Effects of planting distances on production by Washington Navel orange

1983 ◽  
Vol 23 (123) ◽  
pp. 437 ◽  
Author(s):  
PT Gallasch

A field experiment with four planting distances of Washington Navel orange on Sweet Orange rootstocks was planted at Loxton, South Australia, in 1963. Trees were 7.3 m apart between rows and 7.3 (normal), 5.5, 4.4 and 3-7 m apart within rows. At six years the yield per hectare from trees planted at 3.7 m was 121% greater than from those planted at 7.3 m. At 14 years, closely planted trees had continued to outyield those more widely spaced even though they were slightly reduced in width. Cumulative yield per hectare from 3.7 m plantings after 14 years was 150 t (68%) more than from 7.3 m plantings and this fruit was worth $18 000 when calculated on the average return to growers in 1981.

2020 ◽  
Vol 5 (1) ◽  
pp. 243-251
Author(s):  
Akira Horibata ◽  
Tsuneo Kato

AbstractA total of 145 accessions of the genus Citrus and related genera, maintained in the Conservation Garden for Citrus Germplasm at the Experimental Farm of Kindai University, Yuasa, Wakayama, Japan, were examined for their phylogenetic relationships. The present classification was conducted using an inter-retrotransposon amplified polymorphism (IRAP) method based on the insertion polymorphism of a retrotransposon, CIRE1, identified in C. sinensis. The objective of this study was to evaluate the applicability of the IRAP method for citrus classification. The constructed dendrogram showed that the 145 accessions and two outgroup species were successfully classified into five major clades. A large number of C. sinensis accessions were divided into three traditional groups, navel orange, sweet orange, and blood orange, almost corresponding to the sub-clades in the dendrogram. Several other accessions belonging to the same species, and also many hybrid cultivars from crossbreeding, were localized into the respective sub-clades or near positions in the dendrogram. Several unclassified accessions could also be located in the dendrogram, suggesting novel relationships with other accessions. It was concluded that the IRAP method based on CIRE1 insertion polymorphism was suitable for the classification of citrus from a molecular point of view.


1927 ◽  
Vol 18 (3) ◽  
pp. 135-142
Author(s):  
A. D. SHAMEL ◽  
C. S. POMEROY ◽  
R. E. Caryl

1975 ◽  
Vol 15 (72) ◽  
pp. 136 ◽  
Author(s):  
MC Stannard ◽  
JC Evans ◽  
JK Long

Washington navel orange trees on trifoliate orange rootstocks were inoculated at various ages with budwood from either severely dwarfed Washington navel trees with butt scaling caused by exocortis virus or moderately dwarfed Marsh grapefruit trees with no butt scaling. Dwarfing, measured by trunk girth, became apparent four seasons after inoculation, the butt scaling inoculum causing more pronounced dwarfing than the non-scaling inoculum. For both inocula, trees inoculated in the nursery were the most dwarfed, and yielded least, with trees inoculated in the field one, two, three or five years later being successively less dwarfed and high yielding. In a second experiment, Washington navel orange trees on trifoliate orange, which were carrying exocortis virus or were inoculated with it either in the nursery or later in the field, were planted in 1962 at a density of 835 ha-1. The field inoculated trees subsequently grew larger than the others. All were more dwarfed but yielded more heavily on a ground area basis during five years of cropping than exocortis-free trees planted at a normal density of 222 ha-1. Dwarfed trees developed butt scaling symptoms and periodically became unthrifty. The non-scaling form of dwarfing lends itself to the development of high density plantings of small trees with consequent benefits in management and high early production


1989 ◽  
Vol 40 (2) ◽  
pp. 371 ◽  
Author(s):  
H Howie ◽  
J Lloyd

Flowering, fruit set and fruit growth of 'Washington Navel' orange fruit was monitored on 24-year-old Citrus sinensis trees on Sweet orange rootstocks that had been irrigated with either 5 or 20 mol m-3 NaCl for 5 years preceding measurements.Trees irrigated with high salinity water had reduced flowering intensities and lower rates of fruit set. This resulted in final fruit numbers for trees irrigated with 20 mol m-3 being 38% those of trees irrigated with 5 mol m-3 NaCl. Final fruit numbers were quantitatively related to canopy leaf area for both salinity treatments.Despite little difference between trees in terms of leaf area/fruit number ratio, slower rates of fruit growth were initially observed on high salinity trees. This effect was not apparent during the latter stages of fruit development. Consequently, fruit on trees irrigated with 20 mol m-3 NaCl grew to the same size as fruit on trees irrigated with 5 mol m-3 NaCl, but achieved this size at a later date. Measurements of Brix/acid ratios showed that fruit on high salinity trees reached maturity standards 25 days after fruit on low salinity trees.Unimpaired growth of fruit on high salinity trees during summer and autumn occurred, despite appreciable leaf abscission, suggesting that reserve carbohydrate was utilized for growth during this period. Twigs on high salinity trees had much reduced starch content at the time of floral differentiation in winter. Twig starch content and extent of floral differentiation varied in a similar way when examined as a function of leaf abscission. This suggests that reduced flowering and fruit set in salinized citrus trees is due to low levels of reserve starch, most of which has been utilized to support fruit growth in the absence of carbohydrate production during summer and autumn.


2012 ◽  
Vol 3 (8) ◽  
pp. 2335-2345
Author(s):  
Thanaa Ezz ◽  
M. Aly ◽  
Ekbal Ahmed ◽  
M. Khalaf

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