Agriculture Reference
In-Depth Information
mango growing cultivars/strains at PAU Fruit Research Station, Gangian
(Dasuya) in Hoshiarpur district of Punjab was recorded during January-
February, 2008. The plants growing adjoining to the boundary or blocks
covered with windbreak (jamun, eucalyptus trees) recorded minimum fo-
liage damage. Mango trees planted without boundary plantation or away
from the windbreak or shelterbelt had recorded maximum foliage damage.
This situation resulted complete fruit yield loss in 2008 and the following
year due to damage of terminal shoot with frost injury.
In banana, only a half leaf is produced if temperature falls below 15 °C
and leaf emergence stopped below 9-10 °C (Turner, 2003). In subtropical
regions the bunch emergence during winter season show uneven ripen-
ing and deformed fruits. Chilling symptoms are turning of leaf lamina to
yellow in color, midrib may show brown areas which are water soaked
underneath. The symptoms on older leaf resembles to that of potash defi-
ciency. If temperature falls below freezing, bunches become water soaked,
blacken and die (Ravi and Mustaffa, 2011). High temperatures reduce both
the duration of flushing and the interval between flushes. Low temperature
also affects the rate of reproductive development with panicles emerging
earlier but taking longer time to reach anthesis. In litchi, average tem-
perature of 18 °C is associated with higher numbers of female flowers and
temperature of 23 °C decreases number of hermaphrodite flowers. It has
been observed that the areas with winter temperature maximum of above
25 °C are not well suited for litchi cultivation.
2.4
HIGH CARBON DIOXIDE LEVEL
One of the possible beneficial effects of climatic shift for the plants may
be obtained from elevated level of carbon dioxide in the atmosphere. In
general, the plants that are raised under enhanced carbon dioxide show
increased rate of net photosynthesis. This increased photosynthesis ulti-
mately result in higher dry matter production and consequently increased
yields of the plants (Kimball, 1983; Cure, 1985). But, the enhanced rate
of photosynthesis may lead to enhance respiration rate thereby requiring
more water to draw from the soil, resulting water stress under water de-
ficient conditions. In a study, Robinson et al. (1998) reported that during
the initial period of growth of sour orange plants, the bark, limbs, and
fine roots growing in an atmosphere with 700 ppm of CO
2
showed rates
