HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Tewolde, H. Articles by Tsegaye, T. Search for Related Content PubMed Articles by Tewolde, H. Articles by Tsegaye, T. Agricola Articles by Tewolde, H. Articles by Tsegaye, T. Related Collections Agroclimatology Crop Growth and Development Crop Models

Notes and Unique Phenomena

ESTIMATING COTTON LEAF AREA INDEX NONDESTRUCTIVELY WITH A LIGHT SENSOR

^a USDA-ARS, 810 Highway 12 East, Mississippi State, MS 39762
^b USDA-ARS, 230 Bennett LN, Bowling Green, KY 42104
^c Alabama A&M Univ., P.O. Box 1208, Normal, AL 35762

^* Corresponding author (htewolde{at}ars.usda.gov)

Received for publication April 28, 2004. AccuPAR, which is a relatively new instrument for estimating leaf area index (LAI) by measuring light interception, has wide distribution but only limited independent evaluation of its accuracy. The objective of this study was to evaluate the accuracy of AccuPAR for estimating LAI of cotton (Gossypium hirsutum L.) planted on different row spacings. Cotton LAI was measured nondestructively with AccuPAR and destructively by taking plant samples three to four times during each growing season in 2002 and 2003 on research conducted at three locations in Mississippi, USA. The results suggested that meter accuracy was affected by differences between row spacing and the length of the light-sensing segment of the meter. Supplemental tests showed that meter accuracy improved with meter placement, which eliminated length differences and with near solar noon measurements, which minimized row-to-row shading overlap. We conclude that the meter can more accurately estimate row crop LAI when the under-canopy placement of the meter and the time of measurement are selected so that the light-sensing segment of the meter captures shading of an entire row cross-section and that row-to-row shading overlap is eliminated or minimized.

Abbreviations: LAI, leaf area index • PAR, photosynthetically active radiation • SLA, specific leaf area • UAN, urea–ammonium nitrate solution

This article has been cited by other articles:

				H. Tewolde, M. W. Shankle, K. R. Sistani, A. Adeli, and D. E. Rowe No-Till and Conventional-Till Cotton Response to Broiler Litter Fertilization in an Upland Soil: Lint Yield Agron. J., May 7, 2008; 100(3): 502 - 509. [Abstract] [Full Text] [PDF]

				P. Ravishankar, R.R. Lada, C.D. Caldwell, S.K. Asiedu, and A. Adams The Effects of Light, Rehilling, and Mulching on Greenshoulder and Internal Greening in Carrots Crop Sci., May 31, 2007; 47(3): 1151 - 1158. [Abstract] [Full Text] [PDF]