Phytopathology (1996) 86, p. S6 (Widmer et al.)

T.L. Widmer, J.H. Graham and D.J. Mitchell (1996)
Effect of composted municipal waste on growth of young citrus trees in the presence of Phytophthora nicotianae
Phytopathology 86 (11 suppl.), S6-S6
Abstract: Phytophthora nicotianae damages fibrous roots of citrus, which reduces growth and yield of trees on susceptible rootstocks. Sunburst tangerine trees on Sun Chu Sha rootstock were planted in the field in 1994 in soil infested with P. nicotianae or in noninfested soil. Soil around the trees was treated with composted municipal waste (CMW) from two different sources by either incorporating into the backfill at the time of planting (20% v/v) or layering on top as a mulch (20 tons/ha). Controls were included with no CMW. The rate of increase in stem diameter after 1.5 years for trees treated with one source of CMW was significantly greater than the controls (P = 0.05), regardless of infestation with P. nicotianae or placement of the CMW. Growth rate of trees treated with a second source of CMW was not significantly greater than the control. Fibrous root weight of the trees over all treatments was significantly reduced in the presence of P. nicotianae (P = 0.05); however, fibrous root weights were significantly greater in the presence of CMW regardless of the source or placement. Phytophthora nicotianae was difficult to recover from any treatment and populations were not significantly reduced by CMW treatments (P = 0.05).

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phytophthora nicotianae	Citrus (genus)