Submitted to: Agronomy Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/1/2003
Publication Date: 2/1/2004
Citation: Vina, A., A.A. Gitelson, D.C. Rundquist, G. Keydan, B Leavitt, and J. Schepers. 2004. Monitoring maize (Zea mays L.) phenology with remote sensing. Agron. J. 96:1139-1147. Interpretive Summary: Remote sensing is rapidly becoming recognized as a technology that can help characterize soil and plant features on the landscape. Producers and consultants are finding this information useful when making management decisions that would normally be based on plant growth stage. Remote sensing images illustrate the degree of variability in things like canopy closure, initiation of the reproductive process, and onset of senescence. Visualizing the variability component within images is useful when scouting fields to determine the cause(s) of these observations and assess management options. The temporal aspects of phenological events have implications related to irrigation scheduling, remediation of nutrient deficiencies, the practicality of dealing with insect and disease problems, and scheduling harvesting operations.
Technical Abstract: Monitoring crop phenology is required for understanding intra- and inter-annual variations of agroecosystems, as well as for improving yield prediction models. The objective of this paper is to remotely evaluate the phonological development of maize (Zea mays L.) in terms of both biomasss accumulation and reproductive organ appearance. Maize phenology was monitored by means of the recently developed visible atmospherically resistant indices, derived from spectral reflectance data. Visible atmospherically resistant indices provided significant information for crop phenology monitoring as they allowed us to detect: (i) changes due to biomass accumulation, (ii) changes induced by the appearance and development of reproductive organs, and (iii) the onset of senescence, earlier than widely used vegetation indices. Visible atmospherically resistant indices allowed the identification of the timing of phonological transitions that are related to the maize physiological development. They also allowed identification of the onset of the grain-fill period, which is important since maximum yield potential of maize plants depends on optimal environmental conditions during this period.