Variation in carbohydrate reserves and dry matter production of bush tea (Athrixia phylicoides) grown under different environmental conditions

Abstract

Reserve carbohydrates are critical for herbage yields, productivity as well as management strategies of bush tea (Athrixia phylicoides DC). This study was conducted to evaluate carbohydrate accumulation in response to pruning seasons (summer, autumn, winter, and spring) involving different organs grown under different conditions and to determine mean dry matter production of bush tea. Three separate parallel trials were conducted under wild, field, and glasshouse conditions. Seasons and different growing sites were considered as treatments. Treatments for all controlled trials (field and glasshouse) consisted of seasonal pruning (winter, spring, summer, and autumn). Trials were arranged using a randomized complete block design with 25 single plants as replicates per treatment. Seasonal responses revealed that winter had the highest starch (145.0 mg·g-1) in the stems and reserve carbohydrates (480.6 mg·g-1) in the roots, whereas in the roots sugar (400.6 mg·g-1) was highest in summer. The highest significant root reserve carbohydrates occurred in winter (594.6 mg·g-1) and the lowest in autumn (fall) (313.3 mg·g-1). Bush tea plants pruned during winter had the highest overall reserve carbohydrates in the stem (598.7 mg·g-1). Under glasshouse conditions, the highest dry matter production was observed in December (midsummer) (170 g per plant); while in field-grown plants in the same month dry matter production was 400 g per plant. Therefore, the best time to maximize production of bush tea is during the spring and summer seasons.