Issue link: http://read.dmtmag.com/i/57720
HOW TO USE Equilifruit • To ensure that each limb is properly measured and the crop load adjusted, start at the lowest limb on the tree and systematically work up to the top of the tree. • Place the disk around the limb about an inch away from the tree trunk. • Find the notch that fits snugly around the limb. The F-value corresponding to that notch is the number of fruit that should be left on the limb after hand thinning. • Count or estimate the number of fruit on the limb and if the number of fruit is higher than the F- value, then hand thinning is necessary. • When thinning, remove injured or damaged fruit first, then small fruit, then fruit in clusters. The treatments were as follows: Control: No hand thinning treatment Equilifruit disk:Using the standard values present on the disk (F-value) Hand-thinning heuristic:Thinning fruit to 7-8 inches apart In Golden Delicious, trees thinned with the Equilifruit +(.) !%#*' #*.) !%#*' %("&$#&- )*&*' &!$!.*&, &##*"( "%$!#, !(%)& )")&"'$#- &)&# #)&#& /!-!%#*' # *-&%%'!%#*' )#'(&- $#$! %&(# had a 24 percent increase in fruit weight while maintain- ing yields comparable to the control trees. Hand thinning with the heuristic increased fruit size by 34 percent, but total yield was reduced by 30 percent. Buckeye Gala trees had a high crop load before hand thinning (10 fruit per square centimeter of trunk cross- sectional area). Both the Equilifruit and the heuristic were successful in reducing the crop load of Buckeye Gala (to around 6 and 5 fruit per square centimeter, respectively). Yields were not reduced by either hand thinning treatment. On trees in the Equilifruit treatment, 15 percent of the fruit were larger than 3 inches, compared with 12 percent in the heuristic treatment and 5 percent for the control. Neither of the hand thinning treatments affected Honeycrisp yields. However, 44 percent of the fruit from trees subjected to the heuristic thinning were greater than 3.5 inches in diameter. These large fruit are more suscep- tible to poor storage life and are prone to postharvest dis- orders. Only 12 percent of fruit from trees treated with the Equilifruit were larger than 3.5 inches in diameter. The Equilifruit had 73 percent of its fruit in the size range of 3.0 to 3.5 inches, compared with 61 percent of the control and 55 percent of the heuristic. In all cultivars, the Equilifruit did not reduce yield &(!((, 0#$) &$#+)(*.$' $!#)''(- $' )$", !%% when compared to the control, and promoted either larger fruit or a higher proportion of fruit in desirable size categories. The Equilifruit system provides some flexibility in the intensity of hand thinning, because each F-value has an accompanying delta value shown on the disk. Subtracting or adding the delta value from the F-value can intensify or reduce the thinning treatment. This provides an opportu- nity to alter hand-thinning practices based on cultivar, desired crop load, and tree age, etc. We have tested the use of the delta value to modify the intensity of thinning, and it is capable of consistently adjusting crop load to various levels. In our trials on mature trees, the use of the F-value provided the best results. We suggest that the Equilifruit is best used as a training tool for workers in the orchard. After strictly following the specifications of the disk for a few hours, the worker should be comfortable in visually relating limb size to the number of fruit that should remain. After this level of training is achieved, the workers can increase efficiency by assessing the need for fruit removal visually, using the disk only occasionally to recalibrate. The gauge can also be used by supervisors to have a consistent method of evaluating the crew's performance. • 18 MARCH 15, 2012 GOOD FRUIT GROWER www.goodfruit.com