Department of Agriculture, Western Australia

Bee pollination benefits for pear and nashi, persimmon and pomegranate

Extract from Bulletin 4298: Honeybee pollination

Pear (Pyrus communis), Nashi (Pyrus pyrifolia)

Honeybees are used extensively to pollinate nashi crops in Victoria.

Flowering:

Pear flowers are not attractive to bees.

Hives per hectare:

2 to 5; 1; 5; at least 3. 2/0.86 ha arranged in groups of 4 to 5 hives, 140 m apart (South Africa); 2 (USSR).

Higher stocking rates will be needed if there are other more attractive flowering species present. Hives should be placed in the orchard when 25 per cent of the flowers are open. Beehives should be brought in two waves at about five-day intervals using five hives per hectare.

Nectar production:

Nectar has a sucrose content of 7 to 21 per cent (average 15 per cent). Bees are not attracted to the flowers because of the low sucrose in the nectar.

Honey production:

0 to 26 kg honey/ha.

Review of bee pollination benefits:

• 14.2 per cent increase in yields over caged (bee-excluded) trees for variety Packhams and 49.2 per cent for Packhams Triumph over caged (bee-excluded) trees. (Not significant at P>0.05.)
• 91.9 per cent of insect visitors were honeybees, 5.4 per cent hoverflies and 2.1 per cent blowflies for variety Winter Nelis pears.
• 633 per cent increase in yield of Winter Nelis in open and bee-excluded plots.
• Honeybees used in greenhouse production.
• 2.7 times more fruit over that of bee-excluded plots (India).
• Spraying trees with 30 per cent sugar solution increased fruit set due to increased bee activity.
• Bees work flowers mainly for pollen.

Data for Winter Nelis pears. (Langridge and Jenkins (1975) Aust. J. Exp. Agric. An. Husb. 15: 105-7)

Attribute	Open trees	Caged trees	Statistical significance of difference
Fruit set/100 clusters	52.75	4.95	P<0.01
Yield per tree (kg)	87.8	11.5	P<0.01
Seeds per fruit	5.0	2.9	P<0.01

Grower observation in Victoria: Twenty-five hives placed amongst 700 pear Winter Nelis (which prior to bees being used produced on average 1000 cases) increased yield to 2400 cases. The following year, 40 more beehives were introduced and the yield was 3400 cases. Since the introduction of bees, the yield has reached a maximum of 5400 cases and never less than 3300 cases. The trees have become older which may account for some of the observed increase. Hive ratio is one hive per ten trees. -- The Australian Beekeeper (1958) 59.

Apart from William's Bon Chretien, most varieties will set few fruit, if any, without cross-pollination.

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Persimmon (Diospyros kaki)

Hives per hectare:

2 to 3.

Review of bee pollination benefits:

• Mostly wind-pollinated.
• Visited by honeybees for nectar and pollen.
• Cross-pollination may improve fruit set.

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Pomegranate (Punica granatum)

Flowering:

Flowers late spring and summer.

Hives per hectare:

2 to 3.

Nectar production:

Review of bee pollination benefits:

• 10 per cent of the yield can be attributed to pollination by honeybees.

Page reviewed: March 2006