December 1, 2007
- Xanthomonas axonopodis pv. citri,
- Phyllocnistis citrella,
- citrus canker control,
- chemical sprays
Abamectin and copper bactericides applied alone or in combination with other products for control of citrus leafminer (Phyllocnistis citrella; CLM ) and citrus canker (Xanthomonas axonopodis pv. citri) in lemons were evaluated for three seasons in a commercial lemon orchard in Tucuman, Argentina. Citrus canker control treatments were applied on six dates from petal fall to February each year at 28-day intervals with a high volume, air blast sprayer. CLM control treatments with abamectin were applied every 15 days during the period of high CLM pressure. Incidence of citrus canker on fruits was reduced significantly by all spray treatments compared with the non-sprayed control. Control of citrus canker by different sources of copper oxychloride and copper hydroxide was not significantly different. Higher application rates of copper hydroxide (0.20%) were more effective in controlling the disease than lower rates (0.15%). The combination of copper oxychloride with spray oil as an adherent or with disinfectants (quaternary ammonium, peracetic acid) did not improve disease control on fruit. Citrus canker on fruit was reduced 19% by abamectin treatment for CLM control. Addition of abamectin to six copper sprays did not provide greater control than the copper sprays alone.