Performance of Arbuscular Mycorrhiza Inoculated Acacia mangium Seedlings on Degraded Land with Different Rates of Phosphorus

The experiment was conducted in the degraded ex-tin mining farm of Universiti Putra Malaysia during November 1998 to May 1999. The experiment was laid out in split plot design with three replications. Three phosphorus (P) rates, viz., 0, 50 and 100 g Gaphsa phosphate rock (GPR) per plant in combination with and without arbuscular mycorrhiza (AM) inoculation were studied on newly planted tree species Acacia mangium. Mycorrhiza inoculation was assigned to the main plot and P dose to the subplot. Three-month-old AM preinoculated seedlings were planted in the field at 2 m x 2 m spacing. The experiment was continued until 160 days after planting (DAP). Mycorrhiza inoculation and rate of P application significantly influenced growth and development of the A. mangium plants. The highest growth of un-inoculated A. mangium plants was observed with 100 g GPR per plant; whereas for AM inoculated plants the highest growth was observed with 50 g GPR per plant. This indicates that P requirement of newly planted A. mangium plants on degraded ex-tin mining land could be reduced to 50 g GPR per plant, i.e., by 50% with AM inoculation. Keywords: Arbuscular mycorrhiza, Acacia mangium, Degraded land, PhosphorusDOI: http://dx.doi.org/10.3329/bjm.v24i1.1230 Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp 9-18

Influence of Flooding on the Survival of Arbuscular Mycorrhiza

A study was conducted for two consecutive years (2004-2005 and 2005-2006) at Ullapara, Shirajgonj particularly in onion growing flooded area to know the status of arbuscular mycorrhizal fungi (AM) in flooded soil. Twenty farmers were selected for two years who cultivated onion in their fields after flood. Soil samples were collected just after removing of flood water. Again rhizosphere soils with roots of onion were collected from the same plots. After assessment of these samples, two years' results indicate that there is a plenty of AM spores in flooded soil. It proves their ability to survive in flooded condition and after flooding heavy colonization in onion roots was observed. Higher spore population was also recorded from the rhizosphere soils of onion. Keywords: Arbuscular mycorrhiza; flooding; survivabilityDOI: http://dx.doi.org/10.3329/bjm.v25i2.4872 Bangladesh J Microbiol, Volume 25, Number 2, December 2008, pp 111-114