control, 3 fruit/cm 2 TSCA, and both the 6 and 9 fruit/cm 2 , respectively ( Fig. 2 ). Fig. 2. Effect of flower and crop load adjustment on ‘Honeycrisp’ tree canopy volume for 2003 and 2006 ( P < 0.05, n = 4). The results indicate that
Charles G. Embree, Marina T.D. Myra, Douglas S. Nichols, and A. Harrison Wright
Tyler G. Berkey, Anna Katharine Mansfield, Steven D. Lerch, James M. Meyers, and Justine E. Vanden Heuvel
Crop load management treatments were applied to ‘Seyval Blanc’ grapevines (Vitis hybrid) as a 2 × 2 factorial design: no shoot thinning (ST)/no cluster thinning (CL) (i.e., control), ST combined with CL (ST + CL), ST only, and CL only. All treatments reduced yield and crop load (yield/pruning weight) in 2009 and had a smaller impact in 2010 due to the carryover effect of previous year treatments on crop potential. Soluble solids were improved by up to 3.2% by the ST + CL treatment in 2009, but were not impacted by treatments in the second year when the range of yield was smaller and the ripening conditions more favorable. Rank sum analysis for the 2009 vintage indicated that wines produced from the CL treatment were preferred by the sensory panel compared with the control wine, but there were no differences in consumer preference for wines produced in the 2010 season. Grower preferred price in 2009 (required to compensate the grower for labor costs and lost yield) increased from $556/t in the control to $824/t in the CL treatment, an increase which could be justified by the demonstrated consumer preference for the CL wine. Grower preferred price was $1022/t in the ST + CL treatment in 2009, a price increase that was not justified by a demonstrated consumer preference for the wine. In 2010, grower preferred price ranged from $541/t for the control to $610/t for the ST + CL treatment, an unjustified increase based on the lack of demonstrated consumer preference for the wines.
Todd C. Einhorn, Debra Laraway, and Janet Turner
%, and 23% of total yields comprised target fruit, 28.2 mm and larger, for T2, T1, and control trees, respectively. In 2009, the net effect of increasing the percentage of large fruit due to T1 crop load adjustment ( Fig. 3A ) was a higher crop value
Gerry Neilsen, Frank Kappel, and Denise Neilsen
been systematically assessed under Pacific Northwest growing conditions. Crop load adjustment has the potential to affect other cherry attributes such as soluble solids concentration (SSC), although effects are not always consistent ( Whiting et al
Kuo-Tan Li, Jim Syvertsen, and Jill Dunlop
Effects of crop load on leaf characteristics, shoot growth, fruit shape, fruit quality, and return bloom were investigated in 13-year-old `Ruby Red' grapefruit (Citrus paradisi Macf.) on `Swingle' citrumleo rootstock. Trees were hand thinned in June 2003 and 2004 at the end of physiological fruit drop to establish three to four levels of crop load ranging from normal (high crop load without thinning) to extremely low (near 90% fruit removal). Leaves on high crop load trees had higher net assimilation of CO2 (ACO2) than those on low crop load trees. Crop load enhancement of ACO2 continued until harvest. In 2004, however, the effects were diminished in October just prior to the beginning of the harvest season, after leaf and fruit loss from three consecutive hurricanes. There was no difference in leaf dry weight per leaf area and leaf nitrogen among treatments. Nonfruiting branches of high crop load trees produced fewer, but longer, summer flushes than those of low crop load trees. Fruiting branches generally produced few summer flushes with similar shoot lengths among treatments. High crop load trees developed a greater percentage of vegetative shoots, whereas low crop load trees developed more inflorescences. Crop load adjustments did not affect fruit size and total soluble solid content, but low crop load trees produced a higher percentage of irregular shape (sheepnosed) fruit with high acidity.
Duane W. Greene, Alan N. Lakso, Terence L. Robinson, and Phillip Schwallier
Previous reports have provided evidence that measuring fruit growth rate may be a viable method to predict if a fruit will abscise or persist through the June drop period. A series of experiments were carried out over several years to develop a procedure that could be used to predict the response to a chemical thinner application within 7 to 8 days after application and before thinners exhibit their final effect. The procedure developed involves tagging 105 spurs on seven individual trees distributed appropriately in the orchard. A minimum of two measurements must be made, one 3 to 4 days after application and again 7 to 8 days after application. This model requires that fruit measurement should not start before fruit grow to a diameter of 6 mm and individual fruit within a spur should be numbered and identified. The model is based on the assumption that if fruit growth rate of a particular fruit over the measurement period is less than 50% of the growth rate of the fastest growing fruit on the tree during the same growth period, it will abscise, whereas if fruit growth rate exceeds 50% of the growth rate of the fastest growing fruit, it will persist. All data can be entered into an Excel spreadsheet and the output in the summary page gives the predicted fruit set expressed as percentage of the total number of fruit present. The strategy for crop load adjustment with chemical thinners has evolved over the years to a point where most orchardists plan and are prepared to make two or more thinner applications. The dilemma associated with this approach is to determine if additional thinner applications are necessary. Up to this point a tool designed specifically to provide this information has not been developed.
storage at 13 °C; and 3) a fast process involving degreening with ethylene for up to 4 days at high temperature (30 °C). Impacts of Crop Load Adjustment in ‘Seyval blanc’ Winegrapes Shoot thinning (ST), cluster thinning (CL), and a combination of the two
James W. Olmstead, Amy F. Iezzoni, and Matthew D. Whiting
photoassimilate partitioning ( Whiting and Lang, 2004 ). In 2004, prebloom crop load adjustment was performed on ‘Bing’ and ‘Regina’ trees at WSU-IAREC to alter the canopy source–sink relations. Crop load adjustment was performed by hand thinning whole trees to
Gerry H. Neilsen, Denise Neilsen, Sung-hee Guak, and Tom Forge
grew. Crop load adjustment was made on the same trees each year using the most recent annual TCSA values with high and low crop loads alternating from year to year. Composite samples of 30 leaves were collected from the mid-third portion of the
Justine E. Vanden Heuvel, Steven D. Lerch, Celine Coquard Lenerz, James M. Meyers, and Anna Katharine Mansfield
Crop load adjustment in ‘Seyval blanc’: Impacts on yield components, fruit composition, consumer wine preferences, and economics of production HortTechnology 21 593 598 Bordelon, B.P. Skinkis, P.A. Howard, P.H. 2008 Impact of training system on vine