Local Flower Research Articles

生産・流通基盤からみた茨城県友部町におけるキク産地の維持機構

Japan is one of the leading flower producers, with chrysanthemums being typical flowers. Although the plastic green house sector has been developed in Japanese floriculture since the 1970's, a considerable amount of chrysanthemums is still cultivated in open fields. Tomobe town, located in Hitachi diluvial upland, is known as an active chrysanthemum producing area in Kanto Plain. In this research, the author pays attention to the production and distribution basis of floricultural farms to examine the maintain mechanism of chrysanthe mum cultivation in Tomobe town, Ibaraki prefecture.Open field chrysanthemum cultivation at Tomobe town was started by a veteran returning in 1946. Because the major crop cultivation system on the upland fields at the time was a double cropping system of wheat and potato, only a few farms were interested in floriculture. When chrysanthemums were sold at high prices in the flower wholesale market in Mito city, chrysanthemum cultivation began to spread among farms in the Namusanzuke district of Tomobe town.The number of chrysanthemum farms in Tomobe increased from the 1950's to the mid-1960's. Chrysanthemums were shipped to flower wholesale markets in Tokyo metropolis and Tochigi prefecture in the early 1950's. After three shipment cooperatives were founded in the mid-1950's, chrysanthemums were also shipped to local flower wholesale markets in distant regions, such as Kanagawa prefecture and Miyagi prefecture. Although the three cooperatives were united as a branch of Agricultural Cooperatives in 1972, the relationship between farms and wholesale markets still restricts distribution by floricultural farm.Floricultural farms in Namusanzuke district are divided into two types, on bases of total sales revenue from cut flowers: six full-time floricultural farms and 15 part-time floricultural farms. The farm management of the former farms is characterized by two generations of agricultural family labor with chrysanthemum cultivation in open fields and cut flower cultivation in plastic greenhouse facilities. The farm management of the latter farms is characterized by one generation of agricultural family labor and chrysanthemum cultivationin open fields. The aging of family labor and lack of successors is hindering cut flower cultivation in some of the later farms.The former farms sell a large amount of products through cooperative shipments of Central Ibaraki Agricultural Cooperative. The latter farms sell products largely through individual shipments of the Agricultural Cooperative. Cooperative shipments forward cut flowers mainly to large flower wholesale markets in Tokyo metropolis and Kanagawa prefecture. Individual shipments forward cut flowers mainly to various local flower wholesale markets in eastern Japan through distribution centers in Tokyo metropolis.The cut flower's production-distribution mechanism is suitable for the structure of flower wholesale markets of Japan, e. g., several enormous wholesale markets in the metropolitan area and many small wholesale markets in local cities. The individual distribution system for local wholesale markets is an important factor for maintaining the chrysanthemum production, especially by part-time floricultural farms. However, unified flower wholesale markets in Tokyo and large-scale wholesale markets, which request high-quality flowers through cooperative shipments, are to be constructed. The regional organizations, such as the flower section of Central Ibaraki Agricultural Cooperative and the municipality of Tomobe town, should endeavor to introduce producers to new cultivation techniques for producing high-quality flowers that can pass the standard for cooperative shipment.

Floral isolation betweenAquilegia formosaandAquilegia pubescens

The acquisition of floral nectar spurs is correlated with increased species diversity across multiple clades. We tested whether variation in nectar spurs influences reproductive isolation and, thus, can potentially promote species diversity using two species of Aquilegia, Aquilegia formosa and Aquilegia pubescens, which form narrow hybrid zones. Floral visitors strongly discriminated between the two species both in natural populations and at mixed-species arrays of individual flowers. Bees and hummingbirds visited flowers of A. formosa at a much greater rate than flowers of A. pubescens. Hawkmoths, however, nearly exclusively visited flowers of A. pubescens. We found that altering the orientation of A. pubescens flowers from upright to pendent, like the flowers of A. formosa, reduced hawkmoth visitation by an order of magnitude. In contrast, shortening the length of the nectar spurs of A. pubescens flowers to a length similar to A. formosa flowers did not affect hawkmoth visitation. However, pollen removal was significantly reduced in flowers with shortened nectar spurs. These data indicate that floral traits promote floral isolation between these species and that specific floral traits affect floral isolation via ethological isolation while others affect floral isolation via mechanical isolation.

Can wind pollination provide a selective benefit to mast seeding in Chionochloa macra (Poaceae) at Mt Hutt, New Zealand?

Mast seeding, which is very pronounced in Chionochloa (Poaceae) in New Zealand, could provide selective advantages through reduced seed predation or through more efficient wind pollination. The importance of wind pollination in favouring masting was tested experimentally by measuring the pollination success of Chionochloa macro individuals in 10 m x 10 m plots subject to a range of experimentally altered flowering densities within a single season. Very low local flowering densities produced a moderate but non‐significant increase in the proportion of unfilled seeds (assumed to represent unsuccessful pollination). This result is consistent with the conclusions from between‐year observational studies on Chionochloa pollens that wind pollination makes only a small contribution to any present selective benefit of masting in Chionochloa. However, masting may provide larger benefits from higher seed quality (reduced inbreeding depression) than from seed quantity.

Comparative analysis of the mating system of the rare woodland shrub Daviesia suaveolens and its common congener D. mimosoides

Controlled pollinations and allozyme markers were used to compare mating system parameters among three populations of the rare woodland shrub Daviesia suaveolens Crisp. and five populations of its common relative D. mimosoides R. Br. Pollination results show that both species require a vector to facilitate pollination and have strong self-incompatibility mechanisms. Multilocus estimates of outcrossing rates confirm this, with all populations being highly outcrossed (D. suaveolens tm=0.78−1.0; D. mimosoides tm=0.71−0.96). Smaller and less dense D. mimosoides populations had higher correlations of outcrossed paternity than larger ones. The divergence of pollen pool allele frequencies from population frequencies was greater in smaller populations than in larger ones, in keeping with a lower effective size of the male source. Regression analyses generally failed to show effects of either plant size or local flowering environment on estimates of single-plant outcrossing rates. Most variation in these rates probably reflects the combined effects of sampling error, correlated mating and the influence of marker diversity on outcross detectability.

Comparative analysis of the mating system of the rare woodland shrub Daviesia suaveolens and its common congener D. mimosoides

Controlled pollinations and allozyme markers were used to compare mating system parameters among three populations of the rare woodland shrub Daviesia suaveolens Crisp. and five populations of its common relative D. mimosoides R. Br. Pollination results show that both species require a vector to facilitate pollination and have strong self-incompatibility mechanisms. Multilocus estimates of outcrossing rates confirm this, with all populations being highly outcrossed (D. suaveolens tm=0.78−1.0; D. mimosoides tm=0.71−0.96). Smaller and less dense D. mimosoides populations had higher correlations of outcrossed paternity than larger ones. The divergence of pollen pool allele frequencies from population frequencies was greater in smaller populations than in larger ones, in keeping with a lower effective size of the male source. Regression analyses generally failed to show effects of either plant size or local flowering environment on estimates of single-plant outcrossing rates. Most variation in these rates probably reflects the combined effects of sampling error, correlated mating and the influence of marker diversity on outcross detectability.

The effects of season, pretraining, and scent on the efficiency of traps for capturing recruited honey bees (Hymenoptera: Apidae)

A portable trap was designed to capture honey bees recruited to the field by dancers. An infrared phototransistor placed in the entrance tunnel of the trap sensed an incoming bee and turned on a talking clock, which in turn activated a voice-actuated audio tape recorder that recorded the time. We tested the effectiveness of traps for capturing bees recruited by four dancer bees (1) during two seasons when local flower densities differed, (2) with or without a group of bees pretrained to enter traps for food, and (3) when the scent used in traps and at the dancers' feeding station was changed just prior to recruitment trials or was not changed. One trap was put out at each of four distances (50, 100, 150, and 200 m) from the hive, while dancers fed on concentrated sucrose at the feeding station located at 150 m in the same direction. Recruited bees that approached the traps but did not enter were counted by observers. More bees were recruited and captured in traps when the local flora was sparse (fall) than when flowers were abundant (summer), when bees were pretrained versus not pretrained, and when the scent was not changed just prior to recruitment trials versus changed. The distributions of number of bees counted at the four distances at scented recruit stations and trapped were similar only when bees were pretrained and the scent was not changed during recruitment trials. However, the highest proportion of bees trapped in a trial at 150 m (distance to dancers' feeding station) was when bees were pretrained and the scent was changed.

Birch pollen production, transport and deposition for the period 1984–1993 at Kevo, northernmost Finland

Betula pollen production and flowering, pollen transport and pollen deposition are considered for the mountain birch region of northern Finland for the ten-year period 1984–1993. The most abundant flowering year was 1989 and, after that, 1985. In these years the highest values were also recorded for pollen in the air. There is a significant correlation between the amount of pollen released and the thermal sum of the previous year. In terms of pollen deposition the peak years were 1989 and 1986. The correlation between the amount of pollen in the air and that being deposited on the ground is also statisticaly significant. It is evident that some birch pollen is already present in the air before local flowering begins and that, in some years, this non-local pollen can account for more than 20% of the yearly total. This preflowering proportion was highest in 1985 and 1993, the latter being a prolific flowering year in the south of the country. There is a clear relationship between the proportion of the non-local pollen in the air and the proportion ofBetula pubescens/pendula type pollen deposited on the ground and, conversely, there is a significant correlation between the amount of local pollen in the air and the amount ofBetula tortuosa plusB. nana type pollen being deposited on the ground. The questions both of the viability of this long-distance pollen and of its ability to cause allergic reactions are considered. An assessment is also made of the degree to which fossil birch pollen assemblages can be realistically interpreted in terms of local vegetation if a varying proportion of the same pollen type is non-local.

Long-distance transport ofBetula pollen grains and allergic symptoms

An example of the potential importance of air masses as carriers of aero-allergens from distant source areas is provided. Considerable amount ofBetula pollen is relatively often transported to Fennoscandia before the local birch flowering period, mainly by southeastern air masses from eastern part of central Europe. Although the distance and the transport time in some cases can be extensive, the pollen grains seem to cause allergic reactions among sensitive persons. A comparison between the clinical results andBetula pollen counts from the time before the local flowering season in Stockholm in 1989 is presented.

SURVEY OF THE IMPACT OF THE FLORICULTURE INDUSTRY IN MINNESOTA.

A phone survey was conducted to assess the total impact of the floriculture industry on the Minnesota economy. Data were collected from wholesale growers, garden center retailers, chain stores, and florists. Information was gathered on `hard good' sales associated with greenhouse produced plants as well as plant sales. In addition, data on labor and salaries associated with the production, distribution, and retailing of plants and goods associated with the floriculture industry was collected. This data will be provided to local flower growers organizations to enable these groups to actively lobby for their concerns within the state.

Aerobiological studies in subalpine birch forest at Dovrefjell, Central Norway, 1982–1984

Abstract Sampling performed with a Burkard Seven Day Volumetric Pollen and Spore Trap in a meadow situated in the subalpine birch woodland belt at Kongsvold during the pollen seasons of 1982–1984 revealed 33 different pollen types, with Betula, Poaceae and Urtica as the most frequent taxa, constituting 75–80% of the total seasonal sum. Poaceae and Urtica alone contributed more than 50%. The total sum of pollen grains recorded varied greatly from one season to another. The 1983 season showed the highest concentrations of pollen grains and Cladosporium spores of the three years in question. Studies of the start and duration of the main pollen season of the common types of pollen have shown that Urtica, in particular, was remarkably constant from year to year. Special attention is given to the incidence of long‐distance transport of Betula pollen, which showed a maximum prior to the local Betula flowering, reflecting the earlier lowland flowering. Most Cladosporium spores were recorded during July and August...

Flower Usage by Bumble-Bees: A Basis for Forage Plant Management

1. Flower visits by bumble-bees were recorded in a national survey throughout Britain in 1987 and 1988. 2. To avoid misidentifications, recorders were asked to name bumble-bees in terms of five colour groups. Each group included one or two common and widespread species, which are probably responsible for major patterns of flower usage, and several rarer forms. 3. A simple selectivity score ranks plant taxa in terms of the visits they receive from bumble-bees of each colour group. High scores may be due to high local flower abundance or to preference by the bees, and indicate plant taxa that may be worth encouraging to enhance bumble-bee populations locally. 4. A group-specific selectivity score highlights differences between bumble-bee groups in flower choice. It could be used to indicate which bumble-bee groups visit particular crops, and to plan vegetation management to favour particular bumblebee species selectively. 5. Bumble-bees allocate a disproportionately high percentage of their visits to perennial plants of later successional stages. Annual plants of newly disturbed land receive relatively few visits. The implications for management are discussed.

Allergic symptoms caused by long-distance transported birch pollen

Abstract Birch pollen allergy is very common in northern Sweden, and the local flowering season never starts before the middle part of May. In the last week of April 1989 patients with birch pollen allergy developed typical symptoms requiring treatment. This pattern was confirmed in a group of patients who registered their symptoms in diaries, while contemporaneous pollen measurements demonstrated high amounts of birch pollen in the air. At that time in the northern part of Sweden, however, no birches were flowering. Meteorological data indicated that strong winds from the south-east during the period transported birch pollen from the Baltic states. Similar weather conditions in 1982, 1984 and in 1990 have also resulted in high amounts of birch pollen in the air long before the local flowering season. It is concluded that long distance transport of pollen may result in clinically significant allergy problems before, and even after the normal local season.

Evidence of long-distance transport ofbetulapollen

Abstract In April the eastern parts of Fennoscandia are frequently influenced by south to southeastern winds. These air-masses can bring with them large quantities of Betula pollen several weeks before the local flowering season begins. The pollen is transported with air-masses at a high level and then taken down by turbulent transport or washout. The number of pollen grains can be so high that sensitive persons exhibit allergic symptoms. Three localities from Sweden and six from Finland have been selected and numerical air-parcel trajectories have been calculated in order to determine the Betula pollen source. The results indicate that the distant pollen source areas can be identified, and that the travelling times for pollen grains transported in April 1989 were mostly in the range of 9 to 20 hours.

Floral Resource Variation, Pollinator Response, and Potential Pollen Flow in Psiguria Warscewiczii

Fluorescent dyes were used to examine several hypothesized ecological correlates of pollen flow in a natural population of a tropical, butterfly—pollinated vine, Psiguria warscewiczii. The study population consisted of monoecious, perennial vines that flower year round, have a flowering peak during the rainy season, and possess an extreme bias in proportion of flowering plants in male phase. Number of flowers on individual plants, flower density, and pollen surplus in staminate flowers at the end of the day (an indicator of visitation activity, or average resource availability) were monitored periodically over 4 yr from 1980 to 1984. Also monitored were the accumulated number of conspecific pollen grains on stigmas, and presence or absence of tephritid fly larvae (Blepharoneura sp.), which infested between 0 and 15% of the staminate flowers sampled. Local flower density (measured within 50 m of the dye—source plant) explained °50% of the variation in mean dye—dispersal distance. Visitation rate, number of individual visitors, and floral occupation rates of individually marked Heliconius butterflies were negatively correlated with average pollen surplus in staminate flowers. At very low levels of resource availability, many butterflies defended individual flowers for entire mornings against repeated attempts by other butterflies to visit the same flowers; at higher resource levels, butterfly visits were of shorter duration, and more movement among plants was observed.

Pollen seasons: Forecasts of the most important allergenic plants in Finland

Occurrence of airborne pollen in Finland has been studied for 10 years in Turku (southern Finland), 8 years in Oulu, 4 years in Kuopio (central Finland) and 7 years at Kevo (northern Lapland). Observations on the pollen seasons of alder, birch, grasses and mugwort are presented. All these pollens occur in south and mid- Finland in quantities capable of causing allergy symptoms. Except for birch pollen, allergenic pollens occur in far lower concentrations than in central Europe. In northern Lapland only birch and pine pollen concentrations are high. Pollens may occur without signs of local flowering when there are southerly winds. This finding suggests that long-distance transport is an essential contributing factor to the occurrence of pollens. There are wide year-to-year variations in the start of pollen seasons and the quantities of pollens. The variations in the start of birch and grass pollen seasons could very much depend on the mean temperature in April. However, a forecasting model based on this and other spring-time temperature parameters often fails to give sufficiently accurate forecasts.

Pollen seasons: forecasts of the most important allergenic plants in Finland.

Occurrence of airborne pollen in Finland has been studied for 10 years in Turku (southern Finland), 8 years in Oulu, 4 years in Kuopio (central Finland) and 7 years at Kevo (northern Lapland). Observations on the pollen seasons of alder, birch, grasses and mugwort are presented. All these pollens occur in south and mid- Finland in quantities capable of causing allergy symptoms. Except for birch pollen, allergenic pollens occur in far lower concentrations than in central Europe. In northern Lapland only birch and pine pollen concentrations are high. Pollens may occur without signs of local flowering when there are southerly winds. This finding suggests that long-distance transport is an essential contributing factor to the occurrence of pollens. There are wide year-to-year variations in the start of pollen seasons and the quantities of pollens. The variations in the start of birch and grass pollen seasons could very much depend on the mean temperature in April. However, a forecasting model based on this and other spring-time temperature parameters often fails to give sufficiently accurate forecasts.

Nocturnal Bee Abundance and Seasonal Bee Activity in a Panamanian Forest

Bees were monitored weekly for 7 yr at light traps in the tropical monsoon forest of Barro Colorado Island. Fifty species and 17 genera were recorded, including nocturnal Megalopta and crepuscular Rhinetula (Halictidae) and Ptiloglossa (Colletidae). Twenty—eight native meliponines and African Apis mellifera in traps increased the known resident highly social bees to 32 species. Most of the 11,860 bees were Megalopta; these species were present throughout the year, as were Rhinetula and Ptiloglossa. Abundance of Megalopta was lowest during the dry season; this was its only consistent seasonality. Peak abundance occurred at various times during dry—to—wet—season transition and in the first half and the end of the wet season. Centris and Epicharis, large, solitary anthrophorid bees, were present in the early wet season and absent in the late wet season and most of the dry season. The highly social bee Trigona aff. cupira was aseasonal but had abundance peaks during all but the mid—to—late wet season. Megalopta genalis abundance and M. ecuadoria abundance were highly positively correlated within years, and weekly correlated with abundances of other bees. Pairwise correlations between years were low for each Megalopta species and for combined bees of other genera. A singularly large catch of Megalopta genalis in 1978 corresponded to flowering of the monocarpic tree Tachigalia versicolor near light traps. Fluctuation of bee abundance at light traps probably indicates local flower availability for this species and, to a lesser extent, for the other bees. The data suggest large year—to—year variation in seasonal abundance of resources used by nocturnal bees and by bees in general, but are limited to indicating the presence or absence of most other bee species. The yearly variances in abundance of a stingless bee species and of Megalopta in Panama are comparable to those of eight temperate bumble bee species studied in England, but combined diurnal and crepuscular bee abundance is considerably less variable. The African honey bee arrived on Barro Colorado Island in mid—1982 and has produced no noticeable changes in abundance of other bees but has yet to reach its potential, numbers there; light—trap studies could provide perhaps the most reliable information on its impact.

Behavior of Sterile Adult Screwworms (Diptera: Calliphoridae) on Flowering Trees and Shrubs

In a south Texas shrub and brush community, sterile adult screwworms, Cochliomyia hominivorax Coquerel (Diptera: Calliphoridae), were observed or collected on 19 of the 23 sampled species of flowering shrubs and trees. Flies were observed feeding, mating, and resting on flowering shrubs and trees. Most of the flies were found on tenaza, coyotillo, and certain Acacia spp., but not on flowering cacti, herbaceous wild flowers, or grasses. Fly activity on a given plant species appeared to be related to blooming patterns and possibly flower color, but activity was not correlated to the density, frequency, or percent coverage of a plant species. Fewer females were collected (46.1%), and less than half (42.5%) were mated. Flies appeared to aggregate, feed, and mate at local flowering vegetation for up to 5 days after eclosion and then disperse or die. No fly activity other than resting was observed when plants were not in flower, except at two locations where males were waiting for females on nonflowering vegetation. The effect of season and rainfall on flowering could have indirectly affected fly activity, particularly survival, since flowers in a shrub and brush community are a major feeding site.

Stratum, Tree, and Flower Selection by Tropical Bees: Implications for the Reproductive Biology of Outcrossing Cochlospermum Vitifolium in Panama

Forager behavior in three patches of flowering Cochlospermum vitifolium (Malvales, Cochlospermaceae) and fruit, flower, seed, and ovule number on trees in six sites were used to test two incipient paradigms and study the role of bee pollinators in tree reproductive success. Antho- phorid bees of the genus Centris were the most important pollinators. Behavior of both small and large Centris species indicated no consistent preference for flowers either in the densest floral arrays or within the stratum containing most flowers in the local flowering population. Flowers 7-12 m in height were never visited more often than flowers '_4 m from ground level. However, within groups of 5-33 flowers, Centris visited on average at least 50% of the flowers during a foraging bout. Polli- nating bees were indiscriminate in selecting inflorescences within floral arrays, but they appeared to maximize the rate of resource harvest once a small group of flowers was entered. The fruit of Cochlospermum contained an average seed number equal to 13% of the average ovule number per flower. Seed-set per fruit was no higher among flowers visited more often by pollinators than among flowers visited less frequently. Female competition for pollinators was not detected, but male com- petition may have occurred at one site where bees preferred flowers that were most abundant in the patch as a whole. Efficient outcrossing of a tree is in direct conflict with the optimal foraging of its pollinators. Cochlospermum may manipulate pollinators by (1) presenting small numbers of open flowers, (2) presenting large, conspicuous flowers and no leaves, and (3) providing only pollen con- cealed in poricidal anthers as a reward. If pollinators rather than the physiological capacity of a tree limited reproductive success, this probably arose from deposition of incompatible pollen on stigmas, rather than intertree competition or low pollinator abundance.

Spatial and Temporal Components of Resource Assessment by Flower-Feeding Insects

(1) Per-flower insect visitation rates on two plant species within Rocky Mountain subalpine meadows were measured using fluorescent powders and found to be positively correlated with local flower density, suggesting that insects concentrate their foraging in dense patches of flowers. (2) Visitation rates on both species are also correlated with the presence of other plant species which share the same visitors; these correlations are positive, suggesting cooperative rather than competitive plant-plant relationships, at least insofar as visitation is concerned.