Horticultural mineral oil treatments in nurseries during aphid flights reduce Plum pox virus incidence under different ecological conditions

Abstract

The application of horticultural mineral oil (HMO) treatments has been reported as a possible control strategy to reduce Plum pox virus (PPV) incidence in Prunus nurseries. The effect of Sunspray Ultrafine HMO at 1% on the natural viral spread was evaluated in experimental nursery plots of Nemaguard and Mariana GF8-1 Prunus rootstock blocks established under high natural inoculum pressure of the most prevalent PPV-types. Tests were conducted in experimental nursery plots in Plovdiv, Bulgaria (PPV-M and PPV-Rec), in Bistrita, Romania (PPV-D and PPV-Rec) and in Llíria, Spain (PPV-D). Horticultural mineral oil treatments were applied weekly during the vegetative period from spring to fall (treatments were interrupted in the summer). Nursery plants were analysed yearly by double-antibody sandwich enzymelinked immunosorbent assay with 5B-IVIA/AMR monoclonal antibodies. The population dynamics of the aphids visiting plants in each experimental nursery plot was monitored by the sticky-shoot method and also by Moericke yellow water traps. At all three locations, the aphid population first peaked in the springtime. Furthermore, a variable second peak of aphid population was observed in Plovdiv and Bistrita in autumn. The treatments reduced PPV incidence in the three experimental locations and plots and in both assayed Prunus rootstocks grown under high PPV-inoculum pressure. A reduction from 10% to 20% of PPV-incidence between treated and control plants (P < 0.05) in Plovdiv and Bistrita, respectively, was observed at the end of the tests. However, HMO treatments did not prevent PPV infection altogether, probably because of the high PPV prevalence in the area near the experimental nursery blocks. The control of PPV in nursery blocks based on HMO is presented as an environmentally friendly strategy based on the physical action of the treatments.

Plum pox virus and sharka: a model potyvirus and a major disease

“…Infections starting with a completely random spatial pattern which finally reaches a uniform distribution in the orchard have also been reported (Varveri, ). The application of horticultural mineral oil has been shown to be an efficient control strategy to reduce PPV incidence in nursery plots (Vidal et al ., ).…”

Plant virus ecology and epidemiology: historical perspectives, recent progress and future prospects

“…A few examples of other original contributions from the many published in the journal over the last 100 years relevant to the theme of plant virus ecology and epidemiology include:‐ Virus spread by aphid (Broadbent, ; Watson et al ., , ; Elnagar & Murant, ; Tatchell et al ., ); whitefly (Fargette et al ., ), leafhopper (Soleimani et al ., ), mite (Thresh, ), nematode (Harrison, ) and fungus (Rosner et al ., ) vectors; Virus spread by contact (McKirdy et al ., ); Seed transmission of nematode‐borne (Lister & Murant, ; Murant & Lister, ; Hanada & Harrison, 1977), aphid‐borne (Jones, 1988 b ; Jones & Proudlove, ), and contact‐transmitted viruses (Wroth & Jones, ); Weeds as virus reservoirs (Tomlinson et al ., ; Ramappa et al ., ; Pallett et al ., 2002); Virus or vector resistance deployment (Jones, ; Ferris et al ., ); Virus resistance breakdown (Pelham et al ., ; Thomas‐Carroll & Jones, ); Effects of cultural practices on spread of aphid‐borne viruses (Kendall et al ., ; Jones, , ; Difonzo et al ., ; Sauke & Doring, ); Control of aphid‐borne viruses by insecticides (Jones & Ferris, ) or mineral oil (Vidal et al ., ); Control of nematode‐borne viruses by nematicides (Harrison et al ., ); Control of fungus‐transmitted viruses by fungicides (Tomlinson & Faithfull, ); Forecasting virus epidemics (Harrington et al ., ). …”

Alternative Ecological Products for Aphid Control on Plum

“…Overall, the control of aphid populations is very important in order to reduce the direct damages, and to limit the spread of PPV which produces significant additional losses. Previous field studies have shown that the application of mineral oils, which are accepted in ecological farming, is useful in reducing the incidence of PPV infections [ 16 ]. The allelopathic effect of phenolic acids can also be a good tool for protecting plants against aphid infestation; a high concentration of phenolic acid (gallic acid and caffeic acid) inflicts a reduction in aphid infestation [ 17 ].…”