INDUSTRY NEWS
Towards artificial pollination options for Australian almonds
Melissa Broussard and Paul Martinsen ( The New Zealand Institute for Pland and Food Research Limited ); Brian Cutting and Roberta de Bei ( Plant and Food Research Australia Pty Limited )
THE phrase ‘ artificial pollination ’ or ‘ mechanical pollination ’ might suggest orchards swarming with robotic bees sweeping down rows visiting each flower with precision and purpose . While this futuristic vision may not yet be a reality , the related technology is much older than you might expect . Manually enhanced pollination of date palm is mentioned in the Code of Hammurabi , written nearly 4000 years ago – well before changing climate , disease and honeybee parasites threatened this crucial step in the supply chain . While insectsized robots await the discovery of a shrink ray , artificial pollination methods to supplement , and in rare cases substitute for insect pollinators are making their way to commercial kiwifruit , apple , pistachio , and almond orchards . Let ’ s take a look at the technologies , benefits , and barriers to widespread artificial pollination of Australian almonds .
Pollen-deployment technologies
Commercially available pollen applicators range from simple handheld dusters and sprayers used in high-value crops ( e . g ., vanilla , cacao , date palm , dragon fruit , premium pipfruit and stonefruit ), to tractor-drawn machinery blowing pollen through flowering orchards . Other approaches power-up honey bees , preloading them with pollen as they leave the hive . Dusters attached to aerial unmanned drones can quickly dispense pollen over crop on a calm day . Electrostatic sprayers dispense charged pollen , which is attracted to negatively charged flower stigmas , dramatically increasing efficiency while decreasing pollen consumption . Artificial pollination is a mainstay of the kiwifruit industry , which faces some similar challenges as almonds ( Figure 1 ). The flowering window
Figure
1 : Artificial pollination is commonly used in kiwifruit to protect against pollination failure . Photo : Jamie Troughton , Dscribe Media Services
is short , usually less than 10 days , inclement weather can compromise pollination , and asynchrony between major varieties and their pollen-donors can be an issue . To safeguard against pollination failure , approximately 50 % of New Zealand kiwifruit growers supplement bee pollination with hand sprayers or quad-bike mounted blowers . In Italy , Korea , Japan , and parts of China , kiwifruit growers don ’ t stock orchards with honey bees , instead they rely almost exclusively on artificial pollination and incidental pollination from wild insects .
Artificial pollination in almonds
Almond orchards are also suitable for tractor-drawn approaches , and about 30 % of growers in California use some form of artificial pollination . Reports vary , but in most years growers supplementing bee pollination see average yield increases of about 5 %. However , in poor pollination years , some Californian orchards have reported yield increases greater than 30 %. Of course , artificial pollination comes with additional costs such as labour and equipment hire or purchase , and substantial costs associated with collecting or purchasing pollen for application . Economic models predict a ‘ break-even ’ point for almonds somewhere between a 3.5 % and 5.5 % yield increase . So , in normal years growers are expected to see a modest return on investment from artificial pollination , but in years with poor pollination from other sources , the return on investment can be dramatic . Thus , artificial pollination is often seen as an ‘ insurance policy ’ against pollination failure . It is not likely to replace bees in the near future , but may reduce the dependency on bees , especially when conditions are poor , or pollinator populations are low . Self-compatible varieties , which are becoming more popular and reduce the pollination requirements of the crop , still benefit from artificial pollination ( with either self- or crosspollen ), but information is not yet available at the orchard scale .
Pollen supply limits technology deployment in Australia
Most of the machinery required for artificial pollination is already available in Australia or could be quite readily acquired . Several technology start-up companies already working overseas have an eye towards providing pollination services in Australia , and some have done early field trials ( e . g ., XAG , Edete ), but a lack of pollen supply is a key barrier to widespread availability . To date , no substantial quantity of pollen has been successfully imported into Australia . A ‘ home-grown ’ pollen supply might better serve the Australian almond industry . Established pollen supply companies in the USA , New Zealand , Europe and Asia all have their origins in publicly funded research organisations , highlighting the role of research in supporting the early days of a local pollen collection industry . Similar support in Australia could help perfect pollen collection in Australian conditions .
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