Effects of the Diphenylurea Cytokinin CPPU and the Auxin 3,5,6-TPA on Washington Navel Orange Yield,Fruit Size and Quality
California produces picture perfect navel oranges (Citrus sinensis) for the fresh fruit market. A high yield of commercially valuable large size fruit of good quality is required yearly to sustain the California citrus industry. N-2-chloro-4pyridinyl-N-phenylurea (CPPU), a diphenylurea-type cytokinin, and 3,5,6-trichloro-2-pyridyloxyacetic acid (3,5,6-TPA), an auxin, were tested for their ability to increase yield of commercially valuable large size navel orange fruit (6. 9 -8. 8cm transverse diameter). Commercially bearing 24-yearold Washington navel orange scion on Carrizo citrange rootstock (C. sinensis X Poncirus trifoliata) was used in the research. CPPU 20 and 25g active ingredient (a. i.)per ha and 3,5,6-TPA (18.5,28,and 37g a. i./ha) were applied in 1869L of water (pH 5.5)per ha with a high pressure (2.76MPa) handgun sprayer to the foliage of 15 individual trees per treatment at 10％ anthesis in the southwest tree quadrant,75％ petal fall in the northeast tree quadrant or maximum peel thickness (MPT) (CPPU) and when fruit averaged 24mm transverse diameter or at MPT (3,5,6-TPA) in a randomized complete block design, including untreated trees that served as the control. Averaged across the 2 years of the experiment,all CPPU treatments,except 20g/ha applied at MPT, reduced total yield and yield of commercially valuable large size fruit. Leaf phytotoxicity was observed on 20％ to 30％ of the canopy of all trees treated with CPPU before MPT. CPPU applied at 25g/ha at 10％ anthesis or at 20 and 25 g/ha at 75％ petal fall increased juice weight and juice volume per fruit by December, but decreased total soluble solids. Averaged across the 2 years of the experiment,3,5,6-TPA had no effect on total yield or yield of commercially valuable large size fruit,with the exception that 3,5,6-TPA (18. 5g/ha) applied when fruit averaged 24mm in diameter reduced the yield of fruit with transverse diameters less than 6. 9cm and increased the yield of fruit 6.9 to 7. 4cm in diameter both as fruit weight and number of fruit per tree. Application of 3,5,6-TPA (37 g/ha) when fruit averaged 24mm in diameter increased juice weight and juice volume per fruit by November,without decreasing total soluble solids.
Citrus sinensis Phytotoxicity Plant growth regulators
Yusheng Zheng Toan Khuong Leslie Summers Anita Weng Carol J. Lovatt
Dept. of Botany and Plant Sciences, University of California, Riverside, CA 92521 USA
国际会议
11th International Citrus Congress(第11届国际柑橘大会)
武汉
英文
528-537
2008-10-01（万方平台首次上网日期，不代表论文的发表时间）