By Rural Development Practitioner and National Research Institute Research Communication Specialist Dennis Badi
IF THERE were ever a coy starlet in the plant world, hiding away from the glare of publicity, it would be the Neem tree.
Neems are striking beauties, with a reddish crown, white f lowers and smooth-olive-like leaves.
They are synonymous with Port Moresby, being fast growing, drought-resistant, and found throughout the city.
The campus of the National Research Institute abounds with this tropical tree – an exotic wonder which takes on a starring role against Port Moresby’s more common grasslands and eucalyptus flora.
But few are aware that the tree is actually an import, native to India, Pakistan and Bangladesh.
Botanically known as Azadirachta indica, the Neem tres is a member of the mahogany family Meliaceae.
They are known by many names – miracle tree, Nimtree, Nymph tree, Indian Lilac or mosquito tree in respect of its use and its origin.
The English name Neem is derived from the Hindi.
Port Moresby is now the adopted home for Neems. These now naturalised residents can be seen lining shady streets, around churches, near schools or in people’s backyards.
During dry seasons, Neems shed nearly all of their leaves, a fact which recent research has claimed can improve soil fertility and enhance water holding capacity
The United Nations has declared Neem a “Tree of the 21st Century” in relation to its significant role in improving lives in developing countries.
Earliest documentation of Neem revealed that various parts of the tree, which include the fruit, leaves, seed-oil, roots and bark, have benefitted humanity for more than 4,500 years.
The fruit of the tree is known to be quite bitter, but Neem leaves and f lower buds are often used as a flavouring agent in vegetable dishes.
In India, the tree traditionally serves as a “village pharmacy” for treatment of skin problems, leprosy, making soap and other purposes like timber.
Today, about 80 per cent of India’s supply of Neem oil is used by soap manufacturers, with crude oil used in laundry soaps and cold pressed oil going into specialty products.
Neem oil is used for preparing cosmetics, while its twigs can used as a toothbrush – chewed to help reduce plaque and avoid the risk of gingivitis.
Neem gum can be used as a bulking agent in processed foods, while Neem oil can also be used as a lubricant, to grease cart wheels.
It is also an effective insecticide where Neem-seed-derived oil is sprayed on plants to prevent damage from insects.
Today, the tree is a key ingredient in non-pesticidal management, providing a natural alternative to synthetic pesticides, with some groups saying it is also more effective.
Oils from the tree are currently being trialled as an environmentally friendly plant pesticide by the National Agriculture Research Institute (NARI) at Laloki.
This government research facility is training rural farmers to use Neem-seed-derived oil as a pesticide.
The extraction is a discrete process as observed during an experiment at Bagoiudu in Central.
Dry Neem seeds are collected, crushed and mixed with one match-box size grated soap flakes.
This mixture is eventually poured into one litre of water, then stirred and left for overnight with a plastic lid covering.
Lastly the mixture is strained and sprayed immediately on people’s garden.
Neem does not directly kill insects on the crop.
It acts as an anti-feedant and repellent, protecting the crop from damage by caterpillars, leafhoppers, beetles and other insect pests on leafy vegetables, causing them to starve and die within a few days.
Neem oils also suppresses the hatching of pest insects from their eggs.
Exotic plants (and also animals) are brought into the country by humans or natural means, either by accident or on purpose.
They can spread if not contained at an early stage, causing population demise of native flora and the ecosystem. At times these plants are described as invasive aliens or biological pollutants.
Neems have not yet been found to pose a direct threat to Port Moresby’s plant-life, but in Australia, and parts of Middle East and Africa, the Neem is considered a dreadful weed.
Apart from being fast growing, Neem thrives well on harsh conditions, requiring only a little water to survive and thriving in well-drained and sandy soils.
This gives the tree an edge over the local flora.
A good example is the Matico, known biologically as Piper aduncum, but also known as Piper tree or daka diwai.
Like the Neem, the Matico was used as a condiment and as an antiseptic, as well a syptic and astringent for wounds.
This use was the origin of the plant’s common name, Matico – Spanish for “Soldier’s Herb.”
The tree was introduced into the coastal areas of Papua New Guinea, but it was not contained.
It has now spread up to the cooler highlands, where it is notorious for drying out the soil in the areas where it is invasive.
Nonetheless, wood from the plant is often used for fuel and fence posts.
Investing in trees is a joyous experience but it’s good to be wary about exotic plants.
For the Neem, it is performing well against other contenders in Port Moresby’s shade and beauty spectacle.