abid thesis (results and discussion)
TRANSCRIPT
Chapter 4
RESULTS AND DISCUSSION
A field experiment was conducted to investigate the effect of encapsulated
calcium carbide on production and post harvest performance of potato (Solanum
tuberosum L) hybrid “Sante” at the research farm of the Department of Horticulture,
University of Arid Agricuture Rawalpindi during January 2006.
Data regarding the effect of ECC on growth, yield and post harvest life are
presented and discussed in the following pages.
4.1 Number of days required for Seed tuber sprouting
The data regarding number of days required for germination is present in
Table-1. The data shows that maximum number of days (25.57) required for seed
sprouting were observed in the treatment T1 (control) while minimum (21.72) in
treatment T3 (ECC 60 kg ha-1).The ANOVA reveals that the treatments T1 (control), T2
(ECC 30 kg ha- 1),T4 (ECC 90 kg ha-1) and T5 (ECC 120 kg ha-1) did not statistically
differ from each other but differed statistically from the treatment T3 (ECC 60 kg ha-1).
It clearly indicates that the ethylene produced by the calcium carbide
stimulates the germination rate by triggering the respiration rate as in general many
cellular process such as respiration are suppressed during dormancy. It clears the fact
the ECC enhance the seed tubers sprouting by producing ethylene. And these results
are same as Bibik (1995 )and Muromstev et al. (1991).
Table 4.1: Mean values of treatments for number of days required for seed tuber Treatments Original order Ranked order
T1 (control) 25.57a+0.65 T1 25.57a
T2 ( ECC 30 Kg/ha ) 23.95ab+0.96 T2 23.95ab
T3 ( ECC 60 Kg/ha ) 21.72b+0.38 T5 23.55ab
T4 ( ECC 90 Kg/ha) 23.39ab+0.58 T4 23.39ab
T5 ( ECC 120 Kg/ha) 23.55ab+0.82 T3 21.72b
sproutingAny two means not sharing a letter differ significantly at 95 % level of probability.
4.2 Tubers sprouting percentage
The ANOVA regarding sprouting is presented in Table-2 and tabulated in
Appendix II. The analysis variance shows that the sprouting percentage is more in
case where the different doses of ECC were applied. The data shows that maximum
(94.83%) sprouting percentage was found in the treatment T3 (ECC 60 kg ha-1).The
treatment T1 (control) produces lowest tubers sprouting percentage (80.47%). Data
represented shows that the control treatment T1 and T5 (ECC 120 kg ha-1) did not
differ from each other statistically but differ from all other treatments significantly.
The treatment T2 (ECC 30 kg ha-1) and T5 (ECC 120 kg ha-1) also did not differ from
each other but these treatment differ statistically from all other treatments. The
treatment T3 (ECC 60 kg ha-1) differ significantly from the treatments T1, T2, T4 and
T5. The treatment T4 (ECC 90 kg ha-1) also differed significantly from other treatments
T1, T2, T3 and T5.The treatment T5 (ECC 120 kg ha-1) did not differ from the treatment
T1 (control) and T2 (ECC 30 kg ha-1) but differed statistically from the treatment T3
(ECC 60 kg ha-1) and T4 (ECC 60 kg ha-1). The descending order of treatments is like
T3 > T4 > T5 >T2 > T1.
Maximum tubers sprouting percentage (94.83%) was observed due to the
production of ethylene via ECC which breaks the dormancy by enhancing the
respiration rate. It also reduces the growth inhibiting hormone (ABA) produced in
dormant potato tuber. These results are in relation with the results of Bibik (1995) and
Cvikrova et al (1994).
Table 2:- Mean values of treatments for tubers sprouting percentageTreatments Original order Ranked order
T1 (control) 80.47d +0.41 T3 94.83a
T2 ( ECC 30 Kg/ha ) 84.30c +1.45 T4 85.69b
T3 ( ECC 60 Kg/ha ) 94.83a +1.20 T2 84.30c
T4 ( ECC 90 Kg/ha) 85.69 b+1.94 T5 83.35cd
T5 ( ECC 120 Kg/ha) 83.35cd+2.29 T1 80.47d
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
4.3 Plant Height (cm)
Data regarding the effect of ECC on plant height are graphically shown in
Table-3 and presented in Appendix III. Data clearly indicate that ECC application
reduces the plant height. Maximum plant height (36.07 cm) was observed in treatment
T1 (control) while minimum plant height (26.12 cm) was observed in T3 (ECC 60 kg
ha-1). The data in table (4.3) reveals that the treatment T1 (control) differ statistically
from all other treatment. The treatment T2 (ECC 30 kg ha-1) also differ statistically
from the other treatments T1, T3, T4 and T5.The treatment T3 (ECC 60 kg ha-1), T4
(ECC 30 kg ha-1) and T5 (ECC 120 kg ha-1) did not differ significantly among each
other but differed statistically from the treatment T1 (control) and T2 (ECC 30 kg ha-1).
The descending order of the treatments is T1 > T2 > T5 > T4 >T3.
Application of ECC has non-significant effect on plant height over control.
Analysis of variance shows that plant height was significantly decreased by the
application of ECC as compared to control. This decrease in height was significantly
more in T3, T4, T5 where ECC was applied @ 60,90,120 kg ha-1 as compared to
control or T2 where ECC was applied @ 30 kg ha-1. This response is proven character
of ethylene released from ECC. This is because ethylene inhibits the movement of
auxin in stem tissue, possibly reducing auxin’s ability to promote stem elongation
(Morgan and Gausman 1966). Many workers such as Slife and Earley (1970), Brown
and Earley (1973) have reported this behavior of ethylene.
Table 3:- Mean values of treatments for plant height (cm)
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Treatments Original order Ranked order
T1 (control) 36.37a+1.10 T1 36.37a
T2 ( ECC 30 Kg/ha ) 33.07b+1.43 T2 33.07b
T3 ( ECC 60 Kg/ha ) 26.12c+0.99 T5 28.47c
T4 ( ECC 90 Kg/ha) 26.95c+1.09 T4 26.95c
T5 ( ECC 120Kg/ha) 28.47c+1.04 T3 26.12c
4.4 Number of stems per plant
The data regarding number of stem per plant is graphically shown in Table-4
and tabulated in appendix IV. The ANOVA shows a significant difference among the
treatments. The number of stems is more in case where ECC was applied. The data
shows that maximum number of stems (7.01) were produced in case of T3 where ECC
was applied @ 60 kg ha-1 while T4 where ECC was applied @ 90 kg ha-1 follows it.
The minimum number of stems per plant (2.06) were found in the treatment T1
(control).The control treatment T1 differed significantly from the other treatments.
The data in table also shows that treatment T2 (ECC 30 kg ha-1) and treatment T5 (ECC
120 kg ha-1) did not differ significantly from each others but statistically differ with
treatment T1 (control), T3 (ECC 60 kg ha-1) and T4 (ECC 90 kg ha-1) respectively. The
treatment T3 (ECC 60 kg ha-1) differed significantly from all other treatments. The
treatment T4 (ECC 90 kg ha-1) also differed significantly from all other treatments T1,
T2, T3 and T5.The descending order of all the treatments is T3 > T4 > T2 > T5 > T1.
It is because of the production of ethylene and acetylene produces after the
breakdown of ECC. Ethylene triggers the formation of adventitious roots while
acetylene increases the N use efficiency of plant. With the extension of roots and
increase in N use efficiency vegetative growth is enhanced. These results are in line
with the findings of Keerthisinghe et al. (1993), Keerthisinghe et al. (1996),
Seenewera et al. (2003) and Rehim et al. (2004). All of them have reported similar
results in different crops.
Table 4:- Mean values of treatments for number of stems per plant
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Treatments Original order Ranked order
T1 (control) 2.06d+0.16 T3 7.01a
T2 ( ECC 30 Kg/ha ) 2.91c+0.14 T4 3.99b
T3 ( ECC 60 Kg/ha ) 7.01a+0.09 T5 3.02c
T4 ( ECC 90 Kg/ha) 3.99b+0.04 T2 2.91c
T5 ( ECC 120 Kg/ha) 3.02c+0.11 T1 2.06d
4.5 Number of leaves per plant.
Data regarding the effect of calcium carbide on number of leaves per plant
showed significant differences among the treatments means. The data is present in
Table-5 and tabulated in appendix V. Statistical analysis of the data showed that ECC
treatments T3 (ECC 60 kg ha-1) and T4 (ECC 90 kg ha-1) were statistically non
significant from each other but differed significantly from all other treatments.
Maximum number of leaves per plant (98.97) was observed where ECC was applied
@ 60 kg ha-1 while minimum number of leaves (80.47) were observed in the treatment
T1 (control). Similarly treatments T1 (control), T2 (ECC 60 kg ha-1) and T5 (ECC 120
kg ha-1) were found non significant with each other.
It is obvious from the data that ECC had marked influence on plant vegetative
growth. With the extension of roots and increased N use efficiency number of leaves
per plant were increased. While in case of T5 where ECC was applied @ 120 kg ha-1
number of leaves per plant were less (86.5) because of more ethylene production in
the root zone which inhibits the plant growth. These results are similar with the
findings of Keerthisinghe et al. (1993), Keerthisinghe et al. (1996), Seenewera et al.
(2003), Rehim et al. (2004) and Andrew et al (1981). All of them have reported
similar results in different crops.
Table 5:- Mean values of treatments for number of leaves per plant.
Figures in the same column with different letters differ significantly (α = 0.05) by
LSD
Treatments Original order Ranked order
T1 (control) 80.45b+2.22 T3 98.97a
T2 ( ECC 30 Kg/ha ) 86.01b+2.75 T4 98.8a
T3 ( ECC 60 Kg/ha ) 98.97a+2.25 T5 86.5b
T4 ( ECC 90 Kg/ha) 98.8a+2.49 T2 86.01b
T5 ( ECC 120Kg/ha) 86.5b+0.86 T1 80.45b
4.6 Leaf area (cm2)
The data regarding leaf area is graphically presented in Table-6 and tabulated
in appendix VI. The statically analysis of the data showed a significant difference
among the treatments. The data in table reveals that the treatments T3 (ECC 60 kg ha-1)
and T4 (ECC 90 kg ha-1) were non significant from each other and differ statistically
among all other treatments. The treatments T2 (ECC 60 kg ha-1), T4 (ECC 90 kg ha-1)
and T5 (ECC 120 kg ha-1) were also found non significant with each other but
significant with T3 (ECC 60 kg ha-1) and T1 (control).The treatment T3 (ECC @) 60 Kg
ha-1) gave maximum leaf area (65.48 cm2) while minimum leaf area (48.18 cm2) was
found in case of T1 (control).
The treatments receiving ECC gave better results as the ECC produces
acetylene which decreases the nitrification process and enhance the nitrogen use
efficiency in the plants which ultimately results in the more vegetative growth. And as
the acetylene is then converted into ethylene which increases the root area so more
nutrient absorption and more growth of the plants. In case of control where no
acetylene is produced the leaf area is less and so there is less photosynthesis rate and
less metabolic processes. These results are in accordance with the findings of Arshad
et al 1993.
Table 6:- Mean values of treatments for leaf area (cm2)
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Treatments Original order Ranked order
T1 (control) 48.18c+1.06 T3 65.48a
T2 ( ECC 30 Kg/ha ) 59.08b+1.26 T4 61.79ab
T3 ( ECC 60 Kg/ha ) 65.48a+1.94 T2 59.08b
T4 ( ECC 90 Kg/ha) 61.79ab+1.31 T5 58.06b
T5 ( ECC 120 Kg/ha) 58.06b+1.24 T1 48.18c
4.7 Photosynthesis rate
The statistical data concerning photosynthesis rate is presented in Table-7 and
tabulated in appendix VII.The data was collected through Infrared gas analyzer
(IRGA). The data clearly indicates that the treatment T3 (ECC @) 60 Kg ha-1) had
pronounced effect on the photosynthesis rate with maximum photosynthesis rate
(27.10 u mole/ m2/sec) while minimum photosynthesis rate (18.14 u mole/m2/sec) was
observed in the treatment T1 (control). The treatment T3 (ECC @) 60 Kg ha-1) was
closely followed by T5 (ECC @) 120 Kg ha-1), T4 (ECC @) 90 Kg ha-1) and T2 (ECC
@ 30 Kg ha-1) with numerical value 24.82 u mole/m2/sec, 22.86 u mole/m2/sec and
21.02 u mole/m2/sec respectively.
The data clearly indicates that the ECC affects the photosynthesis rate. This
high photosynthesis rate is due to the effect of acetylene on the N fertilizers applied.
The acetylene reduces the losses of N via nitrification inhibition and increasing the
vegetative growth like number of leaves per plant and number of stem per plant. As
no of leaves per plants are more, the photosynthesis rate is more. The treatment T3
(ECC @) 60 Kg ha-1) gave the best results as it provide the optimum level of ethylene
necessary for plant growth while the other treatments, though have significant
difference when comparing with control, have less photosynthesis rate may be
because of more ethylene production in the rhizosphere of the plant which slowed
down the growth gradually. These results coincide with the results of Brown and
Earley (1973), Keerthisinghe et al. (1993), Keerthisinghe et al. (1996) and Seenewera
et al. (2003).
Table 7:- Mean values of treatments for photosynthesis rate
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Treatments Original order Ranked order
T1 (control) 18.14d+0.13 T1 27.10a
T2 ( ECC 30 Kg/ha ) 21.02cd+0.13 T5 24.82ab
T3 ( ECC 60 Kg/ha ) 27.10a+0.07 T4 22.86bc
T4 ( ECC 90 Kg/ha) 22.86bc+0.19 T2 21.02cd
T5 ( ECC 120Kg/ha) 24.82ab+0.08 T1 18.14d
4.8 Number and weight of small size tubers per plant
The statistical analysis of data is given in Appendix (VIII & IX) and
represented in Table-8 and Table-9. In Table-9 mean values for number of small size
tuber differ significantly. Analysis of variance showed that the treatments T1 (control),
T2 (ECC @) 30 Kg ha-1) and T5 (ECC @) 120 Kg ha-1) did not differ statistically from
each other but differed from the treatment T3 (ECC @) 60 Kg ha-1). Maximum number
of small size tubers per plant (3.35) were found in the treatment T5 (ECC @) 120 Kg
ha-1) while minimum number of small size tubers (2.57) were present in the treatment
T3 (ECC @) 60 Kg ha-1).
The data shows clear impact of ECC on potato crop. Calcium carbide produces
ethylene under soil moisture condition which triggers adventitious root formation at
optimum level. In accordance with the data in case of the treatment T5 (ECC @) 120
Kg ha-1), maximum number of small size tubers might be due to the more production
of ethylene gas which inhibits the root and stolons extension. This may lead towards
limited area for tuber production.
The data pertaining the weight of small size tubers per plant is presented in
Table- 9. Weight of tubers is directly related with number of tubers. Statistical
analysis of the data reveals that treatments T3 (ECC @) 60 Kg ha-1) and T4 (ECC @)
60 Kg ha-1) did not differ statistically with each other but these were found significant
from the treatments T1 (control) and T5 (ECC @) 120 Kg ha-1). Maximum weight of
small size tubers per plant (118.32 g) was recorded from the treatment T5 (ECC @)
120 Kg ha-1) while minimum weight of small size tubers (90.94 g) was found in the
treatment T3 (ECC @) 60 Kg ha-1).
Data regarding the weight of small size tubers directly correlate with the
number of small size tubers per plant. It might be due to the more production of
ethylene (T5) which inhibits the root and stolon extension or might be due to the lack
of nutrient uptake efficiency (control).
Table 8:-Mean values of treatments for number of small size tubers per plant
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Table 4.9:-Mean values of treatments for weight (g) of small size tubers per plant Treatments Original order Ranked order
T1 (control) 112.14a+3.01 T5 118.32a
T2 ( ECC 30 Kg/ha ) 108.16ab+4.74 T1 112.14a
T3 ( ECC 60 Kg/ha ) 90.94c+6.01 T2 108.16ab
T4 ( ECC 90 Kg/ha) 96.24bc+6.66 T4 96.24bc
T5 ( ECC 120 Kg/ha) 118.32a+4.20 T3 90.94c
Figures in the same column with different letters differ significantly (α = 0.05) by
LSD
Treatments Original order Ranked order
T1 (control) 3.17a+0.08 T5 3.35a
T2 ( ECC 30 Kg/ha ) 3.06ab+0.13 T1 3.17a
T3 ( ECC 60 Kg/ha ) 2.57c+0.17 T2 3.06ab
T4 ( ECC 90 Kg/ha) 2.72bc+0.18 T4 2.72bc
T5 ( ECC 120 Kg/ha) 3.35a+0.11 T3 2.57c
4.9 Number and weight of medium size tubers per plant
The statistical analysis of data is given in Appendix (X & XI) and represented
in Table-10 and Table-11. In Table-10 data regarding the number of medium size
tubers is presented. These results indicate positive interaction among the treatments.
Data further revealed that there was statistically non significant difference between
the treatments T3 (ECC @) 60 Kg ha-1) and T4 (ECC @) 90 Kg ha-1) while the
treatments T3 and T4 were found statistically significant from the treatments T1
(control), T2 (ECC @) 30 Kg ha-1) and T5 (ECC @) 120 Kg ha-1). In accordance with
the data maximum number of medium size tubers per plant (5.95) were found in the
treatment T3 (ECC @) 60 Kg ha-1) while minimum number of medium size tubers per
plant (3.65) were recorded in the treatment T1 (control).
Data clearly indicates the positive impact of ECC on potato tuber size. Reason
for higher number of medium size tubers per plant might be due to the good nutrients
availability as ethylene accelerates the formation of the adventitious roots, providing
ample supply of nutrients to develop medium size tubers per plant.
Data regarding the weight of medium size tubers are presented in Table-
11.The treatments pertaining calcium carbide application showed that the treatment T3
(ECC @) 60 Kg ha-1) and T4 (ECC @) 90 Kg ha-1) were significantly different from
the treatment T1 (control), T2 (ECC @) 30 Kg ha-1) and T5 (ECC @) 120 Kg ha-1).
Maximum weight of medium size tubers per plant (228.47 g) was recorded with T3
(ECC @) 60 Kg ha-1) while minimum weight of medium size tubers per plant (139.97
g) was noted with T1 (control).
Probable reason for higher weight of medium size tubers per plant might be
due to more number of medium size tubers per plant (Table-10). This might also be
due to the ethylene which develops good root system which ensures more
conservation of the nutrients and water. So, more nutrients are stored which improves
the photosynthesis. Higher rate of photosynthates production and their translocation to
the developing tubers might have resulted in production of more weight of medium
size tubers per plant.
Table 4.10:- Mean values of treatments for number of medium size tubers per plant
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Table 4.11:- Mean values of treatments for weight (g) of medium size tubers per plant
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Treatments Original order Ranked order
T1 (control) 3.65b+0.13 T3 5.95a
T2 ( ECC 30 Kg/ha ) 3.95b+0.13 T4 5.57a
T3 ( ECC 60 Kg/ha ) 5.95a+0.07 T2 3.95b
T4 ( ECC 90 Kg/ha) 5.57a+0.19 T5 3.92b
T5 ( ECC 120 Kg/ha) 3.92b+0.08 T1 3.65b
Treatments Original order Ranked order
T1 (control) 139.97b+5.07 T3 228.47a
T2 ( ECC 30 Kg/ha ) 151.48b+5.07 T4 213.80a
T3 ( ECC 60 Kg/ha ) 228.47a+2.83 T2 151.48b
T4 ( ECC 90 Kg/ha) 213.80a+7.56 T5 150.52b
T5 ( ECC 120 Kg/ha) 150.52b+3.27 T1 139.97b
4.10 Number and weight of large size tubers per plant
The statistical analysis of data is given in Appendix (XII & XIII) and
represented in Table-12 and Table-13. Data in Table-12 shows number of medium
size tubers per plant. The ANOVA of data showed that maximum number of large
size tubers per plant (4.15) were present in the treatment T3 (ECC @) 60 Kg ha-1)
while minimum number of large size tubers per plant (2.25) were present in the
treatment T1 (control). Data revealed that the treatment T3 (ECC @) 60 Kg ha-1) differ
statistically from the treatments T1 (control), T2 (ECC @) 30 Kg ha-1) and T5 (ECC @)
120 Kg ha-1) while non significant interaction was found with T4 (ECC @) 90 Kg ha-
1).
Application of calcium carbide showed positive impact over number of large
size tubers per plant. Calcium carbide on decomposition liberates the ethylene which
triggers the different vegetative phase of plant i.e. adventitious roots, number of stem,
number of leaves, leaf area and photosynthesis rate. Increase in vigour results in more
photosynthates assimilation in the leaf cells. Later on these photosynthates are
exported to the developing tubers through phloem producing more number of large
size tubers per plant. The reason for lower number of tubers per plant in case of T5
might be due to the more production of ethylene which inhibits the root and stolons
extension minimizing the area for tuber production.
Data regarding the weight of large size tubers per plant is presented in Table-
13. Analysis of variance reveals that the treatment T3 (ECC @) 60 Kg ha-1)
significantly differ with T1 (control), T2 (ECC @) 30 Kg ha-1) and T5 (ECC @) 120
Kg ha-1). Maximum weight of large size tubers per plant (158.94 g) was recorded in
the treatment T3 (ECC @) 60 Kg ha-1) while minimum weight of large size tubers per
plant (86.75) was noted in the treatment T1 (control).
Reason for maximum weight of large size tubers per plant might be due to the
production of more number of leaves per plant resulting in more production of
photosynthates which might have translocated to the tuber for storage leading to the
increase in weight of large size tubers.
Table 4.12:- Mean values of treatments for number of large size tubers per plant
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Table 4.13:- Mean values of treatments for weight (g) of large size tubers per plant
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Treatments Original order Ranked order
T1 (control) 2.25d+0.23 T3 4.15a
T2 ( ECC 30 Kg/ha ) 3.1bc+0.19 T4 3.57ab
T3 ( ECC 60 Kg/ha ) 4.15a+0.11 T2 3.1bc
T4 ( ECC 90 Kg/ha) 3.57ab+0.25 T5 3.1cd
T5 ( ECC 120 Kg/ha) 3.1cd +0.26 T1 2.25d
Treatments Original order Ranked order
T1 (control) 86.17d+9.18 T3 158.94a
T2 ( ECC 30 Kg/ha ) 118.73bc+7.49 T4 136.92ab
T3 ( ECC 60 Kg/ha ) 158.94a+4.55 T2 118.73bc
T4 ( ECC 90 Kg/ha) 136.92ab+9.68 T5 96.70cd
T5 ( ECC 120 Kg/ha) 96.70cd+10.2 T1 86.17d
4.11 Total number and weight of tubers per plant
Data regarding the effect of different doses of ECC application on total
number and weight of tubers per plant are graphically shown in Table-14 and Table-
15. Data in Table-14 shows the effect of ECC on total number of tubers. The analysis
of variance revealed that the treatment T3 (ECC @) 60 Kg ha-1) had non significant
difference with T4 (ECC @) 90 Kg ha-1) but significantly differed with T1 (control), T2
(ECC @) 30 Kg ha-1) and T5 (ECC @) 120 Kg ha-1). Maximum number of tubers
(12.68) were recorded in the treatment T3 (ECC @) 60 Kg ha-1) while minimum total
number of tubers per plant (9.07) were noted in T1 (control).
Total number of tubers can be attributed to the number of small, medium and
large size tubers per plant. ECC @) 60 Kg ha-1 might be an optimum level of ethylene
production, providing the suitable conditions for various physiological processes in
plants resulting in better vegetative growth, which might be the possible reason for
more total number of tubers per plant.
Data regarding the total weight of tubers per plant is presented in Table-
15.The results regarding the total weight of tubers per plant indicated that the
treatment T3 (ECC @) 60 Kg ha-1) and T4 (ECC @) 90 Kg ha-1) did not differ
significantly from each other but differ significantly from all other treatments.
Maximum weight of tubers per plant (478.36 g) was recorded with T3 (ECC @) 60 Kg
ha-1) while minimum weight of tubers per plant (338.29 g) was noted with the
treatment T1 (control).
In accordance with the data calcium carbide have positive role in term of
weight. Increase in weight by ECC application might be due to the fact that ECC
reduces the nitrification losses, increase N- use efficiency. Beside that application of
ECC can also attribute to increase in level of ethylene which increases the respiration
and rapid growth of lateral branches and leaves resulting in higher number of tubers
which in turn produced maximum total weight of tubers per plant.
These results are in line with the findings of Slife and Earley (1970), Brown
and Earley (1973), Keerthisinghe et al. (1993), Keerthisinghe et al. (1996) and
Seenewera et al. (2003). All of them reported similar results in different crops.
Table 14:- Mean values of treatments for total number of tubers per plant
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Table 15:- Mean values of treatments for total weight (g) of tubers per plant
Figures in the same column with different letters differ significantly (α = 0.05) by
LSD
Treatments Original order Ranked order
T1 (control) 9.07b+0.32 T3 12.68a
T2 ( ECC 30 Kg/ha ) 10.11b+0.40 T4 11.87a
T3 ( ECC 60 Kg/ha ) 12.68a+0.32 T2 10.11b
T4 ( ECC 90 Kg/ha) 11.87a+0.23 T5 9.8b
T5 ( ECC 120 Kg/ha) 9.8b+0.38 T1 9.07b
Treatments Original order Ranked order
T1 (control) 338.29b+12.22 T3 478.36a
T2 ( ECC 30 Kg/ha ) 378.38b+15.29 T4 446.97a
T3 ( ECC 60 Kg/ha ) 478.36a+12.07 T2 378.38b
T4 ( ECC 90 Kg/ha) 446.97a+9.33 T5 365.55b
T5 ( ECC 120 Kg/ha) 365.55b+14.48 T1 338.29b
4.12 Yield kg ha-1
Yield of potato crop is directly related to number of tubers and their weight
and indirectly related to the plant expansion(i.e. number of stem, number of leaves
and leaf area) to facilitate photosynthetic rate. Data presented in Table-16 showed that
yield differed statistically among all the treatments.
The analysis of variance showed that maximum yield (26281.98kg ha-1) was found
in the treatment T3 (ECC @) 60Kg ha-1) while minimum yield (16930.39kg ha-1) was
observed in the treatment T1(control).The data shows that the treatment T1 (control),
T2 (ECC @) 30Kg ha-1) and T5 (ECC @) 120Kg ha-1) did not statistically differ from
each other but these treatments differed significantly from the treatments T3 (ECC @)
60 Kg ha-1) and T4 (ECC @) 90 Kg ha-1). The treatment T3 (ECC @) 60 Kg ha-1)
significantly differ from all other treatments. The treatment T4 (ECC @) 90 Kg ha-1)
also statistically differ from all other treatments.
In general, results indicate that yield was significantly increased by the application
of ECC and is attributed to the enhanced nutrient uptake by the tubers due to:
Increased adventitious root that was stimulated by ethylene release.
It may occur also due to ability of ECC to inhibit nitrification, thus reducing N
losses and assuring its availability for long period. As N cannot be stored in
leaves and its continuous supply is required especially in tuber forming stage.
These results are in complete compliance with the findings of Rao and Fritz
(1987), Zhang et al. (1992), Bronson et al. (1993), Smith et al. (1993), Tanimoto et
al. (1995), Chaiwanakupt (1996), Hazzrika and Sarkar (1996), Seenewera et al.
(2003) and Rehim et al. (2004).
Table 16:- Mean values of treatments for yield kg ha-1
Figures in the same column with different letters differ significantly (α = 0.05) by
LSD
Treatments Original order Ranked order
T1 (control) 7.59a+0.60 T2 11.63a
T2 ( ECC 30 Kg/ha ) 11.63a+0.70 T3 11.02a
T3 ( ECC 60 Kg/ha ) 11.02a+3.69 T4 10.02a
T4 ( ECC 90 Kg/ha) 10.02a+3.37 T5 8.54a
T5 ( ECC 120 Kg/ha) 8.54a+0.65 T1 7.59a
4.13 Disease Incidence percentage
The data regarding disease incidence percentage is presented in Table-17 and
tabulated in appendix XVII. The ANOVA reflects that maximum disease incidence
percentage (11.63 %) was found in the treatment T2 (ECC @) 30 Kg ha-1) while
minimum disease incidence percentage (7.59 %) was observed in the treatment T1
(Control). Analysis of variance shows that all the treatments have non significant
difference from each other.
Data in table clearly indicates that ECC treatments means were found more
susceptible to disease as compared to control. Potato crop was affected by the
Anthracnose disease (Celletotrichum spp) during the month of February but it was
controlled at initial level with the help of fungicide (Diathian M-45) and no severe
damage was occurred. As for as disease susceptibility is concerned, it might be due to
the application of ECC which enhances the production of the growth regulator
ethylene which triggers the vegetative growth. Such lush green crop with succulent
leaves and stem became susceptible for the pathogens. Similar results were reported
by Jones and Jones (1993).
Table 17:- Mean values of treatments for disease incidence percentage
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Treatments Original order Ranked order
T1 (control) 16930.39c+790.87 T3 26281.98a
T2 ( ECC 30 Kg/ha ) 19471.54c+473.99 T4 23587.98b
T3 ( ECC 60 Kg/ha ) 26281.98a+861.51 T2 19471.54c
T4 ( ECC 90 Kg/ha) 23587.98b+657.10 T5 19011.62c
T5 ( ECC 120 Kg/ha) 19011.62c+1862.94 T1 16930.39c
4.14 Weight loss percentage
Table-18 showed the data regarding weight loss percentage by the tubers. The
statistical analysis showed highly significant results among the treatments. The data
shows that maximum weight loss percentage (19.65 %) was observed in the treatment
T1 (control), closely followed by T5 (ECC @) 120 Kg ha-1) as (19.06 %). Minimum
weight loss percentage was investigated in the treatment T3 (ECC @) 60 Kg ha-1).
Analysis of variance also reflects that the control treatment and T5 (ECC @) 1200 Kg
ha-1) did not differ statistically from each other but these treatments differ statistically
from the treatment T2 (ECC @) 30 Kg ha-1) and T3 (ECC @) 60 Kg ha-1). Like wise
the treatment T4 (ECC @) 90 Kg ha-1) and T5 (ECC @) 120 Kg ha-1) were found non
significant from each other but statistically differ from the treatments T2 (ECC @) 30
Kg ha-1) and T3 (ECC @) 60 Kg ha-1).
The hormonal effect of ethylene liberated by ECC under soil moisture
conditions enhances the activity of nutrient utilization by the plant (saleem at el
2002).Due to high uptake of N the tubers might have developed thick rind (periderm)
which does not allow frequent loss of water from the tubers. So there is minimum loss
of water where the tubers were supplemented with ECC which might have prevented
weight loss.
Table 18:- Mean values of treatments for weight loss percentage
Figures in the same column with different letters differ significantly (α = 0.05) by
LSD
Treatments Original order Ranked order
T1 (control) 19.65a+1.05 T1 19.65a
T2 ( ECC 30 Kg/ha ) 15.85c+0.95 T5 19.06ab
T3 ( ECC 60 Kg/ha ) 14.26c+0.49 T4 16.7bc
T4 ( ECC 90 Kg/ha) 16.7bc+0.80 T2 15.85c
T5 ( ECC 120 Kg/ha) 19.06ab+1.12 T3 14.26c
4.15 Shrivillage percentage
Data regarding the shrivillage percentage is presented in the Table-19. The
statistical analysis of data reveals that maximum shrivillage percentage was observed
in the control treatment (26.25 %) followed by the treatment T5 (ECC @) 120 Kg ha-1)
while the minimum shrivillage percentage (15 %) was observed in the treatment T3
(ECC @) 60 Kg ha-1) .The data reflects that the treatment T1, T2 and T5 did not differ
statistically from each other but these treatments differed significantly from the
treatments T3 (ECC @) 60 Kg ha-1) and T4 (ECC @) 90 Kg ha-1).The treatments T3
(ECC @) 60 Kg ha-1) and T4 (ECC @) 90 Kg ha-1) did not differ statistically from
each other. The descending order of the treatments pertaining to shrivillage
percentage is like T1 > T5 > T2 > T4 > T3.
Data reflects that ECC has positive effect on post harvest life of potato tubers
as acetylene and ethylene assists the plant in uptake and assimilation of nutrients. .
Shrivillage is directly related with the water loss due to which turgidity of the
periderm is decreased. So, the possible reason for minimum shrivillage in T3 might be
the more rigid periderm which might have resulted in less shrivillage percentage. And
it is opposite in case of control. These findings are same as the results of Borton
(1982)
Table 19:- Mean values of treatments for shrivillage percentage
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Treatments Original order Ranked order
T1 (control) 26.25a+3.14 T1 26.25a
T2 ( ECC 30 Kg/ha ) 20ab+3.53 T5 23.75ab
T3 ( ECC 60 Kg/ha ) 15b+2.04 T2 20ab
T4 ( ECC 90 Kg/ha) 16.25b+1.25 T4 16.25b
T5 ( ECC 120 Kg/ha) 23.75ab+3.14 T3 15b
4.16 Sprout percentage
The data regarding sprout percentage is presented in Table-20 and tabulated in
appendix XX. The data pertaining to sprout percentage shows that the maximum
sprout percentage (17.25 %) was found in the treatment T1 (control) while minimum
sprout percentage (3.75 %) was investigated in the treatment T3 (ECC @) 60 Kg ha-1).
Data presented in table reflects that the treatment T1 (control) differed statistically
from the treatments T2 (ECC @) 30 Kg ha-1), T3 (ECC @) 60 Kg ha-1), T4 (ECC @) 90
Kg ha-1) and T5 (ECC @) 120 Kg ha-1). The treatments T2 (ECC @) 30 Kg ha-1), T3
(ECC @) 60 Kg ha-1), T4 (ECC @) 90 Kg ha-1) and T5 (ECC @) 120 Kg ha-1) were
found non significant but numerically minimum sprout percentage (3.75 %) was
recorded in the treatment T3 (ECC @) 60 Kg ha-1).
The data clearly indicates that the ECC decrease the sprout percentage which
is unwanted character. Dormancy weakens as storage continues. Both ABA and
ethylene are required for the initiation of tuber dormancy. This low sprout percentage
in ECC treated might be due to some extra accumulation of ethylene which in
correlation with ABA maintains the tubers dormant in storage. This might be possible
due to the fact that ethylene and ABA are known to interact synergetically and
antagonistically in a number of developmental processes. The ethylene and ABA
reduces the pre mature sprouting by extending dormancy (Suttle 2001).
Table 20:- Mean values of treatments for sprout percentage
Figures in the same column with different letters differ significantly (α = 0.05) by LSD
Treatments Original order Ranked order
T1 (control) 17.5a+1.44 T1 17.5a
T2 ( ECC 30 Kg/ha ) 7.5b+2.5 T2 7.5b
T3 ( ECC 60 Kg/ha ) 3.75b+2.39 T5 6.25b
T4 ( ECC 90 Kg/ha) 5b+2.04 T4 3.75b
T5 ( ECC 120 Kg/ha) 6.25b+2.39 T3 5b