scholarly journals Flowering, nectar production and insects visits in two cultivars of Cucurbita maxima Duch. flowers

2012 ◽  
Vol 61 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Marta Dmitruk
Keyword(s):  
Sugar Content ◽  
Cucurbita Maxima ◽  
Nectar Secretion ◽  
Nectar Production ◽  
Male And Female ◽  
Insect Visitation ◽  
Nectar Sugar ◽  
Winter Squash ◽  
Experimental Plots ◽  
Female Flowers

The study was conducted on experimental plots in the conditions of Lublin. In the years 1998-2000 flowering, nectar secretion and insect visitation of male and female flowers of two winter squash (<i>Cucurbita maxima</i> Duch.) cultivars: 'Ambar' and 'Amazonka', were studied. The plants flowered from July to October. The flower life span was within the range of 7-10 hours. Female flowers of cv. Ambar were marked by the most abundant nectar secretion (129 mg). The nectar sugar content can be estimated as average (25%-35%). Winter squash nectar contained 84% of sucrose as well as 8-9% of fructose and 7%-8% of glucose. Flowers of the studied taxa were frequently foraged by the honey bee (66%-98% of total insects) and bumblebees (1%-30%).

Differential nectar production between male and female flowers in a wild cucurbit: Cucurbita maxima ssp. andreana (Cucurbitaceae)

2002 ◽  
Vol 80 (11) ◽  
pp. 1203-1208 ◽  
Author(s):  
Lorena Ashworth ◽  
Leonardo Galetto
Keyword(s):  
Reproductive Output ◽  
Male Flower ◽  
Female Flower ◽  
Cucurbita Maxima ◽  
Nectar Production ◽  
Male And Female ◽  
Nectar Sugar Composition ◽  
Nectar Sugar ◽  
Male Flowers ◽  
Female Flowers

In dioecious and monoecious plants that depend on animal vectors for reproduction, pollinators have to be attracted to male and female flowers for pollination to be effective. In the monoecious Cucurbita maxima ssp. andreana, male flowers are produced in greater quantity, are spatially more exposed to pollinators and offer pollen in addition to nectar as floral rewards. Nectar traits were compared between male and female flowers to determine any differences in the characteristics of the main reward offered to pollinators. Nectar chemical composition and sugar proportions were similar between flower types. Total nectar sugar production per female flower was threefold higher than per male flower, and nectar removal did not have any effect on total nectar production in both flower morphs. Pollinators reduced nectar standing crops to similar and very scarce amounts in both flower types. Results indicate indirectly that pollinators are consuming more nectar from female flowers, suggesting that the higher nectar production in female flowers may be a reward-based strategy to achieve the high female reproductive output observed in this species.Key words: Cucurbitaceae, Cucurbita maxima ssp. andreana, nectar production, nectar sugar composition, removal effects, standing crop.

Evaluation of the apicultural value of sunflower hybrids

2008 ◽  
Vol 56 (1) ◽  
pp. 91-97 ◽  
Author(s):  
E. Zajácz ◽  
T. Szalai ◽  
G. Mészáros
Keyword(s):  
Honey Bees ◽  
Sugar Content ◽  
Nectar Production ◽  
Honey Production ◽  
Partial Data ◽  
High Sugar Content ◽  
Nectar Sugar ◽  
Production Value ◽  
The Individual ◽  
Selection Of

Sunflower is one of the most important bee-pasture crops and the leading oil crop plant in Hungary. There are very few studies concerning the nectar production of the plant, most of which consist only of partial data that show the apicultural value of sunflower under intensive cultivation conditions.The nectar production and nectar sugar concentration of six sunflower hybrids, Arena, Alexandra, Cledor, Coriste, Hysun 321 PR and Louidor, were examined in Mezőhegyes (south-east Hungary) from 2002 to 2004. The aim was to determine the nectar production and overall apicultural value of the hybrids. In the experiment the agroecological conditions were also examined and recorded. These agroecological conditions showed a distinctive effect on the consistency of the apicultural values of the hybrids.It can be determined from the results that the nectar production and its sugar content can be modified measurably by external factors. The nectar quantity was measurably increased by abundant precipitation during flowering, while an increase in the nectar sugar content was caused by excessively low air temperature. During these three years the average nectar production of the hybrids was 0.147 mg/floret, with a sugar content of 48.8%. Significant differences were found between the hybrids in nectar production and in the nectar sugar concentration.Averaged over three years Coriste displayed the best apicultural value. Its nectar production was stable and high (0.167 mg/floret). Its high sugar content (49.1%) also proved to be attractive to honey bees (sugar value 0.082). The lowest apicultural value was displayed by the hybrid Alexandra, with a sugar value of 0.059. This suggests that the honey production value of the individual hybrids should be taken into consideration during the selection of bee pastures.

scholarly journals Nectar Production in Abutilon III. Sugar Secretion

1971 ◽  
Vol 24 (3) ◽  
pp. 665 ◽  
Author(s):  
Nele Findlay ◽  
ML Reed ◽  
FV Mercer
Keyword(s):  
Osmotic Pressure ◽  
External Medium ◽  
Sucrose Solution ◽  
Sucrose Concentration ◽  
Sugar Content ◽  
Total Sugar ◽  
Nectar Secretion ◽  
Nectar Production ◽  
Steady Rate ◽  
Two Phases

Analysis of Abutilon nectaries shows that the sugar content of the nectary rises sharply as nectar secretion begins. Nectar secretion on the plant occurs at a steady rate of 2-5 mg total sugar per flower. hour for 36-48 hr. A total of about 100 mg sugar per flower is secreted, and this is about seven times the maximum sugar content of the nectary at any time. Secretion of sugar in nectar by isolated nectaries floating on 0--0� 4M sucrose solution is in two phases. During phase I the rate is independent of concentration of sucrose in the external medium, but the rate is decreased by increasing the osmotic pressure of the medium with mannitol. In phase II the rate of secretion of sugar depends on the concentration of sucrose in the external medium and is independent of increase in osmotic pressure with mannitol. The rate is zero on water and reaches a maximum on about O� 4M sucrose. Secretion is reduced in both phases on media of sucrose concentration

scholarly journals Flowering biology, nectar production and insect visits in Cucurbita pepo L. flowers

2012 ◽  
Vol 59 (1) ◽  
pp. 183-197
Author(s):  
Marta Dmitruk
Keyword(s):  
Honey Bees ◽  
Cucurbita Pepo ◽  
Sugar Content ◽  
Nectar Production ◽  
The Mean ◽  
Male Flowers ◽  
Female Flowers

In 1998-2000 studies on length and abundance of flowering and on nectar productivity of zucchini and marrow (<i>Cucurbita pepo</i> L.) were carried out in Lublin area. Flowers visitors were also monitored. Flowering of plants lasted from the end of June till the end of September. The mean number of flowers per plant of zucchini reached: 31 (male flowers) and 26 (female flowers), and for marrow 226 and 22, respectively. Flowers lived, on average, for 5 hours. Female flowers of marrow secreted the highest amount of nectar - 1.354 g per 10 flowers, on average. Sugar content in nectar was 21.84%-27.31%. The mean total amount of sugars secreted by 10 flowers of <i>Cucurbita pepo</i> L. was 21.5-304.3 mg. Pollinators were mainly bumblebees and honey bees.

scholarly journals It Is Not All about Being Sweet: Differences in Floral Traits and Insect Visitation among Hybrid Carrot Cultivars

Insects ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 402
Author(s):  
Ann Gaffney ◽  
Björn Bohman ◽  
Stephen R. Quarrell ◽  
Philip H. Brown ◽  
Geoff R. Allen
Keyword(s):  
Honey Bees ◽  
Sugar Content ◽  
Flower Colour ◽  
Minor Importance ◽  
Sugar Composition ◽  
Visitation Rates ◽  
Significant Difference ◽  
Insect Visitation ◽  
Nectar Sugar Composition ◽  
Nectar Sugar

Cytoplasmically male-sterile (CMS) carrot cultivars suffer from low pollination rates. In this study, insect visitation varied more than eightfold between 17 CMS carrot cultivars in a field-based cultivar evaluation trial. The visitation rates of honey bees, nectar scarabs, muscoid flies, and wasps each significantly differed among these cultivars. No significant difference in visitation rates was observed among cultivars of different CMS type (brown-anther or petaloid) or flower colour, but cultivars of Berlicumer root type had significantly higher insect visitation rates than Nantes. Six cultivars were further compared in regard to selected umbel traits: as umbel diameter increased, so did the visitation of soldier beetles, while that of honey bees decreased. Finally, nectar of these six cultivars was analysed for sugar content, which revealed monosaccharides to be the most common sugars in all. There was high variation in the levels of sugars from individual umbellets but no significant difference in nectar sugar composition among cultivars, suggesting that nectar sugar composition is of minor importance regarding pollinator attraction to hybrid CMS carrot umbels.

Nectar secretion pattern and removal effects in three species of Solanaceae

1993 ◽  
Vol 71 (10) ◽  
pp. 1394-1398 ◽  
Author(s):  
Leonardo Galetto ◽  
Luis Bernardello
Keyword(s):  
Sugar Production ◽  
Nectar Secretion ◽  
Nicotiana Glauca ◽  
Time Intervals ◽  
Nectar Production ◽  
Nectar Volume ◽  
Significant Difference ◽  
Flower Age ◽  
Nicotiana Longiflora ◽  
Nectar Sugar

Nectar secretion pattern and effects of nectar removal were compared in three Argentinean Solanaceae: Nicotiana glauca, which is hummingbird pollinated, and Nicotiana longiflora and Petunia axillaris, which are sphinx moth pollinated. Nectar volume, concentration, and sugar production were measured at different time intervals according to the species' flower life span. Nectar volume and total sugar production increased as a function of flower age in both species of Nicotiana analyzed; however, these parameters were quite stable in P. axillaris. This species produced less nectar and nectar sugar than the other two. When all sets with nectar removal were compared with the controls, significant differences were found in nectar volume and quantity of nectar sugar in N. longiflora, and in sugar concentration in P. axillaris. In the latter, the observed difference did not affect the total amount of sugar secreted. Nicotiana glauca did not show any significant difference in the parameters analyzed. Total nectar production was inhibited by periodic removal in N. longiflora, while in N. glauca and P. axillaris it was unaffected. Key words: nectar secretion pattern, nectar removal, Nicotiana, Petunia, Solanaceae.

scholarly journals Comparative study of wood betony (Stachys officinalis L) melliferousness in different habitat conditions

2005 ◽  
Vol 59 (3-4) ◽  
pp. 475-484
Author(s):  
Marina Macukanovic-Jocic
Keyword(s):  
Sugar Concentration ◽  
Habitat Conditions ◽  
Air Humidity ◽  
Nectar Secretion ◽  
Nectar Production ◽  
Relative Air Humidity ◽  
Close Relationship ◽  
Nectar Sugar ◽  
Lower Temperature ◽  
Forest Conditions

Nectar production in wood betony (Stachys officinalis L), grown under differ-microclimatic habitat conditions (forest and experimental field), was analyzed. Study of tar production included determining of the total daily nectar amount (in 24 hours) per flower, the diurnal dynamics of nectar secretion (nectar amount secreted per flower at two hour intervals during the day), and nectar sugar concentration. The aim of this study was to evaluate the influence of microclimatic parameters humidity, air temperature and evaporation) on the secretion process and nectar sugar concentration. Comparative analyses of nectar secretion in Stachys officinalis, grown in two environmentally different habitats, confirmed that this process varied as a function of micro-climatic habitat conditions, and did not reveal a close relationship between these conditions and sugar concentration in nectar. A diurnal model of nectar secretion with two secretion peaks was found. A higher amount of nectar per flower, with an increasing tendency during the first half of the day, and a decreasing tendency during the afternoon was measured in forest conditions (lower temperature, higher relative air humidity and lower evaporation).

scholarly journals Nectar Production of Cranberries: Genotypic Differences and Insensitivity to Soil Fertility

1997 ◽  
Vol 122 (5) ◽  
pp. 665-667 ◽  
Author(s):  
James H. Cane ◽  
Daniel Schiffhauer
Keyword(s):  
Honey Bees ◽  
Selective Breeding ◽  
Common Garden ◽  
Fertilizer Application ◽  
Genotypic Differences ◽  
Nectar Secretion ◽  
Nectar Production ◽  
Application Rates ◽  
Nectar Sugar ◽  
Nectar Rewards

Cranberry flowers (Vaccinium macrocarpon Ait.) require bee visitation for pollination. Bees visit cranberry flowers for nectar and sometimes pollen, but honey bees (Apis mellifera L.) in particular often work alternative co-flowering species for nectar, presumably because cranberry offers inferior nectar rewards. In a common garden setting, replicated plots of the cultivar Stevens were found to secrete significantly more nectar sugar (25% to 35% more) per flower than either `Ben Lear' or `Early Black', two other common commercial cultivars. The nectar secretion rate of `Stevens' was unaffected by a 4-fold range of fertilizer application rates over the preceding 2 years. These results are compared to studies of other crops involving varietal differences and programs of selective breeding for nectar secretion.

The effects of date pollinizer variety and pollination time on fruit set and yield of Medjhol date palm

2014 ◽  
Vol 2 (2) ◽  
pp. 67-71 ◽  
Author(s):  
Abdoul Amir Rahnama ◽  
Esmaeil Rahkhodaei
Keyword(s):  
Date Palm ◽  
Fruit Set ◽  
Block Design ◽  
Male Flower ◽  
Fruit Weight ◽  
Palm Fruit ◽  
Tropical Fruit ◽  
Male And Female ◽  
Time Interaction ◽  
Female Flowers

Date palm is unisexual, being either male or female. Male and female flowers grow on buds called Spathe, which opens naturally when fully mature. It is easy to identify the male and female flowers. Under the method of manual pollination, pollen from a male flower is smeared over female flowers. The pollen variety and pollination time have important effects on date palm fruit set, yield and quality. This experiment was carried out to study the effect of date pollinizer variety and pollination time on fruit set, growth and development of Medjhol date palm variety, in date palm garden of date palm and tropical fruit research institute of Iran during three years from 2009 to 2011. The trail was randomized complete block design in factorial manner with three pollen variety as Ghaname, Vardy, and Samesmave, two pollination time as 1-3 days before or after spathe opening and four replication. The results showed that the Vardy pollen had significant effects and increased the fertility percent and fruit yield, rather than two other pollen varieties. The pollen variety had no significant effects on fruit quality as total sugar, acidity, and bricx. The pollination time before spathe opening significantly increased fertility percent, decreased fruit weight and date palm yield. Finally the pollen variety and pollination time interaction effects showed that, application of Vardy pollen from 1-3 days after spathe opening with the most production date palm yield, equal 19.9 kilogram per any date palm trees, so this treatment is the best and are recommended.

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