Ali Saebi; Saeid Minaei; Ali-Reza Mahdavian; Mohammad-Taghi Ebadi
Abstract
Precision management of medicinal plant production using mechanical systems, processors, and sensors increases productivity, reduces waste, and manages production processes. This research developed a precision harvesting unit equipped with an automatic height adjustment system for utilization in harvesting ...
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Precision management of medicinal plant production using mechanical systems, processors, and sensors increases productivity, reduces waste, and manages production processes. This research developed a precision harvesting unit equipped with an automatic height adjustment system for utilization in harvesting machines to harvest Hyssop at an optimal height. The unit after development consisted of a power transmission system (converting rotational motion into reciprocating motion), a harvesting platform (cutter-bar, reel, and conveyor), and a system to control the vertical movement of the head. An ultrasonic sensor was employed to detect the highest part of the plant for control purposes. Acentral control board and a driver generated the control signal, with a stepper motor as the actuator. We measured harvesting-related variables, including dry matter, essential oil content and yield, leaf-tostem ratio, and indices related to conservation agriculture to evaluate the developed precision harvesting unit. Results showed that the unit increased the purity of the harvested plant raw material compared to the manual harvesting of Hyssop, a key to extracting more of the target substances, such as essential oil. The steady-state error of the control system measured 2% in adjusting the cutter-bar height for the optimal height of harvesting Hyssop (T15) in elevation and descension modes.
Ali Saebi; Saeid Minaei; Ali Reza Mahdavian; Mohammad-Taghi Ebadi
Abstract
The amount of active compounds of medicinal plants (e.g. essential oil) varies in different plant parts. Thus, it is important to harvest those parts containing the highest levels of active compounds. In the present study the effect of harvest height on quantity and quality of Hyssopus officinalis was ...
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The amount of active compounds of medicinal plants (e.g. essential oil) varies in different plant parts. Thus, it is important to harvest those parts containing the highest levels of active compounds. In the present study the effect of harvest height on quantity and quality of Hyssopus officinalis was investigated based on a randomized complete block design with three replications. Treatments included four harvest heights including 15, 25, 35, and 45 cm (in basipetal order) and the residual stalks. After measuring the essential oil, the component values analyzed by GC and GC/MS. Regarding essential oil content (% v/w), yield and dry matter of different heights, the 15 cm height had the highest amount of essential oil (1.02±0.01%) and the lowest yield (2.17±0.13 g/m2) and dry matter (213.72±15.32 g/m2). On the contrary, the 45 cm height had the lowest amount of essential oil (0.75±0.01%) and the highest yield (5.7±0.57 g/m2) and dry matter (757.52±63.5 g/m2). For all harvest heights, cis-pinocamphone (53.93-44.6%), β-pinene (15.33-12.5%) and trans-pinocamphone (12.2-8.17%) had the highest levels among the compounds of the essential oil. The findings obtained from present study revealed that, if the quality is the matter, the essential oil extracted from the top 15 cm had the highest quality and purity although it was less in quantity.
