scholarly journals SOME FACTORS AFFECTING ORANGE FRUIT SPLITTING OF WASHINGTON NAVEL ORANGE UNDER KAFERELSHIKH CONDITIONS. B- THE EFFECT OF CLIMATIC CONDITIONS AND FRUIT POSITION ON THE TREE CANOPY.

2016 ◽  
Vol 7 (3) ◽  
pp. 339-342
Author(s):  
Somaia El-Sayed
2017 ◽  
Vol 38 (1) ◽  
Author(s):  
Vardis E. Ntoukakis ◽  
Fayek B. Negm ◽  
Carol J. Lovatt

Author(s):  
A. A. EL- Khwaga ◽  
F. M. Abd El- Latif ◽  
M. H. M. Baiea ◽  
S. F. EL- Gioushy

This research was conducted during seasons 2018 & 2019 on nine-years-old Washington navel orange trees. These trees were grafted on Sour orange rootstock, planted at 5 x 5 meters apart, under surface irrigation conditions, in a private orchard at Manzala village, Toukh region, Qalubia Governorate, Egypt. The seven treatments were used for comparison as follows: T1-100% of chemical NPK (NPK fertilization program adopted at 5, 3 and 1 kg/tree from (NH4)2SO4, superphosphate and K2SO4, respectively) according to the Ministry of Agriculture Recommendation (Control or recommended doses RD). T2-RD+Calcium boron 2 cm3 /L; T3-RD+Calcium boron 3 cm3/L; T4-RD+Carpox-K 1g/L; T5-RD+Carpox-K 1.5g/L; T6-RD+Calcium boron 2 cm3 /L +Carpox-K 1g/L, and T7-RD+Calcium boron 3 cm3/L +Carpox-K 1.5g/L.  The main goal of this investigation was directed towards increasing Washington navel orange fruit quality. The obtained data revealed that all investigated treatments increased fruit quality parameters (physical and chemical properties). However, T7- RD + Calcium boron 3 cm3 /L + Carpox-K 1.5g/L was statistically superior. On the contrary, T1- Control or recommended doses (RD) ranked statistically the lowest treatment in this concern. From the obtained results, It can be concluded that the use of RD+ Calcium boron 3 cm3 / L + Carpox-K 1.5g / L or RD+ Calcium boron 2 cm3/ L + Carpox-K 1g / L could be safely recommended under similar environmental and horticultural practises adopted in this experiment.


2020 ◽  
Vol 19 (3) ◽  
pp. 15-24
Author(s):  
Saied Kamel Mohamed Abd El-Naby ◽  
Abdel Monem Ahmed Mohamed Esmail ◽  
Mohamed Hemdan Mohamed Baiea ◽  
Osama Abd El-Fattah Amin ◽  
Amr Abdelkhalek Ahmed Mohamed

High temperature stress can be detrimental to plants, resulting in reduced fruit yield and increased incidences of fruit disorders. One strategy that farmers can use to maintain or increase their yields in the face of a changing climate is to adjust of farm climate by using shade net on the trees. Such, the use of shade netting on Washington navel orange planted on the sandy soil in Al-Nubaria region, Egypt were studied during two successive seasons, either using a permanent shade throughout all the season or using a moveable shade for certain period from the first of March until the end of June for every season. Growth (No. of shoots/one meter branch, No. of leaves/shoot, shoot length and chlorophyll content of the leaves, leaf area and tree canopy), macronutrients (N, P, K, Ca, Mg) and micronutrients (Fe, Zn, Mn, Cu, Na) content in the leaves, fruit characteristics (number, weight, diameter, peel thickness, total soluble solids, total acidity and ascorbic acid), yield and crop efficiency, were determined. It can be concluded that covering Washington navel orange trees grown on sandy soil with shade net especial covering the trees for certain period was very effective at protecting orange trees and led to improve the growth, increase the yield and maintain fruit quality.


1969 ◽  
Vol 85 (3-4) ◽  
pp. 143-149
Author(s):  
Félix M. Román-Pérez ◽  
Agenol González-Vélez

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.


2002 ◽  
Vol 42 (4) ◽  
pp. 495 ◽  
Author(s):  
M. T. Treeby ◽  
R. Storey

Albedo breakdown is a rind disorder of orange fruit that results in significant economic cost to the Australian citrus industry. The effectiveness of calcium sprays as a control measure for albedo breakdown of navel orange fruit was investigated in a series of experiments in which single fruit, 1 m2 quadrats of tree canopy or whole trees were treated with different calcium sprays. Repeated spraying (24×) of single Bellamy navel orange fruit throughout the season with 1% calcium solutions increased the proportion of unaffected fruit from 30 to 65-80%. Repeated applications (15×) of 1% calcium as CaCl2 and Ca(NO3)2 to quadrats increased the proportion of unaffected fruit from 43 to 70-95%. The effect of anion was in the order Ca(NO3)2 CaCl2 >CaCO3. Repeated spraying (15×) of a commercial CaCl2 formulation (Stopit) at a calcium concentration of 0.33% increased the proportion of unaffected fruit in quadrats from 17 to 47%. Generally, early and mid-season calcium sprays were equally effective and tended to be marginally better than late-season sprays. Spray-applications of calcium at a concentration of 0.33% were more effective than calcium sprays at 0.11% applied early in the season. Calcium sprays were less effective than gibberellic-acid sprays based on the number of sprays but calcium treatments did not affect rind quality characteristics such as rind colour; in contrast, gibberellic acid induced regreening of fruit. Calcium sprays (as CaCl2) applied early in the season at 0.33% caused unacceptable fruit drop. CaCl2 (0.33%�calcium) treatment (5×) resulted in leaf chloride concentrations as high as 100 mmol/L in leaf-tissue water (0.7% on dry weight basis) - a level sufficiently high to substantially reduce photosynthesis. Ca(NO3)2 is the preferred calcium source in citrus because it is (i) as or more effective than CaCl2, (ii) does not result in leaf damage and fruit drop and (iii) may provide a small controlled nitrogen supplement to leaves and fruits.


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