Zanthoxylum armatum (Z. armatum) leaves represent more than 50% of by-products with promising potential applications, and there are still largely unknown variations in chemical composition and antioxidant activity in its leaves. In the present study, the changes in carbon (C), nitrogen (N) and phosphorous (P), soluble protein (SP), amino acid (AA), soluble sugar (SS), total phenol (TP) and total flavonoids (TF) content as well as antioxidant capacity in Z. armatum leaves from two plant ages between two shoot types and three leaf positions were investigated. Our results showed that there are significant effects of plant age, shoot type and leaf position and their interactions on almost all the tested parameters. Shoot types were the main factor affecting the accumulation of chemical compositions and antioxidant capacity, followed by leaf positions and plant ages. Shoot type and leaf position had stronger effects than plant age. Statistical analysis revealed a series of correlations between antioxidant capacity, TP and chemical elements. Z. armatum leaves, an agricultural by-product, showed significant differences in chemical composition and antioxidant activity in response to plant age, shoot type and leaf position, which can be valuable to incentive its cultivation management strategy and its better utilization for economic and environmental benefits.

Light and soil environments have extensive heterogeneity for many plants species affecting plant growth, reproduction, and distribution. However, the interaction effects of these two factors on the ecophysiological traits and adaptive strategy of plants remain largely unclear. In the present study, we set four shading levels and three soil types to investigate the effects of shade and soil type on seedlings growth, C:N:P stoichiometry responses, and nutrient use efficiency in Firmiana simplex (F. simplex). The maximum of total biomass was observed in acid purple soil under 75% shade, with a maximum difference of 3.6 times. With the increase in shading intensity, C content in the root, stem, and leaf reached maximum value under 75% shade. However, C content in the root and N content in the stem reached a maximum value of 420.6 g·kg−1 and 13.7 g·kg−1 in acid purple soil, respectively. With the increase in shading intensity, the total C and N accumulation showed a trend of progressive increase and then decrease, reaching the maximum value of 346.2 mg and 10.7 mg under 75% shade, respectively. The N:P ratios of various organ ranged from 3.1 to 11.9 in acid purple soil and red soil, indicating that the seedlings growth was restricted by nitrogen. We concluded that the interactions of shade and soil types might adjust the C:N:P stoichiometry and influence the dynamic balance between nutrients and organs in F. simplex seedlings.

Abelmoschus manihot L. (A. manihot) has received more and more attention due to its potential edible and medicinal value. It shows higher yield and related fine agronomic traits suitable for disadvantaged areas and low-input planting. However, a systemic description of the phenological growth stages of A. manihot, an alternative, multipurpose crop of worldwide interest, does not exist. This study aims to detail the phenological growth stages of A. manihot based on the BBCH scale. Nine principal growth stages were described from seed germination to senescence, along with 69 secondary growth stages, including germination, leaf development, formation of side shoots, primary stem elongation, inflorescence emergence, flowering, fruit development, maturation of fruit and seed, and senescence. However, the morphology and structure of A. manihot become complex with growth, and some growth stages, like inflorescence development, flowering, fruit development, and fruit maturation, overlap totally or partially with each other. Thus, the three-digit scale is considered necessary for a complementary description of these growth stages and illustrations for clarification. Moreover, the unique morphology and structure features of the pistil, stamen, and ovary and the development process of fruits and seeds were described in detail at different stages. The basic and extended BBCH scales will add new information on defining and identifying A. manihot phenological growth stages. They will help farmers efficiently schedule and manage A. manihot cultivation and improve knowledge dissemination among growers and researchers.