Growth responses of sugarcane to mycorrhizal spore density and phosphorus rate
Data(s) |
01/12/2005
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Resumo |
Arbuscular mycorrhizal (AM) fungi, commonly found in long-term cane-growing fields in northern Queensland, are linked with both negative and positive growth responses by sugarcane (Saccharum spp.), depending on P supply. A glasshouse trial was established to examine whether AM density might also have an important influence on these growth responses. Mycorrhizal spores (Glomus clarum), isolated from a long-term cane block in northern Queensland, were introduced into a pasteurised low-P cane soil at 5 densities (0, 0.06, 0.25, 1, 4 spores/g soil) and with 4 P treatments (0, 8.2, 25, and 47 mg/kg). At 83 days after planting, sugarcane tops responded positively to P fertilizer, although responses attributable to spore density were rarely observed. In one case, addition of 4 spores/g led to a 53% yield response over those without AM at 8 mgP/kg, or a relative benefit of 17 mg P/kg. Root colonisation was reduced for plants with nil or 74 mg P/kg. For those without AM, P concentration in the topmost visible dewlap (TVD) leaf increased significantly with fertiliser P (0.07 v. 0.15%). However, P concentration increased further with the presence of AM spores. Irrespective of AM, the critical P concentration in the TVD leaf was 0.18%. This study confirms earlier reports that sugarcane is poorly responsive to AM. Spore density, up to 4 spores/g soil, appears unable to influence this responsiveness, either positively or negatively. Attempts to gain P benefits by increasing AM density through rotation seem unlikely to lead to yield increases by sugarcane. Conversely, sugarcane grown in fields with high spore densities and high plant-available P, such as long-term cane-growing soils, is unlikely to suffer a yield reduction from mycorrhizal fungi. |
Formato |
application/pdf |
Identificador |
Kelly, R.M. and Edwards, D.G. and Thompson, J.P. and Magarey, R.C. (2005) Growth responses of sugarcane to mycorrhizal spore density and phosphorus rate. Australian Journal of Agricultural Research, 56 (12). pp. 1405-1413. |
Publicador |
CSIRO Publishing |
Relação |
http://era.daf.qld.gov.au/1307/1/KellyGrowthResponses-sec.pdf http://era.daf.qld.gov.au/1307/ |
Palavras-Chave | #Cryptogams #Sugarcane #Fertilisers |
Tipo |
Article PeerReviewed |