Research on the ratio and contents of N, P, K by arecanut (Areca catechu L.) leaves in different growth conditions

Aimed to analyze the content of N, P and K of betel leaves, the normal leave the ones with yellow leaf disease were collected from fruit-bearing arecanut (Areca catechu L.) with different production levels, at different growth years in Hainan. The results showed the ratio of N∶P∶K was 1∶0.081∶0.356 in arecanut leaves. The average N contents in high-yield group（HYG）were 10.45%, 21.73% and 36.86% higher than those in middle high-yield (MHYG), middle-yield group(MYG), and low-yield group (LYG), respectively. The average N contents in normal arecanut leaves (low-yield group betel) were 10.15% and 19.49% higher than those in light yellow leaf disease group (LYLDG) and in severe yellow leaf disease group (SYLDG). The average P contents in HYG were 10.71% and 13.64% higher than those in MHYG and MYG, respectively, and with 17.02% higher than those of LYG. The average P contents in normal arecanut leaves (LYG) were 10.87% and 18.48% higher than those in LYLDG and in SYLDG. The average K contents in HYG were 17.24% and 25.00% higher than those in MHYG and MYG, respectively, and with 31.96% higher than those of LYG. The average K contents in normal arecanut leaves (LYG) were 15.15% and 19.42% higher than those in LYLDG and in SYLDG; and those were 5.03% higher in LYLDG than SYLDG. The contents of N, P and K in leaves collected from arecanut at different growth years were different. The content of N in arecanut leaves was the highest, followed by K and P. The contents of N, P, K had a great influence on the arecanut production, and the yellow leaf disease had a negative impact on the arecaunut production.