Own-rooted, 4-year-old kiwifruit plants [Actinidia deliciosa (A. Chev.) C.F. Liang et R. Ferguson var. deliciosa] protected by a Styrofoam insulation wrap with a water-filled pouch (Reese clip-on trunk wrap) or by microsprinkler irrigation sustained less freeze injury than unprotected plants under field conditions at temperatures as low as -17.8C. Trunk splitting occurred on the plants, but no injury was detected on canes, buds, or shoots in the canopy of the plants. Unprotected plants had more trunk splitting and at greater heights than protected plants. New canes developed from suck- ers of cold-injured plants and developed a trellised canopy the following season.
W.A. Dozier Jr., A.W. Caylor, D.G. Himelrick, A.A. Powell, A.J. Latham, J.A. Pitts, and J.A. McGuire
D.G. Himelrick, W.A. Dozier Jr., and A.W. Caylor
Own-rooted four-year-old kiwifruit plants (Actinidia deliciosa) protected by a Reese clip-on styrofoam insulation trunk wrap, or microsprinkler irrigation, sustained less freeze injury than unprotected plants under field conditions at temperatures as low as -17.8C. Trunk splitting occurred on the plants but no injury was detected on canes, buds, or shoots in the canopy of the plants. Unprotected plants had more trunk splitting and at greater heights than protected plants. New canes developed from suckers of cold-injured plants and developed a filled canopy the following season.
Ed Stover, Scott Ciliento, and Monty Myers
In spring 1999, a commercial NAA (1-naphthaleneacetic acid) preparation for trunk sprout inhibition was compared with a corrugated plastic trunk wrap, aluminum foil wrap, bimonthly hand removal of sprouts, use of NAA preparation plus bimonthly hand removal when sprouts appeared, and a nontreated control. Three recently planted groves on three different rootstocks [`Midsweet' orange (Citrus sinensis)] on Swingle citrumelo (Citrus paradisi × Poncirus trifoliata), `Valencia' orange on Volkamer lemon (Volk, Citrus limon), and `Minneola' tangelo (Citrus paradisi × C. reticulata) on Smooth Flat Seville (SFS, Citrus hybrid) received each of the treatments in a randomized complete block experimental design with trees blocked by initial height and circumference. Every 2 months, sprouts were counted on each tree and removed from the hand removal treatments. After 1 year, all sprouts were removed and counted and height and circumference of trees was determined. Across all experiments, 82% to 100% of nontreated trees produced trunk sprouts and all sprout control methods significantly reduced sprouts per tree. NAA treatments were never significantly less effective at sprout suppression than the wraps at the P = 0.05 level, although in two experiments, wraps were more effective than NAA at P = 0.10. Time of sprout appearance varied between the three experimental blocks. Plastic and foil trunk wraps enhanced development of trunk circumference compared with nontreated controls in `Midsweet'/Swingle and `Valencia'/Volk. Greater trunk circumference resulted from use of wraps versus NAA in all three experiments, which appeared unrelated to differential sprout suppression. In these experiments, it appears that either wraps enhanced tree development beyond the suppression of sprouts or NAA influence on tree metabolism somewhat reduced trunk growth. The economics of the sprout suppression methods are also discussed.
Anne E. Connelly, Bernadine C. Strik, Jeffrey Granett, and Glenn Fisher
Grape phylloxera (Daktulosphaira vitifoliae Fitch) was studied in three infested, self-rooted, European wine grape (Vitis vinifera L.) vineyards in western Oregon. Bi-weekly sampling of infested roots at two depths (15-30 cm and 30-45 cm) was done during the growing season in 1992 and 1993. Centrifuged laboratory extractions of insects were seperated into life stages and counted. Results indicate hibernants emerged in April/May when soil temperatures varied from 8 to 21°C. Viable eggs were recovered in June/July. Alates and above ground crawlers were found on sticky trunk wraps in July/August. It appears there were three generations of phylloxera with the third being significantly smaller. Replicated laboratory colonies were reared at 5 temperatures (7, 10, 13, 16, 21 °C). Reproductive rates will be contrasted with field populations.
Sharon Inch, Ed Stover, Randall Driggers, and Richard F. Lee
). Citrus growers take preventative measures to minimize crop losses from freezes such as use of trunk wraps and water applied through elevated microsprinklers ( Bourgeois et al., 1990 ; Davies et al., 1984 ; Jackson et al., 1983 ). However, the
Timothy P. Hartmann, Justin J. Scheiner, Larry A. Stein, Andrew R. King, and Sam E. Feagely
., Wellington, New Zealand Dozier, W.A. Jr Caylor, A.W. Himelrick, D.G. Powell, A.A. 1992 Cold protection of kiwifruit plants with trunk wraps and mircrosprinkler irrigation HortScience 27 977 979 doi: 10.21273/HORTSCI.27.9.977 Ferguson, A.R. 1991 Kiwifruit