Control of aphid‐borne papaya ringspot potyvirus in zucchini marrow(Cucurbita pepo)with reflective mulches and mineral oil‐insecticide sprays

Abstract

Plastic mulches and mineral oil plus insecticide sprays were evaluated for control of papaya ringspot potyvirus (PRV-W) in zucchini (Cucurbita pepo cv. 'Blackjack') in two field experiments in Queensland, Australia. Treatments were compared using a proportional hazards survival model. Mulches with a reflective (silver) surface reduced the hazard ratio (Hr) from 1 in the controls to 0.32, while mineral oil plus insecticide sprays (Hr 0.33) were as effective as reflective mulches used alone (Ρ>0.05). A combination of reflective mulch and oil plus insecticide sprays was the most effective treatment (Hr 0.16). Black mulch alone (Hr 0.66) was partly effective and significantly better than control (Ρ<0.05). Blue and grey mulches were not effective (Hr 0.86 and 0.99, respectively). Spraying with deltamethrin alone (Hr 0.75) improved control compared to the no-spray treatment (Ρ<0.05) but was not as effective as sprays of Albarol ® mineral oil plus demeton-S-methyl (Hr 0.26) (P>0.05). Albarol ® (Hr 0.26) provided significantly better control (Ρ<0.05) than Lovis ® (Hr 0.46) when each was combined with demeton-S-methyl. Improved protection against PRV-W was directly related to low aphid numbers on plants and to low alate numbers collected in water traps placed within the treatments. In both experiments, yield of symptomless fruit was approximately doubled by the combined treatment of reflective mulch and mineral oil plus insecticide sprays, and this increase was due to an extended cropping period of 6.2 commercial picks in the control to 14.5 in the first experiment and from 8.8 to 16.0 in the second. Other treatments resulted in differences in yield and number of commercial picks in proportion to the efficacy of treatments against PRV-W.

Efficacy of Certain Insecticides and Mineral Oil in Controlling Aphid, Aphis gossypii Glov. and Papaya Ringspot Virus in Squash at Kafr El-Sheikh Governorate

“…The rest treatments; KZ oil and pymetrozine achieved a relatively moderate effect without a significant difference between them by 22.78 and 23.89 %, respectively. The obtained results conformed with the finding of Pinese et al, (1994), who reported that spray of mineral oils onto zucchini (Cucurbita pepo cv. 'Blackjack'), had some success in controlling the spread of stylet-borne (non-persistent) viruses, especially with frequent applications below phytotoxic levels.…”

Aphid Transmission of Potyvirus: The Largest Plant-Infecting RNA Virus Genus

“…Reflective mulches applied at the time of cucurbit planting have been shown to be effective in repelling aphids from plants, thereby reducing the incidence of WMV, PRSV, and ZYMV, potyviruses commonly occurring in the U.S. farmscapes [ 129 , 130 ]. Furthermore, the use of mineral oil individually [ 131 , 132 ] and in combination with other treatments such as reflective mulches [ 133 ] and crop borders [ 134 ] has been proved to be effective in the management of multiple potyviruses such as PVY and PRSV. Earlier studies report that mineral oil modifies the feeding behavior of aphids [ 135 ] and interferes with the binding of potyvirus virions to aphid stylets [ 132 ], making it one of the effective strategies for potyvirus management.…”

Control of Cucurbit Viruses

“…For instance, the combined use of insecticide and mulching resulted in suppression of B. tabaci populations and reduced the incidence of the persistently transmitted CuLCrV in zucchini crops (Nyoike & Liburd, 2010) and of the semipersistently transmitted SqVYV in watermelon (Kousik et al, 2012). Similarly, a combination of reflective mulch, mineral oil, and insecticide applications was very efficient in controlling the aphidborne PRSV in zucchini (Pinese, Lisle, Ramsey, Halfpapp, & De Faveri, 1994). However, the use of mulches and row covers has a major drawback; this requires a lot of plastic material that farmers must dispose in an ecologically sound way after the crop cycle.…”