Effects of Paclobutrazol on Podding and Photosynthetic Characteristics
in Peanut
Sachiko Senoo and Akihiro Isoda
(Faculty of Horticulture, Chiba University, Matsudo, Chiba 271-8510, Japan)
Abstract
The effects of paclobutrazol on podding habits and photosynthetic
characteristics (CO2 assimilation rate, quantum yield of photosystem
II (ƒ³PSII) and chlorophyll content) were examined in peanut. The
paclobutrazol treatment at the beginning of the pod formation
stage increased the percentage of podding, particularly by early-blooming
flowers, leading to an increase in seed yield. The major factor
for this effect may have been an acceleration of dry matter distribution
to the early bearing pods with inhibition of stem growth by the
paclobutrazol treatment. The paclobutrazol treatment at the early
pod formation stage increased chlorophyll content andƒ³PSII, resulting
in enhanced CO2 assimilation rates. In the long term, crop growth
rate and net assimilation rate tended to have increased after
the paclobutrazol application, although these effects were not
significant. The effects of the paclobutrazol treatment on the
photosynthetic characteristics, however, were efficacious just
during a rather short period at a proper growing stage, suggesting
that increased efficiencies of the photosynthetic characteristics
would not be the main factor for increasing seed yield.