Caring for trees
TREES are living assets of growing importance in urbanised city living.
Keeping trees healthy in our environment is a rather challenging job for the local councils. Only last year, most of the trees along the roadsides had been rid of the parasitic infestation with some pruned to the safety level. Pests and diseases pose two serious threats to tree health.
A land scarce environment such as housing areas and city streets cannot provide the optimum setting for tree growth and health.
Trees need continuous care and attention. Owing to air pollution and construction and human activities, most trees can still grow well to provide a variety of benefits.
Furthermore, passers-by can enjoy the blooms in purple, yellow, red or snow white – even fruits for good measure.
With appropriate measures, most trees can grow well and provide many benefits expected of them when they were first planted. Pests and diseases Trees are susceptible to attacks by various pests and diseases. The term pests here apply mainly to insects and arachnids whereas diseases refer to plant problems, caused by microscopic pathogens.
Insect pests can be divided into four major groups: 1. Chewing insects (grasshoppers, caterpillars, leaf miners, bagworms and beetles). 2. Sucking insects (scales, mealy bugs, aphids, thrips and leafhoppers). 3.Borers (moths, fruit-flies,
termites). 4.Gall-forming insects (flies and wasps). A common arachnid is the mite which either sucks or gall- forms on leaves. Most of these insects are visible and the kind of damage they cause point straight to the culprits.
They are responsible for distortion, defoliation and holes in leaves. And like termites, they bore holes on tree trunks and cause boughs or whole trees to die. Diseases are caused by micro-organisms like fungi, bacteria, viruses and mycoplasma and nematodes.
They are minute and not visible to the naked eye and their dreaded presence remains undetected until the effects or symptoms of the destruction they wrought start showing up. The tell-tale signs can be wilting, slow growth and death of part of a tree.
Most of the diseases encountered are caused by fungi or bacterial infection, resulting in leaf spots, rotting of fruits and root systems and death of trees. Bacterial infections stem from rotting and ooze a pungent smell. Control measures These problems can be reduced or prevented by the following measures – regulation or quarantine, physical or mechanical methods, cultural and biological methods and integrated pest management methods.
As a last resort, we might have to turn to chemical methods. For this, specialists like plant pathologists are needed to identify the pathogens and related blights in order to come up with the control measures.
Street and laymen are less able to handle the problems in a professional manner and might do the wrong things to cause further damage to the trees.
The common pathogenic diseases are Fusarium wilt, bark rot by Erythrina variegate, Basal and root rot of Khaya Senegalese or cinnamomic liners, twig dieback by Asmanex saman, Ganoderma stem rot or Basal rot of palms, bacterial diseases and root galls. Plant quarantine measures Sarawak is still free from several major exotic pests and diseases which have not touched our shores through air, land or sea ports
We had established plant quarantine measures nearly 100 years ago when the British were still administrating the state.
I inherited the regulatory and control measures in the late 1970’s. As a result, we had been able to check the spread imported diseases such as Fusarium wilt from Africa, which otherwise might have devastated the rubber, pepper, coconut and most importantly, oil palm plantations statewide.
We enforced quarantine measures through implementation of the Physical Cheek and Documentation Process at all major local entry points. Today, we are proud to say the few most deadly pathogens have not reached our shores and we can enjoy the economic production of cash crops in our land.
Let us keep it safe and secure within our border to allow the agricultural industry to continue growing and prospering. Happy Gardening!