Integrated management of sting nematode in newly planted citrus trees

Integrated management of sting nematode in newly planted citrus trees

Report Date: 08/08/2022
Project: 21-013   Year: 2021
Category: Horticultural & Management
Author: Larry Duncan
Sponsor: Citrus Research and Development Foundation

The first oxamyl nematicide treatment occurred in the IPC trial on 25 April 2022 and the second on 24 May.  The effects of these treatments on sting nematode populations were measured on 11 July, 48 days after the final treatment.  Two soil cores (30 cm deep x 2.5 cm dia) per tree were composited in each 4-tree plot.  Samples were weighed and nematodes were separated from subsamples (250 cm3) by sucrose centrifugation. Fibrous roots in the entire sample were collected, air dried and are currently being separated from weed roots for measurement.  The sting nematode populations were low, averaging just 5 nematodes per 250 cm3 soil.  Nevertheless, oxamyl was shown to reduce the (log-transformed ) sting nematodes (P=0.015) by 53% and there was a suggestion of an interaction (P=0.07) with the IPC treatment in which nematodes were reduced by 19% compared to 88% in the non-covered trees.   The first rootstock lines were planted in the four large Rubbermaid tanks on 17 June (UFR-1, UFR-4, UFR-5, UFR-6, UFR-15, UFR-17, MG-11, FG#2, Orange 14, Orange 16, A+VolkxOrange19-11-8, LB8-9xS10-15-18, LB8-9xS13-15-16, S10xx639-12-32, S11xSO+50-7-16-12, LB8-9×50-7-16-4, Blue 1). Two tanks are infested with sting nematode and two are non-infested controls. Each tank contains 4 plants of each rootstock.  The greenhouse renovation improved the ambient conditions, especially the temperature control. The plants will be evaluated for root and shoot mass and nematode induced stubby root and tip gall symptoms.    


Your browser does not support pdfs, click here to download the file.