By Felix Ochieng Akech
The Kenya Tea Improvement Company (KTDA) has issued a brand new spray regime to include a quickly escalating purple spider mite outbreak that’s reducing tea yields by as much as 40 % in some highland zones, after years of drought-driven stress, widespread misuse of chemical substances and repeated crop losses.
KTDA pest administration officer Brandon Ochanda mentioned the infestation has develop into probably the most damaging tea pest disaster in years, with extended dry spells, incorrect pesticide use, and weak farmer steering combining to drive inhabitants explosions throughout Kericho, Kisii and surrounding tea-growing areas.
“The previous three years have had longer dry spells,” Ochanda mentioned. “Throughout drought, tea leaves harden and produce much less sap. That stress makes them extraordinarily susceptible to mites.”
Ochanda mentioned drought alone didn’t clarify the size of the outbreak. He mentioned repeated use of pyrethroid pesticides, together with merchandise resembling Karate, had allowed mite populations to rebound repeatedly and develop resistance.
“Pyrethroids can kill massive shifting mites however they don’t kill eggs,” he mentioned. “Farmers would spray, see a slight discount, and assume the issue was solved. Three to 5 days later the eggs would hatch and the inhabitants rebounded. That cycle has continued for years and now we have now full resistance in some zones.”
In consequence, some farmers are spraying nearly weekly whereas incurring rising prices and declining management. In Kisii County, farmer Vincent Okiyni now sprays practically each week, paying extra for chemical substances however seeing little discount in mite strain.
Ochanda mentioned failure to observe a structured rotation programme has been probably the most persistent error. He mentioned a single spray can not break the mite life cycle.
“An accurate programme should have a double spray,” he mentioned. “The primary kills adults, the second kills newly hatched larvae. With out that second spray you’re losing cash.”
He mentioned KTDA has maintained an inner rotation programme for years however acknowledged it was by no means simplified or broadly communicated to farmers. Below the revised steering now being rolled out, miticides should be rotated throughout completely different modes of motion as follows:
- Cycle 1 – Propargite (Omite): quick knockdown
- Cycle 2 – Fenpyroximate or Abamectin: targets larvae and nymphs
- Cycle 3 – Spiromesifen or Bifenazate: suppresses eggs and early phases.
“Repeating the identical molecule is the largest mistake we see within the area,” Ochanda mentioned. “Farmers have used Karate for five–10 years, even after it turned ineffective.”
He mentioned pyrethroid use has additionally intensified outbreaks by eliminating predatory mites that naturally suppress purple spider mite populations.
“Each time a farmer makes use of Karate, they kill the predators and go away the pest,” he mentioned. “It accelerates outbreaks.”
In accordance with KTDA, extreme infestations scale back inexperienced leaf yields by 20–40 %, with younger shoots bronzing, curling or drying fully. The financial losses are compounded by repeated spending on low-cost chemical substances that don’t work, resulting in increased long-term losses.
Ochanda additionally recognized operational errors that scale back spray effectiveness, together with spraying throughout noon warmth when miticides evaporate rapidly, under-dosing to chop prices, failing to spray the underside of leaves the place mites focus, and utilizing soiled sprayers that neutralise lively components.
Correcting these practices alone would resolve most infestations, he mentioned.
“If farmers repair these points, about 70 % of the mite issues would disappear instantly,” he mentioned.
KTDA is now shifting to shut the knowledge hole by issuing one-page farmer guides outlining accredited rotations, appropriate spray intervals, scouting strategies and warnings towards pyrethroid use. The company can be revising its Built-in Pest Administration pointers to prioritise area scouting and focused spraying.
“Chemical compounds alone gained’t resolve this,” Ochanda mentioned. “We’re shifting into organic controls, resistant varieties, soil enchancment, and higher water conservation. A wholesome, well-watered plant is much much less enticing to mites.”
Within the interim, KTDA is advising farmers to examine the underside of tea leaves weekly for webbing, reddish mites and silvery speckling, and to use two sprays 5–7 days aside utilizing a strict rotation.
“As soon as farmers cease counting on pyrethroids and begin utilizing actual miticides accurately, we are going to see a serious discount in outbreaks,” Ochanda mentioned.
KTDA mentioned implementation of the brand new spray regime is now essential to stopping additional yield losses as dry situations persist throughout main tea-growing zones.
