A minute, less than a sixteenth of an inch long, black slender insect that resembles tiny dark threads when viewed without hand lens, has been Kenya flower farmers’ nightmare having left a trail of destruction and losses as it defaces petals making them unattractive to buyers.
It has been a herculean tasks to tame the pest with North American origin since it nestles deeply into rose blossoms, but a new greener solution could finally be the answer.
Thrip, both young and mature, feed on the sap within the flower petals by rasping the tissue of the petals to suck the sap out and is responsible for upto 70 percent of yield losses. It usually starts out breeding on various grasses and weeds. Once those sources are cut down, it moves onto attacking the ornamentals like flowers.
The pest is known to prefer lighter coloured blooms leaving red spots and brown streaks on the petals. The flower buds are often deformed and typically will not open. In extreme cases the outer petals become so softened from heavy feeding that they dry out as a hard shell, preventing the inner petals from opening in a situation termed as ‘balling.’ Thrips however only cause aesthetic damage to petals and blooms and don’t threaten the growth of the rose bush itself.
The lifecycle of a thrip completes in two weeks presenting another headache for horticultural produce due to their fast multiplication. Females insert eggs into the tissues of flowers, leaves or stems with no requirement to mate in order to reproduce. A female produces up to 80 eggs which hatch within days in warm weather before becoming wingless larvae, the most notorious and voracious stage in the cycle, which feasts on the sap.
Emerging adults fly to the plant and repeat the cycle. Approximately 12 to 15 generations of thrips are born every year with the entire cycle from egg to adult requiring less than 16 days in warm weather. Although thrips have wings, they tend to rely on wind currents to carry them as much as several miles. Since thrips are poor fliers, they tend to spread slowly through a plant or garden, unless a heavy migration arrives throughout the garden.
But the pest’s tiny appearance pales in comparison to the trail of destruction it has left behind especially to most flower farmers in Kenya.
Angelo Muthusi the leader of the Viking Flower Outgrowers, a flower farmers group that works with exporters in production and sale of carnations and rose flowers has lived to tell the thrip menace tale. Having been in business for the last ten years which saw him mobilize over 50 farmers to delve into flower cultivation for exports and sealing many export deals everything was blossoming. On average each consignment would fetch the farmer group between Sh30 and 50 million in earnings.
Until the little pest struck. Early this year, flowers ready for harvest started coiling and drying at the petals. Unaware that it was a bigger problem and the petals were still hidden in the deep within the flower bloom, those in the packaging department mixed the defaced flowers with the healthy looking ones, with the defaced flowers tucked where they could not be visible.
But on exportation the entire consignment was rejected and destroyed. “We approximated losses of upto Sh30million. We have never seen anything like this. Most of the farmers we had brought on board have pulled out because they never got their share while majority of the clients have also pulled out of our deal,” said Muthusi. He further added that in their ten years in existence, their flowers have never been rejected.
It’s a sorry state of affairs that has been reverberated in Thika where a Rose Farm was forced to cancel its entire flower exports for last year to its prime markets in Netherlands after two incidents that saw their roses rejected for being ‘unattractive.’ The Damage was so severe that the farm was forced to lay off workers as it set out on massive fumigation. “We have never seen anything of this magnitude. Before we realized our flower farm was infested with thrips it was too late. The little pests did unimaginable damage to the farm,” said a farm manager at the rose farm. The damage goes beyond economical with the reputation even in the local market where demand had started picking having been bruised as evidenced by scathing attacks on social media according to a staff at the farm.
While there is no documented economical impact of the pest on the Sh93billion Kenyan horticultural industry, studies quote the pest as one of the biggest headache for majority of flower growers and a major determinant of what gets accepted or rejected in the importing market.
Yet new technologies and crop protection chemicals are offering fast and environmentally friendly solutions to taming the menacing pest. One such solution is Delegate™ 250WG, has entered the Kenyan market as a solution for flower farms to produce perfect flowers for export. Its success in taming thrips in South African citrus farms has positioned it as the ultimate solution to thrips in Kenyan flower farms.
The crop protection chemical which is designed to be sprayed in the evenings when bees and other pollinators are not foraging, controls plant eating pests within hours and continues to protect the flowers for a further one to two weeks. Within six hours of spraying, once the spray deposit has dried,, it is safe for bees, butterflies, and all mammals as long as it is used according to label recommendation. It leaves no persistent residues in the soil and does not accumulate.
“Delegate 250WG is made from a molecule derived from soil bacteria that breaks down naturally, but kills thrips and caterpillars that eat and damage flowers,” said Johan Janse van Rensburg, the marketing specialist at Dow AgroSciences for fungicides and insecticides in southeast Africa. “The launch of this product to the Kenyan flower industry marks an expansion of our engagement in East Africa, which we see as having huge agricultural potential, in line with the region’s development aims.”