Abstract

Arabica coffee is an important crop in many regions of Thailand, particularly in highland areas with cool climates. However, environmental factors such as sunlight, humidity, and temperature play a crucial role in the growth and development of coffee plants. The amount of sun received by coffee plants affects photosynthesis and overall growth. Therefore, the objective of this experiment was to evaluate the differences in agronomic characteristics of Arabica coffee plants grown under different environmental conditions: in open areas, in shade, and the area between open space and shade. The experiment was conducted in the highlands of Loe Tor Subdistrict, Mae Ramat District, Tak Province. The experiment involved surveying and randomly collecting data on the agronomic characteristics of coffee plants, including plant height, canopy width, trunk diameter, and the number of coffee cherries per branch. The results showed that the average values of these characteristics were differed, indicating that environmental conditions influence the growth of coffee plants. When analyzing the data using standard deviation, it was found that coffee plants grown in semi-shaded areas had the lowest variation, meaning they exhibited more uniform growth than those grown in open spaces or under full shade. The results of this experiment show that growing coffee in semi-shaded areas is a suitable approach. It promotes balanced growth and may contribute to higher yields in the long term. This information is valuable for farmers select to optimize their cultivation methods and management of shade trees to enhance productivity and efficiency.