SENSITIVITY OF FLORAL SHOOT GROWTH, FRUIT-SET AND EARLY FRUIT SIZE INACTINIDIA-DELICIOSA TO LOCAL CARBON SUPPLY

The sensitivity of pre-anthesis shoot growth, fruit set and early frui t size in kiwifruit [Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson] to cane girdling and defoliation treatments was tested, a nd the results discussed in terms of shoot carbon balance. The nature and degree of responses obtained was dependent on the time of applicat ion. When treatments were applied soon after budbreak, defoliation ini tially reduced growth, whereas increasingly severe girdling treatments induced responses progressing from stimulation to severe impairment o f growth and photosynthetic capability. Similar treatments imposed lat er in shoot development produced qualitatively different results. The development of floral tissues on the shoot is shown to be sensitive to shoot carbon status during a period close to anthesis, and the signif icance of this result in relation to fruit heterogeneity at maturity i s discussed. (C) 1998 Annals of Botany Company.