The study was
conducted to investigate the effect of
Rhizobium inoculation and supplementation of phosphorus and potassium on growth and total
leaf chlorophyll content to the three released bush bean varieties in northern
Tanzania. To achieve this aim, the glasshouse experiment was conducted at
Nelson Mandela African Institution of Science and Technology while field
experiment were carried out at Tanzania Coffee Research Institute, in
Kilimanjaro, Tanzania between April-July 2014. The experiment was laid out in
factorial arrangement. Factor I comprised of three bush bean varieties. Factor
II involved two inoculation treatments viz 1) inoculation with
Rhizobium spp. and 2) without
inoculation. Factor III included four fertilizer levels (0 Kg·ha
-1 20 Kg K ha
-1, 30 Kg P ha
-1 and 20 kg·K + 30 Kg P ha
-1).
Both screen house and field experiments were replicated four times. Plan
t growth parameters (plant height (cm), number
leaves per plant, stem girth (mm)) were measured at 2, 4 and 6 weaks
after planting (WAP). The chlorophyll was extracted by using Dimethylsulphoxide
(DMSO) and absorbance was determined at 645 and 663nm using UV/Visible
spectrophotometer. Results showed that
Rhizobium application
significantly improved the number of leaves per plant, plant height, pant girth
and total leaf chlorophyll content. Furthermore, co
mpared with the zero treatment control, potassium fertilization
significantly increased the number of leaves per plant, plant height,
pant girth and total leaf chlorophyll content of the three varieties. In
general, these parameters were significantly increased with phosphorus supplied
at 30 kg/ha. The combination of these supplies at different levels resulted in
significant interactions in some parameters and thus indicating need for these
inputs in the study area.