Quantification of mineral oil accumulation and movement in potato plants and its significance in potato virus Y management.
BACKGROUND
Mineral oils are increasingly sprayed to manage potato virus Y (PVY). However, the mode of accumulation and movement of mineral oil in the potato plant has not been understood. This information is important for optimisation of the concentration and frequency of spraying. During the 2012 season, cvs Russet Burbank and Shepody were planted in the field and in the greenhouse, respectively, and were subjected to mineral oil treatments. The plant samples from the treatment plots were collected, and oil was extracted and quantified using gas chromatography-mass spectrometry.


RESULTS
Mineral oil stayed in the vicinity of the sprayed leaves and did not move from leaflet to leaflet or from leaflet to stem, stolon, tuber or root. Following spraying, the oil content in the plant leaves diluted as time progressed. At plant maturity, leaves sampled from the greenhouse sprayed plants had about 4 times more oil content than those sampled from the field sprayed plants. Plots treated with regular spray of mineral oil showed low PVY incidences at crop harvest.


CONCLUSION
The information generated in this study on the pattern of accumulation and movement of mineral oil in greenhouse- and field-grown potato plants shows that, as the oil does not move from leaflet to leaflet, frequent mineral oil sprays from crop emergence to harvest are required to prevent PVY infection in newly emerged leaflets and seasonal spread of PVY. The frequency of sprays may be kept higher from early to mid-stage, when plant growth is faster, and lower close to plant maturity.
['Fageria|Manphool|M|', 'Boquel|Sébastien|S|', 'Leclair|Gaetan|G|', 'Pelletier|Yvan|Y|']
D000818:Animals D001042:Aphids D007300:Insect Control D007303:Insect Vectors D008899:Mineral Oil D010935:Plant Diseases D018515:Plant Leaves D018517:Plant Roots D018547:Plant Stems D017800:Potyvirus D011198:Solanum tuberosum
spray concentration gas chromatography-mass spectrometry aphids non-persistent virus vector