Abstract
Spring oilseed rape (Brassica napus L. var. oleifera) is an important oilseed crop whose cultivation area has increased significantly in Estonia. It is predominantly autogamous but cross-pollination can have several positive effects, including higher seed yield. We studied the effect of fertilization with different foliar microfertilizers on the flower density and pollen and nectar production of spring oilseed rape as well as the impact of these factors on the abundance of flower visiting bees – honey bees, bumble bees and solitary bees. Field experiments were carried out in 2004 and 2005. The field consisted of 32 plots (10 m2 each): control plots (no mineral fertilizers used), plots fertilized with the complex fertilizer OptiCrop (NPK 21-08-12 + S + Mg + B + Ca) alone and plots treated with OptiCrop and one of the six foliar microfertilizers (Mn, S, Cu, B, Mg, Mo). There were four replicates of each treatment. Flower visiting bees were counted twice a week on sunny days. Flowers were counted at the same time on an area of 1 m2 on each plot. Nectar production by the flowers was measured in the field by inserting a 1 μl capillary into the corolla tube of flowers isolated for 24 h. Pollen grains were counted from previously isolated flowers after dissolving the flower tissues. The density of flower visiting bees (honey bees, bumble bees and solitary bees) on spring oilseed rape depended mainly on flower density. Fertilization increased not only the number of flowers but also the amount of nectar and pollen per flower. Additional foliar fertilization had no effect either on the number of flowers or the amount of pollen grains per flower. Nectar production per flower seemed to be inhibited by additional manganese. Therefore, to secure higher number of pollinators for achieving higher seed yield and other benefits deriving from crosspollination, spring oilseed rape should be given proper complex fertilization. Microfertilizers turned out to be useless in terms of increasing the number of pollinators.
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Claims 7
Claim · model-written summary
Bee density depended mainly on flower density.
- Taxon
- spring oilseed rape
_Brassica_napus_-_Habit.jpg?width=60)
Brassica napuse0 - Organ / stage
- flower densitye0
- Interactor
- beesAnthophilae0pollinator
- Outcome
- density of flower visiting beese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Brassica_napus_-_Habit.jpg?width=500)
Verbatim
e0“The density of flower visiting bees (honey bees, bumble bees and solitary bees) on spring oilseed rape depended mainly on flower density”
Claim · model-written summary
Fertilization increased flower number.
- Taxon
- spring oilseed rapeBrassica napust0
- Treatment
- Fertilizatione0
- Outcome
- number of flowerse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Fertilization increased not only the number of flowers but also the amount of nectar and pollen per flower”
t0“spring oilseed rape”
Claim · model-written summary
Fertilization increased nectar and pollen per flower.
- Taxon
- spring oilseed rapeBrassica napust0
- Treatment
- Fertilizatione0
- Outcome
- amount of nectar and pollen per flowere0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Fertilization increased not only the number of flowers but also the amount of nectar and pollen per flower”
t0“spring oilseed rape”
Claim · model-written summary
Additional foliar fertilization did not affect flower number or pollen grains per flower.
- Taxon
- spring oilseed rapeBrassica napust0
- Treatment
- Additional foliar fertilizatione0
- Outcome
- number of flowers or the amount of pollen grains per flowere0
- Direction
- no effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Additional foliar fertilization had no effect either on the number of flowers or the amount of pollen grains per flower”
t0“spring oilseed rape”
Claim · model-written summary
Additional manganese seemed to inhibit nectar production per flower.
- Taxon
- spring oilseed rapeBrassica napust0
- Treatment
- additional manganesee0
- Outcome
- Nectar production per flowere0
- Direction
- inhibitede0
- Qualifier
- seemed to bee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nectar production per flower seemed to be inhibited by additional manganese”
t0“spring oilseed rape”
Claim · model-written summary
The authors recommend complex fertilization to attract more pollinators.
- Taxon
- spring oilseed rapeBrassica napuse0
- Outcome
- proper complex fertilizatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spring oilseed rape should be given proper complex fertilization”
Claim · model-written summary
Microfertilizers did not increase pollinator numbers.
- Taxon
- spring oilseed rapeBrassica napust0
- Treatment
- Microfertilizerse0
- Interactor
- pollinatorse0pollinator
- Outcome
- number of pollinatorse0
- Direction
- useless in terms of increasinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Microfertilizers turned out to be useless in terms of increasing the number of pollinators”
t0“spring oilseed rape”
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