Agriculture Reference
In-Depth Information
beneficial. The impact of temperature change can be clearly seen from the
fact that the northern parts of India are warmer than the southern parts,
with a general increase of 3-6°C over the base-period average (Lal et al.,
1995; Lonergan et al., 1998). Studies carried out on perennial trees have to
be contiguous and long range. Since experiments are carried out for short
periods, these studies more often than not have become pointers rather
than conclusive. The increase in temperature has been reported to affect
the phenology of perennial trees. In certain regions where prevailing tem-
peratures are already high, shifts in growing areas may take place. In the
peninsular regions of India, it has been noticed that flowering was en-
hanced by a month in mango, thus affecting the fruit maturity and season
of harvest. In the case of crops like guava, which has adapted very well to
both tropical and subtropical climate environments, changes in tempera-
ture have contributed to shifting of fruiting season.
Under the influence of climate shift, both early and delayed flowering
will be characteristic features in mango. Low temperature (4 to 11.5°C),
high humidity (>80%) and cloudy weather in January delay panicle emer-
gence whereas low temperatures during inflorescence development reduce
number of perfect flowers. The perfect flowers were significantly higher in
the temperature regime of around 27/13°C than in a temperature regime of
21/14°C in mango. If panicle development coincides with an unusual cold
spell, mango production will face several problems. Owing to variations in
temperature, unseasonal rains and higher humidity, fruit trees show altered
flowering trends, with delays in panicle emergence and fruit set. Avail-
ability of hermaphrodite flowers for pollination and fruit set have an effect
on yield due to pollen and stigmatic sterility. Temperature above 30°C
induces maximum flower and fruit drop and high temperature after pol-
len release decreased fruit set and fruit yield in tomato. In papaya, higher
temperatures have resulted in flower drop in female and hermaphrodite
plants as well sex changes in hermaphrodite and male plants. Experimen-
tal findings indicate increased leaf production in banana with increase of
1-2°C temperature beyond 25-30°C, thereby reducing crop duration, and
increasing production. Occurrence of frost during January in Rajasthan
has been reported cumin resulting in total crop failure (Chadha and Ku-
mar, 2012).
