Effects of nozzle-canopy interaction on pesticide-spray distribution and on-target deposition | |
| Author | Sanjika, Thawani Mpatama |
| Call Number | AIT Thesis no.AE-03-05 |
| Subject(s) | Pesticides Nozzles Spray nozzles |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AE-03-05 |
| Abstract | Many studies on the independent effects of factors on pesticide spray distribution and on-target deposition have been carried out over the years. Considering the importance of interaction between variables in biological systems and the fact that the factors rarely act independently of each other, the results from such studies might have given an incomplete picture. A 3x5 factorial experiment arranged in a split-plot Randomized Complete Block Design (RCBD) with three replicates was therefore carried out with nozzle type and crop canopy as main plot and subplot factors respectively. Nozzles; ConeJet® Dl-23, disc-core hollow cone type (Nozzle-1), ConeJet® Dl-31, disc-core full cone type (Nozzle-2) and XR TeeJet® TPU80015, extended range flat spray tip type (Nozzle-3) constituted the three levels of the main plot factor whereas crops; maize, soybean, tomato, mungbean and carrot were the five levels of the subplot factor. The study intended to determine if the interaction between nozzle type and canopy characteristics has an effect on pesticide-spray distribution and ontarget deposition, and to quantify the interaction effects, and to propose ways on improving spray distribution and on-target deposition based on the results. The results of the study indicated that nozzle-canopy interaction significantly affected spray distribution at 5% level of significance. It was also found that the nozzle-canopy interaction significantly affected spray deposition at application rates of 150 and 600 I/ha but not at 1200 I/ha. The effects of nozzle-canopy interaction on spray distribution in maize, soybean, tomato, mungbean and carrot were ±49, ±77, ±140, ±164, and ±79 droplets/cm2 respectively. Nozzle-canopy interaction effects on spray deposition in maize, soybean, tomato, mungbean and carrot were respectively ±2.09, ±1.19, ±1.73, ±5.80, and ±7.53 μ.g-Mn/cm2 at 150 I/ha and ±16.13, ±18.32, ±42.63, ±6.69, and ±22.82 μ.g-Mn/cm2 at 600 I/ha. Nozzle-3 was found to be the best for spray distribution in maize, soybean, tomato and carrot while Nozzle-2 was the best for mungbean. Nozzle-1 was found to give the best spray deposition results in maize at 150 I/ha, soybean at all spray application rates, tomato at 600 and 1200 I/ha and carrot at 1200 I/ha. Nozzle-2 gave the best deposition results in maize at 600 and 1200 I/ha, mungbean at 150 I/ha and can-ot at 150 and 600 I/ha. Nozzle-3 was the best for spray deposition in tomato at 150 I/ha and mungbean at 600 I/ha. Based on the results, it was recommended that future nozzle design should optimally combine the good spray distribution qualities offered by fan type nozzles with the deposition qualities in cone nozzles. It was also recommended to carry out experiments on nozzle-canopy interaction incorporating groups of crops with similar canopies in order to determine which crops could be efficiently sprayed using the same nozzle types. Furthermore, experiments on the effects of the interaction between factors on spray distribution and on-target deposition should be carried out. |
| Year | 2003 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AE-03-05 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Jayasuriya, H.P.W.; |
| Examination Committee(s) | Salokhe, V. M. ;Chaiyaphol Kaewprakaisaengkul; |
| Scholarship Donor(s) | University of Malawi - Bunda College of Agriculture; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2003 |