Effect of Different Organic Fertilizers on Fruit Quality in a Pear Orchard

This study was conducted using 8-year-old 'Niitaka' (Pyrus pyriforia) pear trees to investigate the effect of different organic fertilizers on fruit quality and level of total phenolicsin a conventionally managed orchard. Trees were treated with one of five different fertilizers: 1) control (60 g of chemical fertilizer [16N-11P-12K] per tree) 2) rice bran (RB, 10 kg per tree); 3) coffee bran compost (CBC, 10 kg per tree); 4) chitin-incubated compost (CIC, 10 kg per tree); or 5) RCC (RB+CBC+CIC, 30 kg per tree). Soluble solid content, hardness, and titratable acidity were significantly higher in fruit from RCC-treated trees compared with fruit from trees exposed to other treatments. Overall, control fruit had smaller stones and lower calcium concentration than had organically fertilized fruit. Also, control fruit showed a reduced level of total phenolic compounds and lower antioxidant activity in both peel and flesh than did organically fertilized fruit. Compost-treated trees yielded fruit of enhanced edibility and with longer shelf-life owing to a reduction in stone size and increased calcium concentration, respectively. Overall, fruit from trees treated with organic fertilizers was of higher quality and had greater antioxidant levels compared with fruit from trees treated with chemical fertilizer.