011. Pyrethrum yield estimation by digital image analysis. Phytopathology 101:S162)
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Pyrethrum is grown for the production of insecticidal pyrethrins. Production in Australia is constrained by a number of fungal pathogens, including Stagonosporopsis ligulicola and Sclerotinia spp. To accurately assess control strategies for these and other diseases, a practical method of yield assessment is required. Previously, yield assessment has relied upon destructive, manual harvesting, which is both costly and time consuming. As an alternative, yield estimation by digital image analysis was trialled at 29 sites in summer 2010, with replication. Images were taken at a height of 0.9 m above the crop canopy, encompassing a defined 0.7 0.7 m quadrat, placed level with flower height. Image capture occurred once over 50% ray florets were open within a crop. With the software package ImageJ, HSB color thresholding was used to isolate the yellow centres of individual flowers, from which the particle analyser function estimated the number of flowers per quadrat. Linear regression indicated a strong relationship between automated (AC) and manual (MC) flower counts, (AC = 21.1 + 0.97*MC; R2 = 0.95, P < 0.0001) with an intercept not significantly greater than zero. A significant correlation was also obtained between automated flower counts and hand harvested dry weight of flowers (DW) from each quadrat (AC = 109.1 + 3.45*DW; R2 = 0.488, P < 0.0001). These results highlight the potential for predicting yield using non-destructive image capture.

Item Details

Item Type:Conference Extract
Keywords:pyrethrum, image analysis, yield estimation
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant pathology
Objective Division:Plant Production and Plant Primary Products
Objective Group:Horticultural crops
Objective Field:Horticultural crops not elsewhere classified
UTAS Author:Scott, JB (Dr Jason Scott)
UTAS Author:Pethybridge, SJ (Dr Sarah Pethybridge)
UTAS Author:Hay, FS (Dr Frank Hay)
ID Code:100312
Year Published:2011
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2015-05-11
Last Modified:2015-05-11

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