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The inescapable conclusion to blueberry pollination is that blueberries 

 must be pollinated by bees, and in most areas native bee populations are 

 insufficient to provide adequate pollination. 



St rawber r i es 



Most modern strawberry cultivars produce hermaphroditic Flowers, and 

 the arrangement of the flower parts (pistils surrounded by taller stamens) 

 encourages self-pollination. However, a characteristic common to many 

 cultivars is that primary flowers often lack well developed stamens and may 

 not be well pollinated. Research conducted in Arkansas has shown that 

 strawberries benefit greatly from insect pollination, and that bees are 

 important pollinators. 



Experiments conducted over a period of four years showed that excluding 

 insects by covering strawberry plots with l8 mesh screen wire during bloom 

 resulted in yield reductions of an average of 50 percent and fruit size 

 reduction of up to 31 percent. Furthermore, a high percentage of fruits 

 produced on caged plants were badly malformed, exhibiting evidence of 

 incomplete pollination. 



Most strawberry growers do not provide bee colonies to their fields. 

 However, most strawberry plantings are small and apparently attract adequate 

 numbers of native bees. For large plantings, or plantings located near 

 large plantings of other bee-attracting crops, growers should consider 

 providing additional bees in order to achieve maximum yields oF good quality 

 berr ies. 



Blackberries 



Many species and some cultivars of blackberries are self-unfruitful and 

 must be cross-pollinated for Fruit set to occur. Most erect, thorny culti- 

 vars grown in Arkansas are fully self-fertile and require no other pollina- 

 tor. 



There is little information on pollinating agents for blackberries. 

 Both honeybees and bumblebees readily forage on blackberry flowers. Wind 

 may also be an important pollinating mechanism, since the pollen is produced 

 in abundance, and the flower is so constructed that wind-borne pollen may 

 readily reach the pistils in the Field. 



Experiments conducted in Arkansas compared blackberry Fruit set under 

 three conditions. Plants in bloom were placed in a greenhouse in which both 

 wind and insect pollination was excluded, other plants were placed in a 

 field and caged to prevent bee, but not wind, pollination, and other plants 

 were uncaged in the field. The lowest percent fruit set and smallest berry 

 size was produced by the greenhouse-grown plants. Good fruit set and normal 

 fruit size was produced by both groups of field-grown plants. The conclu- 

 sion was that insect pollination was not essential for greater yields. No 

 doubt, under natural conditions, bees are also effective in distributing 

 pollen in blackberry Fields. 



