A study on the mineral nutrient accumulation properties and use efficiency in different pineapple varieties

Abstract:【Objectives】China has good diversity of pineapple cultivars. However, cultivation of pineapple is based on management which is basically the same across different cultivars. The unreasonable fertilization strategy and the shortage of diverse variety structure has become the most important restricting factor in the development of pineapple industry in China. The aim of the present work was to compare nutrient accumulation properties and use efficiency in different pineapple varieties under the same fertilization regime so as to provide theoretical and practical references for nutrient management and selection of best pineapple varieties in Hainan province. The biomass production and mineral accumulating properties and fertilizer efficiency nutrients in different pineapple varieties were examined.【Methods】Four pineapple cultivars were used as materials, namely‘Tainong No.17' (‘TN17') , ‘Tainong No.11' (‘TN11') , ‘DelMonte Gold' (‘MD-2') , and‘Smooth Cayenne' (‘SC') . A field plot experiment was conducted in Hainan Wanzhong breeding farm which belongs to Jianfeng town in Ledong county. At maturity, all plants were harvested to record yield of each plot. Meanwhile, whole plant samples were obtained by uprooting and roots washed with tap water, and the biomass of each part was determined. The contents of N, P, K, Ca, and Mg in different parts were measured. Fertilizer contribution rate (FCR) , the nutrient agronomic efficiency (AE) , partial factor productivity (PFP) , and apparent recovery efficiency of applied nutrient (RE) in the four varieties of pineapple were compared.【Results】 (1) In the non-fertilization treatment, the average pineapple yield was 30.09 t·hm^-2. Fertilization significantly increased dry matter accumulation and yield for all the pineapple varieties.‘SC'had the highest dry matter production and yield, which were36.98 t·hm-2and 55.73 t·hm^-2, respectively, with a yield increment of 21.93 t·hm^-2 (64.88%) compared to the non-fertilization treatment. The percentage of yield increase was 57.37% in‘MD-2', followed by46.96% in‘TN17'and 31.72% in‘TN11'. The order of the dry matter accumulation in the four pineapple varieties was‘SC'>‘MD-2'>‘TN17'>‘TN11'. (2) The dry matter of leaves was higher than the other plant parts in all varieties. A significant positive relationship was observed between the whole plant dry matter and yield across pineapple varieties and the linear regression equation was y=1.529 8x-0.056 8, R2=0.902**. (3) For production of 1 000 kg fruit (NRF) , ‘MD-2'needed the highest amount of total nutrients (26.47 kg per 1 000 kg) , followed by‘TN17' (25.91 kg per 1 000 kg) .‘MD-2'had higher requirements especially for N, K and Mg. The absorption amount of various nutrients was in the order of K>N>Ca>P>Mg. (4) FCR was low for each pineapple variety, with an average value of 33%;‘SC'and‘MD-2'had a relatively higher FCR, being 39.32% and 36.41%, respectively. (5) ‘SC'had the highest AE (10.39kg·kg^-1) and PFP (20.70 kg·kg^-1) , and its AE was 78.22%, 143.32%, and 19.70% higher compared to‘TN17', ‘TN11'and‘MD-2', respectively. (6) RE of P fertilizer was the lowest in each pineapple variety, with an average value of 11.94%, and‘TN11'had the lowest value (7.24%) ;‘MD-2'had higher RE for N and K fertilizers while‘SC'had higher RE for P and Ca fertilizers;‘TN17'had an average level of RE for all the nutrients tested. (7) ‘MD-2'had the best economic benefit, with a net profit of435 986.3 Yuan·hm-2, being 76.05%, 135.76%, and 102.18% higher compared to‘TN17', ‘TN11'and‘SC', respectively; the greatest ratio of output to input was 3.92∶1 from MD-2 as well.【Conclusion】Compared with the traditional varieties under Hainan conventional fertilizer condition, ‘MD-2'pineapple has higher yield, higher RE and higher economic profit.‘TN17'is another new variety with higher NRF and medium FCR. The single cultivar of pineapple has been unable to meet the needs of consumers, and extending pineapple industry. The development of new valuable cultivars is urgent. Among the new cultivars, ‘MD-2'and‘TN17'meet the market demands and display good productivity. In conclusion, understanding the pineapple variety characteristics and the development of scientific fertilization management are important for achieving higher yield and higher commercial and environmental benefits.