Rcn. Rao et al., Rapid assessment of specific leaf area and leaf nitrogen in peanut (Arachis hypogaea L.) using a chlorophyll meter, J AGRON CR, 186(3), 2001, pp. 175-182
Citations number
27
Categorie Soggetti
Agriculture/Agronomy
Journal title
JOURNAL OF AGRONOMY AND CROP SCIENCE-ZEITSCHRIFT FUR ACKER UND PFLANZENBAU
The present study investigates the potential use of a hand-held portable SP
AD chlorophyll meter for rapid assessment of specific leaf area (SLA) and s
pecific leaf nitrogen (SLN), which are surrogate measures of transpiration
efficiency(TE) in peanut (Arachis hypogaea L.). The effects of sampling (le
af position, time of sampling and leaf water status) and climatic factors (
solar radiation and vapour pressure deficit, VPD) on SLA and SPAD chlorophy
ll meter reading (SCMR) were studied in a range of peanut genotypes grown u
nder field and greenhouse conditions. The correlation between SLA and SCMR
was significant (r = -0.77, P < 0.01) for the second leaf from the apex but
the correlation declined for leaves sampled from lower nodal positions. Th
e diurnal fluctuation in SLA ranged from -20% to +10%, whereas SCMR was rel
atively unaffected by these diurnal changes. Solar radiation and VPD during
the sampling period had a significant influence on the relationship betwee
n SLA and SCMR, largely through their effects on SLA. However, standardizat
ion of SLA for these environmental factors significantly improved the relat
ionship between SLA and SCMR from -0.50 to -0.80 (P < 0.01), suggesting tha
t, when protocols for leaf sampling and SLA measurements are followed, SCMR
call be a surrogate measure of SLA. There were significant relationships b
etween SLN and SCMR (r=0.84, P < 0.002) and SLN and SLA (r=-0.81, P < 0.01)
. These significant interrelationships amongst SLA, SLN and SCMR suggested
that SCMR could be used as a reliable and rapid measure to identify genotyp
es with low SLA or high SLN (and hence high TE) in peanut.