This would also enable them to keep accurate records of production made at a given season and qualify them of COCOBOD scholarship for their wards.
Mr Bismark Tetteh, an opinion leader of Ningo Nankese in the Suhum Municipality, gave the advice at a meeting with farmers of Armajaro Company Limited at Nankese at the weekend.
He said entries in their passbook would determine whether or not the marketing clerks were paying the right producer prices and bonuses.
Mr Tetteh appealed to the management of the company to support them to procure tools such as cutlasses, spraying machines and other farming implements to facilitate work on their farms.
Mr Samuel K. Amankwah, a former Technical Officer of COCOBOD, appealed to farmers to start clearing their farms of weeds and mistletoes to get them ready for the mass spraying exercise.
Mr Amankwah said the exercise had just begun and warned that farms that were not cleared of weeds would not be sprayed.
He called on the farmers to complement the spraying exercise by carrying out intermittent spraying with fungicide to rid their farms of black pod diseases.