Effect of hedging on the productivity of Valencia orange trees

1978 ◽  
Vol 18 (93) ◽  
pp. 591 ◽  
Author(s):  
KB Bevington ◽  
PE Bacon
Keyword(s):  
Yield Loss ◽  
New South ◽  
Fruit Size ◽  
Alternate Bearing ◽  
Cumulative Yield ◽  
Irrigation Districts ◽  
South Wales ◽  
Valencia Orange ◽  
Row Space ◽  
Orange Trees

The effect of hedging on the productivity of 9- and 17-year-old Valencia orange trees was studied in two trials located in inland irrigation districts in New South Wales. At both sites the trees were double planted in north-south rows, and were hedged on their east and west sides in spring 1969 and again in late spring 1973, at two levels of severity. Light hedging (0.2-0.3 m of canopy removed from each side of the tree) was effective in restricting tree spread into the inter-row space without adverse effects on yield. With light hedging the yield loss in the first season was recovered by increased production in the second season after hedging. More severe hedging caused a significant reduction in cumulative yield. By timing the hedging to coincide with the setting and early development of a potential heavy crop the extent of alternate bearing was reduced. There were no consistent effects of hedging on fruit size.

Evaluation of rootstocks for Marsh and Davis grapefruit in the Murray Region of New South Wales

1990 ◽  
Vol 30 (3) ◽  
pp. 405 ◽  
Author(s):  
KB Bevington ◽  
BR Cullis
Keyword(s):  
Fruit Quality ◽  
Production Efficiency ◽  
Sweet Orange ◽  
New South ◽  
Fruit Size ◽  
Trifoliate Orange ◽  
Cumulative Yield ◽  
South Wales ◽  
Canopy Volume ◽  
Troyer Citrange

The influence of 5 rootstocks (Parramatta sweet orange, trifoliate orange, Troyer citrange, Appleby Smooth Seville and Somersby Smooth Seville) on the productivity and fruit quality of Marsh and Davis grapefruit was studied over 15 years in the Lower Murray region of New South Wales. Annual yields of mature trees and cumulative yield were highest on Troyer citrange; cumulative yield was lowest on trifoliate orange. Canopy volume was largest on Troyer citrange and smallest on trifoliate orange. Production efficiency (fruit yield per unit of tree size) was significantly greater on trifoliate orange than all other rootstocks. Canopy volume was 44% smaller on trifoliate orange than on Troyer citrange, but cumulative yield was only 26% lower. Because of their small size and high production efficiency, trees on trifoliate orange would be suitable for high density plantings. Trifoliate orange produced the best quality fruit. Fruit from trees on trifoliate orange had the highest total soluble solids (TSS) and TSS :acid ratio. Sweet orange and Appleby Smooth Seville produced the least acceptable fruit due to low TSS :acid ratios. Fruit size was largest on Troyer citrange and trifoliate orange. Trees on trifoliate orange accumulated excessive chloride (Cl-) during periods of high irrigation water salinity; however, no adverse effects on growth or long-term productivity were apparent. Leaf C1- concentrations for trifoliate orange varied from 0.42 to 1.10%. Leaf C1- concentrations remained below 0.30% for the other rootstocks. There were no significant effects of scion cultivar on tree size, yield or production efficiency, and differences in fruit quality were slight. Fruit size was larger with Marsh than Davis.

Effects of bunch trimming and double bunch covering on yield of bananas during winter in New South Wales

1996 ◽  
Vol 36 (2) ◽  
pp. 229 ◽  
Author(s):  
GG Johns
Keyword(s):  
Average Length ◽  
New South ◽  
New South Wales ◽  
Fruit Size ◽  
Double Covering ◽  
Finger Length ◽  
South Wales ◽  
Commercial Plantation

Bunch trimming (removal of male bud and several distal hands from bunches soon after flowering), and double covering (use of 2 bunch covers simultaneously) of banana bunches that emerge during winter in northern New South Wales could have the potential to increase the size, and hence grade and price of harvested fruit. Consequently bunches were either trimmed to 6, 8 or 10 hands or left untrimmed (male bud retained), and either single or double bunch covers were applied on a commercial plantation on 3 occasions during winter, and the effects on fruit size and quality were recorded. Bunch emergence to bunch harvest interval was reduced by an average of 5 days by bunch trimming. Finger length increased with increasing severity of bunch trimming, with the average length for the top 6 hands increased by 2.3% (P<0.01) for the 10-hand treatment to 6.1% (P<0.001) for the 6-hand treatment. Finger weight increased with increasing severity of bunch trimming, with weights for the top 6 hands increased by up to 14% (P < 0.001) on the 6-hand treatment. Double covering increased finger weight of the top 6 hands by 4% (P < 0.01). Trimming to 10, 8 and 6 hands increased the yield per bunch of extra large grade fruit by 18, 23 and 39% respectively. Double covering did not affect the yield of extra large fruit significantly. After excluding hands suffering from the mixed ripe condition, the 6-hand treatment yielded 51% more marketable extra large fruit than untrimmed bunches. Potential profitability of the treatments depended on price scenario. When prices were low the 6-hand treatment appeared most profitable, but at higher prices the 10-hand treatment would be preferable. Double covering appeared not to be worthwhile for all price scenarios used.

Tolerances of wheat cultivars to pre-emergence herbicides

1985 ◽  
Vol 25 (4) ◽  
pp. 922 ◽  
Author(s):  
D Lemerle ◽  
AR Leys ◽  
RB Hinkley ◽  
JA Fisher
Keyword(s):  
Grain Yield ◽  
Spring Wheat ◽  
Yield Loss ◽  
New South ◽  
New South Wales ◽  
Yield Reduction ◽  
Wheat Cultivars ◽  
Yield Losses ◽  
South Wales

Twelve spring wheat cultivars were tested in southern New South Wales for their tolerances to the recommended rates and three times the recommended rates of trifluralin, pendimethalin, tri-allate and chlorsulfuron. Recommended rates of these herbicides did not affect the emergence or grain yield of any cultivar. However, differences between cultivars in their tolerances to trifluralin, pendimethalin and chlorsulfuron at three times the recommended rate were identified. The extent of the reduction in emergence and/or grain yield varied with herbicide and season, and there was also a herbicidexseason interaction. Durati, Songlen and Tincurrin were the most susceptible cultivars to trifluralin, and Teal was the most tolerant. Yield losses from trifluralin were more severe in 1979 than in 1980 or 1981. The differential between cultivars treated with pendimethalin was smaller and more variable; Tincurrin was the only cultivar with a yield reduction in more than one season. Durati, Songlen and Shortim were the only cultivars affected by chlorsulfuron. A reduction in crop emergence of a cultivar treated with trifluralin or pendimethalin did not correlate consistently with any grain yield loss, and reductions in emergence were always greater than yield loss.

Improving fruit size and packout of Late Valencia oranges with ethephon fruit-thinning sprays

1992 ◽  
Vol 32 (6) ◽  
pp. 753 ◽  
Author(s):  
RJ Hutton
Keyword(s):  
Fruit Quality ◽  
Fruit Size ◽  
High Volume ◽  
Cropping Pattern ◽  
Alternate Bearing ◽  
Fruit Thinning ◽  
Unaffected Control ◽  
Marketable Fruit ◽  
Orange Trees ◽  
Spray Treatment

This study set out to establish concentrations of ethephon sprays that could reliably thin alternate cropping orange trees in a heavy set year to improve fruit quality for fresh marketing. An optimum concentration of ethephon as a thinning agent was identified for the practical control of alternate cropping in Late Valencia oranges. A single, high volume spray of ethephon (as Ethrel, 42-60 mL/100 L water), applied in a heavy-set year at 6-8 weeks post bloom when fruitlet size was 10-15 mm diameter, induced a 15-20% reduction in fruit number. This resulted in significantly improved fruit size and marketable outturn with negligible yield penalty. In the 2 successive harvests following spray treatment, the cropping pattern remained uniform and a 14% improvement in packout (marketable fruit size <100 counts per carton) was maintained. Internal fruit quality was unaffected. Control of alternate bearing was carried forward for at least 2 seasons with relatively stable yields following a single spray treatment.

scholarly journals Large-scale Field Trials of Imidacloprid for Control of the Spined Citrus Bug

HortScience ◽  
2003 ◽  
Vol 38 (4) ◽  
pp. 555-559
Author(s):  
J. Mo ◽  
K. Philpot
Keyword(s):  
Natural Enemies ◽  
Large Scale ◽  
New South ◽  
Field Trials ◽  
Negative Effects ◽  
South Wales ◽  
Tree Canopies ◽  
Scale Field ◽  
Large Scale Field ◽  
Orange Trees

Four large-scale field trials were carried out in 2001 and 2002 in lemon orchards in south-western New South Wales to assess the suitability of imidacloprid as a replacement for endosulfan in controlling the spined citrus bug (SCB), Biprorulus bibax Breddin (Hemiptera: Pentatomidae). The results showed that imidacloprid was at least as effective as endosulfan in controlling SCB, even when it was applied at a rate corresponding to half of its discriminate dose (100% kill). The application of imidacloprid did not reduce numbers of wasps and spiders foraging in tree canopies. However, imidacloprid was more toxic than endosulfan to parasitoids of the red scale and to lacewings. These negative effects can be minimised by timing the sprays in winter, when SCB adults congregate in neighbouring orange trees and the numbers of natural enemies of citrus pests are generally low.

Energy Reserves, Reproductive Status and Population Biology of Overwintering Biprorulus-Bibax (Hemiptera, Pentatomidae) in Southern New-South-Wales Citrus Groves

1990 ◽  
Vol 38 (4) ◽  
pp. 415 ◽  
Author(s):  
DG James
Keyword(s):  
Population Biology ◽  
New South ◽  
New South Wales ◽  
Reproductive Status ◽  
Energy Reserves ◽  
Citrus Groves ◽  
South Wales ◽  
Behavioural Strategy ◽  
Large Numbers ◽  
Orange Trees

Information is presented on energy reserves, reproductive status and population biology of over- wintering Biprorulus bibax (Breddin) in southern New South Wales citrus groves. Large numbers of adult bugs overwintered in clusters on orange trees adjacent to a lemon grove at Cudgel in the Murrumbidgee Irrigation Area (M.I.A.). Clusters of up to 50 tightly packed bugs were found on single trees, and dispersed into the adjacent lemons in early October. Clustering was observed on all citrus except lemon. Overwintering bugs were non-reproductive. Individuals obtained from overwintering clusters at Dareton in Sunraysia were larger, heavier and contained greater lipid reserves than bugs which overwintered alone. These differences did not occur in cluster and non-cluster bugs from the M.I.A. Bugs overwintering on lemons in the M.I.A. weighed less and contained lower reserves of lipid than did individuals which overwintered on orange, mandarin and grapefruit. Lipid reserves of B. bibax were not greatly depleted during overwintering. Overwintering in clusters on citrus hosts other than lemon appears to be an important and successful behavioural strategy for B. bibax in commercial citrus groves in southern New South Wales.

The effect of Alar on vegetative growth and fruiting behaviour of three varieties of apples in the Central Tablelands of New South Wales

1968 ◽  
Vol 8 (33) ◽  
pp. 450 ◽  
Author(s):  
Margaret A Oldham ◽  
WJ Greenhalgh
Keyword(s):  
Succinic Acid ◽  
Vegetative Growth ◽  
Shoot Growth ◽  
Fruit Set ◽  
New South ◽  
New South Wales ◽  
Fruit Size ◽  
Growth Retardant ◽  
Apple Varieties ◽  
South Wales

Trials were conducted in three successive years to test the response of Granny Smith, Jonathan, and Delicious apple varieties to Alar (succinic acid 2, 2-dimethyl hydrazide) applied at various times and concentrations. The results confirmed overseas reports of reduced shoot growth, increased fruit set, reduced fruit size, reduced pre-harvest drop, and, in some cases, increased blossoming the following spring. The Jonathan variety was less responsive to the growth retardant than Delicious, which was, in turn, less responsive than Granny Smith.

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