Uji shade growing: the “staircase of shade” and theanine accumulation
How many layers of black shade cloth, the southern opening, and the photon flux density that shifts at the boundary with open-field rows. Rather than shading all at once, we organize the field's criteria for drawing out greenness in stages, alongside garden logs.
In Uji's Minami-Yamashiro, deciding 'on which day to apply which shade ratio' under cover determines the balance of theanine and flavonoids. Rather than going fully dark all at once, the first few days leave some transmitted light to draw out greenness, and only afterward do layered screens cut the photon flux density — this staged design connects directly to the aromatic core of tencha.
Field logs show that the more a slope faces south, the stronger the morning direct sun, so the leaf-temperature peak runs higher even under the same shade cloth. In northeast-facing gardens, leaf thickness tends to be more uniform, and we observed less uneven heat penetration during the steaming step.