Investigating the Effectiveness of Manual Drum Pulper on Genotypes of Robusta Coffee (Coffea canephora L.) for Seed Production

Abstract

Mortar and pestle has long being in used to de-pulp coffee cherries for planting either in small or in large scale farm. This method is very laborious, time consuming and is not devoid of seed damage. Therefore it becomes imperative to use mechanical pulper for both small and large scale seed production. Ripe coffee cherries were harvested during 2019 season from three different genotypes of Robusta coffee planted on the field. Two genotypes were selected from coffee germplasm and the third genotype was from agronomy plot all from cocoa research institute of Nigeria. The cherries were processed using both traditional method of depulping and manual drum pulper. Three operators were used to create different speed rate of 40, 75 and 90 rev/min. Equal quantity of cherries were fed into the pulper. The de-pulped coffee seeds were air dried, undamaged seed were selected for planting at pre-nursery. Data on seed emergence were collected periodically, twenty five days after sawing, forty days after sawing and sixty days after sawing. Data were subjected to analysis of variance (ANOVA) using statistical analysis system (SAS) version 9.1. The result shows best percentage de-pulping efficiency (99.91), separation efficiency (98.87) and percentage beans damage (0.2) were achieved with the machine speed range between 40-75 rev/min. The percentage seed emergence of genotype T797 (66.67), FM (66.67) and T45 (64.44) were statistical similar irrespective of de-pulping method used. Better machine performance was observed on genotype T797. Genotype FM de-pulped with manual drum pulper gave least germination percentage; lowest machine performance was observed on genotype FM. Coffee seed production with minimal affection on seed emergence, could be achieved through use of manual drum pulper to reduce time and labour required using traditional de-pulping method.

Physical and Mechanical Properties of Coffee Cherries and Beans in Africa: Review and the State of Arts

“…Besides, Ghana and Nigeria produce Robusta coffee and this implies that coffee density can vary based on agro-ecological conditions apart from the season, processing, and varietal differences. Hence, according to the size, moisture content, and maturity of the cherries and parchment coffee; the coffee quality is linked to the pulping machine performance parameters such as pulping mechanism setting-up, de-pulping rate of more than 95 percent, and damaging beans rate of less than 3.5 per cent according to different studies [54][55][56]and standard (PAES 252:2011). The pulps take up to 1m thick of the cherries.…”