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Into Horticulture

Issue 18   July 2015

Plant & Garden News

Path to rose fragrance takes unexpected turn

Researchers studying the biochemistry of rose fragrance has found that fragrance in all plants is not produced by enzymes called terpene synthases. Comparison of the cultivars Papa Meilland (highly scented) and Rouge Meilland (low scent) allowed them to identify RhNUDX1 in a different class of enzyme. Located in in the cytoplasm of rose petal cells it produces the primary part of rose oil, geraniol. This knowledge may be used in the future to help breed fragrance back into new rose varieties. Source: Unexpected enzyme may resurrect roses' fading scents

Flies outperform bees in mango pollination

A study of pollinators visiting mango flowers in the Mareeba region of Queensland has shown that native flies are more important than bees. Overall, 44 different insects were observed. When it came to amount of pollen transferred to a single mango flower, a native bee and several fly species were more effective than the honeybee. It is hoped that effects on mango crop yield can be investigated in future work. Source: Native flies leading the charge to help pollinate mango trees in new UNE study

Bamboo popularity raises concern

The increasing popularity of bamboo for landscaping could have an unexpected consequence The phenomenon of bamboo mass flowering (also known as masting) leads to massive seed production, which can go on for 18 months. Consequently, booms in rodent populations have been observed in Asia and South America associated with these events. Now, there is a concern that widespread landscape planting of bamboo in North America could lead to population booms of deer mice which can carry a potentially fatal human disease. Recommendations include eradication of aggressive running bamboos on public land and evaluation of varieties' flowering abilities and seed palatability before import. Source: WSU ecologist warns of bamboo fueling spread of hantavirus

Veggies in urban soils - how dangerous?

A study measuring uptake of various pollutants suggests the risk of growing vegetables in contaminated urban soils may not be as high as previously thought. Root crops remain a slight concern but were considered a minor risk at normal levels of consumption. Good horticultural practices and thorough washing of produce is also helpful in reducing risk. Read more: Gardening in a polluted paradise

Pollen makes another kind of seed

Pollen particles in the atmosphere were previously thought to be too large to nucleate clouds and that they would settle out too quickly, anyway. However, it's known that pollen grains can break up into fragments which cause allergenic responses in sensitive people. When the affect of moisture on pollen grains was tested, it was found that these can rupture readily into pieces small enough to seed clouds. So, it's possible that a tree's pollen could help make the rain that keeps that tree alive. Source: Pollen and clouds: April flowers bring May showers?

Fighting plant disease with nanoparticles

Silver nanoparticles are an emerging new anti-fungal treatment for plants. Researchers in the USA have found that silver nanoparticles prepared with an extract of wormwood (Artemisia sp.) are effective against Phytophthora. They say that it works on all stages of the pathogen's life cycle without affecting plant growth. The multiple modes of action means development of resistance is unlikely. Source: Researchers Find a "Silver Bullet" to Kill a Fungus That Affects More Than 400 Plants and Trees

Genetic insights into Citrus evolution

A large study of chloroplast DNA from 30 species of has confirmed that a single common ancestor gave rise to all Citrus fruit, although hybridisation occurred frequently during evolution of the genus. Furthermore, two genes believed to help the Australian species adapt to hotter and drier climates were identified. Source: Most comprehensive study to date reveals evolutionary history of citrus

Posh trees

A study has looked at the the number of trees and income levels in seven U.S. cities. The findings? "Simply put, wealthier neighborhoods, regardless of their ethnic makeup, are more likely to have more and denser trees." Source: Boise State Economist Gets to the Root of Urban Tree Cover

Origins of the bisexual papaw

Analysis of papaya (papaw) chromosomes, in particular the male chromosome and the altered form of the male chromosome which gives rise to hermaphrodite (bisexual) plants, has indicated that hermaphrodites arose about 4000 years ago. Papaya has been cultivated for more than 6000 years, and no hermaphrodites have been found in wild populations (Central America). It seems that this trait was selected during domestication of the crop, possibly by the Maya people. Source: Cultivated papaya owes a lot to the ancient Maya, research suggests

Sweet potato leaves nutritious, too

Tissue analysis reveals the vitamin B6 content of sweet potato leaves is comparable with other produce such as broccoli, carrots, avocados and bananas as well as being a valuable source of other vitamins. Source: Sweet potato leaves a good source of vitamins

Origins of the peach

In spite of their popularity worldwide, or perhaps because of it, nobody has ever been sure where the crop was first domesticated. Radiocarbon dating of ancient peach stones found in the Lower Yangtze River Valley in Southern China indicates that selection for larger fruit size was going on there at least 7500 years ago. Its likely that people selected for other characteristics such as flavour and productivity, too. As peaches have a relatively short time to fruiting from seed this would have been quite feasible, but early orchardists would have probably also developed methods of vegetative reproduction (like grafting) to multiply the improved forms. The researchers think it took about 3000 years of breeding for the peach to be developed into the fruit that we recognise. Source: It's the Pits: Ancient peach stones offer clues to fruit's origins

UQ investigates office greenery

A collaboration between the University of Queensland and several international universities has studied the effects of plants in offices. The results suggest that increases in worker happiness and productivity will make the investment in office greenery worthwhile. Source: Leafy-green better than lean


Apologies for the rather extended period between this and the last newsletter, but the show must go on.

Or not, in the case of three developments which seriously affect the ability of the garden industry to promote their products specifically and the gardening culture more generally.

While these may be local issues, many communities worldwide will be be going through similar changes and the implications for horticulture are worth consideration.

1. Australia's national open garden scheme closes

In September 2014, a surprise announcement came from the Open Gardens Australia (OGA) board of directors. They had decided to end the scheme at the end of the 2014-2015 season. It is now closed and the website offline.

A certain amount of mystery still surrounds the closure, with "increasing costs and falling revenue" [1] and "developments in the economy and technology" [2] blamed, but not well explained.

Anyone with a particular interest in this topic will want to listen to the critical 3AW radio interview with the CEO [3].

Whatever attempts were made to improve efficiency, they did not include abandonment of the printed guide book. Such a concept was way past its use-by date, of course. Extra visitor numbers obtained by free and generous sharing of information offline and online, including on the scheme's own website, might well have made up for lost guide book profits (if there still were any).

Presumably it was thought that the 2011 change of name from Australia's Open Garden Scheme to Open Gardens Australia was going to be somehow helpful.

Curiously, there has been no mention (as far as the author knows) of the droughts and other natural disasters around Australia in recent years. These surely must have impacted the number and quality of gardens available.

Subsequent media reporting [e.g. 4,5] has indicated that increased competition from locally-organised garden openings and shows has been an issue. OGA did indicate that they saw such community efforts, based on the OGA model, being the future of garden openings in Australia. They developed a kit to assist future organisers, and donated all their records to the State Library of Victoria.

A number of state and territory groups have indeed since formed to carry on where OGA left off. It remains to be seen if they can have the same impact as a national body. Likewise, the wisdom of the OGA decision may be judged by the the success or otherwise of other community-based and individual efforts going forward.

2. Media Consolidation

A significant blow to the gardening scene here in Southeast Queensland has been the the loss a popular locally-sourced gardening talkback show on commercial radio. To save money, much of the content on the station is now fed from a network partner in Sydney instead of being produced in Brisbane. Although the Sydney show is now meant to cover both regions, it is 700 kilometers away, so a lot of the content will be of dubious relevance.

Although local Australian Broadcasting Corporation (ABC) radio retains its talkback, the move reduces the total amount of airtime carrying regionally-relevant gardening information. Furthermore, opportunities for business to advertise to a local gardening audience is diminished because the ABC is a commercial-free public broadcaster.

3. Community Television Faces the Axe

There have been various gardening shows produced for community television over the years (including a short run of shows by yours truly). However, none have truly flourished in the way they could have with better support from the garden industry. Now it seems that the chance to exploit this low-cost medium in the future has gone with the federal government closing down community TV nationwide at the end of 2015 [6,7].


Perhaps the decision to close the open garden scheme will ultimately prove a good one. Time (and examination of the records) may eventually tell. Either way, anyone operating similar schemes in other countries might be able to learn some lessons from what happened here.

With respect to the commercial garden and landscape industry, garden visits must surely have inspired many people to redouble their efforts at home, as well as encouraging some of their non-gardening companions to have a go. Also, garden openings were often covered in local media, giving the general public exposure to gardening. That more concern has not been expressed by the garden industry about such a potential negative impact is in itself a concern.

Meanwhile, many forms of old media are facing financial problems. The internet provides many opportunities for low-cost publishing including video and audio productions. However, they generally require an already-motivated consumer to seek them out. The same applies to specialist print publications and open gardens, too, for that matter.

Free-to-air broadcast programs are important because they can catch the channel-surfing novice or non-gardener. If such means of promotion continue disappearing, the industry may have to think of new ways to introduce potential new customers to the joys of gardening in an inspirational and non-intimidating way.

[1] Open Gardens Australia FAQ Open Gardens Australia via Wayback Machine internet archive
[2] Open Gardens Australia to cease operations in 2015 Open Gardens Australia via Wayback Machine internet archive
[3] Neil Mitchell interviews Liz White, 3AW (mp3) Fairfax Radio Network
[4] Wilting business ends Open Gardens The Age, Fairfax Media
[7] Commit to Community TV Supporters' website

No feature article this time, but hoping to get back on track in the next issue. All the best until then!

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