EFFECT OF HONEYBEE (APIS MELLIFERA L.) POLLINATION ON FRUIT SETTING AND YIELD OF CUCUMBER (CUCUMIS SATIVUS L.)

Abstract

A field study was conducted to determine the effect of honeybee pollination on monoecious cucumber (Cucumis sativus L.) yield at National Agriculture Research Centre Islamabad during kharif 2006. The experiment was laid out in a complete randomized block design with three treatments (i. plants caged with bees. ii. open visits of bees and iii. plants caged without bees-control). Fruit set percentage, individual fruit weight, length, circumference and yield per plant were measured. Both the open pollinated plants with bees and caged plants with bees significantly increased fruit set percentage, individual fruit weight, circumference and yield per plant as compared to the control. It is concluded from this experiment that honeybees visitation to the flowers are important for pollination as they influence both quantity and quality of cucumber production. It is recommended that honeybee hives should be moved into cucumber fields 2 to 3 days after the onset of flowering.

Full text

Pak. Entomol. Vol. 30, No.2, 2008
185
EFFECT OF HONEYBEE (APIS MELLIFERA L.) POLLINATION ON FRUIT SETTING AND YIELD
OF CUCUMBER (CUCUMIS SATIVUS L.)
Ghulam Sarwar, M. Aslam*, M.S. Munawar, Shazia Rajaand Rashid Mahmood
Honeybee Research Institute, National Agri. Res. Centre, Islamabad
*Department of Entomology, PMAS University of Arid Agriculture, Rawalpindi, Pakistan
ABSTRACT
A field study was conducted to determine the effect of honeybee pollination on monoecious cucumber (Cucumis
sativus L.) yield at National Agriculture Research Centre Islamabad during kharif 2006. The experiment was
laid out in a complete randomized block design with three treatments (i. plants caged with bees. ii. open visits of
bees and iii. plants caged without bees-control). Fruit set percentage, individual fruit weight, length,
circumference and yield per plant were measured. Both the open pollinated plants with bees and caged plants
with bees significantly increased fruit set percentage, individual fruit weight, circumference and yield per plant
as compared to the control. It is concluded from this experiment that honeybees visitation to the flowers are
important for pollination as they influence both quantity and quality of cucumber production. It is recommended
that honeybee hives should be moved into cucumber fields 2 to 3 days after the onset of flowering.
Key words: Apis mellifera; pollination; cucumber; fruit set; yield.
INTRODUCTION
Cucumber (Cucumis sativus L. cucurbitaceae) locally
known as “Khira” is native to Asia and Africa, where
it has been used for 3,000 years. Today cucumbers
are grown all over the world for popular salad and
pickling. The fruit is commonly harvested while still
green. They are eaten as a vegetable, raw, cooked, or
made into pickled cucumbers. Artists use cucumbers
in decorative food art whereas beautician use slices
of cucumber for skin care, wrinkles treatment as well
as for freshness of eyes. Although less nutritious
than most fruit, the fresh cucumber is a source of
vitamin C, thiamine, niacin, iron, phosphorus,
calcium and dietary fiber (Gopalan et al., 1982).
In Pakistan the cucumbers are grown on an area of
900 hectares in all provinces with production of 5500
tons annually (FAO, 2005). Most varieties are
monoecious which means that there are both
staminate (male) and pistillate (female) flowers on
the same plant.
The need for insect pollination of cucumbers has
been known for years. Most cucumbers whether
monoecious or gynoecious, require insects to transfer
pollen between flowers of same or different plants
because pollen grains are large and sticky and well
suited to pollination by bees rather than wind. The
stigma is receptive throughout the day but most
receptive in early morning (Seaton et al., 1936).
Monoecious cucumbers are dependant upon
honeybees for pollination because the flowers only
open for one day (Lord, 1985). McGregor (1976)
stated that honeybees are the primary and only
dependable pollinators of cucumbers. Cucumber
requires insect pollination for fruit set and many
cucumber growers rent honeybee colonies to ensure
the maximum fruit set and development occurs
(Schultheis et al., 1994; Stanghellini et al., 1997).
Pistillate cucumber flowers require multiple bee
visitations for adequate fruit set (Stanghellini et al.,
1997).
The Honeybee, Apis mellifera L., is of great
economic importance in terms of increased yield and
quality of commercially grown insect pollinated
crops and many field and fruit crops in the United
States and Canada are dependent on the rental of
managed honeybee colonies for high quality fruit
(Free, 1993; Delaplene and Mayer, 2000).
Unfortunately, farming community is facing the
problem of declining population of natural insect
pollinators and possible reasons for this may be the
decline in habitat, with the accompanying decrease in
food supplies, and negative impacts of modern
agricultural interventions e.g., use of chemical
fertilizers and pesticides (Deodikar and
Suryanarayana, 1977). Due to this reason, in the
developed countries of the West, attention is given to
the management of pollinating insects (especially
honeybees) but in the developing countries, although
both the need and the potential exist, the practice of

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managing crop pollination using honeybees is limited
as farming community in these countries is not aware
of the pollination role of honeybees.
The present study was conducted to determine the
effect of honeybee (A. mellifera L.) on cucumber
production with respect to fruit quality and quantity.
MATERIALS AND METHODS
The field area of National Agricultural Research
Centre Islamabad during 2006 was selected for this
study.
The experiment was arranged in a randomized
complete block design (RCBD) with three treatments
and three replications each. The plot size (4 x 4 m2)
consists of two rows with row to row distance of 2m
and plant to plant distance of 0.5m. Treatments
applied were: (i) plots caged with bees (T1), (ii) open
plots allowing free visits of bees + other pollinators
(T2) and (iii) plots caged without bees (control - T3).
Cucumber seeds were germinated in green house and
seedlings at two to three true-leaf stages were
transplanted into raised beds. Agronomic practices
like hoeing, weeding, application of fertilizer (NPK)
and farmyard manure were same in all the treatments.
The crop condition was observed daily, intensity of
flowering was recorded from the date when male
flowers began to open about 10 days before the
female flowers emergence by the mid of May, 2006
to 25th June, 2006 i.e. end of flowering. Cages
covered with muslin cloth were placed over the
planted seedlings when male flowers buds began to
develop that is prior to flowering. Approximately 200
worker honeybees of Apis mellifera L. were
introduced in imported thermo pore with mated
queen, which proved good insulator against heat.
Nucs were placed in trial 2-3 days after male
flowering initiation. These nucs were placed on
wooden boards nailed with strong pegs two feet
above the ground level to save the nucs from rain,
water and termites attack. Some wooden pieces were
placed in plastic bowls for easy access of bees to
water source. It eliminated the chance of dipping of
bees while sucking water. Water bowls were replaced
twice a week to avoid water contamination with
fungus etc. As some weeds also attract bees so
complete eradication of weeds was done in
experimental plots for maximizing exposure of
cucumber flowers to honeybees.
DATA COLLECTION
Flower produced per plant:
From each replication, 5 plants were randomly
selected and marked with specific cards. From
already selected five plants, female flowers were
counted daily early in the morning during the whole
flowering period. Data on opening of female flowers
were recorded from 25th May to 25th June, 2006 i.e.
end of flowering and the average female flowers per
plant were calculated.
Fruit setting percentage:
The variety of cucumber under study was
monoceious and the percentage of fruit set was
calculated as follows:
Number of cucumbers produced
--------------------------------------------- × 100
Number of female flowers
Number of fruits harvested per plant:
Cucumber fruits were harvested twice a week in all
replications of each treatment throughout the
harvesting period i.e. four weeks and the average
number of fruits per plant was calculated.
Weight (kg), circumference of fruit, and length of
fruit (cm):
Randomly selected five fruits in each replication
were harvested, weighed and their
circumference/length was measured individually and
then average fruit weight/ circumference/length was
calculated.
Yield (kg):
During the whole fruit harvesting period yield was
recorded on five randomly selected plants and
calculated the average yield per plant. Later on, yield
per hectare was calculated by multiplying the yield of
one plant with the number of plants in one hectare.
The data collected was analyzed statistically applying
analysis of variance technique using MSTATC
software. Treatment means were compared by using
LSD test at 5% probability by performing
Randomized Complete Block Design (RCBD)
according to Steel and Torrie (1980).
RESULTS AND DISCUSSION
Number of Flowers Produced Per Plant:
The observations pertaining to flowering revealed
initiation of male flowering w.e.f. 15 May, 2006 that

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is 10 days before the pistillate flower initiation. This
fact has already been supported by Judson (1929)
who also observed initiation of staminate flowers
about ten days before the initiation of female flowers.
The rate of male to female flowers was influenced by
temperature and climatic conditions. Alex (1957)
observed that normal ratio of male to female flower
ranges about 100-10 to 1. In the present study, the
season remained dry with high temperature during
the vegetative growth and flowering period of the
crop. Hence, more staminate flowers per plant were
produced. The numbers of male flowers produced
were not found to be significantly different (F= 2.03,
P > 0.05, Fig 1).
0
50
100
150
200
250
300
350
400
T1 T2 T3
Fig.1. Mean number of male flowers produced per
plant of cucumber in response to different treatments
(T1=plots caged with bees, T2=open plots allowing free
visits of bees + other pollinators, and T3=plots caged
without bees)
Pistillate flowers initiated 10 days after the first male
flower initiation, borne solitary on a stem and were
easily recognized by the large ovary at the base on
the flower. It is evident from the analysis of the data
(F= 0.814, P > 0.05, Fig 2).
0
2
4
6
8
10
12
14
T1 T2 T3
Fig.2. Mean number of male flowers produced per
plant of cucumber in response to different treatments
(T1= plots caged with bees, T2=open plots allowing free
visits of bees+other pollinators, and T3=plots caged
without bees)
Fruit Setting Percentage Per Plant:
In cucumber, pollination is accomplished when
pollen is transferred from the dehiscing anthers of
male flower to female flower. It was observed that
the stigma remained most receptive in early morning
which is in general agreement with previous results
reported by Seation et al. (1936). The results showed
significant differences (F= 262.10, P < 0.05, Fig 3),
among treatments and revealed that treatment T2
(open plot free visit of bees + other pollinators) gave
maximum percentage (85.4) of fruit setting followed
by 81.28% fruit setting in treatment T1 (Cages
covered with honeybees). However, fruit setting
percentage was lowest 12.60% in control treatment
T3 (cages covered without bees).
0
10
20
30
40
50
60
70
80
90
100
T1 T2 T3
Fig.3. The percentage of fruit set per plant of cucumber
in response to different treatments (T1= plots caged
with bees, T2= open plots allowing free visits of bees +
other pollinators, and T3 = plots caged without bees).
Similar results have been reported by (Sajjanar et al.,
2004) who observed higher fruit set (81.43%) in open
pollinated crop with honeybees than the caged
conditions (75.00%) and (10.71%) for control. Lord
(1985) reported that monoecious cucumbers are
dependent on honeybees pollination for fruit set.
According to Collision and Martin (1979), a
significant positive correlation was obtained between
daily percent fruit set and the amount of pollen being
distributed with each bee visit. Martin (1970)
indicated that honeybees were more effective if they
were moved to the cucumber field after flowering
had started. Lord (1985) also recommended that bee
hives should be shifted into cucumber fields 2 to 3
days after the onset of flowering. McGregor (1976)
recommended two or three colonies per 0.4 ha
for cucumber pollination. During the present
investigation, it was found that 12.60% fruit set
occurred in control plots (Fig.3). The reason for fruit
setting in control may be parthenocarpic development

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(Gustafson, 1939; Woyke and Bronikowska 1984;
Lord, 1985).
Number of Fruits Harvested Per Plant:
The results regarding number of fruits harvested per
plant indicated that the treatments were statistically
significant (F= 313.04, P < 0.05, Fig 4). Among
treatments, T2 (open free visits of bees and other
pollinators) produced more fruits than treatment T1
(plots covered with honeybees) and treatment T3
(plots covered without bees). Fruits of T2 and T1 were
uniform, well shaped than those observed in
treatment T3 (Cages covered without honeybee).
Similar results had been reported by Steinhaur (1970)
who mentioned that honeybee pollination on fresh
cucumber give the higher average number of
cucumber fruits with uniform quality per unit area.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
T1 T2 T3
Fig.4. Mean number of fruits harvested per plant of
cucumber in response to different treatments (T1= plots
caged with bees, T2= open plots allowing free visits of
bees+other pollinators, & T3=plots caged without bees)
Underwood and Eischen (1992) reported that
pickling cucumber’s flowers produced significantly
better formed cucumber fruits in uncovered condition
than covered plots. Flowers that produced fruits were
associated with higher number of visits by
honeybees. The results of the present investigations
further revealed that flowers in T3 (cages covered
without bees) that received zero visits did produce
cucumber. This might be due to auto pollination as
reported by Jenkins (1942) who stated that between
30-35% of auto pollination could occur in the
absence of insects.
Weight of Fruit (kg):
The results of the individual fruit weight showed
significant difference among different treatments (F=
21.30, P < 0.05, Fig 4). Comparison of mean values
through least significant difference test at 5% level of
probability revealed that T1 (Cages covered with
bees) and treatment T2 (open plot free visits of bees +
other pollinators) were not statistically different from
one another but significant from the T3 control
(Cages covered without bees) (Fig. 5). The weight of
fruit was influenced by honeybee pollination. Similar
view point had been expressed by Gingras et al.
(1999). They mentioned that weight of cucumber
fruit was correlated with honeybee pollination.
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
T1 T2 T3
Fig.5. Comparison of mean weight of fruit of cucumber
in response to different treatments (T1= plots caged
with bees, T2= open plots allowing free visits of bees +
other pollinators, and T3 = plots caged without bees)
Circumference and Length of Fruit (cm):
The results regarding the circumference of fruit
indicated that difference among the treatments were
statistically significant (F= 63.26, P < 0.05, Fig 6).
Comparison of mean values through least significant
difference at 5% level of probability revealed that
circumference of individual fruits among treatments
T1 (Cages covered with bees) and T2 (open free visits
of bees + other pollinators) was not statistically
different but was statistically significant from the
treatment T3 (cages without bees). It was concluded
that honeybees (A. millifera L.) pollination was
correlated positively with circumference of
cucumbers. These results are in accordance with the
findings of Gingras et al. (1999) who reported that
circumference of cucumbers fruit was correlated
positively with pollination of honeybees (A. mellifera
L.).
The fruit length of cucumber (F= 1.69, P > 0.05, Fig
7) indicated no significant differences among various
treatments. These results are supported by Gingras et
al. (1999). They reported that the length of
cucumbers was not influenced by pollination. Other

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studies have shown that the length of cucumbers is
primarily determined by genetic factors (Imam et al.,
1977), while Kauffeld and Nilson (1982) obtained the
larger size cucumber from the plots pollinated by A.
mellifera L. These results are contrary to our findings
and the possible reason may be the varietal variation.
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
T1 T2 T3
Fig.6. Comparison of mean circumference of fruit of
cucumber in response to different treatments (T1= plots
caged with bees, T2= open plots allowing free visits of
bees + other pollinators, and T3 = plots caged without
bees)
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
T1 T2 T3
Fig.7. Comparison of mean length of fruit of
cucumber in response to different treatments (T1= plots
caged with bees, T2= open plots allowing free visits of
bees + other pollinators, and T3 = plots caged without
bees)
Yield Per Plant:
It may be seen from the analysis of data regarding
yield per plant that difference among treatments were
statistically significant (F= 204.96, P < 0.05, Fig 8).
Least significant difference test at 5% level of
probability revealed that treatment T2 (open plot free
visits of bees + other pollinators) produced more
yield per plant than treatment T1 (Cages with covered
bees) and treatment T3 (Cages covered without bees).
However, treatments T2 and T
1 were statistically
similar to each other but significant from control (T3
cages covered without bees).
These results are in general agreement with those of
many of the previous scientists including Kochetov
(2004) who reported that use of honeybees for
pollination increased the productivity of hybrid
cucumber by 35 to 50% and Sajjanar et al. (2004)
who stated that higher fruit yield 81.43% was
obtained in open pollinated crop with honeybees
compared caged condition with honeybees 75% and
the control (10.71%).
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
T1 T2 T3
Fig.8. Comparison of mean yield of cucumber/plant
(kg) in response to different treatments (T1= plots caged
with bees, T2= open plots allowing free visits of bees +
other pollinators, and T3 = plots caged without bees)
Steinhauer (1970) reported that honeybee pollination
of cucumber field produced the higher average
number and weight of cucumber per unit area. Garcia
et al. (1998) evaluated the effects of no pollination,
manual pollination and pollination by A. mellifera in
melons and found that bee pollination results in
highest fruit and seed weight. Noguera and Calmona
(1993) reported that honeybee (A. mellifera L.)
constitute 82.6% of visitors to cucumbers flower and
showed that plots netted with bees yielded more
furits/m2 heavier and high quality than other plots
(open and covered without bees).
It may be seen from the analysis of variance of the
data pertaining to yield per hectare that statistically
significant differences were found among different
treatments (F= 204.96, P < 0.05, Fig 9). Among the
treatments T2 (open plot free visits of bees + other
pollinators) produced more yield per hectare than
treatment T1 (Cages covered with honeybees) and
treatment T3 (Cages covered without bees). Yield per
hectare of T1 and T
2was not statistically different
from one another but was significant from control (T3
cages without honeybees).

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0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
T1 T2 T3
Fig.9. Comparison of mean yield of cucumber/hectare
(tons) in response to different treatments (T1= plots
caged with bees, T2= open plots allowing free visits of
bees+other pollinators, & T3=plots caged without bees)
REFERENCE
Alex, A. H., 1957. Honeybees aid pollination of
cucumber and cantaloupes. Gleaning Bee
Cult., 85: 398-400.
Collision, C. H and E. C. Martin, 1979. The
relationship of foraging activity of fruit set and
shape in the pollination of pickling cucumber,
Cucumis sativus L. Proc. 4th Int. Sym. on
Pollination M., D. Agric. Exp. Sta. Spec.
Misc. Publ., 1: 183-188.
Delaplane, K. S. and D. F. Mayer, 2000. Crop
pollination by bees. CAB Intl. Walleny food,
U.K.
Deodikar, G. B. and M. C. Suryanarayana, 1977.
Pollination in the services of increasing Farms
Production in India. In: Advances in Pollen
Spore Research, Nair, P. K. K. (ed.). Today &
Tomorrow Printers and Publ., New Delhi. p.
60-82.
FAO, 2005. Cucumber Production in Pakistan.
http:/www.faostat.fao.org.
Free, J. B, 1970. Insect Pollination of Crops. 1st Ed.
Academic Press, London. 544 pp.
Garcia, R. C., F. V. Resende, A. A. Marcos, D. P.
Toloi, J. A. G. Faleiros, R. P. Turquino, S. de.
Souza and S.de. Souza, 1998. Study of melon
(Cucumis melo) pollination by Apis mellifera
in the greenhouse. UNIMAR. Ciencias. 7(2):
123-131 (Cab. Absts. 1998/08-2000/04).
Gingras. D., J. Gingras and D. de-Oliveria, 1999.
Visits of honeybees (Hymenoptera: Apidae)
and their effects on cucumber yields in the
field. J. econ. Entomol., 92 (2): 435-438.
Gopalan, C., S. B. V. Rama and S. C.
Balasubramanian, 1982. Nutritive value of
Indian Foods, Indian Council Med. Res., Natl.
Instt Nutr., Hyderabad. India.
Gustafson, F. G., 1939. The cause of natural
parthenocarpy. Amer. J. Bot., 26: 135-138.
Imam, M. K., A. Abobakr and H. M. Yacoub, 1977.
Inheritance of some characters in cucumber,
Cucumis sativus L. II. Some quantitative
characters. Libyan J. Agric., 6: 115-125.
Jenkins, J. M, 1942. Natural self-pollination in
cucumbers. Proceed. Amer. Soc. hort. Sci., 40:
411-412.
Judson, J. E., 1929. The morphology and vascular
anatomy of the pistillate flower of cucumber.
Amer. J. Bot., 16: 69-89.
Kauffeld, N. M and P. H. Williams, 1972. Honeybee
as pollinators of pickling cucumbers in
Wisconsion. Amer. Bee J., 112: 252-254.
Kochetov, A., 2004. Use of Carpathian bees for
cucumber pollination in film green houses
Kartofel-I-Ovosbchi, (6): 28.
Lord, W. G, 1985. Successful cucumber production
will continue to depend on honeybees in the
near future. Amer. Bee. J., 125: 623-625.
Martin, E. C., 1970. The use of honeybees in the
production of hybrid cucumber for mechanical
harvest. In the indispensable Pollinators, Ark.
Agr. Ext. Serv. Misc. Pub., 127: 106-109.
McGregor, S. E., 1976. Insect Pollination of
Cultivated Crops. U.S. Dept. Agr. Res. Serv.
Agr. Handbook. 496 pp.
Nogueira, C. R. H. and R. C. Calmona, 1993. Insect
pollination of cucumber (Cucumis sativus L.)
Naturalia Sao Paulo, 18: 77-82.
Sajjanar, S. M., G. C. Kuberappa and H. P.
Prabhuswamy, 2004. Insect visitors of
cucumber (Cucumis sativus L.) and the role of
honeybee (Aips cerana F.) in its pollination.
Pest Manage. eco. Zool., 12 (1): 23-31.
Schultheis, J. R., J. T. Ambrose, S. B. Bambara and
W.A. Magnem, 1994. Selective bee attractants
did not improve cucumber + watermelon yield.
Hort. Sci., 29 (3): 155-158.
Seaton, H. L., R. Hustan and J.H. Muncie, 1936. The
production of cucumbers for pickling
purposes. Mich. Agri. Experim. Stat. Spec.
Bull., p. 131 and 273.

Pak. Entomol. Vol. 30, No.2, 2008
191
Stanghellini, M. S., J. T. Ambrose and J. R.
Schultheis, 1997. The effects of honeybee and
bumble bee pollination on fruit set and
abortion of cucumber and water melon. Amer.
Bee. J., 137: 386-391.
Steel, R. G. and J. H. Torrie, 1980. Principles and
Procedures of Statistics: A Biometrical
Approach. 2nd ed. McGraw-Hill Book Co.,
Inc., New York
Steinhauer, A. L., 1970. Honeybee pollination of
cucumbers in Maryland. Amer. Bee J., 110:
12-13.
Underwood, B. A. and F. A. Eischen, 1992. High
density cucumber trials in the lower Rio Grand
valley Amer. Bee J., 132 (12): 816-817.
Woyke, H. W. and K. Bronikowska, 1984. The
influence honeybee population on pickling
cucumber yield. In: 5th International
Symposium on pollination, Versailles, 27-30
September 1983. Les Colloques de I’INRA,
No. 21. INRA, Paris. p. 323-327.

Pak. Entomol. Vol. 30, No.2, 2008
192