Caracterización del efecto de estrés usando índices espectrales de la vegetación para la estimación de variables relacionadas con la biomasa del área

the use of spectral indexes or vegetation vi, based on iso-lai lines in the spectral space of red (r) and near infrared (nir), presents different relations in vegetative and senescence periods with biophysical variables such as aerial biomass or bm, the index of foliar area or lai, or aerial vegetation cover or fv. with the isvi index based on iso-soil lines of the r-nir space, the temporal patterns may be identified by an expo-linear and exponential model. thus, the slopes for the vegetative phase and for senescence can be used to quantify the stress level utilizing the concept of environmental equivalence. this scheme of characterization was analyzed with radiometric and fv measurements in crops of bean (phaseolus vulgaris l.), chickpea (cicer arietinum. l.), safflower (carthamus tinctorius l.), sorghum (sorghum bicolor, l. moench), and wheat (triticum spec. l.) of the valle del yaqui, state of sonora, méxico. the obtained results support the approximation of the characterization proposed for the stress level.