Autonomous tractors can operate in open fields by using the RTK-GNSS (Real-time Kinematic-Global Navigation Satellite System). However, RTK-GNSS signal might not be available at all geographical locations, which could make autonomous driving unsafe. To avoid such situations, we sought to develop a vision-based agricultural road detection system that does not rely on RTK-GNSS. It takes the RGB images obtained from an HD onboard camera, removes camera distortion, filters the images, detects the road edges, and calculates the lateral error. Experimental runs showed that the lateral error was less than 0.2 m for unpaved roads and 0.4 m for paved roads. This shows that the system can detect agricultural roads and thus can be used in place of RTK-GNSS.

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The effects of potassium concentration on the metabolomic and electrical responses of strawberry fruits were investigated. The potassium concentration of fruit harvested in January, March, and April were determined. Quality differences were observed in April, with lower potassium levels resulting in lower Brix values and acidity. Intracellular resistance and cell membrane capacity, as determined by impedance analysis, were correlated with acidity and sugar content, respectively. In addition, metabolomic analysis by gas chromatography-tandem mass spectrometry (GC-MS / MS) indicated that stress markers, such as putrescine, were detected before quality differences appeared. While impedance analysis is useful for evaluating the tissue condition of strawberries, metabolomic analysis can be used to predict quality changes.

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This study aimed to clarify the characteristics of gamma-aminobutyric acid (GABA), citrulline (Cit), nicotianamine (Nit), angiotensin I-converting enzyme (ACE) inhibition, antioxidant capacity, and antioxidant contents in the inedible sites of Earl’s melon that are discarded during food processing: placental tissue, fruit skin, and seeds. These sites are antihypertensive, contain GABA, Cit, Nit, and antioxidants, and have ACE inhibitory activity, and antioxidant capacity; however, these sites have different characteristics. In particular, placental tissue had the highest GABA, Cit, antioxidant levels, and antioxidant capacity. These properties suggest that it is a useful raw material for new health foods; this provides a solution to utilize unused resources. These compounds are potential anti-hypertensive materials.

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This research proposes a new cassava root-cutting machine designed as a cylinder saw and grasper mechanism. The machine’s performance was assessed to prove its utility, and two factors affecting the performance were investigated: the cassava branching type (erect, dichotomous, and tetrachotomous) and the surrounding gap between the cylinder saw and cassava stalk (10, 15, 20, and 25 mm). The result showed that the average loss, trash, cutting time, compressive force, torque, and power consumption were 3.49 % and 2.34 %, 62 s / stalk, 141.69 N, 15.04 Nm, and 587.75 W, respectively. To prevent high loss and trash, a 20 mm gap is optimal for all branching types.

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