Enhancing almond pollination efficiency (AL11003)

What was it all about?

Pollination by bees is a critical component of commercial almond production, with almonds being highly reliant on honey bee pollination.

This project investigated the effect of hive placement, including hive density and distance, in almond orchards and the flower-to-fruit conversion ratio, which is substantially determined by pollination. In particular, researchers looked for strategies that supported higher yields.

They also examined data on seven years of variation in almond yield and related it to records of the weather during flowering to see if weather conditions adverse to honey bees affected pollination rates.

The effects of pollen traps and enpollination felt fitted at hive openings on pollination effectiveness and the health of bee hive health were also explored. Experiments were conducted over many orchards and two flowering seasons.

Key findings from the research included:

• Pollen removal was significantly lower on trees far from hives, and this was reflected in a decline in fruit per flower at increasing distance from hives
  
  
• Pollen traps had a strong negative effect on brood production and a more variable effect but mostly negative effect on bee numbers
  
  
• Enpollination felt had little effect
  
  
• Weather favouring bees was not a strong predictor of yield
  
  
• Higher hive density improved fruit set, with best fruit per flower outcomes obtained with a high hive density (approximately 6.7 hives per hectare) but using smaller placements with shorter distances between them.

The researchers recommend a ‘spread them around’ strategy for pollination and almond production.