scholarly journals Structural Basis of the Rind Disorder Oleocellosis in Washington Navel Orange (Citrus sinensis L. Osbeck)

2002 ◽  
Vol 90 (6) ◽  
pp. 765-773 ◽  
Author(s):  
T. G. KNIGHT
Keyword(s):  
Citrus Sinensis ◽  
Structural Basis ◽  
Navel Orange ◽  
Washington Navel

Response of orchard 'Washington Navel' orange, Citrus sinensis (L.) Osbeck, to saline irrigation water. II. Flowering, fruit set and fruit growth

1989 ◽  
Vol 40 (2) ◽  
pp. 371 ◽  
Author(s):  
H Howie ◽  
J Lloyd
Keyword(s):  
Leaf Area ◽  
Citrus Sinensis ◽  
Fruit Set ◽  
High Salinity ◽  
Starch Content ◽  
Fruit Growth ◽  
Leaf Abscission ◽  
Navel Orange ◽  
Washington Navel ◽  
Floral Differentiation

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.

Response of orchard 'Washington Navel' orange, Citrus sinensis (L.) Osbeck, to saline irrigation water. I. Canopy characteristics and seasonal patterns in leaf osmotic potential, carbohydrates and ion concentrations

1989 ◽  
Vol 40 (2) ◽  
pp. 359 ◽  
Author(s):  
J Lloyd ◽  
H Howie
Keyword(s):  
Leaf Area ◽  
Irrigation Water ◽  
Osmotic Potential ◽  
Citrus Sinensis ◽  
Soluble Sugars ◽  
Seasonal Patterns ◽  
Navel Orange ◽  
Washington Navel ◽  
Leaf Osmotic Potential ◽  
Chloride Concentrations

Effects of irrigation water salinity on tree canopy volume, leaf area, rates of leaf abscission and production, as well as seasonal patterns in leaf osmotic potential (=), starch, soluble sugars and sodium and chloride concentrations were determined for 24-year-old 'Washington Navel' orange trees (Citrus sinensis [L.] Osbeck) on sweet orange (C. sinensis) rootstock. Trees had been irrigated with water containing either 5 or 20 mol NaCl m-3 for 5 years prior to measurements.Trees irrigated with 20 mol NaCl m-3 had a greater number of vegetative flushes in spring. This occurred at the expense of flowering, as numbers of reproductive and mixed flushes were reduced by salinity. Despite a high number of vegetative buds on trees irrigated with 20 mol NaCl m-3, leaf area was still less than low salinity trees.Extensive abscission of spring flush leaves occurred from mid-summer onwards for trees irrigated with 20 mol NaCl m-3. This was not a consequence of leaf water deficit, as more negative leaf osmotic potentials resulting from increased foliar sodium and chloride concentrations resulted in maintenance of leaf turgor. Excessive concentrations of sodium and/or chloride may have been responsible for abscission observed. Some acclimation of foliage to salinity was evident.Irrespective of salinity treatment, leaf osmotic potential became more negative as the season progressed. This was partly due to increased concentrations of soluble sugars in foliage during autumn and winter. Levels of soluble sugars and starch were consistently lower in leaves on trees irrigated with high salinity water, indicating that production rather than utilization of carbohydrate may limit citrus productivity under saline conditions.

scholarly journals Growth, yield and fruit quality of 'Washington Navel' orange on four rootstocks during the first four years of production.

1969 ◽  
Vol 85 (3-4) ◽  
pp. 143-149
Author(s):  
Félix M. Román-Pérez ◽  
Agenol González-Vélez
Keyword(s):  
Puerto Rico ◽  
Fruit Quality ◽  
Citrus Sinensis ◽  
Growth Yield ◽  
Tree Canopy ◽  
Navel Orange ◽  
Washington Navel ◽  
Canopy Volume ◽  
Swingle Citrumelo

Performance of the rootstocks 'Swingle citrumelo', 'Naronja' and mandarins 'Cleopatra' and 'Sun Chu Sha' on 'Washington Navel' orange [Citrus sinensis (L.)] was evaluated at Corozal and Isabela, Puerto Rico, during the first four years of production. Mean number of fruit per tree was significantly different between locations and among rootstocks for 1996-97 and 1997- 98. Data were not taken in 1998-99 because of damage caused by Hurricane Georges. The first two years the amount of fruit was significantly higher at Corozal than at Isabela, with Swingle producing greatest fruit yield. In 1999-00 (fourth year of production) no significant differences between locations were detected for tree canopy volume. Significant differences for internal fruit quality were detected between locations and among rootstocks for acidity, brix/acidity ratio and pH. No significant differences were observed for brix between locations or among rootstocks.

scholarly journals 590 PB 138 LOW-TEMPERATURE STRESSED-INDUCED FLOWERING OF THE `WASHINGTON' NAVEL ORANGE (CITRUS SINENSIS L. OSBECK) WAS INCREASED BY APPLICATION OF PUTRESCINE OR SPERMIDINE TO THE FOLIAGE

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 516d-516
Author(s):  
Anwar G. Ali ◽  
Carol J. Lovatt
Keyword(s):  
Low Temperature ◽  
Citrus Sinensis ◽  
Temperature Treatment ◽  
Navel Orange ◽  
Flower Number ◽  
Low Temperature Treatment ◽  
Washington Navel ◽  
Orange Trees ◽  
Positive Effect

The ability of arginine (50 mM), putrescine (10 and 20 mM), and spermidine (10 and 20 mM) to enhance low temperature stressed-induced flowering of 5-year-old container-grown `Washington' navel orange trees was evaluated. The metabolites were applied to the foliage at the end of the 4-week low-temperature treatment of 8-h days at 10°C and 16-h nights at 7°C; the trees were then moved to warmer conditions. All treatments had a positive effect on floral intensity. Putrescine (20 mM) and spermidine (10 mM) significantly increased (P = 0.05) total flower number and both the number and proportion of leafless inflorescences per tree. However, the number of floral shoots per tree, as well as the number of leafy inflorescences and number of vegetative shoots were not significantly influenced by the metabolites. The results suggest that polyamines are important to the development of flowers, but not leaves, along the axis of the inflorescence.

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