Effect of balanced fertilizers on pineapple yield and quality in Guangxi
IPNI-2008-CHN-GX10
09 Jan 2009
2008 Annual Interpretive Summary
Effect of Balanced Fertilization on Pineapple Yield and Quality in Guangxi, 2008
Pineapple is a major fruit for the southern regions of Guangxi Province. The region’s higher rainfalls of up to 2,000 mm/year contribute to high yields, but also lead to a high potential for nutrient loss through leaching. This project’s objective is to find optimal (OPT) fertilizer rates for improved fruit yield and quality and minimal nutrient loss. Thirteen treatments tested four rates of N (0, 330, 495, and 660 kg/ha), four rates of P (0, 150, 300, and 450 kg P2O5/ha), four rates of K (0, 225, 450, and 675 kg K2O/ha), Mg at 30 kg MgO/ha, B at 2.25 kg borax/ha, and Zn at 3 kg zinc sulfate. The OPT treatment, based on soil testing and preliminary research, was set at 495-300-450-30 kg N-P2O5-K2O-MgO/ha.
Yields responded to N, P, and K application and reached a peak yield of 51 t/ha under the OPT. Yields were lower under the two lowest N rates, the three lowest P rates, and the two lowest K rates. Removing Mg from the OPT also resulted in a significantly lower yield. Addition of Zn or B along with the OPT improved yield only marginally, which implies that critical values for these micronutrients need to be adjusted since soil testing did indicate existing deficiencies.
Agronomic efficiency (kg fruit increase per kg added nutrient) for the macronutrient application rates ranged from 7.5 to 13.7 kg fruit/kg N; 14.2 to 22 kg fruit/kg P2O5; and 12.4 to 18.5 kg fruit/kg K2O. Tissue analyses found very minor portions of P and K in the fruit at maturity as 65% of both were stored in the stem and up to 30% of P and K were stored in the bud. Up to 77% of N, Ca, and Mg was found in the stem, 21% in the bud, and the remainder was stored in the fruit. Pineapple stems are a large source of potential nutrient supply to succeeding crops if properly utilized. Guangxi-BFDP-08