Mango (Mangifera india L.) is the most important fruit
crop of Indian sub-continent as well as in other tropical
countries of the world. Although, India is a largest mango
producing nation in the world but we export a very
negligible amount of fresh fruit. In West Bengal the
productivity is lesser because unregulated the mango
orchard causing severe deterioration of productivity. After
planting continuously neglect the mango orchards as result
orchard become jungles and covered by Loranthus causing
poor light penetration and mutual shading of canopy. The
scientific cultural practices are not applied by farmer as
result ultimately reduces dry matter production and
deteriorates the vigour and yield of trees have declined
markedly. Due to the low productivity there is very little
incentive gain by farmers. Productivity and profitability of
mango orchard may be enhanced by changing its bearing
habit (namely irregularity and seasonality) and by canopy
management that reduce the problem of excessive vegetative
growth. Growth regulators may be an effective way for
checking vegetative growth & regularized seasonal
flexibility in bearing habit with different bio-physical
processes of mangos. Paclobutrazol a plant growth retardant,
reduce vegetative growth and enhance percentage of
flowering (Khader 1991) and inhibit gibberellin biosynthesis
has been reported to be effective for flowering induction in
mango (Anan et al. 2000) and high yield also (Burandkar et
al. 2000). Side by side Paclobutrazol increased chlorophyll a
and b content, and photosynthetic efficiency. PBZ treatment
increased the net photosynthetic rate and internal CO2
concentration in Catharanthus roseus (Jaleel et al. 2007).
Paclobutrazol is eco-friendly, non-toxic, can safely be use in
crop field having various influential roles in physiological
system of mango plant is well known, but is unknown or
little known about its effect on different seasonal fraction.
Hence, the present experiment was conducted in mango cv.
Himsagar to study the effect of paclobutrazol on
photosynthesis and respiration in different months of year.