Affordable and easy-to-use methods for assessing biomass and leaf area index （LAI） would be of interest in most breeding programs. Here, we describe the evaluation of a protocol for photographic sampling and image a...Affordable and easy-to-use methods for assessing biomass and leaf area index （LAI） would be of interest in most breeding programs. Here, we describe the evaluation of a protocol for photographic sampling and image analysis aimed at providing low-labor yet robust indicators of biomass and LAI. In this trial, two genotypes of triticale, two of bread wheat, and four of tritordeum were studied. At six dates during the growing cycle, biomass and LAI were measured destructively, and digital photography was taken on the same dates. Several vegetation indices were calculated from each image. The results showed that repeatable and consistent values of the indices were obtained in consecutive photographic samplings on the same plots. The photographic indices were highly correlated with the destructive measure-ments, though the magnitude of the correlation was lower after anthesis. This work shows that photographic assess-ment of biomass and LAI can be fast, affordable, have good repeatability, and can be used under bright and overcast skies. A practical vegetation index derived from pictures is the fraction of green pixels over the total pixels of the image, and as it shows good correlations with all biomass variables, is the most robust to lighting conditions and has easy interpretation.展开更多
基金funded by the Spanish Ministry of Science and Innovation,project AGL2005-07257-C04-03the Spanish Ministry of Agriculture,projects RTA2010-00007-00-00 and RTA2012-00011-00-00
文摘Affordable and easy-to-use methods for assessing biomass and leaf area index （LAI） would be of interest in most breeding programs. Here, we describe the evaluation of a protocol for photographic sampling and image analysis aimed at providing low-labor yet robust indicators of biomass and LAI. In this trial, two genotypes of triticale, two of bread wheat, and four of tritordeum were studied. At six dates during the growing cycle, biomass and LAI were measured destructively, and digital photography was taken on the same dates. Several vegetation indices were calculated from each image. The results showed that repeatable and consistent values of the indices were obtained in consecutive photographic samplings on the same plots. The photographic indices were highly correlated with the destructive measure-ments, though the magnitude of the correlation was lower after anthesis. This work shows that photographic assess-ment of biomass and LAI can be fast, affordable, have good repeatability, and can be used under bright and overcast skies. A practical vegetation index derived from pictures is the fraction of green pixels over the total pixels of the image, and as it shows good correlations with all biomass variables, is the most robust to lighting conditions and has easy interpretation.
