Pollinating almonds: how many bees do you need? Saul Cunningham Research Scientist June 2013 SUSTAINABLE AGRICULTURE FLAGSHIP
Project Partners Ben Brown Kim James Me Danny le Feuvre 2 Almond Pollination Saul Cunningham
Importance to industry Benefit - pollination necessary for good yield Cost - is a significant input cost for growers Industry-wide demand will increase as more productive area comes on line Bee diseases, like Varroa mite, could make supply of sufficient hives more difficult Costs may increase Includes a per hive component and a labour component So lets get pollination just right good yield, while keeping input costs under control 3
Questions: Can you get the same flower nut conversion rate with half the density of hives? (saves $$$) Can we place hives in fewer locations, far apart, and still get good pollination? (saves labour, $$$) If trees far from hives have fewer bees, do they also get fewer nuts? (what is the threshold?) Do trees very close to large hive placement show high or low pollination rates? 4
139 111 Three big placements Image is 1 km wide 56 5 Presentation title Presenter name
6 20 hives in each placement Image is 1 km wide
Even longer distances: up to 760m from nearest hive 7
8 2.5 km top to bottom
This grower is using about 3.7 hive per ha, compared with 6.7 elsewhere 9 Almond Pollination Saul Cunningham
2012 (yr 2) 7 orchards, 88 transects, 469 trees, 2375 branches, etc. Each tree has hand pollination and open pollination Potential vs. Actual: Hand pollination reflects what a tree could do if it gets pollinated, open pollination reflects what it did do. Focus on the difference between these 10
Each point is a transect Fruit per flower, open 0.7 0.6 Even high Even low Far Isolated Near 0.5 0.4 0.3 0.2 0.1 0.0 0.2 0.4 0.6 0.8 Fruit per flower, hand poll 1.0
Each point is a transect Fruit per flower, open 0.7 0.6 Even high Even low Far Isolated Near 0.5 0.4 0.3 Low fruit set 0.2 0.1 0.0 0.2 0.4 0.6 0.8 Fruit per flower, hand poll 1.0
Each point is a transect Fruit per flower, open 0.7 0.6 Even high Even low Far Isolated Near 0.5 0.4 0.3 0.2 0.1 0.0 0.2 0.4 0.6 0.8 Fruit per flower, hand poll 1.0
Each point is a transect Fruit per flower, open 0.7 0.6 Even high Even low Far Isolated Near 0.5 0.4 0.3 0.2 0.1 0.0 0.2 0.4 0.6 0.8 Fruit per flower, hand poll 1.0
Fruit per flower from open pollination (adjusted means) 0.450 0.425 Even high 0.400 near 0.375 0.350 lsd far 0.325 Even low 0.300 0.275 isol. block 0.250
Treatment open mean open CV HP mean HP CV Even high 0.41 0.31 0.51 0.50 Even low 0.32 0.35 0.53 0.32 Far 0.37 0.43 0.59 0.48 Isolated 0.27 0.26 0.58 0.21 Near 0.41 0.33 0.60 0.30 Same order (though not using covariate) Highest CV for open pollination at Far. Sometimes high CV on hand pollination (imperfect)
17 Almond Pollination Saul Cunningham
Does the treatment effect the hive? 1.0 0.8 Change in amount of brood 0.6 0.4 0.2 0.0-0.2-0.4 control felt pollen trap 18 Almond Pollination Saul Cunningham
Does the treatment effect the hive? En-pollination felt looks promising does not have too bad an effect on the hive Manning et al 2010 show felt increases pollen on the body (but did not test in almond orchard, and did not measure crosspollination) Does it increase cross-pollination? Yield? What cost to implement? 19 Almond Pollination Saul Cunningham
Bee efficiency Counting bee activity is a poor window into what matters movement between rows These moves are a tiny percentage of all bee activity i.e. cross pollination rate might be very poorly correlated with overall activity level Surveying pollen load on anthers might be a better index of bee activity 20 Almond Pollination Saul Cunningham
Over the threshold? If most pollen is gone (removed from anthers) at the end of the day, then you clearly have enough bees Adding more bees will not help Brian Johnston 21 Almond Pollination Saul Cunningham
Pollen tubes: cross pollen http://www.vcbio.science.ru.nl/en/virtuallessons/pollenfertilization/ 22 Almond Pollination Saul Cunningham
all flowers make fruit 100% What else is keeping fruit set below max? No flowers make fruit 0 23 Almond Pollination Saul Cunningham
all flowers make fruit 100% 90 Some stigmas/ovaries are no good (e.g. developmental?, fungicide damage?) 80 70 60 Resource constraints? Structural constraints? Hand pollination: more fruit set (maximum?) 30 Open pollination: some pollination, some fruit set No flowers make fruit 0 No pollination: no fruit set 24 Almond Pollination Saul Cunningham
Plans for this flowering season Keep working toward a better understanding of hive number and arrangement for best cost/benefit outcome More data with even hive arrangement (even low?) How much underperformance is due to heavy fllowering on light branches? Survey of pollen removal and pollen receipt: are we over the threshold? Pilot larger trial of en-pollination felt 25
Thank you Saul Cunningham Research Scientist t +61 2 6246 4356 e saul.cunningham@csiro.au SUSTAINABLE AGRICULTURE FLAGSHIP