12 Jan 2016
Banana quality and yield affected by optimal rates and of ratios of nitrogen and potassium fertilizers in Guangdong
Differing from many other crops, banana is a crop that needs sufficiently higher amount of potassium (K) than nitrogen (N) to obtain best yield and quality. Besides fertilization rates, the ratio of K: N is the key factor to determine banana growth and yield, and thus proper ratio of K: N plays an important role in banana production.
A field experiment, aimed to explore the effect of different ratio of K: N on banana growth, yield and quality, was conducted at a banana orchard located in Dingtang village, Baoguang town, Gaozhou city, Guangdong province. The experiment consisted of four rates of N (0, 228, 555, 832.5 kg N /ha) and four rates of K (0, 306, 610.5, 916.5 kg K2O/ha). All treatments received the same rates of P (165kg P2O5/ha). The fertilizers used were urea for N, single superphosphate (SSP) for P, and potassium chloride (KCl) for K. All fertilizers were split to seven times, including one basal, three topdressings at vegetative stage and three topdressings at reproductive stage. 20% of N ,15% of K and 50% of P were applied before stage of flower bud differentiation, and 45% of N,55% of K and 30%of P were applied before budding stage, and then 35%, 30% and 20% of N, K and P were applied after budding stage.
The results showed at the same level of K, banana yield increased with an increase in N rates and topped at 555 kg N/ha (Table1). This same trend was also observed for N rates and the highest yield obtained at 615kg K2O/ha (data not shown in this Table). The highest fruit yield was obtained at the optimal ratio of N: K but soluble sugar varied with K:N ratios, which was not related to K but to N. Regression analysis indicated that the OPT for banana of this experiment was 570kg N/ha and 705 kg K2O/ha, with a K2O:N ratio of 1.25, resulting in the highest yield and economic profit.
| Table 1 Banana yield, quality and profit as affected by different rates of N and K | ||||
| Fertilization rate(kg/ha) | Yield | Soluble sugar | Economic profit | |
| N | K2O | （Kg/ha） | （%） | （$/ha） |
| 0 | 610.5 | 9450d | 18.1c | 549 |
| 228 | 610.5 | 35100ab | 18.1abc | 18528 |
| 555 | 610.5 | 37620a | 20.2ab | 20132 |
| 832.5 | 610.5 | 34560ab | 18.8bc | 17745 |
| The price for fertilizers and banana ($) N 0.71$/kg, K2O 0.77 $/kg, banana 0.67$/kg.1$=6.48 yuan. | ||||
