Extract from Bulletin 4298: Honeybee pollination
LOW HONEY BEE ATTRACTIVENESS TO FLOWERS BECAUSE OF LOW SUGAR CONCENTRATION IN FLOWERS
Fruit harvested when 80% to 90% red in colour. The number of seeds/fruit ranged from 37 to 175 (Ref. 6).
The flowers are gamopetalous (the petals united into a tube). Flowers open for three days on average. Under high temperature and humidity, flowers abscise (drop off) plants and this happened regardless of whether flowers were pollinated or had been fertilised (Ref. 1).
Low night temperatures significantly reduce pollen fertility that subsequently affects seed content/fruit and fruit size (Ref. 3).
Pollen viability ranged from 31.5% to 61.8%, pollen production ranged from 289 000 to 407 000 grains in low temperature greenhouses.
Nectar is produced from swellings at the base of the ovary. Different genotypes produced varying quantities of nectar, the volumes ranged from about 0.1 to 10.5 microlitres/flower. Nectar production is highest at midday (noon) and early afternoon compared with morning hours. There was a high correlation between nectar volume and sugar concentration. Sugar concentration increased throughout the day (Ref. 9).
Male-fertile flowers produced more nectar and had a higher sugar concentration than male-sterile flowers. Nectar contains 52% to 82% fructose (dominant) with the only other sugar being glucose. Sugar concentration ranged from about 4.9% to 24.6% depending upon genotype and whether male-fertile or male-sterile (Ref. 9). Sugars in pepper flower ranged from 0.59 to 1.41 mg and the amount of nectar ranged from 1.09 to 2.59 mg with sugar contents of 33.4 to 68.9% (Ref. 6).
Optimum growing conditions are 30°C (day time) and 20°C (night time) (Ref. 3). Plantings at 3 plants/m2 .
Sweet peppers are widely regarded as a self-pollinating plant. It is not 100% self-pollinating and insect pollination appears to have a positive impact on seed set and fruit weight particularly in green houses.
The benefits of mechanical and bee pollination compared with self-pollination are likely to be greater when plants are under stress, that is, low light conditions, high temperature and humidity.
In one experiment, two cultivars showed a reduction in the length of time from fruit set to harvest from 2 to 4 days which corresponded to an increased profit margin of $34 to $55 000/ha in 1992 because an extra picking period could be managed. The cultivar that had harvest time reduced by 4 days also had an increase fruit weight of 6% which was calculated to be worth an additional $53 500/ha.
Male-sterile flowers had 18 honey bees/100 flowers/15 minutes (Ref. 9).
Male-fertile flowers had 4 honey bees/100 flowers/15 minutes (Ref. 9).
The number of effective visits on the male-sterile line (after coming from male-fertile lines) varied between 5 and 29. With increasing number of visits increased the number of seeds in the pepper fruits. This experiment used 250 g of queenless bees in isolation cages (Ref. 6).
Cost of honey bee hives will probably start at about $2/hive/day, that is, $600/hive/season with hives being swapped around every 2 to 3 weeks.
TITLE: The non-impairment of pollination
and fertilisation in the abscission of chilli
(Capsicum annuum L. Var. Kulai) flowers under high
temperature and humid conditions.
ABSTRACT: Pollination and
fertilisation in abscising chilli flowers were studied under glasshouse
and field (pot plants planted in the field) conditions of high temperature
and high humidity. Pollen viability, pollen tube growth and fertilisation
in abscising chilli flowers were similar under both conditions. The number
of seeds per fruit and percent seed germination were also similar.
Findings indicate that abscission of chilli flowers in Kulai variety under
high temperature and humid conditions proceed independently of the
processes of pollination and fertilisation.
AUTHOR: I. S. Usman,
A. S. Mamat, H. S. Z. S. Mohd, H. S. Aishah, A. R.
Anuar.
JOURNAL: Scientia Horticulturae 79(1/2): 1-11
(1999).
TITLE: Effects of seed number on
competition and dominance among fruits in
Capsicum annuum L.
ABSTRACT: The effects of seed number
on set, development and growth of a fruit, and on inhibition of
later-developed fruits were studied by varying the pollen load on the
stigma of sweet pepper flowers (Capsicum annuum L.). Despite much
variation, a linear increase in individual fruit weight with seed number
could be observed. Seed number affected the growth rate rather than the
growing period of fruit. When seed numbers were low, the probability of
fruit setting was positively related to seed number. However, a relatively
low seed number (50-100 seeds/fruit: 20-30% of the maximum seed number)
was sufficient for maximal fruit set.
An increase in seed number
increased the inhibitory effect of a fruit on set and growth of
later-developing fruits. As a result, when pollination treatments were
applied to all the flowers of a plant, results could be quite different to
those obtained when only a limited number of flowers were
treated.
Fruit set of the second fruit was reduced by the application
of a high pollen load to the first flower, even when the first fruit
aborted before it had accumulated much dry matter. Our results suggest
that growth inhibition of the second fruit by seed number of the first
fruit is controlled both by competition for limited assimilates, as well
as by dominance due to the production of plant growth regulators by the
developing fruit.
AUTHOR: L. F. M. Marcelis, L. R. B.
Hofmaneijer.
JOURNAL: Annals of Botany 79(6): 687-69 (1997)3.
TITLE: Effects of hand-pollination,
paclobutrazol treatments, root temperature and genotype on pollen
viability and seed fruit content of winter-grown
pepper
ABSTRACT: Pepper plants were cultivated under optimum
(30/20°C, day/night) and suboptimum (24/12) temperature regimes. Low night
temperature significantly reduced pollen fertility, seed content per fruit
and fruit size.
Hand-pollination of cold affected flowers of hybrid
'Latino' with pollen collected from plants grown at optimum night
temperature slightly increased the seed content per fruit and fruit
length. However, fruit weight and diameter were not modified by this
treatment.
Application of paclobutrazol, at concentrations of 1 and
0.1 mg/L, to 'Latino' plants growing at suboptimum temperature diminished
the cold induced pollen abortion and increased the seed content per fruit.
These fruits were smaller than those produced by non-treated plants of the
same temperature regime.
When the root temperature of 'Latino' plants
growing in the cold regime was maintained at 20°C, pollen viability and
fruit size remained as low as in plants of the same temperature regime
with unheated roots. The evaluation of the cold sensitivity of different
pepper genotypes indicated that all the accessions were affected by cold
but to different degrees. Capsicum baccatum, C. frutescens
and C. annuum cvs Miguelino and Guindilla had the most cold
tolerant pollen.
AUTHOR: J. A. Mercado, B. Vinegla, M. A.
Quesada.
JOURNAL: Journal of Horticultural Science
72(6): 893-900
(1997).
TITLE: Pollination of sweet pepper
(Capsicum annuum L.) in green-house by the syrphid fly Eristalis
tenax (L.)
ABSTRACT: Experiments were carried out in
southern Quebec to assess the possibilities of using Eristalis
tenax (L.) as a pollinator of sweet pepper under glasshouse
conditions. To measure the influence of insects on seed settling and fruit
weight, each flower was tagged before blooming and submitted to one of the
following conditions: one in which insect visits were prevented, the
second where a specific number of visits was attributed and the third in
which insects could have an unlimited access to the flower during its
receptive period. Fruits were allowed to grow for 30 days and
harvested.
Higher seed set was observed in both insect-pollinated
groups as well as a shift toward a greater percentage of heavier fruits
when compared to those produced from unvisited flowers. Furthermore, the
duration of insect visits significantly increased both seed set and fruit
weight. Results of the present experiments tend to suggest that E. tenax may possess desirable attributes for the pollination of sweet
pepper and deserves further needs for investigation.
AUTHOR:
Jarlan, A., de Oliveira, D. and Gingras,
J.
JOURNAL:Proceedings of the International Symposium on
Pollination. Acta Hort. 437: 335- (1997).
TITLE: Pollination of male-sterile green
pepper line (Capsicum annuum L.) by honeybees
ABSTRACT:
The activity of honeybees on green pepper (Capsicum annuum L.) male-sterile line Sivria 600 and male-fertile line
California Wonder grown under cover was high. Honeybees visited the
flowers of both lines and they changed lines frequently. The number of
the effective visits on the male-sterile line flowers (that is, after
coming from the male-fertile line) varied between 5 and 29. With
increasing number of visits increased the number of seeds in the pepper
fruits. The production of hybrid seed was negatively influenced by the
not satisfying male-sterility of the used line Sivria 600. The
amount of sugars in the nectar of one pepper flower ranged between
0.6 and 1.4 mg.
AUTHOR: Kubia.ová, S.; Háslbachová, H.
JOURNAL:
6th Pollination symposium. Acta Horticulturae
288: 364- (1991).
TITLE: The pollination of paprika by honey
bees
ABSTRACT: Honey bees had a positive effect on the
pollination of paprika [Capsicum annuum] grown under glass.
The average fruit weight and number of seed per fruit were increased.
Paprika flowers produce both nectar and pollen and are attractive to honey
bees.
AUTHOR: Ruuter, A. De; Euned, J. Van
Den.
JOURNAL: Bijenteelt 69(9): 193-194 (1991).
TITLE: Effects of Eristalis tenax
(Diptera: Syrphidae) pollination on characteristics of greenhouse sweet
pepper fruits.
ABSTRACT: The pollinating effects of the drone
fly, Eristalis tena (L.), on greenhouse sweet pepper. Capsicum
annuum L. were assessed by measuring fruit characteristics.
Individual flowers were exposed to either no insect visits, a restricted
number of visits, or a continuous exposure to flies during floral
receptivity. A 5% increase in pericarp circumference was observed in
fruits obtained from the continuously exposed newer group (18.2±4.5 cm
[mean±SD]) compared with those from the non-visited group (17.4±3.6 cm).
A shift toward a greater percentage of heavier and wider fruits was
observed in both fly-visited flower groups. Fruit weight, circumference,
and length were highly dependent on seed set and increased as a function
of cumulative visit duration. Although the pollinating behaviour of
E. tenax on sweet pepper flowers is still unexplained, our results
indicate that fly pollination has a significant positive impact on the
physical characteristics of pepper fruits.
AUTHOR: Jarlan, A.;
Deoliveira, D.; Gingran, J.
JOURNAL: Journal of Economic
Entomology. 90(6): 1650-4
(1997).
TITLE: Flower and nectar attributes of pepper
(Capsicum annuum L.) plants in relation to their attractiveness
to honey bees (Apis mellifera L.)
ABSTRACT
Pepper nectar contains fructose and glucose only. Nectar volumes
were higher during noon and afternoon hours. Male-fertile flowers
produced more nectar and higher sugar concentration than sterile ones.
Pepper genotypes varied in frequency of honey bee visits and significant
correlation between sugar quantity and number of honey bee visits per
flower was evident. The considerable variation in nectar characteristics
can be exploited to increase attractiveness to honey bees thus
facilitating bee pollination in commercial production of F1 hybrid seeds
and improve fruit quality.
AUTHOR: Rabinowitch, H. D.; Fahn,
A.; Tal Meir and Lensky, Y.
JOURNAL: Annals of applied
biology 123: 221-232 (1993).
Page reviewed: March 2006