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Titre du document / Document title

Using leaf color charts to estimate leaf nitrogen status of rice

Auteur(s) / Author(s)

YANG Woon-Ho (1) ; SHAOBING PENG (2) ; JIANLIANG HUANG (2) ; SANICO Arnel L. (2) ; BURESH Roland J. (2) ; WITT Christian (2) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) Rice Cultivation Res. Div., Natl. Crop Exp. Stn., Rural Dev. Administration., 209 Seodundong, Suwon 441-100, COREE, REPUBLIQUE DE
(2) Crop, Soil, and Water Sci. Div., Int. Rice Res. Inst. (IRRI), DAPO Box 7777, Metro Manila, PHILIPPINES

Résumé / Abstract

Leaf color charts (LCCs) have substituted for chlorophyll meter (SPAD) to estimate leaf N status of rice (Oryza saliva L.) and to properly time N fertilizer application. The objectives of this study were to (i) compare three different types of LCC in estimating leaf N status, (ii) determine if specific leaf weight (SLW) affects the estimation of dry weight-based N concentration (Ndw) by LCC, and (iii) determine the relationship between LCC scores and SPAD values. Two field experiments were conducted in the Philippines with different N rates and cultivars grown during 2000 wet season and 2001 dry season. The LCC score and SPAD reading were taken on uppermost fully expanded leaves at three growth stages, and SLW was calculated as the ratio of dry weight to leaf area. Nitrogen content was determined by micro-Kjeldahl procedure and expressed as Ndw and leaf area-based N content (Na). There was a linear relationship between LCC scores and Ndw at each growth stage (R2 range of 0.25-0.97) and across growth stages (R2 range of 0.46-0.62). Adjusting LCC scores for SLW (LCC/SLW) greatly improved the prediction of Ndw across growth stages (R2 range of 0.84-0.92), suggesting that leaf thickness affects LCC scores. Leaf color chart estimated N, better than Ndw across growth stages. Leaf color chart scores were closely related to SPAD values (R2 range of 0.62-0.98). Strong correlations existed among the scores of the three types of LCC (r range of 0.93-0.99). They are all suitable for use by rice farmers in timing N topdressing.

Revue / Journal Title

Agronomy journal    ISSN  0002-1962   CODEN AGJOAT 

Source / Source

2003, vol. 95, no1, pp. 212-217 [6 page(s) (article)] (22 ref.)

Langue / Language

Anglais

Editeur / Publisher

American Society of Agronomy, Madison, WI, ETATS-UNIS  (1949) (Revue)

Mots-clés anglais / English Keywords

Cereal crop

;

Asia

;

Spermatophyta

;

Angiospermae

;

Monocotyledones

;

Gramineae

;

Philippine Islands

;

Nitrogen fertilizer

;

Oryza sativa

;

Experimental study

;

Comparative study

;

Comparison test

;

Color

;

Plant leaf

;

Decision aid

;

Application time

;

Nutritional status

;

Nitrogen fertilization

;

Mots-clés français / French Keywords

Plante céréalière

;

Asie

;

Spermatophyta

;

Angiospermae

;

Monocotyledones

;

Gramineae

;

Philippines

;

Engrais azoté

;

Oryza sativa

;

Etude expérimentale

;

Etude comparative

;

Test comparaison

;

Couleur

;

Feuille végétal

;

Aide décision

;

Epoque traitement

;

Etat nutritionnel

;

Fertilisation azotée

;

Mots-clés espagnols / Spanish Keywords

Planta cerealista

;

Asia

;

Spermatophyta

;

Angiospermae

;

Monocotyledones

;

Gramineae

;

Filipinas

;

Fertilizante nitrogenado

;

Oryza sativa

;

Estudio experimental

;

Estudio comparativo

;

Test comparación

;

Color

;

Hoja vegetal

;

Ayuda decisión

;

Epoca tratamiento

;

Estado nutricional

;

Fertilización nitrogenada

;

Localisation / Location

INIST-CNRS, Cote INIST : 553, 35400010390905.0230

Nº notice refdoc (ud4) : 14514175



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