Follow the process that PollenPlus™ uses to prepare kiwifruit pollen for use in artificial pollination, from picking male kiwifruit flowers to pollen extraction and testing at a mill near Tauranga.
In the orchard - Picking flowers
Male kiwifruit flowers are picked by hand. One picker can collect 30–40 kg of flowers a day, and up to 800 pickers work at the busiest time. PollenPlus™ gets about 80 tonnes of flowers from its orchards in the western Bay of Plenty. One picker fills up to four of these 10 kg bags a day.
At the mill - Collecting anthers
Each bag of flowers is fed into a machine that lightly chops them up. A spinning drum separates the small anthers, which contain the pollen, from the rest of the flower parts. The anthers fall into a tray beneath the drum. The flowers pass through three drums to make sure all the anthers are collected.
The anthers from beneath the separating drums are spread evenly onto trays for drying. About 1 kg of anthers goes on each tray. The trays are then put in racks, where they are dried at 30 °C for 20 hours.
Dried anthers and pollen are vacuumed up into a cyclone separator. A spinning stream of air separates the fine pollen from the larger particles of the anthers. Pollen from the cyclone separator is filtered to remove the last of the impurities.
Pollen is packed into 250 g jars – this amount of pollen comes from about 25 kg of flowers. Just 1 gram of pollen contains about 5 million pollen grains. The pollen is frozen for storage. It will later be sent to kiwifruit growers in New Zealand and other countries.
Every 2 kg of pollen is sampled to check that the pollen is viable (still able to pollinate female flowers). Samples of pollen are put in sugar solution for 2 hours, then examined under a microscope to see how many pollen tubes have grown. A viability of at least 80%, which is 80 pollen tubes per 100 pollen grains, is needed for the pollen to pass the test.