Responses of Phosphorus Applications in Two Cultivars of Thailand’s Dwarf Yard-Long Beans

Phosphorus (P) fertilizer applications have been determined to greatly improve the growth and yield of dwarf yard-long beans. If the plants receive an insufficient amount of P, growth and yield may be reduced. We conducted a pot experiment to investigate the responses of two cultivars of dwarf yard-long beans (KKU25 and CLGC30), and the effects of the application of P fertilizer (0 and 150 kg/ha) on the growth, yield, nutrient values, P uptake and partitioning after harvesting in two soil series [Tha rua (Tr) and Ayutthaya (Ay) soil]. Our results demonstrated that the application of P fertilizer in soil with low available P (Tr soil) produced a significant difference in the yield and yield component of the plants. Pod tissue was an important source of P in the plants at maturity. The results also showed that over 40% of P was accumulated in the pod tissue. The CLGC30 variety showed higher total P uptake in plant tissue than that of the KKU25. It was also found that the application of P fertilizer gave a higher total P uptake than the control. Above-ground biomass (AB) and above-ground P content (APC) were significantly affected by cultivar with the application of P fertilizer. CLGC30 with applied P fertilizer produced higher AB and APC values than that of KKU25 without the application of P fertilizer. Consequently, the application of P fertilizer for dwarf yard-long bean production is recommended for the application of soil with low available P.