ABSTRACT

Studies on the responses of ginger (Zingiber officinale Rocs') to various Agroforestry- based crop management practices were carried out in 2004 and 2005 at Umudike, Nigeria. A 3x3x3 factorial experiment in a randomized complete block design (RCBD) with three replications was used to evaluate the effect of zero leaf litter mulch, Dactyladenia barteri, and Dialium guineense leaf litter mulch, three rates (0, 400, 600kgl ha'1) of inorganic fertilizer (NPK 15:15:15) and three ginger minisett sizes (10, 20 and 30g) on the growth and yield of ginger. Each of the two other experiment utilized a 3x3 factorial in RCBD with three replicatipns to determine the performance of ginger in a ginger + maize intercropping treatment in two different agroforestry ecosystems involving two woodbased plant; Dactyladenia barteri and Dacryodes edulis.The study utilized no intercropping (ginger only) and ginger + maize treatments as well as three inorganic fertilizer rates (0, 400 and 600kg ha-1 NPK15:15:15). Again, a 2x3 factorial experiment in RCBD with three replication was used to evaluate the effect of weed density and also the growth and yield of ginger. Three rates (0, 2 and 4t h-1) of D. barteri leaf litter mulch and two: fertilizer rates 0 and 400kg ha-1 NPK 15:15:15 were used in the study. A single-factor experiment in RCBD with three replication was further used to evaluate the growth and yield performance of 2004 sown and post harvest recovered ginger minisetts (rattoons) remains (10, 20, 30g ginger minisetts) which were planted in 2005.The 20g and 30g ginger sett sizes generally gave similar ginger plant survival (%), plant height and diameter (cm plant'1) which were significantly higher than those of 10g set. In 2004 and 2005 leaf litter mulch of Dialium guineense gave significantly higher number of flowers ginger plant'1 and ginger rhizome yield than Dactyladenia barteri leaf litter mulch while the zero mulch gave the least values. No significant differences existed between the growth and yield attributes ofthe 10, 20 and 30g ginger set sizes over time. The 0, 400 and 600kg ha 1 NPK 15:15:15 inorganic fertilizer rates had no significant effects on ginger survival rate (%), plant height and diameter (cm plant'1), flower number plant'1 and ginger rhizome yield (t ha'1) in 2004 and 2005 trials. In both Dactyladenia barteri and Dacryodes edulis- based ecosystems, intercropping ginger with maize had no significant effect on the growth and yield attributes of maize. The ginger + maize intercropping more significantly enhanced the survival rate(%) and the growth and yield attributes of ginger than the sole ginger cropping in both agroforestry ecosystems in 2004 and 2005. The 400 and 600 kg ha’1 NPK 15:15:15 rates gave statistically similar, positive effect on the growth and yield of maize and of ginger in the ginger + maize intercropping treatments. The growth and yield of the 400 and 600 kg ha’1 NPK 15:15:15 were significantly higher than those of the control (O kg ha'1 NPK 15:15:15) fertilizer treatment for both crops. The 2.0 and 4.0 t ha’1 D. barteri leaf litter mulch treatment gave statistically similar weed densities in 2004 and 2005 and more significantly depressed weed growth compared to the zero mulch treatment. Other growth and yield attributes of ginger overtime (2004 and 2005) were significantly and positively enhanced in the following order of mulch rales: 4>2> 0 t ha’1 D. barteri leaf litter mulch. Plant survival (%), plant height and diameter (cm plant’1), tiller number plant’1 and rhizome yield (t ha’1) of ginger were not significantly affected by the various ginger set sizes sown and recovered in 2004 (rattoon). However, the 10g set (43.6%), followed by the 20g (41.8%) had the highest weight loss; while 30g set size had statistically the least weight loss (38.0%) ofthe 2004 sown and recovered ginger rhizome sett (rattoon).