每日跟讀#549: Beating back the worms: intravenous injections for trees

National Central University (NCU) has set aside an annual budget for regular treatment to deal with the “pine wood nematode” worm invasion that attacks the 1,500 pine trees on the campus. As part of this treatment, the trees are given an intravenous drip, with the medicine being injected into their trunks.

中央大學為了搶救校內約一千五百棵松樹免於「松材線蟲」入侵，每年編列預算，定期將藥劑加壓灌注入樹幹內，猶如為松樹「打點滴」。

According to the university, the worms, transmitted into the branches of the trees by insects, cause the leaves to wilt and die. Agricultural experts advise the use of a “trunk injection,” which infuses the medicine into the trunk, and from there throughout the entire tree. This process can take three to four months for the agent to take effect.

中大表示，昆蟲傳播將松材線蟲帶入松樹的枝幹上，導致樹葉萎淍枯死，目前農業學者的建議是利用「樹幹注射法」，將藥劑加壓灌注入樹幹，讓藥劑運行全株運行，至少要三至四個月才能讓藥劑在松樹內發酵。

Last year, some of the coral trees — which are indigenous to Taiwan — along the streets in Taichung were harmed by Quadrastichus erythrinae, an exotic wasp species. National Chung Hsing University’s (NCHU) Plant Teaching Hospital launched a rescue operation, opting for trunk injections instead of the traditional spraying approach. As a result, 133 dying trees were brought back to life.

去年台中市部份行道樹「台灣原生種刺桐」出現受外來種刺桐釉小蜂危害，中興大學植物教學醫院也展開搶救大作戰，用樹幹注射法取代傳統噴藥，讓一百三十三棵奄奄一息的病樹起死回生，重現盎然綠意。

Plant Teaching Hospital director Tang Li-cheng said that, in the past, spraying was the only option available, but the chemicals stayed on the surface of the leaves and would not penetrate into the diseased tissue. As a result, the treatment was mostly ineffective.

興大植物醫院院長唐立正指出，以往的防治或治療方式均採噴藥去病，但藥劑只留在樹葉表面，根本未能深入病害組織，因此防治成效有限。

The “plant doctors” at the hospital now use a more precise, targeted method, applying trunk injections to infuse the medicine into the trunk through a borehole. After this, through capillary action, the medication is transported to the infected leaves by water absorbed by the tree. Tang compared it to treating a sick person: applying ointment on the skin has limited effect, while injecting the drug into the blood vessels allows it to be absorbed more efficiently.

興大植物醫院植物醫師「對症下藥」，採樹幹注射法，把治療藥物施打進入鑽孔的樹幹，隨著樹木自體吸收水份後的毛細現象，讓藥劑慢慢被吸收到病灶葉片治療。唐立正說，這就像是人體內生病，以往只在皮膚表面塗藥，效果有限，於是改以針劑注射藥劑到血管，漸被人體吸收達到治療效果。

Tang says that two doses are sufficient for a whole year for trees with a diameter an adult can put their arms around. In addition, the treatment is inexpensive and does not carry the risks associated with pesticide spraying, such as harming non-targeted plants or creatures, or even people out for a stroll in the park.

唐立正指出，一般成人可圈抱的樹木，約施打兩劑即可維持近一年的藥效，成本低廉，更不像噴灑殺蟲劑一樣可能會波及其他植物或生物，甚至危害前往公園活動的民眾。

Source article: http://www.taipeitimes.com/News/lang/archives/2019/03/06/2003710907