12 April, 2014

Importance of bee pollination for cotton production in conventional and organic farms in Brazil

By Viviane C. Pires et al.

Native bee on a cotton flower
Cotton production is not entirely dependent on insect pollination, but can be increased by bee visits to the cotton flower. In Brazil, this bee-generated yield increase is poorly studied and, for this reason, is ignored, especially in conventional plantations. In this production system, soil preparation is mechanized and insecticide is intensively employed, especially during flowering. These practices reduce bee nesting and foraging in and around the cotton fields, and bee benefits may not be noticeable. On the other hand, in organic farms, where mechanization and insecticide use are minimized, the yield increase promoted by bees is evident and helps making this production system economically viable for smallholding

Read the whole summary in: English or Portuguese!
Read the scientific publication in JPE.

01 April, 2014

Pollen from dandelions reduces seed set of native plants

by Deirdre Loughnan, James D. Thomson, Jane E. Ogilvie, and Benjamin Gilbert

Flower-visiting insects tend to visit single species of plants, but in some circumstances they switch flower types within a foraging bout and therefore deposit mixed loads of pollen on stigmas.  In a few species, the receipt of foreign pollen has been shown to depress fruit or seed set in the recipient flower.  This phenomenon is termed “pollen allelopathy,” and the presumed mode of action is through soluble chemicals leached from the pollen grains.  

Read the whole summary in: English!
Read the scientific publication in JPE.
Non-native dandelions (Taraxacum officinale, yellow flower heads) invade a subalpine meadow below Mt. Crested Butte, Colorado, USA, where the study was performed.