A Growth Model to Estimate Shoot Weights and Leaf Numbers in Tea

Abstract

Increases in plant weight are strongly correlated with the amount of solar radiation that the plants receive. However, tea (Camellia sinensis) growth models are limited in their ability to integrate solar radiation into the predictions. In this study, we developed a predictive model for estimating tea shoot weights based on solar radiation and air temperatures. We combined information on daily solar radiation and daily air temperature to estimate the dry weight and fresh weight of a shoot in a tea crop. In addition, the range of shoot weights and leaf numbers could be estimated based on weather records. The estimated dry weight increases per unit of solar radiation for air temperatures of < 15, 15–17, 17–19, 19–21, 21–23, 23–25, 25–27, 27–29, and >29°C were 0.043, 0.074, 0.075, 0.334, 0.480, 0.283, 0.122, 0.079, and 0.028 g MJ–1, respectively. The model results suggest that the estimated shoot weights were highly correlated with the observed weights for both dry weight (r = 0.75, p < 0.001) and fresh weight (r = 0.79, p < 0.001). The estimated fresh weight ranges of shoots having two to six leaves were 0.31–3.48, 0.16–3.53, 0.44–5.60, 0.66–6.74, and 2.09–9.91 g, respectively. This study provided a statistical procedure that can be used to estimate the growth of tea crops for agricultural researchers. The results provide a means of assessing production and planning harvesting dates for tea farmers in Taiwan. Core Ideas A method to predict the weight of tea shoot was developed using field investigations. Data of solar radiation and air temperature were used to estimate shoot weights. The highest dry weight increases to solar radiation was 0.48 g MJ–1 at 21 to 23°C. The estimated weight range of shoots can be used to schedule dates for shoot plucking.

Effects of plant density on the aboveground dry matter and radiation-use efficiency of field corn

“…High maize yields tend to be obtained under conditions of relatively low temperature and high solar radiation [15]. Theoretically, crop yields can therefore be improved by enhancing radiation-use efficiency (RUE) [16,17], a parameter used to quantify the relationship between solar radiation and biomass production, which is the input basis for growth and yield models [18,19]. Several studies with regards to climate change and RUE have been reported recently [20][21][22].…”

Temporal variation of the relationships between rice yield and climate variables since 1925

“…In addition, cultivars used in the early period of the experiments are no longer cultivated today. It is also difficult to thoroughly account for other factors that may affect crop growth, such as soil fertility, insects, disease, and plant density ( Altieri & Nicholls, 2003 ; Chen, Yamagishi & Kishino, 2014 ; Chen et al, 2019 ; Chen, 2019 ; Li, Dai & Chen, 2022a , 2022b ); as well as for human-induced effects, such as improving technology, modern management, and differences in practices of cultivators ( Chen, 2018 , 2019 ), especially for over nine decades of observations. Nowadays, climate change also includes the increasing frequency of extreme climatic events, which results in frequent agricultural meteorological disasters.…”

A Temperature-Dependent Model for Tritrophic Interactions Involving Tea Plants, Tea Green Leafhoppers and Natural Enemies

“…Briefly, the coefficient for temperature-driven effect ( TF ) can be expressed as: where T 0 denotes the optimal temperature on tea growth. Following the work by Chen et al [ 23 ], T 0 was set to be 23 °C, and β was estimated to be 20 °C. The temperature-dependent tea growth rate can then be expressed as: …”

“…Temperature is a determinant factor and has significant impact on processes related to ecological community, particularly predator–prey or consumer–resource interactions [ 20 , 21 ]. For example, the growth rate of crops, the oviposition, and the lifespan of pests can be altered by temperature [ 22 , 23 ]. For predator–prey systems, variations in temperature usually have a nonlinear effect on the short-term interaction strength by regulating the foraging and attack rates of predators [ 24 ].…”