Farmers have been cautioned against harvesting immature macadamia nuts.
Agriculture Executive Annie Nyaga, Jared Owino from Kenya Nuts Company and Ruguru-Ngandori MCA Sammy Muturi said the trend was affecting earnings.
Speaking at Kariuri Stadium in Embu North, the officials said harvesting immature macadamia was the main problem affecting the crop.
They noted that the farmers were being lured by brokers who offered them quick cash.
"Selling immature nuts complicates marketing and ends up fetching poor prices," said Mr Owino, adding that consumers were rejecting the immature nuts because they were not tasty.
"Farmers should understand that only mature macadamia nuts fetch good money. They should avoid falling prey to middlemen."
The farmers are said to accept the brokers' offers to enable them to meet pressing needs such as school fees.
Owino also urged the farmers not to mishandle the nuts during harvesting.
Ms Nyaga urged the growers to reject cash offers from brokers in exchange for immature nuts.
"Farmers should give macadamia time to mature. The county government will not allow selling of immature nuts. As we work to enforce the ban on immature nuts, we ask for support in exposing those who are doing it,” she said.
Mr Muturi said the county assembly was working on a Bill to streamline production.
Statistics from the Agriculture and Food Authority (AFA) show prices of unshelled nuts rose to Sh180kg last season, up from Sh70.
Other major producers of macadamia are Kiambu, Murang’a, Meru, Nyeri, Baringo, Trans Nzoia, Bungoma, Taita Taveta, Kirinyaga, and Tharaka Nithi counties.
Last year, Kenya produced 41,614 tonnes of macadamia worth Sh7.5 billion, representing a 20 per cent growth in the last two years, according to AFA.