Agriculture Reference
In-Depth Information
vorable year (1981-1982) revealed that during both adverse years, there
was a distinct break in the rainfall during critical period following flower
initiation. Though the break was experienced during different crop growth
stages, the pepper yields were only 24.3% of the normal years yield. But
in the favorable year, rainfall was steady without any break and the pep-
per yield was also high (Pillay et al., 1988). This gives an indication that
climate change in terms of drought period during the normal monsoon
season affects black pepper productivity. All these studies point to the fact
that there is a climate change in recent years, which is affecting flowering
pattern and yield of black pepper.
11.2.2 RAINFALL DEFICIT AND PEPPER PRODUCTIVITY
Government of India had declared 1987 and 2002 as drought years as the
rainfall during those years was less than 80% of long-term average through-
out India. The rainfall deficit during 1987 was around 20% for Wynad and
Coimbatore, 15% for Kannur and only around 7% for Idukki while the
deficit during 2002 was more than 30% for black pepper growing regions
except Coimbatore (28.5%). The black pepper productivity also was below
normal (mean of 1984-04) for all the places (except Coimbatore where the
black pepper growing area is very less) indicating the negative influence
of rainfall deficit on black pepper productivity. Interestingly, though the
rainfall deficit was more pronounced during 2002, productivity reduction
was more during 1987 compared to 2002 for Wynad and Idukki. When we
analyzed the reason, we found that good premonsoon (January to May)
and early monsoon (June-July) rains and well distributed rainfall during
2002 compared to 1987 contributed for better productivity.
11.2.3 CLIMATE CHANGE AND PEPPER PRODUCTION
W.R.T. TEMPERATURE
Though black pepper is a crop of humid tropics and tolerates temperatures
between 10 and 40
o
C, the ideal temperature for its growth is 23-32 °C
with an average of 28 °C. Optimum soil temperature for root growth is
26-28 °C (De Waard 1969; Wahid and Sitepu 1987). A study on 140 years
of climatic data of Kerala indicated increase in day maximum by 0.64 °C
