Tsn-RNA Dwarfing and High Density Planting of Citrus on Poncirus trifoliata Rootstock
Citrus trifoliate rootstock (Poncirus trifoliata) interaction with Transmissible Small Nuclear-RNA IIIb (Tsn-RNA IIIb, syn. Citrus Viroid IIIb) reduces tree canopy volume and enhances fruit size of Valencia orange (Citrus sinensis). A replicated field trial of Parent navel orange (C. sinensis) on trifoliate rootstock with Tsn-RNA IIIb in two planting densities, either, standard (6 m×6. 7 m) or high (3 m×6. 7 m) was established in order to; a. Determine effects of the transmissible agent and planting density on the yield and/or fruit quality and b. Evaluate the commercial potential for increase production per land surface and/or reduced grove management costs. Tsn-RNA IIIb significantly reduced the canopy volume of the navel orange on the trifoliate rootstock by an average of 44％ and 53％ on the standard and high density planting respectively (ANOVA, P <0. 05). Total yield (kg) of six to eight years old trees was not significantly different between the two planting densities of the dwarfed trees or the controls. However, the high density planting block had an increased yield over the standard planting and the controls by 66％ and 11％ respectively. Total yield of nine to eleven years old trees of the control block was significantly higher than the Tsn-RNA dwarfed standard planting block (ANOVA, P < 0. 05 ). On the contrary, the yield of the control block was not significantly different from the Tsn-RNA dwarfed high density planting block. Total yield of the high density planting block was significantly higher than the standard planting of the Tsn-RNA dwarfed trees (ANOVA, P < 0. 05 ). Fruit grade (i. e. fancy or choice) , and size (i. e. California packing house standards) of the dwarfed trees were not significantly different between the two planting densities or the controls for the past six years. An 18％ -35％ increase of the fruit production per canopy volume (kg/m3) and a 5％ - 10％ increase in the higher commercial value fruit (i. e. fancy grade and large size) were determined for the Tsn-RNA dwarfed navel trees. The differences in yield and fruit quality among the TsnRNA and plant density treatments translate to substantial profits for a commercial grove when combined with the reduced management demands (i. e. irrigation, fertilization, and harvesting cost).
Poncirus trifoliata rootstocks Tsn-RNA Dwarfing High density planting
Georgios Vidalakis John A. Bash Joseph S. Semancik
Department of Plant Pathology and Microbiology, 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
1024-1029
2008-10-01（万方平台首次上网日期，不代表论文的发表时间）