In situ earthworm breeding in orchards significantly improves the growth, quality and yield of papaya ( Carica papaya L.)

• Published in: PeerJ (San Francisco, CA) CA), 2016-12, Vol.4, p.e2752-e2752, Article e2752
• Main Authors: Xiang, Huimin, Zhang, Jia-En, Guo, Lei, Zhao, Benliang
• Format: Article
• Language: English
• Subjects: Agricultural Science; Ascorbic acid; Carica papaya; Caricaceae; Cattle; Composting; Crop yields; Earthworm in situ breeding; Ecology; Electrical conductivity; Fertilizer application; Food quality; Fruits quality; Growth; Manures; Oligochaeta; Orchards; Organic farming; Organic fertilizers; Papaya; Plant breeding; Plant growth; Soil fertility; Soil Science; Sugar; Total yield; Transplantation; Urea; Worms
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.2752

The aim of this study was to compare the effects of four fertilizer applications-control (C), chemical fertilizer (F), compost (O), and in situ earthworm breeding (E)-on the growth, quality and yield of papaya ( ). In this study, 5 g plant urea (CH N O, %  = 46.3%) and 100 g plant microelement fertilizer was applied to each treatment. The fertilizer applications of these four treatments are different from each other. The results showed that the E treatment had the highest growth parameters over the whole growth period. At 127 days after transplantation, the order of plant heights from greatest to smallest was E > F > O > C, and the stem diameters were E > F > O > C, with significant differences between all treatments. Soluble-solid, sugar, vitamin C, and protein content significantly increased in the E treatment. In addition, the total acid and the electrical conductivity of the fruit significantly decreased in the E treatment. Fruit firmness clearly increased in the O treatment, and decreased in the F treatment. The fresh individual fruit weights, fruit numbers, and total yields were greatly improved in the F and E treatments, and the total yield of the E treatment was higher than that in the F treatment. In conclusion, the in situ earthworm breeding treatment performed better than conventional compost and chemical fertilizer treatments. Furthermore, in situ earthworm breeding may be a potential organic fertilizer application in orchards because it not only improves the fruit quality and yield but also reduces the amount of organic wastes from agriculture as a result of the activities of earthworms.