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- Title
Escala diagramática de quantificação de dano causado por granizo em folhas de girassol.
- Authors
Lucas, Dionéia Daiane Pitol; Heldwein, Arno Bernardo; Maldaner, Ivan Carlos; Dalcin, Joner Silveira; Loose, Luis Henrique
- Abstract
The objective of this study was to develop a diagrammatic scale for the visual assessment and the quantification of hail damage in sunflower leaves. The study was carried out in an experimental area in Santa Maria (RS) during the agricultural year of 2008/2009, the damage being caused by a hail-storm event which occurred on 8 January, 2009, with the sunflower plants in full bloom (R5.1) and a leaf-area index of 2.2 m2m-2. A total of 243 damaged leaves were collected, which before collection had their outlines redrawn with the aid of complete leaves of similar shape. After determining the percentage of the damaged area, images were selected to make up the diagrammatic logarithmic scale. A test of the scale was undertaken by 10 different observers on 24 randomly selected leaves from the 243 collected. The accuracy and precision of each appraiser were determined by simple linear regression of actual damage and that estimated with the aid of the diagrammatic scale, in addition we used the Root Mean Square Error (RMSE), the absolute error and the coefficient of determination (R2) of the linear regression. It was found that the scale is suitable for the observation of leaf damage caused by hail.
- Subjects
SUNFLOWERS; HAIL; EFFECT of hail on plants; LEAVES -- Environmental aspects; PLANTS &; the environment; REGRESSION analysis; PHYSIOLOGY
- Publication
Revista Ciência Agronômica, 2012, Vol 43, Issue 4, p822
- ISSN
0045-6888
- Publication type
Article
- DOI
10.1590/S1806-66902012000400026