Effect of Sheath Blade Removal on Phyllostachys violascens Shoot Quality

Sheath blades are the first bamboo organ exposed to sunlight after shoots initially emerge. However, it remains uncertain whether sheath blades affect bamboo shoot growth and quality. Accordingly, this study explores variations in Phyllostachys violascens shoot growth and quality, comparing natural growth conditions to periodic sheath blade removal treatments. Results show that sheath blade removal and interactions between sheath blade removal and duration had no significant effect on the morphology, protein nutritional quality, or value of bamboo shoots. However, the length of bamboo shoot was significantly lower 4 d after treatment compared to 4 d after natural growth conditions. Moreover, sheath blade removal did have a significant effect on soluble sugar, total acid, oxalic acid, tannic acid, and cellulose content as well as sugar–acid ratios of bamboo shoots, while having no significant effect on the content and proportion of amino acid flavor compounds. Interactions between sheath blade removal and duration only had a significant effect on total acid and sugar–acid ratios. Soluble sugar, oxalic acid, tannic acid, and sugar–acid ratios increased significantly 2 d after sheath blade removal, while total acid and cellulose content decreased significantly. Lastly, soluble sugar content and sugar–acid ratios increased significantly 4 d after sheath blade removal. Findings from this study indicate that sheath blades affect shoot quality, particularly taste, which is mainly driven by carbon metabolism, but the effect of nitrogen metabolism was not obvious. This study gave a new perspective for revealing the formation mechanism of shoot quality, and also provided possible methods of improvement for the shoot quality.