Effects of split application of nitrogen on yield and quality of pineapple

With farmers confused by frequency of split fertilization status, this research was carried out to study the effects of frequency of N fertilizer application on yield and quality of pineapple. Ananas comosusr cv. Yellow Mauritius and N 400 kg/ha as a fixed rate which is the farmers traditional fertilization rate were selected for the study. It was designed as single application, splitting in 2 equal dosages during the slow and accelerating growth stages, splitting in 3 applications with N 80, 200 and 120 kg/ha during the slow, accelerating and fast growth stages, splitting in 4 applications with N 80, 70, 150 and 100 kg/ha during the slow, accelerating, fast growth stages and before the forcing stage, respectively. The contrast was no N fertilization. The aim was to study effects of increasing frequency of split application on weight, yield and quality of pineapple fruits. The results show that the splitting in more than 2 applications significantly improve leaf chlorophyll contents, carotenoid contents, leaf weights, plant weights, fruit weights and yields of pineapple, and pineapple fruit weights and yields both have the increased trends with the increase of the fertilization frequency. With the splitting in more than 2 applications, a single fruit would be increased by more than 10%. The splitting in 4 applications improves pineapple yield significantly compared with the single application. However, the qualities of the pineapple are different. The titratable acidity, sugar content and vitamin C content have downward trends when adding the N fertilization frequency, and the vitamin C content reduction is most obvious and is decreased by 14%-26%. This study concludes that frequency of the splitting application should be more than 2 to achieve high yields. On the contrary, it should be less than 2 to maintain good fruit quality. The research provides a reference for farmers engaged in pineapple cultivation.