The developed low-drift orchard sprayer for trellis-trained crops has the same spraying performance as conventional sprayers, even when the machine reduces engine speed and air volume. It is thought that the noise level of the low-drift orchard sprayer can be reduced. Therefore, we evaluated the effects of noise reduction.

The noise level of the new sprayer at the operator’s ear was 82 dB (A), which was lower than that of conventional sprayers. The area where the noise level was above 85 dB (A) was 53 to 211 m² with conventional sprayers, whereas it was 0 m² with the new sprayer. Thus, the area with a high noise level was small.

Range finder sensors are commonly used to measure distance to the top of the plant. Plants have a complicated uneven structure due to leaves and flowers. In this study, a PSD, ToF, and ultrasonic sensor were evaluated. For distance measurements, the range of measurement distance, magnitude of error, influence of sunlight, etc. must be considered. Using the ultrasonic sensor, the error was 1 cm or less both indoors and outdoors. While the PSD and ToF are affected by sunlight, it is possible to take measurements within an error of about 2-3 cm by performing them at nighttime.

In this study, we proposed and examined the “Multiple Rolling Process” as a new tea manufacturing system involving the application of the rolling process many times sequentially. We found that this method increased the drying rate and extended the first falling drying rate period. Further we discovered a higher moisture transfer from stem to leaves. Following sensory testing, we judged that the test section had a better quality than the control, but the particle size was different from the section in crop season. The new system led to efficient drying and increased yield in terms of weight and quality, but the purpose and season need to be considered prior to application.