scholarly journals Water availability affects nectar sugar production and insect visitation of the cup plant Silphium perfoliatum L. (Asteraceae)

2020 ◽  
Vol 206 (5) ◽  
pp. 529-537 ◽  
Author(s):  
Anna Lena Mueller ◽  
Christian A. Berger ◽  
Siegfried Schittenhelm ◽  
Burkhard Stever‐Schoo ◽  
Jens Dauber
Keyword(s):  
Water Availability ◽  
Sugar Production ◽  
Insect Visitation ◽  
Nectar Sugar

scholarly journals Flowering, Forage Value, and Insect Pollination in Borage (Borago Officinalis L.) Cultivated in Se Poland

2020 ◽  
Vol 64 (1) ◽  
pp. 77-89
Author(s):  
Ernest Stawiarz ◽  
Anna Wróblewska ◽  
Marzena Masierowska ◽  
Dagmara Sadowska
Keyword(s):  
Fruit Set ◽  
Seed Set ◽  
Flowering Pattern ◽  
Borago Officinalis ◽  
Se Poland ◽  
Insect Visitation ◽  
Nectar Sugar ◽  
The Mean ◽  
Flower Visiting ◽  
Forage Value

AbstractThe three-year study on borage was conducted in Lublin, SE Poland. The aims were to investigate the flowering pattern and abundance, and the attractiveness (in terms of nectar and pollen production) for flower-visiting insects, mainly bees. Insect visitation and the effect of pollinators on fruit set and seed set were assessed as well. Flowering of borage started in the latter half of June and lasted eight weeks. The mean number of flowers · m−2 of the crop was 4570 per season. A borage flower produced on average 4.0 mg of nectar with a mean sugar concentration of 31.5%. The mean total sugar amount secreted in nectar was 1.2 mg. The pollen amount · flower−1 was 1.1 mg. A borage plant can supply insects with 1.1 g of nectar sugars and 1.1 g of pollen. The estimated nectar sugar yield and pollen yield per 1 m2 of the crop were similar, i.e. 5.2 g. Bees accounted for 73.0% of all insect visits to the borage flowers. The presence of insect pollinators increased the fruit set by 43.3% and seed set by 26.8%.

Nectar quality in open-pollinated, pol CMS hybrid, and dominant SI hybrid oilseed summer rape

1998 ◽  
Vol 78 (1) ◽  
pp. 79-89 ◽  
Author(s):  
S. F. Pernal ◽  
R. W. Currie
Keyword(s):  
Apis Mellifera ◽  
Brassica Napus ◽  
Sugar Content ◽  
Total Sugar ◽  
Breeding Systems ◽  
Sugar Production ◽  
Sugar Composition ◽  
Total Sugar Content ◽  
Bloom Period ◽  
Nectar Sugar

Nectar sugar composition and temporal patterns of nectar sugar production were examined in oilseed summer rape (Brassica napus L. ssp. oleifera (Metzg.)) from six open-pollinated, eight pol cytoplasmic male-sterile (CMS) hybrid and seven dominant self-incompatible (SI) hybrid cultivars at three field plot sites in Manitoba. The total sugar content of nectar samples was measured by the Dreywood anthrone reaction for total carbohydrate, and simple sugar composition was determined using an enzymatic bioanalysis for D-glucose, D-fructose and sucrose. Hybrid and open-pollinated cultivar flowers had similar sugar content. Mean total sugar content per flower also did not vary among hybrid breeding systems when compared within individual weeks of the bloom period or within daily sampling periods. However, for all cultivars, total nectar sugar content per flower was lower during the 08:00 and 11:00 h sampling periods and increased to maximum levels during the 14:00 and 16:00 h sampling periods. Significant differences in nectar sugar content were also found in relation to the bloom phenology of the cultivars. Cultivars produced the greatest amount of sugar per flower during the first 2 wk of the bloom period, then sugar production decreased in the third and fourth weeks. Nectar sugar ratios from all cultivars averaged approximately 1:1 glucose:fructose. Nectar glucose content among cultivars was similar but, among breeding systems, CMS cultivars tended to have lower amounts of glucose than SI or open-pollinated cultivars. Selecting for higher total sugar content may produce nectars more attractive to foraging honeybees (Apis mellifera L.), thereby ensuring adequate pollination of hybrid parental lines and F1 hybrid plants. Selecting for lower nectar glucose will produce honeys with more desirable granulation characteristics. Overall, the production and quality of nectar sugar in oilseed rape hybrids are similar to those of open-pollinated cultivars, and are not likely to adversely affect the pollinating activities of honeybees or their potential for honey production. Key words: oilseed summer rape, Brassica napus, honeybees, Apis mellifera, nectar, simple sugars

scholarly journals Nectar Sugar Production across Floral Phases in the Gynodioecious Protandrous Plant Geranium sylvaticum

PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e62575 ◽  
Author(s):  
Sandra Varga ◽  
Carolin Nuortila ◽  
Minna-Maarit Kytöviita
Keyword(s):  
Sugar Production ◽  
Nectar Sugar

Nectar sugar production in alfalfa fields treated with several herbicides

1995 ◽  
Vol 75 (2) ◽  
pp. 521-524
Author(s):  
P. S. Curry ◽  
J. Waddington ◽  
N. Malik ◽  
G. G. Bowes
Keyword(s):  
Field Studies ◽  
Early Spring ◽  
Sugar Production ◽  
Winter Dormancy ◽  
Megachile Rotundata ◽  
Cocoon Production ◽  
Leafcutter Bee ◽  
Nectar Sugar ◽  
Medicago Sativa L ◽  
Herbicide Effects

Field studies were conducted at three sites in northeastern Saskatchewan to determine the effects of several herbicides applied in late fall or early spring on nectar sugar production in alfalfa (Medicago sativa L.) grown for seed. In general, sugar production was not affected detrimentally by the herbicides, but at one site alfalfa treated annually with metribuzin for 4 yr at the break of winter dormancy produced flowers in early July containing significantly less nectar sugar than flowers of plants not treated with herbicide. Increases in nectar sugar production sometimes occurred. At one site, chlorsulfuron at 0.11 kg ha−1 or more, hexazinone at 1.0 kg ha−1 and dichlobenil at 2.4 kg ha−1 increased nectar sugar production in early August. Herbicide effects were not consistent among sites, and it seems unlikely that leafcutter bee (Megachile rotundata Fabr.) cocoon production will be affected significantly by these weed control practices. Key words: Metribuzin, hexazinone, chlorsulfuron, terbacil, dichlobenil, imazethapyr

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.

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%).

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