An assessment of rice postharvest systems: postharvest practices

Abstract

This study confirmed that rice postharvest operations are broadly similar across the three rice production systems in Ghana although there are minor regional differences. In the irrigated schemes in the south, farmers harvest by hand and thresh the paddy in the field. After drying, the crop is bagged for storage, or more commonly for immediate sale either to small-scale traders or to larger traders, either direct, or through a farmers association. The majority of small-medium mills are of the Engelberg Huller Type and of variable quality, but there are sophisticated machinery, including de-stoners prior to milling and a whitener after milling, produce a better quality rice than the small local mills. Both men and women participate in the postharvest handling of rice. Generally, men are responsible for harvesting, threshing and storage and women are responsible for cleaning (winnowing) and parboiling. In Upper West Region women play a more important role in harvesting, although men alone are responsible for threshing. In Northern and Upper East Regions and in at least one irrigated scheme in the south (Asutsuare in Greater Accra Region), threshing is mainly carried out by women. Threshing of paddy is usually carried out manually by teams of family, communal or hired casual labour. Various threshing machines have been field tested in different parts of Ghana over the years but to date none has been widely adopted. In the inland valley systems, paddy is usually threshed by beating panicles with sticks on bare earth floors thus contamination with soil particles and stones is common. This can lead to damage to milling machinery and to presence of stones in milled rice. Concrete threshing floors are often provided in the irrigated rice schemes and so contamination with soil and stones should be less of a problem in paddy from these areas. Generally, drying poses no particular problem for farmers in the Northern Region of Ghana. Paddy is usually very dry at harvest. The main season rice and non-irrigated rice, harvested in December when the humidity is very low, may be too dry, with moisture contents of 12% or below. In Upper East and Upper West Regions the majority of farmers sun-dry their paddy, wither on the flat roofs of their houses or on beaten earth floors in the compounds but again drying is not a particular problem