Influence of air-assistance on spray application for tomato plants in greenhouses

Jordi Llop, Emilio Gil, Jordi Llorens, Montserrat Gallart, Paolo Balsari
2015 Crop Protection  
 11 Protected horticulture production represents one of the most important agricultural businesses in 12 Southern Europe. However, many problems related to the lack of mechanisation, intensive use of 13 pesticides, and, in some cases, undesirable residues on food, have not been solved yet. In this 14 context, application technology is a key factor for the improvement of the efficacy and efficiency 15 of plant protection products. Spray guns and knapsack sprayers are the most common 16
more » ... ies that have been used for this purpose. However, several studies have demonstrated 17 that, compared with spray guns, the use of vertical boom sprayers in greenhouses improves spray 18  Abbreviations: PPPplant protection products; DISAFA -Dipartimento di Scienze Agrarie, Forestali e Alimentari; LAIleaf area index; LWAleaf wall area; TRVtree row volume; LADleaf area density; ANOVAanalysis of variance; HSDhonest significant difference; SEMstandard error of the mean. 2 distribution and reduces labour costs and operator exposure. The main objective of this study 19 was to evaluate the influence of air-assistance on spray application in conventional tomato 20 greenhouses. For this purpose three different spray conceptions were evaluated: 1) a modified 21 commercial handheld trolley sprayer with two air assistance concepts; 2) a self-propelled 22 sprayer; and 3) an autonomous self-propelled sprayer with remote control. All the sprayers 23 considered were evaluated in terms of absolute and normalised canopy deposition, uniformity of 24 distribution, and losses to the ground. In addition, the vertical liquid and air velocity distributions 25 of the sprayers were assessed and compared with the canopy profiles and spray depositions. 26 Yellow tartrazine (E-102 yellow) was used as a tracer for deposition evaluation. The results 27 indicated that increasing the air velocity does not increase the efficiency of a spray application. 28 In general, the modified handheld trolley sprayer showed the best results in terms of deposition 29 and uniformity of distribution, especially at the lowest air assistance rate. These results were 30 confirmed with evaluation of the uniformity of the air and liquid distribution. 31 32
doi:10.1016/j.cropro.2015.09.026 fatcat:nqr6vejdivge7fuvbbsbuqajhq