TCA (cm 2 ) was calculated every year from 2004 through 2007. Yield per tree was recorded at harvest time and yield efficiency was calculated as: (total yield per tree in kg)/TCA in cm 2 . Twenty fruits were randomly sampled from each tree between 10
Esmaeil Fallahi, Bahar Fallahi, and Bahman Shafii
Sudip Kunwar, Jude Grosser, Fred G. Gmitter Jr., William S. Castle, and Ute Albrecht
-150; CAS, East Rutherford, NJ) and the average yield per tree was calculated. Yield efficiency was calculated by dividing the yield per tree (kg) by the canopy volume (m 3 ). Before harvest, a random fruit sample of 48 fruits per replicated plot was
Marisa T. Potter, Richard J. Heerema, Jill Schroeder, Jamshid Ashigh, Dawn VanLeeuwen, and Cheryl Fiore
did not take into account the overall size of the tree, so yield efficiency rating was also calculated per experimental unit. Yield efficiency (g·cm −2 ) is a measure of tree nut weight per square centimeter of trunk cross-sectional area. For yield
Mark V. Coggeshall
a range of commercially important nut traits, including precocity, percent kernel, nut bearing habit, anthracnose tolerance, season length, and yield efficiency. Based on phenological and morphological descriptor data, a series of control pollinated
Thomas J. Tworkoski and D. Michael Glenn
Competitive effects of different grass species were evaluated on growth, yield, leaf N, and leaf water potential of 8-year-old peach [Prunus persica (L.) Batsch.] trees and on weed abundance. Two cultivars (`Loring' on Lovell rootstock and `Redhaven' on Halford rootstock) of peach trees were planted in separate orchards in 1987. Nine orchard floor treatments were installed beneath the peach trees in 1995: Festuca arundinacea Schreber (tall fescue); Lolium perenne L., var. Manhattan II (perennial ryegrass); Lolium perenne L., var. Linn; Agrostis gigantea Roth (red top); Dactylis glomerata L. (orchardgrass); Phleum pratense L. (timothy); Bromus carinatus Hook. and Arn. (brome); weedy control; and herbicide weed control (simazine, glyphosate). In general, grasses reduced vegetative growth and yield in both cultivars. Orchardgrass was one of the most competitive species and reduced vertical water sprout length by 15% to 27% and lateral shoot length on fruit-bearing branches by 19% to 30% compared with herbicide treatments. Orchardgrass reduced yield by 37% and 24% in `Loring' and `Redhaven', respectively. All grasses were not equally competitive; `Linn' perennial ryegrass did not significantly reduce growth or yield in `Redhaven'. Control treatments with weeds also did not differ from herbicide treatments in peach tree growth and yield. Grass and weed ground covers consistently reduced peach tree leaf N by at least 10%, compared to herbicide treatment, possibly due to reduced root growth. `Redhaven' root density in the top 10 cm of soil was ≈12 cm·cm-3 in herbicide strips vs. 1 cm·cm-3 in weedy or ground-covered strips. Peach leaf water potential was not affected by grass and weeds. Weed weights were significantly reduced by all grasses compared with weedy control. The results indicate that peach cultivars respond differently to grass competition, but the relative competitiveness of each grass species was similar for both cultivars. Grass competition reduced growth, yield, and pruning weights of mature peach trees, but the reduction in vegetative growth did not significantly reduce pruning time per tree. Grasses that are less inhibitory to peach yield may be useful for weed management in orchards.
Michele R. Warmund
late spring frosts, low yield efficiency, high labor costs associated with hand harvesting, and lack of long-term research in the United States. There are relatively few nurseries producing grafted Chinese chestnut trees and tree costs are high ($16 to
Jose A. Yuri, Claudia Moggia, Carolina A. Torres, Alvaro Sepulveda, Valeria Lepe, and Jose L. Vasquez
clear pattern among cultivars ( Table 8 ). Although M.M.106 rootstocks delivered higher yields, the yield efficiency of M.9 EMLA trees was significantly higher (with some exceptions) as a result of smaller TCAs ( Tables 6 and 7 ). When fruit size
M. Lenny Wells
kernel, pecan tree yield efficiency, and alternate bearing. Materials and Methods Study site, experimental design, and soil sampling. Studies were conducted at the University of Georgia Ponder Research Farm located near Tifton, GA, at lat. 31°51′N and
J.L. Anderson, D.R. Walker, and T. Lindstrom
A `Montmorency' sour cherry planting was established on 20 clonal rootstocks in April, 1987, as part of the NC-140 cherry rootstock trial. After 5 seasons scion/rootstock combinations showed a 2.5-fold range in trunk circumference. During the fifth season there was a 6-day range in bloom date, a 4-fold range in growth rate, a 7.5-fold range in yield and a 3-fold range in yield efficiency as influenced by rootstock. Trees on GM 9 were the smallest, had the lowest yields, smallest fruit and were among the lowest in yield efficiency. Mahaleb has been the standard cherry rootstock in Utah. Rootstocks whose trees were comparable or exceeded those on mahaleb in both yield and yield efficiency during the fifth season included 148-1, 196-13 and M×M 2. Differences were also observed in root sucker tendency.
Wilbur Reil, David Ramos, and Ronald Snyder
Three selections from different bud sources of Bartlett pear were planted in a split block experiment grafted to five rootstocks in 1971. In 1992 and 1993, significant yield and yield efficiency differences occurred between the three selections. The highest yielding selection produced 51 and 40% greater weight then the lowest. The lowest yielding selection also had smaller fruit and lower soluble solids.
Differences of 37 and 52% occurred between the highest and lowest yielding rootstocks. There were also significant differences in trunk cross sectional area, yield efficiency. fruit pressure and soluble solids between rootstocks.