Effects of Sett Size and Spacing on the Growth and Yield of Ginger (Zingiber officinale Rosc.) at Areka, Wolaita, Southern Ethiopia

Abstract

An experiment was conducted to determine the effects of sett size and spacing on the growth and yield of ginger during 2008 cropping season, at Areka, Southern Ethiopia. The experiment consisted of factorial combination of  three inter row spacings (20, 30 and 40 cm), three intra-row spacings (5,10 and 15 cm) and three ginger rhizome sett sizes(£ 3 cm, 3.1 to 6 cm and 6.1 to 9 cm). The design was split-split-plot with three replications. Inter row spacing, intra-row spacing and sett size were assigned to the main plot, sub-plot and sub-sub-plot, respectively. Data on plant growth parameters, yield and yield components were recorded and analyzed. The results showed that in general plants attained higher canopy establishment and reached maximum growth between 120 and 165 days after planting and thereafter declined due to senescence. The interaction effect of inter row spacing by sett size was significant on total biomassha^-1and dried rhizome yield ha^-1.Inter row spacing had significant (P <0.05) effect on number of tillers plant^--1, leaf area per plant, leaf area index, rhizome length, rhizome width, rhizome fingers plant^--1, rhizome fresh weight ha^-1 and harvest index but non significant effect on date to 50% emergence and 90 % maturity and other growth parameters. Intra-row spacing had significant (P <0.05) effect on number of tillers plant^--1, plant height, number of leaves per plant, shoot dry weight plant^-1, leaf area, leaf area index, rhizome fingers and total biomass. Sett size also significantly (P <0.05) affected emergence, maturity, number of tillers plant^-1, plant height, leaf length & width, shoot dry weight leaf area, leaf area index rhizome fresh weight ha^-1 and harvest index. All the parameters increased with increased in rhizome sett size. The findings showed that growth, yield and yield components of ginger can be improved by using appropriate sett size. In the study the maximum fresh rhizome yield (41808 kg ha^-1) was achieved using sett size 6.1 - 9.0 cm irrespective of the inter and intra-row spacings, which is similar with  recommendation from Tepi and it could be recommended for use by ginger producers in the experiment area and its surroundings. Influence of inter row spacing (20 and 30 cm) was significant while that of intra-row spacing was not on fresh rhizome yield. However, higher yield was obtained from 10 and 15 cm inter row spacing. Therefore, it is advisable to use 20x15 cm and/or 30x10cm inter row and intra-row spacings interchangeably. However, further studies should be conducted to see consistency of the results and come up with site specific recommendation.

Keywords: Ginger; spacing; sett size; Growth; Yield