Growth, yield and preliminary selection of seedling guavas in Queensland

1981 ◽  
Vol 21 (108) ◽  
pp. 119
Author(s):  
KR Chapman ◽  
B Paxton ◽  
J Saranah ◽  
PD Scudamore-Smith

Five guava seedlines of Hawaiian origin, namely GA9-37, GA12-1 6, GA10-48, GA11-56 and GA9-39 were yield tested in coastal sub-tropical south-eastern Queensland. The work demonstrated that seedling guavas produce attractive yields comparable with overseas countries. First crop mean yields were 30.72 kg/tree after 18 months in the field, demonstrating the precocious bearing of the guava. Yields for second and third cropping years were 45.6 and 77.9 kg/tree. These yields equate to 24.7, 37.2 and 61.5 tonnes ha-1 at a planting density of 805 trees ha-1. Third crop yields give the attractive gross returns of around $15,000 ha-1, at current prices paid by processors in Queensland. No differences were found between seedlines in annual yields, accumulated crop yields, fruit Number/tree, annual yield per unit cross sectional area of butt (an index of fruitfulness) and accumulated yield per unit cross sectional area of butt. Within seedline, variability masked differential response and these aspects are discussed. Fruit yields and relative increase in butt cross sectional area of butt varied with cropping year. Fruit. number per tree and yield per unit cross sectional area of butt varied with years, as did fruit number per kg (an index of fruit size). The latter also varied with seedlines. These effects were attributed to water rationing in spring of the second crop year. Preliminary selection based on fruit quality aspects of individuals identified four individuals which are undergoing detailed processing assessment, namely GA9-39R1T2, GA11-56T7, GA11-56R5T2 and GA1 1-56R5T1. Two further individuals were selected for fresh fruit market testing, namely GA11-56T3 and GA11 -56R1T1. We believe that market development rather than horticultural problems to be overcome will dictate the success of the guava as a crop for Australia, since the guava is comparatively easy to grow and manage.

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 792F-793
Author(s):  
James R. Schupp

To evaluate the interactions between cultivar and rootstock, four apple (Malus domestica Borkh.) cultivars, `Pioneer Mac', `Marshall McIntosh', `Ginger Gold', and `Empire' on two rootstocks, M.26 and Mark, were planted in a split-plot design. After 5 years, `Pioneer Mac' and `Ginger Gold' had larger trunk cross-sectional area (TCSA) on M.26 than on Mark. `Marshall McIntosh' and `Empire' had larger TCSA on Mark than on M.26. Precocity, expressed as both number of flower clusters and yield, was greater for trees on Mark for all cultivars except `Ginger Gold', which had greater flower cluster numbers and yield on M.26. Fruit size was variable from year to year, depending on crop load; however, `Pioneer Mac' and `Ginger Gold' usually produced the largest fruit, while `Empire' consistently produced the smallest fruit—'Ginger Gold' appears to be incompatible on Mark. The results of this study demonstrate that cultivar × rootstock interactions can be significant and need to be considered when rootstock and planting density recommendations are made.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 539g-539
Author(s):  
Raouel Cano-Medrano ◽  
Rebecca L. Darnell

Exogenous applications of GA, have induced pathenocarpic fruit set in blueberry; however, size of GA,-treated fruit is smaller than pollinated fruit. The small fruit size in GA3-treated fruit may be related to either cell number and/or cell size. Thus, these parameters were examined throughout development in pollinated, non-pollinated and GA3-treated fruits. Fruit growth followed a double sigmoid pattern. During Stage I (0-25 DAA), fruit size in GA,-treated, pollinated, and non-pollinated fruits averaged 0.33, 0.39, and 0.16 g, respectively. There was little change in fruit size in Stage II (25-45 DAA). At ripening, fruit size averaged 1.7 g for GA,-treated and 2.6 g for pollinated fruits. Non-pollinated fruit abscised in Stage II. At anthesis, mesocarp cell number averaged 9910 cells per median cross sectional area and remained constant up to ripening. In Stage I, cell size in G A3-treated and pollinated fruits increased 7X and 9X respectively. Cell size in both fruit types increased 1.5X and 2.8X during Stage II and Stage 111, respectively. Fruit cell number was set at anthesis and differences in fruit size were due to differences in cell ellongation in Stage I.


HortScience ◽  
2017 ◽  
Vol 52 (9) ◽  
pp. 1233-1240 ◽  
Author(s):  
James R. Schupp ◽  
H. Edwin Winzeler ◽  
Thomas M. Kon ◽  
Richard P. Marini ◽  
Tara A. Baugher ◽  
...  

Pruning is the cutting away of vegetation from plants for horticultural purposes. Pruning is known to reduce apple tree size, increase fruit size and quality, and decrease yield. Methods for studying the effects of varying degrees of severity of pruning on a whole-tree basis have used qualitative descriptions of treatments rather than repeatable whole-tree quantitative metrics. In this study, we introduce a pruning severity index calculated from the sum of the cross-sectional area of all branches on a tree at 2.5 cm from their union to the central leader divided by the cross-sectional area of its central leader at 30 cm from the graft union. This limb to trunk ratio (LTR) was then modified by successively removing the largest branches of ‘Buckeye Gala’ to achieve six severity levels ranging from LTR 0.5 to LTR 1.75, with lower values representing more extreme pruning with less whole-tree limb area relative to trunk area. Pruning treatments were applied for three consecutive years and tree growth and cropping responses were observed for the first 2 years. With increasing pruning severity the following characteristics increased after seasonal growth: number of renewal limbs, number of shoots, shoot length, number of shoot leaves, shoot leaf area, final fruit set, fruit size, yield of large fruit, crop value from large fruit, soluble solids, and titratable acidity. The following characteristics decreased: limb age, number of secondary limbs, number of spurs, number of spur leaves, spur leaf area, the ratio of spur leaf area to shoot leaf area, fruit count per tree, yield, yield efficiency, crop value from small fruit, overall crop value, and sugar:acid ratio. The LTR provides a measurable way to define and create different levels of pruning severity and achieve consistent outcomes. This allows a greater degree of accuracy and precision to dormant pruning of tall spindle apple trees. The use of the LTR to establish the level of pruning severity allows the orchard manager to set crop load potential through regulation of the canopy bearing surface. This metric is also a necessary step in the development of autonomous pruning systems.


1992 ◽  
Vol 117 (3) ◽  
pp. 380-383 ◽  
Author(s):  
Amy F. Iezzoni ◽  
Colleen A. Mulinix

Yield components were measured from 115 sour cherry (Prunus cerasus L.) hybrid seedlings from 13 full-sib families to investigate the potential of breeding for increased yield. Those families with the highest number of fruit and reproductive buds had the highest yields. In general, increased fruit size was not able to compensate for low fruit count. Fruit set and flower count per bud were inversely related, suggesting compensation between these two components. Yield components from six selections chosen for differing fruiting habits were measured for an additional 2 years. In year 1, those selections with a majority of their fruit on l-year-old wood had higher yield efficiencies (yield per branch cross-sectional area) than those with fruit on spurs; however, but year 3, the higher-yielding selections were those that fruited primarily on spurs. The data are discussed relative to selecting for yield in a sour cherry breeding program.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 481C-481
Author(s):  
Terence L. Robinson ◽  
Warren Stiles

A field experiment was established in 1993 in a 3-year-old `Empire'/M.9 apple orchard. An incomplete factorial treatment design compared nitrogen only fertilization with nitrogen plus potassium fertilizer applied either on the ground with and without trickle irrigation or through the trickle irrigation system. Timing of potassium fertigation treatments compared season-long K fertigation to early season or late-season K fertigation. Results of main effects showed that K fertilization reduced trunk cross-sectional area increase, but increased yield, fruit size, and fruit red color. There was no benefit of fertigation compared to ground application of fertilizers plus trickle irrigation. There was no effect of source of K fertilizer (KCl vs KNO3) on tree growth, yield, fruit size, or color. Time of K fertigation showed that late-season K fertigation resulted in greater trunk cross-sectional area increase compared to early season fertigation or season-long fertigation. Fruit size was greatest when K fertigation was done in the early season. There was no effect of time of fertigation on yield or fruit red color. Potassium fertilization increased leaf K levels and reduced leaf Mg levels. Time of fertigation did not affect leaf K levels, but early season fertigation resulted in higher leaf N levels.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 886A-886
Author(s):  
Preston K. Andrews ◽  
Margaret L. Collier

Effects of crop load and time of thinning on productivity of young `Fuji'/M.9 apple trees were tested by hand blossom (B) or fruit (F) thinning to two crop densities (fruit number/trunk cross-sectional area). Heavy (H) crop densities resulted in higher yields in both 2nd and 3rd leaf than light (L) crop densities. Time of thinning had no effect on yields in either year. In the 2nd leaf, fruit size was largest from trees B thinned to L crop densities, and smallest from trees F thinned to either crop density from mid-June through harvest. Both 1° and 2° vegetative growth were greatest in noncropped trees, intermediate in trees with L crops, and least in trees with H crops. Noncropped 2nd-1eaf trees had the highest flowering indices (flower clusters/100 total buds) the following spring and H cropped trees had the lowest. The flowering index was higher when trees were B thinned in the 2nd leaf than when F thinned. In the 3rd leaf, fruit size was largest when borne on weak upright shoots, intermediate on spurs, and smallest on 1-year-old terminal wood. Fruit on spurs had the highest incidence of sunscald (17%) and fruit on weak upright shoots the lowest (8%). Previous-season crop densities affected current-season's vegetative and fruit growth.


1969 ◽  
Vol 49 (6) ◽  
pp. 655-658 ◽  
Author(s):  
R. G. Ross ◽  
A. D. Crowe ◽  
R. P. Longley

A five-year study was conducted on the effect of captan, dodine and dichlone on the performance of mature McIntosh apple trees. There were no significant differences in yield, trunk cross-sectional area, amount of bloom, fruit size and fruit color. Dodine injured 0.5% of the fruit in one year of the test and pre-cover sprays of dichlone caused some fruit russeting. The results indicate that any harmful effect of dichlone on yield occurs from pre-cover applications, or pre-cover followed by cover sprays.


1988 ◽  
Vol 68 (4) ◽  
pp. 1177-1183
Author(s):  
F. KAPPEL ◽  
H. A. QUAMME

Two rootstock plantings, with Bartlett and Harvest Queen as scion cultivars, were planted in 1976 and 1977 to compare a number of Old Home × Farmingdale (OH × F), Pyrus communis L., clonal rootstocks with Quince A, Cydonia oblonga L. (Buerre Hardy interstock), and Bartlett seedling rootstocks. Many of the Bartlett trees died because of infection by fire blight whereas very few Harvest Queen trees have died. Trunk cross-sectional area was affected by rootstock with OH × F 69 producing the largest trees and Quince A or OH × F 333 the smallest trees. Annual yield was affected by rootstock with OH × F 69 and OH × F 87 having the highest per tree yields. Mean fruit size of Harvest Queen was greater on Quince A, OH × F 69 and OH × F 87 whereas, OH × F 333 produced the smallest fruit. OH × F 51 had the best yield efficiency (accumulated yield/trunk cross-sectional area), followed by OH × F 69 and OH × F 87. Predicted per hectare yields and optimum tree densities were calculated and discussed.Key words: Pyrus communis, Old Home × Farmingdale rootstock, accumulated yield, trunk cross-sectional area


HortScience ◽  
1993 ◽  
Vol 28 (6) ◽  
pp. 616-617 ◽  
Author(s):  
Stephen C. Myers ◽  
Andrew King ◽  
Amy T. Savelle

Mature `Winblo'/Lovell peach [Prunus persica (L.) Batsch] trees in Georgia were treated with five concentrations of D-88, a 79 % to 82 % active ingredient formulation of monocarbamide dihydrogensulfate: 0 (water only), 2.5, 5.0, 7.5, and 10.0 ml·liter-1. All treatments were made by airblast application at 1200 liters·ha-1 when trees were at 95% full bloom. The number of flowers on three limbs per tree was counted 3 days before and fruitlets 25 days following treatment. Regression analysis revealed a linear thinning response to concentration, with 10.0 m1·liter-1 reducing the number of flowers per limb cross-sectional area by 56% over the nonthinned control. Mature `Fantasia' nectarine trees in New Zealand were treated with four concentrations of D-88: 0 (water only), 2.5, 3.75, and 5.0 ml·liter-1. All treatments were made by handgun application to runoff when trees were ≈2 days past full bloom. The number of flowers per limb was counted 6 days before and fruit 62 days following treatment. Regression analysis revealed a linear thinning response to concentration, with 5.0 ml·liter-1 reducing the number of flowers per limb by 55 % over the nonthinned control. Total yield (kilograms of fruit) per tree was the same for all treatments, although fruit size on sprayed trees was larger. No phytotoxicity or fruit finish injury was observed.


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