Effect of Planting Depth and Orientation on Germination of Yam (Dioscorea) Minisett

Abstract

Adoption of yam minisett technology in mechanization call for a study to ascertain whether planting depth and orientation of yam (Dioscorea alata) in the soil affects germination, since much work has not been done in that regard. Knowledge of the effects of yam minisett planting depth and the orientation in the soil on germination provide useful information for the development of planter since minisett falling from planter could be at any position. A survey was conducted to investigate how germination affected by vary position of yam minisett. A rubber "pots experiment" were carried out within a period of 180 days after planting (DAP), under natural conditions of light, temperature and relative humidity. Minisett weighed 40g -80g was subjected to seven (7) main treatments; planting depth and planting orientation which consist of four (4) and three (3) levels respectively. Planting depth (d1=5cm, d2=10cm, d3=15cm and d4=20cm) and planting orientation with the skin of the sett facing upward (SSU), skin facing side (SSS) and skin of the sett facing down (SSD). The experiment was laid out by complete randomized design (CRD) with three replications. There was significant difference (p<0.05) between the 5cm in planting depth variables for two germination parameters (GeT and GSI) as well as interaction with orientation observed. However, there was no significant effect (P>0.05) among planting depth and orientation variables on germination parameters (GeT and GSI). Minisett orientation and planting depth interaction had no effect on the germination (P>0.05) with the exception of 5cm depth. The higher rate germination setts were recorded SSS (44%) and planting depth 20cm (35%). Based on general results, yam minisett germination has no correlation with depth and orientation. Therefore, the use of mechanical yam sett planter is feasible, since placing the setts in any orientation with variable condition will germinate.

Development of a Double Row Tractor Operated Yam Minisett Planter

“…To mechanize the planting of yam minisett, the potato planter was adopted and modified to suit the planting of yam minisett. The features of minisett (planting material) is a form of sector which has five (5) faces of about 80% fresh and remaining 20% skin [8], unlike potato planting material which has skin all round. Due to the nature of the sett, modification of potato planter included metering mechanism, positioning of hopper, furrow opener and coverer.…”

“…The selection and design calculations of the planter components were based on materials specification, soil and yam physical properties. The design of yam minisett planter did not consider the orientation of sett from the hopper into the soil since results from Arkoh and Bobobee [8] confirmed that healthy sett germinates so far as soil touches the skin of the minisett. However, the following considerations were made:…”