ISA HK/China --- China Tree News (Whitewashing) (树干涂白)

国内朋友请查閱 "百度博客 --- 国际树木学会" (http://hi.baidu.com/%B9%FA%BC%CA%CAF7%C4%BE%D1%A7%BB%E1/blog ) 以取得其他文章。本分会的发表文章都已放弃版权, 任何人都可以自由转载作为教育目的, 但不能作为商业目的盈利。 任何人仕都可以申请免費加入本分会, 本分会员名单从不公开, 有意者请将真实姓名、年龄、单位、职衔、最高学历、电邮和手机号传真到 +852-2679-5338 便可. 如有查询, 请电邮至 egc@netvigator.com 。本分会的一切发表内容, 谨供参考。

会员们:


据本分会的了解, "树干涂白" 是一种很古老的植保技术, 源自欧洲的果园生产, 本来以为可以防虫和冬天树干防日晒破裂. 目前这技术在西欧国家已基本仃用, 在东欧的落后地区还可以普遍看到.


传统的树干涂白, 涂料基本上是采用石灰水, 涂上的时间多在初冬. 在用过了这种技术若干年后, 西欧的果树生产商开始对这工序, 产生了以下的疑问:


1. 在冬天, 病虫害都跑去冬眠了, 哪还防甚麽虫?


2. 在下雨或浇水期间, 从树干脱落的石灰水是强碱性, 改变了根部泥土的pH值, 令多种矿物原素不被吸收, 也令土质局部板结, 是好事吗?


3. 涂了白的薄树皮树木品种, 向南的部份在春天的太阳照射下, 照样会产生破裂, 而厚树皮的品种则不涂白也不会破裂, 哪这 "涂白" 真的是有效吗?


过了一段时间, 某些西欧的果农又在涂白料上面 "加工", 例如拌上硫磺、农药和其他, 但上述的疑点还是解决不了, 哪就乾脆仃用了. 在仃用以后, 他们发觉 "防虫" 的效果结果是同样, 泥土的pH值没有被石灰破坏, 而在树干向南的部份放上垫层的防破裂效果比采用涂料更好, "树干涂白" 这种做法也在西欧地区慢慢的画上了句号.


在我国, 不管它大江南北, 不管它有否效果, 园林树木涂白好像是变成了 "指定动作", 附上的报导更提出了使用 "纳米" 涂料, 可算是国内园林届的一个 "发明创造", 足叫老外叹为观止. 但愿这家厂商能把技术材料翻译成为英语, 本分会乐于为其作全球性分享报导.


科技的真实性需要通过公开评审, 越是国际审查过的, 可信性越高, 这就可能是为何许多专业牌照分成 国际 --> 地区 --> 国立 --> 省立 --> 市立 的原因吧. ISA 是国际组织, 可信性自然很高.


会员们, 下次见到有人在树干涂白的时候, 不妨聆听一下理由, 说不定会有意外收获.


谨此致意!


国际树木学会中国地区分区会会长


欧永森
美洲顾问树艺师学会 顾问树艺师号 RCA#497 (http://isahkchina.blogspot.com/2010/12/isa-hkchina-rac-in-asia.html)
澳洲顾问树艺师学会 顾问树艺师号 ACM 0412011 (www.iaca.org.au)
资深树艺师/注册攀树师号 HK-0174BT (http://isahkchina.blogspot.com/2011/03/isa-hkchina-frist-bcma-in-asia.html)
执业树艺师号 IPA-010908 (http://isahkchina.blogspot.com/2010/04/isa-hkchina-tree-news-1441-report.html)
专业调解及谈判学会 注册调解员 (www.wegomediation.org.hk)



“不深入诊断和参照研究来批出处方, 是专业失当。 ”


“速成出来的树木评估员, 只会作出胡乱的树木评估。 大自然会决定成败。 ”



*** Our weekly Station Mail is for the information of Station Members only, but Station Mail has given up copyright & can be freely circulated. For administrative reasons, comments from outsiders are usually not entertained & may be circulated within our system locally & overseas. Anyone can join ISA HK/China by providing their full name, age, organization, position, highest education, email & mobile no. to egc@netvigator.com . Joining is free & withdrawal is at an email notice. Station Membership is never publicly disclosed. Please note that Station Mail is sometimes given in Blog at http://isahkchina.blogspot.com , although images are usually not attached due to size. All our information is for reference without liabilities. ***

Dear Station Members,

Bark Whitewashing is a common practice for landscape trees in China for decades. However, if the landscapers are asked why they are doing it, maybe very few can provide a convincing answer. Most do it because the others are doing it, & think it can not be wrong in doing so.

Whitewashing in China would commonly use raw limestone to mix with water to form a thick solution for painting on to the bark. The maximum height would be as far as the arm can reach. It is thought to repel insects & kill fungi on the bark. It is also thought to reduce bark cracks during the Spring sunshine. Sometimes, sulphur or pesticides would be mixed in to form various formulation. No matter what the mixture would be, only the bark would be cared for. Anywhere else is usually left untouched.

Whitewashing would block lenticels on the bark surface to reduce air exchange. The lime peeling off or washing down during raining or irrigation would increase pH to obstruct nutrient absorption in the rooting area . As for pest repulsion, as the process is normally carried out in early winter, most of the pests would have gone to hibernation already. Thus what's the point?

It is very rare to see Whitewashing to be practiced in western countries nowadays. The harms may outweigh the benefits. As for bark protection during Spring sunshine, an insulating wrap may be more effective than applying lime on trunk. Thick bark species are also less susceptible to temperature differences.

In the attached newspaper clip, China has claimed that they have developed a "nano" technology in producing whitewash with active carbon to produce a more effective Whitewash. This is unheard of anywhere in the world & may be seen by some as another commercial gimmick of the manufacturer. If whitewash can go also "nano", what would be the scientific research behind?

China is full of adventure when it comes to Tree Care nowadays. Snake Oil is spilling everywhere. ISA HK/China would do our best to share our knowledge, one tree & one arborist at a time.

best regards,

Sammy Au
President (Station Manager) of ISA HK/China
Registered Consulting Arborist no. RCA#497 (http://isahkchina.blogspot.com/2010/12/isa-hkchina-first-rca-in-asia.html)
Institute of Australian Consulting Arboriculturists Accredited Member no. ACM 0412011 (http://www.iaca.org.au/)
ISA Board Certified Master Arborist / Certified Tree Worker no. HK-0174BT (http://isahkchina.blogspot.com/2011/03/isa-hkchina-first-bcma-in-asia.html)
Independent Practicing Arborist no. IPA-010908 (http://isahkchina.blogspot.com/2010/04/isa-hkchina-hk-tree-news-14410-report.html)
Certified Mediator of the Society of Certified Mediators and Negotiators (http://www.wegomediation.org.hk/)

"Providing treatment without in-depth diagnosis & research support is professional misconduct. "


"Casual tree assessor delivers wanton tree assessment. Mother Nature makes the rules."