Agriculture Reference
In-Depth Information
over an average of 105 days. However, deviations to this normal showed,
the extended rainfall (15 to 42 days) with increased intensity (122 mm to
1500 mm). This situation leads to unavailability of sufficient physiological
stress conditions, very much crucial for satisfactory induction of flower-
ing in '
Alphonso
' under tropical conditions, thereby impacting flowering
adversely.
Normally rainfall ceases by September end followed by onset of win-
ter from November that continues up to February in the Konkan region.
However, due to delayed and extended rains, this normal weather cycle
is found disturbed and the much needed physiological stress preceding
fruit bud differentiation are lacking and as a consequence, uncontrolled
vegetative flushes have been occurring. Agro-climate, further impacted by
extended cold periods (>122 days of <17 °C in 2011-2012), '
Alphonso
'
manifested three reproductive flushes in the fruiting season despite favor-
able weather conditions prevailing subsequently. Similarly, continuance
of severe cold for extra long periods (62 to 74 days) also prevailed during
2009 and 2010 fruiting seasons that resulted in altered phenophases dy-
namics in '
Alphonso
.' As a result the inflorescences emerging during this
period were abnormal like extra long flowering panicles (42 to 45 cm);
instead of normal (29 to 32 cm), mixed panicles and changed sex ratio.
During 2010-2011, severe cold period (<17 °C) continued for 72 days (in-
stead of 4 to 5 spells of 15 days period) which led to development of extra
long inflorescences with altered sex ratio (4 to 5% hermaphrodite flowers)
characterized by preponderance of male flowers (96%) adversely impact-
ing fruit set; the reduced number and activity of pollinators further com-
pounding the problem. Majority of the inflorescences of this period failed
to set fruits due to inadequate pollination and hence subsequently dried up.
Intermittent flowering phenomenon in the peninsular region in the re-
cent years since 2008 is posing serious problems. During January 2013,
T
Tmin
of the region, ranged between 13 and 16 °C, but on majority of the
days it was between 14 and 15 °C. In the first fortnight of January 2013,
T
Tmin
recorded was between 11 to 18 °C and 10 to 16 °C. Hence, during
2013 fruiting season, the flowering flushes occurred more than twice at-
tributable to this variation. During February 2013, the T
max
was 28.7 °C and
the T
Tmin
was 17.4 °C and the RH was 73%. The data recorded for two fort-
nights revealed very little difference between T
max
and T
Tmin
. However, large
variations in the T
Tmin
were seen during February. On some days the T
Tmin
was 21 °C and in some days after a gap of 6 to 7 days, the same declined to
