a type of millet, a type of herb
朮 centers on a plant used for food and medicine: a type of millet and a type of herb. The two meanings are linked by the idea of a useful plant, though the exact botanical identity is not specified.
The exact historical origin of 朮 is uncertain. It may have originally depicted a plant with a distinctive root or grain, but the modern form is too abstract to confirm.
The top dot 丶 looks like a seed or grain, and the lower part resembles a plant with a stalk and roots. Picture a millet plant with a grain at the top, or an herb with a medicinal root.
For ジュツ, imagine a juicy millet grain: juicy -> ジュツ, and the dot on top is the juicy part of the plant.