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Two Methods for the Rapid Assessment of Leaf Yield of Erythroxylum Coca Var. Coca
Author(s) -
Acock Mary C.
Publication year - 1998
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/agronj1998.00021962009000050021x
Subject(s) - coca , canopy , interception , yield (engineering) , mathematics , environmental science , botany , agronomy , biology , geography , ecology , physics , archaeology , thermodynamics
Methods for estimating yields of Erythroxylum coca var. coca were devised and compared. For the PCA method, yields were estimated from canopy light interception, specific leaf area (SLA), and a calibration factor. For the canopy subsample method (CSS), yield was estimated from leaf number, size, and SLA subsamples multiplied by the ratio of canopy to subsample volume. Corrected PCA overestimated yields by 9% and CSS underestimated yields by 7% for a test dataset. The CSS method requires more field time, but uses simple equipment that can be applied at any time. The PCA method requires expensive equipment and uniform light, and it cannot be used when it is raining.