A comparative study of three drying methods of baobab leaves have been conducted and reported. Mixed mode solar drying, indirect mode solar drying and open sun drying of baobab leaves were conducted based on three drying models viz a viz Lewis,. Page and Henderson and Pabis models were employed in this research. Baobab leaves dried faster when dried under the mixed mode on-farm solar dryer. Drying time reduced considerably using the mixed mode on-farm solar dryer. Drying data were fitted into Lewis, Page and Henderson and Pabis models. Henderson and Pabis model (R2=0.9999, 0.9611, 0.9656; X2= 1.0297, 0.7931, 0.7710; RMSE= 0.5859, 0.6898, 0.6802 and MBE= -0.4.135, -0.4.231, -0.4176) gave the best prediction for the mixed mode drying). In the same way Henderson and Pabis model (R2=0.7450, 0.7699, 0.8243; X2= 1.9025, 0.4026, 0.2006; RMSE= 1.0684, 0.5181, 0.4058 and MBE= -0.8966, -0.3823, 0.2789) gave the best prediction for the indirect mode drying of baobab leaves. Effective moisture diffusivity of baobab leaves varied between -6.382 X 10-04 and -1.108 X 10-03 m2/s.

Groundnut roasting for oil extraction is a common practice among local women in Nigeria. As a result of this a manually operated groundnut roaster was developed in the Institute of agricultural Research (IAR). This machine requires human power to operate. In this study, ergonomics analysis was carried out considering a view of differences in energy expenditure on this machine using two women as subjects. A hand ergometer was used to calibrate the two subjects. From the results obtained, the roaster consumes an average of 3250J/m and 3400J/m from subjects A and B respectively. Keywords— Ergonomics, Groundnut roaster, Energy, Women, Ergometer

Fresh fruits and vegetables are important foods both from economic and nutritional point of view. Fruits and vegetable of all types are valuable part of our diet, however, many vegetables are highly seasonal in nature, they are available in abundance at a particular season and sometimes result in market glut, while at off-season they become very scarce and expensive. Large quantities of these vegetables are lost during or shortly after harvest due to their perishable nature.  Drying of vegetables as a means of reducing post-harvest losses and improve storability has been practiced for many centuries. As compared to fresh vegetables which can be kept for few days, dry products can be stored for months or even years without substantial loss of nutrients. This paper reviews some commonly dried fruits and vegetables consumed in northern Nigeria, which includes; Tomato, Okra, Baobab leaves, Sweet potato, Cassava, Moringa, Sorrel and Jute. A comprehensive review of preservation methods, price variation with season, storage and duration of these fruits and vegetables is presented and recommendations are made for further studies. Fresh fruits and vegetables are important foods both from economic and nutritional point of view. Fruits and vegetable of all types are valuable part of our diet, however, many vegetables are highly seasonal in nature, they are available in abundance at a particular season and sometimes result in market glut, while at off-season they become very scarce and expensive. Large quantities of these vegetables are lost during or shortly after harvest due to their perishable nature.  Drying of vegetables as a means of reducing post-harvest losses and improve storability has been practiced for many centuries. As compared to fresh vegetables which can be kept for few days, dry products can be stored for months or even years without substantial loss of nutrients. This paper reviews some commonly dried fruits and vegetables consumed in northern Nigeria, which includes; Tomato, Okra, Baobab leaves, Sweet potato, Cassava, Moringa, Sorrel and Jute. A comprehensive review of preservation methods, price variation with season, storage and duration of these fruits and vegetables is presented and recommendations are made for further studies.

Draft requirements of two animal – drawn (IAR) weeders operating on loam soil were determined in the study. The implements include a straddle row weeder and an emcot attached rotary weeder evaluated under the same soil conditions, using a pair of white Fulani breed of oxen. The animal draft requirement was first estimated from the animal ergonomics measurements. Using area of 0.054 hectare as experimental plot for each implement the draft requirement of each implement was investigated after taking soil samples for soil moisture content and bulk density determinations. The implements tested showed variation in their average draft requirement. The straddle row weeder had the highest value of 338.15 N respectively while the emcot attached rotary weeder had the lowest value of 188.12 N with 47.03%, respectively. The average soil moisture contents and bulk density were 13.0% and 1.46%/cm3, respectively.

This research work was carried out to provide local farmers with on-farm solar dryers to minimize post-harvest losses of vegetables. Two dryers (Mixed mode and Indirect mode on-farm solar dryers) were constructed using locally available materials. The dryers basically consist of a blower, a collector area and a drying chamber. Aluminum sheet is placed inside the collector which serves as the absorbing material. An electrical axial fan was placed before the air duct to supply air responsible for forcing heated air to blow over the vegetables to be dried. Incorporated in the drying chamber are trays which provide a platform where the products to be dried were spread evenly. Transparent polythene material of 0.2 mm thickness with wooden frame was used as cover for the dryers. The dryers were evaluated to determine drying time and performance efficiencies, using Baobab leaves, Tomato and Okra slices as test crops. Collected data were analyzed using Statistical Analysis Software (SAS). The effects of variation of the independent factors were verified using Analysis of variance (ANOVA) at 1% and 5% levels of significant. Mean separation was carried out on significant factors using Duncan Multiple Range Test (DMRT). The results obtained showed the performance of the developed dryers, which indicates that drying time of mixed mode on-farm solar dryer stood at 56 hrs and 46 hrs while that of the indirect mode dryer was 76.67 hrs and 57 hrs and that of open sun drying was 154 hrs and 127 hrs for tomato and okra slices respectively. Results obtained showed that average system drying, energy collection and pick up efficiencies for the three test crops were 16.35%, 21.1% and 8.05% for mixed mode dryer respectively and 28.63%, 45.3% and 0.3% for indirect mode dryer, respectively. From the results obtained the mixed mode dryer dried all the products faster while indirect mode has superior energy efficiencies.