Observations on the streets and Google Streetview in June

Trenching or excavation was being done very close to trees, presumably right outside the structural root zone of the trees.

One side of the root zone being cut about 0.5m or 0.6m away from trunk.

Trees appear to be well supported on the opposite of the root cut.

At a certain traffic island, wood chip mulching formed a berm around tree base, and away from base of the trunk.

Trees in tree wells along Cluny road were observed to be felled, the wells backfilled and metal grills removed. The tree closest to Gleneagles Hospital was removed somewhere between Jun 2021 and Oct 2021. The trees in tree wells further back were removed somewhere between Mar 2018 and Nov 2020, according to Google Streetview.

Along Cluny Road, trees that were in tree wells were removed, and the wells backfilled.

Tree wells in another location along Thomson Road were also removed. Two of them between Nov 2019 and Nov 2020, and the rest between Nov 2020 and Mar 2021, according to Google Streetview.

Removed between Nov 2019 and Nov 2020.

Removed between Nov 2020 and Mar 2021

As of Mar 2021. Tree wells were later removed.

Road works were presumably for the North-South korridor.

Crinkled Palm Crown

In this installment of Detective Dendro, it appeared in the Dec 2005 issue of Arborist News. Old but still good.

The dynamic duo was invited by a staff of Disney's Polynesian Village Resort (about USD 1000 a night, as of Jun 2024) to take a look at their palms. They have been pre-conditioned by a case elsewhere where the crown of a Phoenix canariensis (Canary Island date palm) fell and killed two people. It was later found to be caused by Fusarium oxysporum, which showed signs of withering outside but had actually decayed the insides of the palm.

Even Dendro had to brush up his palm  knowledge with a Feb 2005 Arborist News article. The client met them at the entrance of the hotel, and was shown a palm with yellow and frizzy top. Dendro proceeded to get to work by inspecting the base of a Syagrus romanzoffiana (Queen palm), and Codit got on a bucket truck to inspect the crown. There was no signs of fungus. The truck was tapped on, and a very solid sound was heard. Dendro got on the bucket truck after Codit alighted, and realised the problem was not fungal infection such as butt rot, heart rot or Fusarium rot. 

The crinkled crown was a sign of potassium, magnesium or manganese deficiency. Older fronds seemed undamaged, so Dendro ruled out magnesium and potassium deficiencies, which affect the older leaves first. The necrotic streaking between leaf veins further confirms that the palm was manganese deficient. The frizzle top is a common problem in many palms, especially Syagrus romanzoffiana, Acoelorrhaphe wrightii, Phoenix roebelenii, Elaeis guineensis and Latania spp. The palms they were inspecting could have endured the manganese deficiency for several months, but if nothing was done, the emerging fronds would get even more curled and stunted, with a withered and scorched appearance. At a later stage of severe deficiency, the palm would die. 

The palm at this frizzled state could be treated with foliar or ground application of manganese sulfate. The tree specialist of the estate came by and informed them that she noticed the problem a few weeks ago. She found that the palms were mildly manganese deficient with slightly less than 40ppm, after doing leaf nutrient analysis. If the deficiency had been more severe, or if the soil pH was high, the tree specialist would have used a foliar application. The client inquired if the frizzled fronds would become unfurled, and was replied in the negative. However, healthy and green fronds will grow after the palm's nutrient deficiency was addressed.

Reference: Arborist News, Jun 2024, pages 16, 17 and 73