Hi, and welcome to Taiga Bonzai, in this post we continue our journey bringing to light the catastrophic failures of mankind’s idiosyncratic actions.

Introduction – according to the Botanical Gardens Conservation International (BGCI) and its network of 500 member organisations, there are 60,065 species of trees in the world; Many are rare and threatened with extinction.

If we multiply the number of tree species with the number of known pests and disease all with different triggers, the statistics would not only be bewildering but also incomprehensible. Here we highlight more increasing problems the world has to face beginning with a few examples of the many deadly diseases, for which at this juncture there is little or no control.

Disease – Armillaria Root, according to Guido Schnabel of the Clemson University School of Agricultural, Forest and Environmental Sciences. “Armillaria root rot caused by the fungus Armillaria tabescens wreaks havoc on rootstocks, killing young and old peach and cherry trees before spreading to neighbouring trees.” “Between 1987 and 1992 Armillaria root rot caused an estimated $3.86 million to the peach industry and between 2000 and 2002, more than $1.5 million in damage to the Georgia peach industry.”

The first symptoms of an Armillaria infection are chlorotic leaves, stunted growth and sudden collapse of shoots. An obvious sign that infection is there due to the presence of clusters of mushrooms around the base of an infected plant. Fungi sprouting from an A. mellea infection are honey-coloured to dark brown and have a domed cap. “Depending on species, the mushrooms may or may not have an annulus around the stalk or caps that are more disc-shaped.”

This devastating disease can be caused by other Armillaria species including, A. mellea a the primary pathogen in northern states causing premature peach tree decline. The potential for significant annual losses in Michigan, is due to the predominant fungus A. ostoyoe found in tart cherry orchards. There is no ‘silver bullet’ solution to protect trees and Armillaria infections have taken many prime orchard sites out of production causing a huge loss of revenue.

Anthracnose – high on the list of devastation is widespread and considered an important disease in most countries. It is caused by a group of fungi in the genus Colletotrichum, that attacks leaves, twigs, flowers and fruits of a great number of tree and shrubs.

Apple scab is a common disease of apple and crab apple tree varieties, as well as Mountain ash Sorbus and pear. It is caused by a fungus Venturia inaequalis that infects leaves and fruit, leaving the latter unsuitable for consumption. Leaf spots are olive green at first, later turning dark brown to black. Infected fruit turns colour in a similar fashion, ending up brown, corky and deformed.

Thousand canker disease – affects many plants including walnuts Juglans sp. It is mainly found in the Western United States however, black walnuts trees in Tennessee were found to be infected in the summer of 2020. It is vectored by walnut twig beetles Pityophthorus juglandis and forms small cankers around their galleries.

As time progresses these small cankers coalesce to girdle branches and stems, trees can be infected for years before symptoms become visible for example. Foliage in the upper branches of declining trees wilt and become yellow. Once a tree begins to decline it is often dead within a few years and at present there are no chemical management solutions to control the disease.

Thus far we have given examples (albeit in brief) of the devastation caused by some of the many thousands of insects and disease. Adding more examples would probably substantiate the argument further, but this task has already been accomplished. In the book ‘Taiga Bonzai – Simplifying The art’ (Revised Edition), where 2 chapters reveal extensive information on these subjects, c.13 concentrates on ‘Pest and Disease’ and c.14 discusses ‘Toxicity’.

We now turn our attention to plants required for our consumption namely fruit and vegetables starting with one of the world’s oldest fruits the humble apple. The bureaucracy over production and the controversy surrounding it including the diseases that attack various species of this particular fruit.

The apple – Malus domestica, its ancestor Malus sieversii originated in Central Asia 4 thousand years ago. Today there are 7,500 apple varieties throughout the world – 2,500 of which are grown in the United States. In the 2019/2020 crop year, China was the leading producer of apples, it’s production amounted to 41 million metric tons. The European Union came in second place with approximately 11.48 million metric tons.

The UK has been producing apples since the Roman occupation (AD 43 to AD 410) however, production is now in serious decline due to bureaucracy and trade problems with the EU. Hence growers are given payments to burn their orchards.

Natural England and the National Trust claimed 60% of England’s orchards had disappeared since the 1950s and have launched a £500,000 project aimed at halting the decline. The crisis has been even worse in some areas such as Devon, which has lost almost 90% of its orchards.

According to David Bullock, the head of nature conservation at the National Trust, “Traditional orchards have been disappearing at an alarming rate. We are in real danger of losing these unique habitats.” (https://www.theguardian.com April 2009)

The orchard – apple trees need space to grow, dwarf varieties require a minimum of 5m, standard trees need a distance of 9 to 11m. But this distance is inadequate because, as the trees mature they spread out, thus the risk of cross contamination from bacterium and fungal spores increases.

In 2017 the total area harvested in the world for apples was 4,933,841 hectares. But, apples are not the only fruit produced, other varieties include apricot, pear, peach, plum and damson. Hence the land mass required increases – these varieties predominantly cultivars are also susceptible to attack, thus the orchard becomes the playground for disease.

Such diseases include: Fire Blight a contagious disease affecting apples, pears, and some other members of the family Rosaceae. It is a serious concern to apple and pear producers and is believed to be indigenous to North America, from where it spread world-wide.

Powdery mildew Podosphaera leucotricha a fungus that forms a dense white fungal growth (mycelium) on the host tissue affecting leaves, buds and shoots. Black Rot and FrogEye Leaf Spot Botryosphaeria obtusa attack fruit, leaves and bark of apple trees. Phytophthora Rot a soil-borne fungal disease by the pathogen Phytophthora sojae causes seed rot and attacks roots and stems; trees infected by such pathogens are usually destroyed.

However, there are apple tree varieties that are said to be disease resistant for example, Liberty, Freedom, Dorsett Golden, Enterprise, Goldrush, Pristine, Arkansas Black and Williams Pride which are American cultivars. European apple trees include, Topaz, Herefordshire Russet and Otava, but can the claims of being disease resistant to all insects and pathogens be substantiated – in short the answer is probably not.

Arguably much depends on a particular climate zone; arid, humid, wet and cold. Moreover, these zones harbour other pests for example, the Round headed apple tree borer, European red mites, Red banded and oblique banded leaf rollers, Rosy aphids, Woolly aphids, Green fruit worms, Leafhoppers and Japanese beetles. Until next time, BW, Nik.

Hi, welcome to Taiga Bonzai in this post we share some of the comments we have received regarding the articles ‘Unseen invasion’.

Introduction – the viewpoints of our readers are many and varied with all having concerns on the ever increasing problem of pests and disease that are threatening our very existence. But to discuss them all at length would make this article far too long therefore, we will take a small selection 10 in total in reverse order and we thank all whom have commented on our articles. In addition, there were also questions that will be answered at the end.

• 10. Amy Hardcastle – “I had heard of the problem with declining insect populations but I did not realise the situation was so severe, I do now! Thank you.”
• 9. Leon Sanchez – “Your posts Unseen Invasion: ‘Portugal confirmed its first case in 2019 on lavender’ certainly shows the severity of the problem with the deadly disease Xylella fastidiosa, congrats.”
• 8. Gillian P. Simmonds – “Taiga bonzai certainly knows how to get people’s attention on topics that most fail to understand, we do have problems and I do agree they need to be addressed, please keep writing.”
• 7. Jonas Olsson – “Great work, you have given the powers that be a strong clear message will they listen! I sincerely hope they do otherwise we will be in serious trouble.”
• 6. Lilian Gough – “Many bloggers write good work but yours is on another level, your work is artistic informative and a pleasure to read if only there were more like you.”
• 5. Heinz Muller – “Unseen invasion really drive the message home here’s hoping the bureaucrats take note, very good articles.”
• 4. Andrew Billings – “Talent is a hard to find in these days especially on subjects such as yours – you are able to get the message across, enjoyable reading, I look forward to more.”
• 3. Galen Jonak – “It’s hard to come by well-informed people on this topic however, you seem like you know what you’re talking about! Thanks”
• 2. Taren Vanlier – “May I simply say what a relief to uncover a person that really understands what they are talking about on the internet. You actually know how to bring an issue to light and make it important. A lot more people really need to check this out and understand this side of the story. I can’t believe you’re not more popular given that you certainly possess the gift.”
• 1. Dalton Beitz – “I’m amazed, I must say. Seldom do I come across a blog that’s both educative and entertaining and without a doubt, you have hit the nail on the head. The issue is an issue that not enough men and women are speaking intelligently about. I am very happy that I stumbled across this in my search for something concerning this.”

The questions – there were many on pests and disease for example, how to eradicate them and by what methods, the protection of forests and woodland, tighter restrictions on importation, new phytosanitary regulations and will there be any detriment to bonsai horticulture.

1. Eradicating pests and disease – “What methods of eradicating pests and disease are currently in use and what is the success rate?”

For aeons agriculturists and horticulturists around the globe have been trying to halt the onslaught of pest and diseases that have devastated crops, forests and woodland. Many of these unwanted entities have arrived either by wind (pathogens) and wing (Insects) and through packaging in more recent times.

To date over 1 million species of insects have been discovered and described, but it is estimated that approximately 10 million exist on earth. There are 60,065 species of trees on the planet that we know of and more are being discovered. For each tree species there are over 100 pathogens, (60,065 X 100) plus.

Many we know of and are able to eradicate via insecticide and fungicide, but many chemicals are no longer effective and/or are not available for general public use for obvious reasons. Pesticides widely used include Cypermethrin, Glyphosate, Lambda Cyhalothrin, Chlorpyriphos, Cypermethrin Acetamiprid and Profenos Cypermethrin.

However, insects can become immune for example, the cotton bollworm Helicoverpa armigera has documented resistance to 49 pesticides. Pathogens are able to mutate and many are not affected by fungicide sprays and in some cases there is no chemical cure. Hence the success rate is minimal to say the least. Science has to find solutions that are safe not just for humans but also the environment.

2. Woodland and forest protection – “What methods or practises are in place to protect forests and woodland?”

Practically all foresters are knowledgeable regarding the health and status of their plants and are able to detect problems quite quickly when symptoms appear. However, there are diseases that attack tree root and water conducting systems for which the signs are not visible until it is too late for example.

Armillaria and Xylella fastidiosa, Anthracnose and Fire blight are visible as they attack foliage and small branches. Infected trees die within a short space of time, hence they are normally removed and burnt to avoid further contamination.

The World Trade Organization (WTO formed on January 1st 1995 with 164 members) is an intergovernmental organization that regulates and facilitates international trade between nations. Governments use the organization to establish, revise and enforce the rules that govern international trade.

However, there are 14 countries who are not members including, Aruba, Eritrea, Kiribati, Kosovo, Marshall Islands, Micronesia, Monaco, Nauru, North Korea, Palau, the Palestinian Territories, San Marino, Sint Maarten and Tuvalu.

Therefore, it is extremely difficult to enforce rules and regulations further if there is stiff opposition, because trade rules for agriculture remain an extremely sensitive issue. This is particularly the case when agricultural imports carry the threat of disease. Nonetheless, under the rules of the WTO member countries are allowed to restrict the importation of agricultural products from diseased regions should potential risks be apparent.

4. New phytosanitary regulations – “What do these new rules entail and can they be enforced?”

Every country on the planet is a sovereign nation and has the supreme right to make or change laws as it so desires, regardless of what treaties or agreements are in place. However, the nations in the EU block have to abide by the rules laid down by the commission, but the UK has parted company with the block and has no obligation to adhere to any mandate.

The latter passed new phytosanitary regulations in January 2021 due to diseases that are now rife in Europe, any country wishing to trade with the UK has to abide these new measures. Such mandates are regulatory in other nations including Australia, North America, Canada and Russia.

5. A detriment to bonsai horticulture – “Will these new restrictions have an effect on the bonsai fraternity?”

We are researching and monitoring new laws and what we can divulge is the from the 1st January 2022 according to the UK’s Department for Environment Food and Rural Affairs

“All plants, plant products and other objects categorised as either ‘regulated and notifiable’ or ‘regulated’ must be accompanied by a Phytosanitary Certificate – All plants, plant products and other objects categorised as ‘regulated’ will require pre-notification, but only if instructed to do so upon submitting a customs import declaration.”

Since leaving the EU, importing goods from the UK has and is an arduous affair with more paperwork and additional import duty costs and these new regulations now in situ just exacerbate the issue. Meaning purchasing bonsai products from the UK will not be impossible, but extremely tedious and time consuming.

No doubt the EU will probably reciprocate due to their petty minded bureaucracy because of the UK’s actions. However, there are many bonsai outlets on mainland Europe and other countries where the restrictions although in force are less rigid. Until next time, BW, Nik.