Influence of honey bee (Apis mellifera) on kiwifruit pollination and fruit quality under Australian conditions

Abstract

The influence of honey bee (Apis mellifera L.) pollination of kiwifruit (Actinidia deliciosa (A.Chev.) C.F. Liang et A.R. Ferguson) under different pollination regimes (viz. honey bee supplementation, honey bee saturation in a cage with a single male cultivar, and honey bee exclusion) was investigated under Australian conditions during 1993/94 and 1995/96 seasons. Vines that had no access to honey bees had significantly (P 0.01) lower fruit set (24%) compared to honey bee supplementation (91%) and bee saturation (89%). The mean yield (kg/vine) and the mean number of fruit/ vine in bee-supplemented and bee-saturated treatments did not differ significantly, although vines that were excluded from honey bees produced significantly (P 0.01) lower yields. However, individual fruit weight in the bee-saturated treatments was affected. There were significantly more small fruit in bee-saturated vines than in vines that were supplementary pollinated by honey bees. Bee activity as assessed by the number of bee visits on flowers (bees/vine per min) was significantly higher on male vines than female vines during the first 2 weeks of the flowering period. Honey bees were the main contributor to pollination and fruit set, although low numbers of other potential insect pollinators such as ladybird beetles and hover flies were also observed. The mean seed numbers in comparable fruit from higher weight groupings (i.e., 70-89, 90-109, and 110 g) in bee-supplemented and bee-saturated vines did not differ significantly, suggesting adequate pollination and fertilisation of ovules in these two treatments. Vines that were caged with a single male cultivar produced fruit with significantly higher (P 0.01) total soluble solids concentration than did those that were honey bee supplemented. Possible reasons for the reduced mean fruit weight under honey bee saturation are discussed.

Pollination services provided by wild insects to kiwifruit (Actinidia deliciosa)

“…Kiwifruit is one of 13 leading global food crops for which entomophilous pollination is essential (Klein et al 2007). Kiwifruit is dioecious, and insects are needed to transfer pollen from male to female vines because wind pollination is insufficient for a successful kiwifruit yield (Donovan and Read 1990;Costa et al 1993;Vaissiere et al 1996;González et al 1998;Howpage et al 2001;Pomeroy and Fisher 2002). Insects are needed not only for fruit set but also to obtain commercial fruit size because kiwifruit size is strongly correlated with seed number (Costa et al 1993;González et al 1998;Pomeroy and Fisher 2002), which depends on the number of pollen grains reaching the ovules.…”

“…Several studies have demonstrated the effectiveness of using managed honeybees (Apis mellifera ) (Vaissiere et al 1996;Howpage et al 2001, but see Clinch 1984;Costa et al 1993) and bumblebees (Bombus spp.) (Pomeroy and Fisher 2002) to pollinate kiwifruit, yet reliance on a single species for pollination is an inherently risky strategy.…”

“…Most studies of kiwifruit pollination by insects have been conducted in orchards with introduced hives of honeybees or bumblebees to measure the ability of those insects to pollinate this crop (Clinch 1984;Read et al 1989;Donovan and Read 1990;Testolin et al 1991;Costa et al 1993;Vaissiere et al 1996;González et al 1998;Howpage et al 2001;Pomeroy and Fisher 2002). The wild pollinator community in those studies was either not described (Read et al 1989;Donovan and Read 1990;González et al 1998;Pomeroy and Fisher 2002) or was negligible compared with the managed bee species (Clinch 1984;Testolin et al 1991;Costa et al 1993;Vaissiere et al 1996;Howpage et al 2001). A recent study conducted in India, however, described a rich insect community visiting kiwifruit flowers with half of the foragers being other than Apis or Bombus insects (Sharma et al 2013).…”

Peer Review #2 of "Contribution of insect pollinators to crop yield and quality varies with agricultural intensification (v0.1)"

“…We put the nets over the flower buds before the onset of flowering. Leaves and plant parts with no flowers were left as much as possible outside the net bag to minimize any effects of the bag on the photosynthesis (Howpage et al 2001). As soon as flowers had wilted, we removed the nets, and the tagged plants were left to ripen in the field until harvest.…”

Detection of <i>Pseudomonas syringae</i> pv <i>actinidiae</i> in kiwifruit pollen samples

“…Each seed is the result of a successful fertilisation by a single pollen grain. herefore production of an export quality kiwifruit requires that a large number of viable pollen grains are deposited on the stigmas of a female lower (Howpage et al 2001). Although kiwifruit lowers are fragrant, they do not produce nectar and therefore they are not very attractive to pollinating insects such as honey bees, yet pollination needs to occur in the relatively short period of time (ca 6 days) when the stigmas are receptive to pollen (Gonzalez et al 1995).…”