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Prediction of Daily Green Leaf Area Index for Corn 1
Author(s) -
Dale Robert F.,
Coelho Dirceu T.,
Gallo Kevin P.
Publication year - 1980
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1980.00021962007200060032x
Subject(s) - leaf area index , phenology , canopy , sowing , agronomy , growing season , evapotranspiration , crop , population , growing degree day , linear regression , sunshine duration , mathematics , environmental science , biology , relative humidity , botany , geography , meteorology , ecology , statistics , demography , sociology
Growth and duration of green leaf area of a crop determines the percentage of incident solar radiation intercepted by the crop canopy and thereby influences canopy photosynthesis, evapotranspiration, and final yields. The objective of this study was to develop a method for predicting the green leaf area index (LAI) for corn ( Zea mays L.) on a daily basis through the growing season. Weekly measurements of the green leaf area (LA) of full‐season corn hybrids planted on one date in 1968 and two dates from 1969 to 1974 at the Purdue University Agronomy Farm, West Lafayette, Indiana, and air temperatures from the adjacent weather station were used to develop the model. A seasonal LAI curve was divided into three phenological periods, based upon the summation of a temperature function from date of planting to day t, ΣFT t . The LAI t during the first period (planting to silking) was described as a logistic function of population and ΣFT t , during the second period (silking to rapid senescence) by a linear regression of LAI t on population and ΣFT t , and during the third period (rapid senescence) by a linear regression of LAI t on the number of days past a ΣFT t threshold. LAI curves were predicted for, and tested against, independent LAI measurements. The predicted curves compard well with the LAI measurements when used on nonstressed full season hybrids similar to those from which the equations were developed.