The effects of drift reducing nozzeles on efficacy of herbicides for control of weeds in maize were studied. AVI nozzles can cause poor weed control only if used for applications of small spray volumes (less than 200 l ha-1) with droplet VMD values larger than 400 μm, otherwise weed control results comparable to standard API nozzles are achieved and the use of drift-reduction AVI nozzles does not result in maize yield reduction.
COBISS.SI-ID: 3454508
This research demonstrates the basic elements of a prototype automated orchard sprayer which delivers pesticide spray selectively with respect to the characteristics of the targets. The density of an apple tree canopy was detected by PROWAVE 400EP250 ultrasound sensors controlled by a Cypress PSOC CY8C29466 microcontroller. The ultrasound signal was processed with an embedded computer built around a LPC1343 microcontroller and fed in real time to electro-magnetic valves which open/close spraying nozzles in relation to the canopy structure. The analysis focuses on the detection of appropriate thresholds on 15 cm ultrasound bands, which correspond to maximal response to tree density, and this was selected for accurate spraying guidance. Evaluationof the system was performed in an apple orchard by detecting deposits of tartrazine dye (TD) on apple leaves. The employment of programmable microcontrollers and electro-magnetic valves decreased the amountof spray delivered by up to 48.15%. In contrast, the reduction of TD wasonly up to 37.7% at some positions within the tree crown and 65.1% in the gaps between trees. For all these reasons, this concept of precise orchard spraying can contribute to a reduction of costs and environmental pollution, while obtaining similar or even better leaf deposits.
COBISS.SI-ID: 3424812