This document summarizes a study on the influence of sowing period on floral characteristics of maize during rainy and spring seasons. Key findings include: 1) During the rainy season, first pollen shed and silking occurred earliest when sowing was done in August, while highest pollen viability was observed with June sowing. September sowing resulted in the longest tassels. 2) In the spring season, earliest first pollen shed and silking was observed with September sowing. Highest pollen viability and longest tassels also occurred with September sowing. 3) Sowing date significantly impacted various floral traits like days to pollen shed and silking, tassel characteristics, and

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Agricultural Science Research Journal Vol. 5(11): 140 - 145, November 2015
Available online at http://resjournals.com/journals/agricultural-science-research-journal.html
ISSN: 2026 –6073 ©2015 International Research Journals
Full length Research Paper
INFLUENCE OF SOWING PERIOD ON FLORAL
CHARACTERS OF MAIZE (ZEA MAYS L.) DURING RAINY
AND SPRING SEASONS
*V Sandeep Varma, K Kanaka Durga, K Keshavulu and N Sunil
Seed Research and Technology Centre, Rajendranagar, Hyderabad.
*Corresponding Author’s Email: sandeepvunnam81@gmail.com
Abstract
Studies on “Influence of sowing period on floral characters of Maize (Zea mays L.) during rainy and spring
seasons” was carried out under field conditions at SRTC, Hyderabad, India during the year 2012. Female (BML 6)
and male (BML 7) parents of DHM 117 were sown at fortnightly intervals (from first fortnight of June to second
fortnight of December) in 4:1 row ratio in RBD with three replications. During rainy season, first pollen shed (57
days), 50 % pollen shed (61 days), first silking (54 days) and 50 % silking (60 days) were early when Maize was
sown during August second fortnight, while high pollen viability (97.5 %) was recorded during June second
fortnight. With respect to tassel characters, long tassels (36.5 cm) during September first fortnight sowing, more
number of pollen shedding spikelets tassel
-1
(758) and total spikelet branches tassel
-1
(13.3) during first fortnight
of june were observed. Sowing in June first fortnight resulted in tall female plants (128.4 cm), while tall male
plants (162.3 cm) were observed during September first fortnight sowing. During spring season, first pollen shed
(66 days), 50 % pollen shed (70 days), first silking (64 days) and 50 % silking (68 days) were early when Maize was
sown during September second fortnight. High pollen viability (98.1 %) at 9 AM and at 2 PM (94.4 %) was
recorded during September second fortnight. Among tassel characters, long tassels (34.1 cm), more number of
pollen shedding spikelets tassel
-1
(801) and total branches tassel
-1
(15.2) were observed during September
second fortnight and October first fortnight sowing.
Keywords: Maize, Sowing date, Pollen and Floral characters
Introduction
Maize (Zea mays L., 2n=20) occupies third position
among the cereal crops after rice and wheat in the world.
It is the most versatile crop with wide adaptability to varied
agro-ecologies. The most contributing factor for its
success is the highest genetic yield potential among the
food grain crops. The crop is cultivated in different parts of
the country throughout the year for various purposes like
grain, fodder, green cobs, sweet corn, baby corn, popcorn
etc. Nonfood products of commercial importance such as
starch, alcohol and dextrinsare also manufactured from
Maize. Ethanol is produced from Maize which is a
substitute for petroleum based fuels. The United States of
America is the largest producer, contributing 20 % of the
world’s Maize production. The other important Maize
growing countries are China, Brazil, Mexico, India and
Indonesia. The time of sowing is one of the basic
agronomic practices which have a greater and a very
important role on seed productivity particularly in India
where the optimum time of sowing varies considerably
due to widely varying agro-climatic conditions and due to
the intricate crop weather relationship especially in Maize.
With the development of hybrids, the yield has been
enhanced to a greater extent. But a bottle neck comes in
this way is the difference in the flowering time of the
parental lines, which has drastic effect on the seed set.
The most important determining factor for the hybrid seed
production of Maize is the synchronization of flowering of
male and female parents.
To achieve the effective seed set, the stage of stigma
receptivity and the stage of anthesis of the seed parent
and pollinator parent should coincide. These relationships
with climate can also be useful for estimating planting
dates in regions where there are no observations. With

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this background, the present investigation on effect of
sowing date on floral behavior in Maize was undertaken.
Materials and Methods
A field experiment was conducted at Seed Research and
Technology Centre, Acharya N.G.Ranga Agricultural
University, Rajendranagar, Hyderabad and was laid out in
a Randomized Block Design (RBD) with three replications.
Planting of female (BML 6) and male (BML 7) parents of
DHM 117 was taken up in ratio of 4:1 in a plot size of
49.25 m
2
per each plot with a spacing of 60 x 25 cm.
Fortnightly sowings were taken up during first fortnight of
June to second fortnight of December with a total of seven
sowings for rainy season and seven sowings for spring
season as treatments.
Observations like days to first pollen shed, days to 50 %
pollen shed, days to first silking, days to 50 % silking,
tassel length (cm), number of pollen shedding spikelets
tassel
-1
, total number of silks cob
-1
, and pollen viability (%)
were taken on male and female parents. The data
collected from the experiment was analyzed statistically as
per the procedure given by Panse and Sukhatme (1985).
Critical differences were calculated at 5 % level.
Results and Discussion
During Rainy season
The first pollen shed was early in August second fortnight
sowing (57 days) and first silking was early in August
second fortnight sowing (54 days) which was due to the
prevailing moderate temperatures (26.35 ºC) and
relatively high relative humidity (87.27 %) at the time of
sowing, favouring the crop growth (Tab. 1). August first
fortnight sowing recorded 75 days for 50 % pollen shed
whereas delay in sowing to August second fortnight
recorded 61 days for 50 % pollen shed which was early by
two weeks. This was in conformity with the findings of
Sangoi (1993) who reported that the period between
emergence and anthesis of Maize hybrids planted earlier
in the season can be up to two weeks longer when the
same cultivar is planted later.Days to 50 % silking were
early in August second fortnight sowing (60 days) followed
by September first fortnight (64 days) (Fig. 1). This was in
conformity with the findings of William et al. (1977) who
reported that differences in development rate from
planting to half-silk (when 50 % of plants have silked)
varied with location and with planting date within a
location.
Table 1: Influence of planting window on flowering behavior of the parental lines (BML 6 and BML 7) of Maize hybrid,
DHM 117 during Rainy season, 2012
Dates of
sowing
Days to
first
pollen
shed
Days to
50 %
pollen
shed
Days to
first
silking
Days
to 50
%
silking
Tassel
length
(cm)
No. of
pollen
shedding
spikelets
tassel
-1
No. of
pollen
shedding
days
Total
spikelet
branches
tassel
-1
Pollen
viability (%)
9 AM 2 PM
01-06-2012
66 68 59 71 31.1 758 4.3 13.3 96.7 96.3
15-06-2012
61 65 57 72 30.2 618 4.3 11.2 97.5 93.9
01-07-2012
65 70 67 70 33.2 675 4.3 12.1 93.2 85.6
15-07-2012
66 68 62 69 33.1 504 4.0 9.0 90.7 83.1
01-08-2012
63 75 60 71 32.3 670 5.3 12.8 95.4 92.6
15-08-2012
57 61 54 60 29.0 665 4.7 10.9 97.3 96.5
01-09-2012
63 66 59 64 36.5 559 4.7 12.4 95.2 94.6
Sowing in September first fortnight produced significantly
long tassel (36.5 cm), mainly due to the expansion of the
tassels under favorable weather conditions like moderate
rainfall coupled with adequate relative humidity and proper
sunshine hours. June first fortnight sowing recorded
significantly more number of pollen shedding spikelets
tassel
-1
(758) compared to July first fortnight sowing (675).
Sowing in June second fortnight recorded higher pollen
viability (97.5 %) followed by August second fortnight
(97.3 %) sowing and Pollen viability was more in early
plantings (June) and slowly decreased for July sowings
and further increased during late sowing (August and
September) (Fig 2). The decrease in pollen viability might
be due to the changes that occurred in the weather
conditions i.e., high rainfall of 16.6 mm coupled with low
sunshine hours (6.3) which might have contributed to the
low pollen viability for July sowings. Lower pollen viability
at high temperatures could be related to degeneration of

3. 142
tapetum layer in snap bean (Suzuki et al., 2001), and/or
decreased carbohydrate metabolism (Datta et al., 2001
and Karni and Aloni, 2002), all of which could significantly
influence nourishment of pollen mother cells there by
leading to infertile pollen.
Fig. 1: Days to 50 % pollen shed and silking at different planting windows during Rainy, 2012
Fig. 2: Influence of planting window on pollen viability during Rainy Season, 2012
During spring season
The first pollen shed was early in September second
fortnight sowing (66 days) followed by October first
fortnight (69 days) and this could be due to prevailing
moderate temperatures (26.6 ºC) coupled with relatively
high relative humidity (88.9 %) at the sowing time, which
favored the crop growth (Tab. 2). The appearance of first
tassel was late in December first fortnight sowing (79
0
10
20
30
40
50
60
70
80
JUNE I
FN
JUNE II
FN
JULY I
FN
JULY II
FN
AUG I
FN
AUG II
FN
SEP I FN
Numberofdays
Dates of sowing
Days to 50 % pollen shed Days to 50 % silking
96.7
97.5
93.2
90.7
95.4
97.3
95.2
96.3
93.9
85.6
83.1
92.6
96.5
94.6
82.0
84.0
86.0
88.0
90.0
92.0
94.0
96.0
98.0
100.0
JUNE I
FN
JUNE II
FN
JULY I
FN
JULY II
FN
AUG I
FN
AUG II
FN
SEP I FN
Pollenviability(%)
Dates of sowing
9:00 AM 2:00 PM

4. 143
days) followed by November second fortnight sowing (78 days) and December second fortnight sowing (74 days).
Table 2: Influence of planting window on flowering behavior of the parental lines of Maize hybrid, DHM 117 during Spring,
2012
Dates of
sowing
Days to
first
pollen
shed
Days to
50 %
pollen
shed
Days to
first
silking
Days to 50
% silking
Tassel
length
(cm)
No. of
pollen
shedding
spikelets
tassel
-1
No. of
pollen
shedding
days
Total
spikelet
branches
tassel
-1
Pollen
viability (%)
9
AM
2
PM
01-06-
2012 66 70 64 68 34.1 801 5.3 15.2 98.1 94.5
15-06-
2012 69 74 66 72 33.4 737 4.7 14.3 94.2 90.9
01-07-
2012 69 75 66 74 28.7 671 4.7 14.2 93.8 90.9
15-07-
2012 73 76 71 74 30.5 668 5.0 13.9 93.6 89.7
01-08-
2012 78 82 73 81 31.3 625 4.3 14.0 92.8 88.7
15-08-
2012 79 82 73 82 30.0 630 4.3 13.9 92.5 88.6
01-09-
2012 74 79 73 77 26.7 591 4.0 13.6 92.3 86.8
Delay in shedding of pollen on the male parent during
December could be attributed to low temperature (21.5
ºC), low relative humidity (79.8 %), zero rain fall coupled
with more sunshine hours (8.5 hours) which might have
led to poor growth of the plants. These findings were in
general agreement with the results of Matzenauer et al.
(1998), who reported that early planted Maize flowers
earlier in the growing season when the atmospheric
evaporative demand is usually smaller, thus decreasing
the probability of moisture stress.Days to 50% pollen shed
varied from 70 to 82 days (Fig 3). However, the 50 %
pollen shed was early in September second fortnight
sowing (70 days) and significantly different from October
first fortnight sowing (74 days) and other sowing dates.
The appearance of tassel in 50 % of plants was late in
December first fortnight sowing (82 days) followed by
November second fortnight sowing (82 days). Matzenauer
et al. (1998) opined that early planted Maize flowers
earlier in the growing season when atmospheric
evaporative demand is usually smaller, thus decreasing
the probability of moisture stress.

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Fig. 3: Days to 50 % pollen shed and silking at different planting windows during Spring, 2012
The first silking was early in September second fortnight
sowing (64 days) followed by October first fortnight (66
days). During September second fortnight sowing, the
temperatures were optimum (26.6 ºC), comparatively high
relative humidity (88.9 %) and high rainfall (3.2 mm),
which enhanced the crop vegetative growth, so that the
plants might reach the reproductive phase very quickly.
This was supported by Tamura et al. (1989) who reported
that environmental parameters like temperature and
rainfall had a significant effect on flowering behaviour of
Maize where in development of silk and air temperature
followed a sigmoid curve and days to flowering had a
negative correlation with temperature.Tollenaar and
Bruulsema (1988) found that the time from silking to
physiological maturity lengthened with delay in planting
date. The 50 % silking was early in September second
fortnight sowing (68 days) and during this time, Maize crop
was subjected to optimum temperature, comparatively
high relative humidity (88.9 %) and high rainfall (3.2 mm),
which enhanced the crop vegetative growth, so that the
plants may reach the reproductive phase very quickly.
This was in accordance with Jong et al., 1982, who
reported that increase in temperature by 1 ºC decreased
the time to silking by 4.3 days. William et al. (1977)
reported that differences in development rate for time from
planting to 50 % silking varied by location and by planting
date within a location. The difference between days to 50
% pollen shed and days to 50 % silking was very low i.e.,
either one day or two days, throughout all the sowing
dates. This difference might be minor for good pollen–silk
synchrony in seed production, especially if time to silking
is modified to the same extent, detasselling efforts
become easier to manage across many fields when the
time to pollen shed is most accurately predicted.
Sowing in September second fortnight produced
significantly long tassel (34.1 cm) and it could be mainly
due to the expansion of the tassels under favorable
weather factors like moderately rainfall with adequate
relative humidity and proper sunshine hours. September
second fortnight sowing recorded significantly more
number of pollen shedding spikelets tassel
-1
(801)
followed by October first fortnight sowing (737). As the
total length of the tassel during September first fortnight
increased, the production of total number of pollen
shedding spikelets tassel
-1
also increased to a similar
extent at the same sowing date which leads to more
number of pollen shedding spikelets during that sowing
period. Sowing in September second fortnight recorded
higher pollen viability (98.1 %) followed by October first
fortnight (94.2 %) sowing. Pollen viability was more in
early plantings (September and October) and slowly
decreased for later sowings (November and December)
(Fig. 4). The decrease in pollen viability in November and
December sowings might be due to the changes that
occurred in the weather conditions i.e., low temperatures
of 20.0 ºC, no rainfall (0.0 mm) coupled with high sunshine
hours (8.8 hours) which might have contributed to low
pollen viability in December sowings. Due to the presence
of cool climatic conditions, generally dehiscence of pollen
will be prolonged and this could be one reason for low
pollen viability at 9 A.M. In contrast, Schoperet al. (1986)
reported that high temperatures had negative effect on
pollen viability in Maize. Similarly, Vara Prasad et al.
(2006) also reported that growing grain sorghum at
temperatures beyond 36 °C significantly decreased pollen
production and pollen viability.
0
10
20
30
40
50
60
70
80
90
SEP II
FN
OCT I
FN
OCT II
FN
NOV I
FN
NOV II
FN
DEC I
FN
DEC II
FN
Numberofdays
Dates of sowing
Days to 50 % pollen shed Days to 50 % silking

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Fig. 4: Influence of planting window on pollen viability during Spring season, 2012
Conclusion
To get the perfect synchronization of male and female
lines of maize hybrids and also to get high pollen viability
maize was sown during August second fortnight during
rainy season and September second fortnight during
spring season.
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98.1
94.2 93.8 93.6
92.8 92.5 92.3
94.5
90.9 90.9
89.7
88.7 88.6
86.8
82.0
84.0
86.0
88.0
90.0
92.0
94.0
96.0
98.0
100.0
SEP II
FN
OCT I
FN
OCT II
FN
NOV I
FN
NOV II
FN
DEC I
FN
DEC II
FN
Pollenviability(%)
Dates of sowing
9:00 AM 2:00 PM