Effect of GA3 and Urea Treatments on Improvement of Microtuber Production and Productivity of Different Types of Planting Material in Greater Yam (Dioscorea alata L.)

Abstract

An experiment was under taken to study the effect of different concentrations of urea and GA3 treatments on the improvement of microtuber production in the vine cuttings of Dioscorea alata L. From the experimental finding it was observed that Urea 2% and GA31ppm treatment shows better response for days taken for rooting, root length, number of roots per cutting survival % in the field and nursery condition and mean number of micro tubers production per cuttings. Similarly for productivity study and observations on all other vegetative and tuber characters were highest in planting of whole tubers (200 gm) followed by planting of whole tubers (150 gm) and cut tubers of 50 gm. The value for all the observations was lowest in planting of rooted vine cuttings.

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Not. Bot. Hort. Agrobot. Cluj 37 (2) 2009, 81-84
Print ISSN 0255-965X; Electronic ISSN 1842-4309
Notulae Botanicae Horti Agrobotanici
Cluj-Napoca
Eect of GA3 and Urea Treatments on Improvement ofMicrotuber
Production and Productivity of Dierent Types of Planting
Material in Greater Yam (Dioscorea alata L.)
Kambaska Kumar BEHER A1) , Debashrita PANI1) , Santilata SAHOO1)
Trinanth MAHARANA2) , Bijay Kumar SETHI1)
1) Utkal University, Department of Botany, Vanivihar, Bhubaneswar-751004, Orissa, India; kambaska@yahoo.co.in
2) OUAT, Bhubaneswar, Department of Horticulture, Orissa, India; vcouat@ouat.ori.nic.in
Abstract
An experiment was under taken to study the eect of dierent concentrations of urea and GA3 treatments on the improvement
of microtuber production in the vine cuttings of Dioscorea alata L. From the experimental nding it was observed that Urea 2% and
GA31ppm treatment shows better response for days taken for rooting, root length, number of roots per cutting survival % in the eld and
nursery condition and mean number of micro tubers production per cuttings. Similarly for productivity study and observations on all
other vegetative and tuber characters were highest in planting of whole tubers (200gm) followed by planting of whole tubers (150gm) and
cut tubers of 50gm. e value for all the observations was lowest in planting of rooted vine cuttings.
Keywords: cut tubers, GA3, microtuber, whole tuber, vine cutting, urea
Introduction
Among tropical tuber crops the greater yam (Dioscorea
alata L.) occupies an important position because of their
food, nutritional, medicinal and industrial signicance.
Dioscorea alata is an old monocot from the family Diosco-
reaceae (Ayensu, 1972). In India D. alata tubers are con-
sumed mainly in the southern and northern states. ey
are also cultivated as a cash crop in some area where they
are more important than potato. ese crops have wide
adaptability and are less stringent in input needs like fertil-
izer application, irrigation and plant protection. ey are
ecient converters of solar energy to dry matter (Behera et
al., 2009). Yams underground tubers are seriously aected
by pathogen accumulation (Malauri et al., 1998) which
reduces the quality of planting material. Transportation of
high volumes of planting material for eld planting is dif-
cult during planting seasons. About 2,500 to 3,000 kg of
planting material is required to plant one hactare. us the
cost of planting material increases the cost of production
(Onwueme, 1978: Shiwachi et al., 2005).
Under conventional propagation the rate of multiplica-
tion of tubers is very slow as a piece of tuber has only one
or two sprouts. To counter the scarcity of planting mate-
rial an attempt was made to standardize and develop an in
vivo rapid multiplication method through the use of vine
cuttings treated with Urea and GA3 to accelerate microtu-
ber production, which could be used fully as seed tuber for
yam planting. Similar attempts were made to study ecacy
of productivity by using dierent types of planting mate-
rial viz. whole tubers (200 gm), whole tubers (150 gm), cut
tubers of 50 gm and rooted vine cuttings and the results
were presented.
Materials and methods
e experiment was conducted during the year 2007-
2008 at the Botanical garden of the Post Graduate Botany
Department, Utkal University, Vanivihar, Bhubaneswar.
e soil of the experimental eld was sandy loam. Aer
the layout of the experimental plots and prior to the ap-
plication of manure or fertilizer, soil samples were collect-
ed from each plot from the top layer of 15 cm soil depth
by using a soil agar. e result of the soil analysis are viz.
total N2 (0.068 %), Available P (0.00128%), Available K
(0.00347%) followed by Organic carbon 0.6936% and Soil
pH (5.8).
Vine cuttings from 45 days old plants of D. alata were
taken as explants by trimming the leaf during the month of
May-June. Before starting the experiment the nursery bed
was prepared (90 cm X 90 cm) by mixing with sun dried
sand and cow dung and was sterilized with Tricoderma viri-
dae followed by Steptocycline at 0.015%. e nursery bed
was wetted and the vine cuttings were planted, one by one
in the nursery bed at close spacing by dipping with 0.02
% bavistin to prevent further fungal incidence. Beds were

Behera, K. K. et al. / Not. Bot. Hort. Agrobot. Cluj 37 (2) 2009, 81-84
82
beds of the planted vine cuttings. In the vine cuttings days
taken for rooting was earliest in 2% Urea (6.98 days) fol-
lowed by 3% Urea (7.61days) and most delayed in control
(12.36 days). Similarly length of root was highest in 2%
Urea (7.68 cm) followed by 3% Urea (7.65 cm) and short-
est in control (4.16 cm).Among the treatments number
of roots per cutting was highest in 2% Urea (38.16) fol-
lowed by 3% Urea(32.00) and least number of root was
recorded in the control (12.84). Survival % in the nursery
bed was highest in control (68.45%) followed by 1% Urea
(58.48%) and least in 1% Urea (27.62%) treatment. Sur-
vival % in the eld condition was highest in 2% (42.42%)
followed by 3% Urea (41.26%) and least in the control
(34.64%). Axillary bud development % was highest in 1%
Urea (42.37%) and least in the control (26.76%). Mean
number of micro tuber was highest in 2% Urea (1.84) fol-
lowed by least number (0.78) in control. Average weight of
the micro tubers was at par in 3% Urea (2.64 gm) followed
by 1% Urea (2.54 gm) and least was in 2% Urea (1.98 gm).
Average length of the tuber was highest in 1% Urea (1.64
cm) followed by control (1.28 cm). Similarly width of the
micro tuber was highest in the control (0.98 cm) followed
by 2% Urea (0.87 cm) (Tab. 1). From the observation it
was found that spraying of Urea helps in rooting as well as
increased the size of microtuber and increased the num-
bers of root per cutting but the survival rate was decreased
with increase in Urea concentration.
Similarly a signicant dierence was found amongst
dierent treatments of GA3. Days taken for rooting were
earliest in GA3 1ppm (14.12 days) treatment followed by
control (16.45days). Percentage of success in the nursery
bed was highest (62.32%) in GA3100 ppm treatment where
as 1ppm GA3 (47.82%) and 10ppm GA3 (47.30) are at par
and followed by control (42.38%).Survival % in the eld
condition was highest (60.02%) in GA310 ppm treatment
followed by GA3 100 ppm (57.48%) and lest percentage
(37.13%) of survival in eld condition was found in con-
trol. Axillary bud development was highest in GA3 100
ppm (41.54%) treatment and least in control (9.34%) fol-
lowed by GA3 1ppm (9.89%).Length of shoot was highest
(8.81 cm) in GA3 100 ppm treatment and least was found
in control (3.46 cm) followed by GA31ppm (4.02 cm).
Number of roots per cuttings was highest (4.92) in 1ppm
watered twice daily depending on rainfall and the status
of the environmental condition of the days. To arrest the
senescence process of leaves of vine cuttings 1%, 2%, 3%
Urea was spread in one nursery bed and concentration of
GA3 1ppm,10ppm and 100 ppm was spread to another
nursery bed and an untreated control bed. Various pa-
rameter like days taken for rooting, length of root (cm),
number of roots/cutting, survival (%) in nursery and eld,
axillary bud development (%), number of tubers/plant,
weight of tuber (gm), length and width of tuber (cm)
were observed and tabulated. Similarly for productivity
trial dierent type of planting material viz. whole tubers
(200 gm), whole tubers (150 gm), cut tubers of 50 gm and
rooted cuttings were taken and planted in the eld.
Field preparation and experiment design
Before planting, the eld was ploughed, leveled and
furrows were made at 30 cm distance from row to row.
Sprouted sets were planted on ridges. e experiment was
conducted following FRBD (Factorial Randomized Block
Design). Considering the heterogeneous planting material
a spacing of 60×60 cm was provided. e fertilizers dose
was 100:100:100 Kg NPK/ha. Entire quantity of P205 was
applied as basal dose, 50 percent N and K was applied at
30 days and rest 50 percent N and K was applied at 60
days aer planting. e crop was planted during end part
of June and harvested during February. Observations on
survival % length of the vine (cm), number of branches,
number of leaves /plant, number of tuber per plant, tuber
weight (gm) tuber length and width (cm) was recorded.
e total yield was calculated per hectare.
Results and discussion
Production of microtuber from the vine cuttings came
across several problems i.e.(i) leaves turn yellow(ii) root
system cease to function (iii) immediately aer planting
tuber production starts from axillary position. Although
the longevity of vine cutting is around 60 days but leaves
turn yellow and start to wither even aer planting. ere-
fore to arrest senescence process of leaves of vine cuttings,
1%, 2%, 3% Urea and GA3 was spread to dierent nursery
Tab. 1. Eect of Urea spraying on micro tuber production in D. alata vine cuttings
Treatment Days taken
for rooting
Length
of root
(cm)
No. of
roots /
cutting
Survival
rate in
nursery (%)
Survival
in eld
(%)
Axillary bud
development
(%)
No. of
tubers
Weight
of tuber
(gm)
Length
of tuber
(cm)
Width
of tuber
(cm)
T1 (Urea 1%) 8.67 5.48 23.28 58.48 38.42 42.37 0.54 2.54 1.64 0.84
T2 (Urea 2%) 6.98 7.68 38.16 48.28 42.42 39.48 1.84 1.98 1.21 0.87
T3 (Urea 3%) 7.16 7.65 32.00 27.62 41.26 32.45 1.16 2.64 1.22 0.83
T4 (Control) 12.36 4.16 12.84 68.45 34.64 26.76 0.78 2.34 1.28 0.98
S.E.M.± 0.55 0.32 1.58 1.75 1.72 1.76 0.14 0.22 0.13 0.11
C.D. (0.05) 1.67 0.99 4.87 5.39 5.30 5.42 0.45 0.68 0.40 0.32

Behera, K. K. et al. / Not. Bot. Hort. Agrobot. Cluj 37 (2) 2009, 81-84
83
GA3 followed by control (4.83).Length of root was high-
est in control (5.32 cm) followed by GA3 10ppm (5.19).
Number of microtubers per plant was highest in GA3 100
ppm (1.74) and least in control (0.34).Weight of micro-
tuber was highest in 100 ppm GA3 (7.28 gm) followed by
10ppm GA3 treatment (5.39 gm) and least in 1ppm GA3
(3.79 gm) followed by control (3.85 gm)(Tab. 2).From the
result it was concluded that GA3 1ppm treatment were ear-
liest to complete rooting as compared 10 and 100 ppm of
GA3. Senescence could not be arrested in GA3 treatment
but application of GA3 10 ppm and 100 ppm delayed the
rooting, percentage of axillary bud production and shoot
length. Tuber weight was highest in GA3 100 ppm treat-
ment as against control (Tab. 2).
Shiwachi et al., (2005) reported that microtubers were
produced from two varieties of D. rotundata using vine
cuttings planted in carbonized rice husk or coco-peat in
a screen house. e cuttings established better and pro-
duced more microtubers in carbonized rice husk than in
coco-peat 100 days aer planting. Vine cuttings of seven
varieties planted in carbonized rice husk produced 1.7
± 0.8 minitubers per cutting with mean weight of 3.0 ±
2.7 gm and 70.1% moisture content. About 63% of these
sprouted aer 77-105 days of storage under ambient air
temperature. Vine cuttings of D. rotundata can be used to
produce microtubers within 100-120 days that could be
used in germplasm exchange and for production of seed
yams. Vander and Escobar (1990) reported that expanded
potato production in developing countries using cuttings
as a source of good quality planting material is the simple
low cost methods for root induction and establishment
of the in vivo propagules for potato cultivation in warm
tropical sites of Philippines.
Productivity study of dierent types of planting mate-
rial of D. alata presented in Tab. 3. e survival percent-
age was highest (93.40%) in planting of whole tubers (200
gm) followed by whole tubers (150 gm) (86.60%) and 50
gm cut tubers (83.60%). e lowest survival percentage
was noticed in planting of rooted cuttings (79.20%). e
length of the vine was highest (386.00 cm) in planting of
whole tuber of 200 gm followed by cut tuber 50 gm (324.00
cm) and least was found in rooted cuttings (141.00 cm).
Observations on all other vegetative and tuber characters
was highest in planting of whole tubers (200 gm) followed
by planting of whole tubers (150 gm) and cut tubers of 50
gm. e value for all the observations was lowest in plant-
ing of rooted cuttings. e highest yield (61.10 t/ha) was
obtained from planting of whole tubers (200 gm). e
yield was 43.16 t/ha by using 150 gm whole tubers. Cut
tubers weighing 50 gm produced 39.62 t/ha. Planting of
vine cuttings yielded least i.e.,16.84 t/ha (Tab. 3).
From the experimental nding, it can be concluded
that more storage from of carbohydrate in the planting
material has direct inuence on the vegetative character
and the yield potential. From the study it was conrmed
that over all vegetative and tuber characters were highest
in planting of whole tubers of 200 gm followed by plant-
ing of whole tubers of 150 gm and cut tubers of 50 gm.
e value for all the observations was lowest in planting
of rooted cuttings among the four planting materials of D.
Tab. 2. Eect of GA3 spraying on micro tuber production in D. alata vine cuttings
Sl.
No. Treatments
Days
taken for
rooting
Percentage
of success
Percentage of
axillary bud
development
Length
of shoot
(cm)
No. of
roots/
cutting
Length
of roots
(cm)
No. of
tubers/
plant
Survival
rate (%)
Weight
of tuber
(gm)
1. GA3 1 ppm 14.12 47.82 9.89 4.02 4.92 4.93 0.54 46.47 3.79
2. GA3 10 ppm 17.61 47.30 35.72 5.04 4.11 5.19 0.88 60.02 5.39
3. GA3100 ppm 18.01 62.32 41.54 8.81 3.58 4.30 1.74 57.48 7.28
4. Control 16.45 42.38 9.34 3.46 4.83 5.32 0.34 37.13 3.85
S.E.M. ± 0.45 2.11 1.31 0.29 0.24 0.27 0.09 1.88 0.37
C.D. (0.05) 1.41 6.50 4.04 0.90 0.74 0.85 0.27 5.79 1.14
Tab. 3. Productivity of dierent types of planting material of D. alata
Treatments Survival
%
Length of
vine (cm)
No. of
branches
No. of
leaves/plant
No. of
tubers/plant
Tuber
weight
(gm)
Tuber
Length
(cm)
Tuber
width (cm)
Yield
(t/ha)
Rooted cuttings 79.20 141.00 2.20 94.00 1.60 772.00 23..40 9.40 16.84
Whole tuber
(150 gm) 86.60 287.00 2.80 111.00 2.00 1796.00 28.80 12.00 43.16
Whole tubers
(200gm) 93.40 386.00 4.80 183.00 2.40 2354.00 28.60 13.00 61.10
Cut tubers
(50gm) 83.60 324.00 3.60 172.00 2.20 1710.00 30.80 11.80 39.62
S.E.M± 0.937 7.849 0.32 5.99 0.24 45.57 0.81 0.56 0.081
C.D (0.05) 2.88 24.18 0.99 18.48 0.77 140.43 2.50 1.74 0.25

Behera, K. K. et al. / Not. Bot. Hort. Agrobot. Cluj 37 (2) 2009, 81-84
84
alata. Whole tubers weighing 150 or 200 gm when used as
planting material produced very good yield followed by 50
gm cut tubers. Kayode (1984) studied the eect of sett size
and spacing on D. rotundata in three locations of Savana-
zone of Nigeria. Spacing had no signicant eect on tuber
yield but sett size less than 400 gm gave the highest yield
while Nwoke et al., (1984) reported that larger setts gave
higher tuber yield. Akoroda (1985) reported that setts of
200-250 gm were suitable for maximizing the present lev-
els of available crop growth resources and for optimizing
SMR under mono crop system on tractor made ridges us-
ing stakes of about 2 meters in yam cultivation.
Conclusions
From the experimental nding it is concluded that
spraying of Urea helps in rooting and increased the num-
bers of root per cutting, but the survival rate was de-
creased with the increase in Urea concentration but there
is an increase in the weight of the microtuber. Similarly,
lower concentrations of GA3 induce earliest to complete
rooting as compared to higher concentration. Senescence
could not be arrested in GA3 treatment, whereas higher
concentration of GA3 10 ppm and 100 ppm delayed the
rooting, percentage of axillary bud production and shoot
length but tuber weight was doubled as against the con-
trol. Productivity study on dierent types of planting ma-
terial in D. alata concludes that more storage from car-
bohydrate in the planting material has direct inuence on
the vegetative character and the yield potential, which for
higher yield whole tubers weighing 150 or 200 gm were
preferred in the commercial scale of yam faming.
Acknowledgments
Authors are thank full to Dr. S. Roy Chowdhury, Prin-
cipal Scientist (WTCER, ICAR) for their encourage-
ment and valuable suggestion for smooth completion of
the work.
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