28 SEPTEMBER 2014 @ 8:09 AM
BY SUZANNA PILLAY
AS far as sustainable farming goes, some practices are something to hoot about.
For 30 years, Sime Darby (SD) Plantation has successfully run a Barn Owl programme in its estates.
“Today, there are owls in our estates in Malaysia, except for Sarawak, as well as some of our operations in Indonesia. The number of owls are estimated at around 21,000 birds in Peninsular Malaysia alone. Work is in progress for us to bring the owls to our estates in Sarawak, and later in Liberia,” said SD’s head of research and development Dr Mohamed Nazeeb Ali Thambi on a visit to its oil palm estates on Carey Island and Jomalina refinery plant.
SD Plantation first started to consider the viability of barn owls as a sustainable and environmentally friendly method of pest control on its oil palm plantations in the early 1980s, when commercial-scale trials proved their effectiveness in the biological control of rats.
According to Nazeeb, commercial-scale implementation at SD’s oil palm plantations commenced in 1987.
“There was no purchase, or training of the owls. All we did was to set up nesting boxes for them and the population naturally increased. They occupied the nest boxes erected at the estates and will continue to do so as long as there are rats available as a food source.”
Biannual census is conducted to ascertain the population of barn owls in the estates, he added.
The ratio of owls per estate is worked out based on the occupancy rate per box and the territorial range of the owls.
“Usually, there will be a pair of adult owls occupying a box for every 10 hectares of an estate. There are two breeding seasons — July to October, and November to February. The eggs hatch after 32 days. The chicks will remain in their nests until they can feed on their own after about eight to nine weeks, when they fly out of their nests and live on their own as adults.”
He said with the use of barn owls, the oil palm plantations are able to reduce rat control costs by 30 to 40 per cent.
“A barn owl eats an average of one rat per day. A family that comprises two adults and two baby birds could consume 1,200 rats per year.”
It has been estimated that rats consume up to six per cent of crop production each year. In severe cases, the losses can be higher.
“To maintain the prey-predator equilibrium and keep the damage caused by rats below the economic threshold, we still need some chemical intervention, albeit, in a much smaller quantity compared with when barn owls are not used.”
Aside from rats, Nazeeb said leaf-eating insects, like bagworms, nettle caterpillars, rhinoceros beetles and termites, also cause damage at oil palm estates.
“Encouraging the presence of more beneficial predatory insects, parasitoids and entomo-fungi help eliminate leaf defoliating insects in oil palm estates, while cultivating beneficial plants and flowers that provide shelter and supplementary food like nectar will encourage the population of predators and parasites.”
Crop losses caused by such insects could be devastating, he said.
He cited leaf-eating caterpillars, which are able to strip the leaves of the palm resulting in crop losses over a period of two years following an infestation.
Another common oil palm pest, rhinoceros beetles bore into the cluster of developing spears in the crown of the palm to feed on the soft tissues. They could also bore through the frond bases into the soft tissues of young, unopened leaves. The damage caused by rhinoceros beetles will result in crop losses upon maturity.
Pests like termites attack oil palm trees by damaging the meristem in the crown and feed on the living tissue in the trunk, eventually killing the tree.
“Using direct bio-control agents, such as viruses and fungi to infect the pests, at oil palm estates is also a must,” he said.
Rhinoceros beetles can be killed using entomopathogenic (parasitic) fungi. The fungi’s spores penetrate the beetles’ cell tissue and secrete toxins. Entomopathogenic fungi are also used to control termites, but this method is still a work in progress for commercial use.
Pheromone trapping is efficient in controlling the population of flying insects, like rhinoceros beetles, which would otherwise require fortnightly spraying of insecticides in plantations.
“Spraying is costly and labour intensive. The pheromone attracts the beetles and traps them inside a bucket, where they will eventually die. These methods were introduced in the 1960s and, suffice to say, there have been significant savings in terms of cost as well as the improvement of our yield.”
In an outbreak of pests, where natural enemy pressure is no longer sufficient, environmentally friendly insecticides will be used until the situation is under control.
“An outbreak is deemed to have occurred when damage can be seen very clearly on leaves and pest counts have gone up above the defined threshold. Normally, one to two rounds of insecticide will bring back equilibrium. The estates practice an alert and survey system to monitor pest levels so that early intervention is possible with minimal use of insecticides.”
JAKARTA (Reuters Life!) - The palm oil industry has gone bird crazy by drafting owls to combat the menace of rodent pests, hoping in the process to burnish its green credentials and save money.
Leading Southeast Asian producers of the vegetable oil have tried different pest control schemes over the years, from snakes to poisons, but the high success rate -- and low cost -- of owls has prompted more planters to turn to them for help in reducing damage.
Some even have designated "owl trainers" who tend the birds from when they are still in the shell.
"We are using owls in our South Sumatra estates," said Michael Kesuma, head of investor relations at Indonesian palm oil producer Sampoerna Agro, which has taken such pains to introduce the birds that houses have been built for them in some areas.
"In those problem areas, I personally have seen the results of having owls. At the bottom of the owl houses, which are on a trunk, you see rat or rodent bones -- they are doing their job."
Malaysia and Indonesia account for more than 90 percent of the world's supply of palm oil, while other smaller producing nations include Colombia, Benin, Kenya and Ghana.
The edible oil, which originates from Africa, is used to make everything from biscuits to ice cream.
But according to the green group Deforestation Watch, crop losses caused by rats feeding on the palm fruit has been estimated to be around 5 percent of the oil yield.
Enter the owl, usually a nocturnal bird of prey, which eats mainly small mammals like mice, voles and shrews -- prime palm oil pests.
Barn-owls, the breed most commonly used on palm plantations, have a large heart-shaped face but have suffered declines over the past fifty years due to intensive agricultural practices.
They first appeared on palm plantations more than 20 years ago and have proved quite effective, palm associations say.
THREE TO FIVE RATS PER DAY
"The (plantations) say it's cheaper because they can decrease costs by 50 percent compared with using chemicals," said Chaerul Saleh, a biologist at WWF-Indonesia.
"They are barn-owls ... they can eat three to five rats every day. It is using a natural predator."
Indonesian palm oil producer BW Plantation (BWPT) says owls now save the firm about $300,000 each year that would otherwise have been spent on poisons.
"We have an owl trainer who takes care of our owls, starting from the egg until they mature and are then released into the field," said Kelik Irwantono, corporate secretary at BWPT.
"When an owl egg is found, the owl trainer will monitor this and eventually take the young owl to be placed in our owl training camp," added Irwantono.
The firm introduced owls in 2009 and now has about 250 barn owls on its estates.
"After being released into the field, the owl is naturally free to control the rat population," Irwantono said.
And there's an additional side benefit unseen with either snakes or poisons, palm associations said.
"Investors who visit our plantation all want to take an owl home with them," said Sebastian Sharp, head of investor relations at BWPT. "They are very beautiful."
(Editing by Elaine Lies)
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