Comparison of a new air-assisted sprayer and two conventional sprayers in terms of deposition, loss to the soil and residue of azoxystrobin and tebuconazole applied to sunlit greenhouse tomato and field cucumber.
BACKGROUND
Plant protection products (PPPs) are applied in China and many other developing countries with knapsack sprayers at high volumes with coarse spray quality, resulting in a high percentage of pesticide losses. In this study, a new air-assisted electric knapsack sprayer and two conventional knapsack sprayers were evaluated in terms of pesticide deposition, residues and loss into the soil. Artificial targets fixed to the upper side and underside of the leaf surface in six zones (at two depths and three heights) were used to collect the deposition, which were analyzed by liquid chromatography triple-quadrupole mass spectrometry.


RESULTS
The air-assisted electric knapsack sprayer produced more deposition and better penetrability and uniformity than the two traditional spraying methods. In particular, the air-assisted electric knapsack sprayer reduced pesticide losses to the soil by roughly 37% to 75% and deposited 1.18 and 1.24 times more pesticide than the manual air-pressure and battery-powered knapsack sprayers, respectively. The residues of azoxystrobin and tebuconazole in tomato and cucumber were below the maximum residue limits (MRLs).


CONCLUSION
In general, use of the the air-assisted electric knapsack sprayer in tomato and cucumber crops could improve the effectiveness of PPPs, reduce the risk of contamination and protect food safety. © 2017 Society of Chemical Industry.
['Li|Yanjie|Y|', 'Li|Yifan|Y|', 'Pan|Xiang|X|', 'Li|Qing X|QX|', 'Chen|Ronghua|R|', 'Li|Xuesheng|X|', 'Pan|Canping|C|http://orcid.org/0000-0002-7616-1615', 'Song|Jianli|J|']
D000383:Agriculture D018553:Cucumis sativus D005659:Fungicides, Industrial D018551:Lycopersicon esculentum D010573:Pesticide Residues D011743:Pyrimidines D012987:Soil D000073739:Strobilurins D014230:Triazoles
sprayer deposition air assistance pesticide residue