scholarly journals Citrus Red Mite Pesticide Efficacy Trials, 1995, 1996

1997 ◽  
Vol 22 (1) ◽  
pp. 69-70
Author(s):  
E. E. Grafton-Cardwell ◽  
C. A. Reagan
Keyword(s):  
Predatory Mites ◽  
Predatory Mite ◽  
San Joaquin Valley ◽  
Navel Orange ◽  
Citrus Red Mite ◽  
Single Tree ◽  
Efficacy Trials ◽  
Washington Navel ◽  
Extension Center ◽  
Orange Trees

Abstract Acaricides for control of citrus red mite were evaluated in the spring of 1995 and 1996 on ≈20 year old ‘Washington navel’ orange trees at the Lindcove Research and Extension Center, Exeter, CA. The acaricides were compared for efficacy against citrus red mite as well as their impact on populations of a predatory mite, which feeds on citrus red mite in San Joaquin Valley orchards. The acaricides were applied on 19 May in 1995; and on 8 Apr in 1996 using a Bean hand-sprayer at 300 psi and approximately 300 gpa (3^1 gal/tree). Single tree treatments were assigned based on pretreatment sampling of citrus red mite conducted on 9 May 1995 and 7 Apr 1996. Samples consisted of five leaves from the periphery of four quadrants of each tree (20 leaves per tree). The number of all active stages of citrus red mite and predatory mites per leaf were recorded weekly.

scholarly journals Citrus Cutworm Insecticide Efficacy Trials, 1997

1998 ◽  
Vol 23 (1) ◽  
pp. 64-65
Author(s):  
E. E. Grafton-Cardwell ◽  
C. A. Reagan
Keyword(s):  
Bacillus Thuringiensis ◽  
Navel Orange ◽  
Water Control ◽  
Single Tree ◽  
Efficacy Trials ◽  
Insecticide Efficacy ◽  
Washington Navel ◽  
Pre Treatment ◽  
Extension Center ◽  
Orange Trees

Abstract Two insecticide efficacy trials for the control of citrus cutworm were conducted in 1997. In the first experiment, three formulations of Bacillus thuringiensis were tested and compared with a water (check) spray in a commercial block of 32-year-old ‘Washington’ navel orange trees of Exeter Farms, Exeter, California. Applications of MYX 300, MYX 324, and CRYMAX WDG were made on 8 Apr using a Bean hand-sprayer at approximately 300 gpa, 300 psi. In the second experiment, two rates of RH-5992 70 WP and one rate of RH-2485 80WP, each combined with the surfactant Latron CS-7, and a treatment of Spinosad 2SC were compared to a water control spray in a block of 14-yr-old ‘Washington’ navel oranges at the Lindcove Research and Extension Center, Exeter, California. The applications were made on 11 Apr using the same equipment, rate, and pressure as the Exeter Farms test. In both experiments, eight replicated single-tree treatments were used and treatments were assigned on the basis on pre-treatment sampling of larvae. Larvae were collected by placing a canvas beating sheet (112 cm X 75 cm) beneath the outside foliage of the tree and vigorously shaking the foliage 10 times. Citrus cutworm larvae falling on the canvas were counted and recorded, then returned to the foliage. Pre-treatment larval counts involved sampling the Northeast and Southwest corners of the trees at Exeter Farms on 7 Apr and at Lind-cove on 4 Apr. All four tree quadrants were sampled for post-treatment larval counts on 15 Apr and 22 Apr at Exeter Farms; and on 18 Apr and 25 Apr at Lindcove.

scholarly journals Citrus Cutworm Pesticide Efficacy Trials, 1994

1995 ◽  
Vol 20 (1) ◽  
pp. 57-57
Author(s):  
E. E. Grafton-Cardwell ◽  
C. A. Reagan
Keyword(s):  
Honey Bees ◽  
Ground Level ◽  
Navel Orange ◽  
Above Ground Level ◽  
Sample Tree ◽  
Efficacy Trials ◽  
Washington Navel ◽  
Extension Center ◽  
Orange Trees ◽  
Detrimental Impact

Abstract Insecticides for the control of citrus cutworm were evaluated on 29 yr old ‘Washington navel’ orange trees at the Lindcove Research and Extension Center, Exeter, CA. The insecticide applications were made on 28-29 Apr with a Bean hand-sprayer at 450 psi and approximately 300 gpa (3—4 gal/tree). Lorsban was applied after sunset to reduce the detrimental impact of the insecticide on honey bees in the orchard. The 14 treatments were assigned based on pretreatment sampling of larvae and each of the treatments were applied to single trees, replicated 8 times. Larval collections were accomplished by placing a canvas beating sheet (112 cm × 75 cm) beneath the outside foliage of the tree and vigorously shaking the foliage 10 times. Citrus cutworm larvae which fell onto the canvas were counted and recorded by instar, then returned to the foliage. Pretreatment larval counts were made on 20 Apr by sampling the northeast and southwest quadrants of each tree. Post treatment counts were made on 9 May by sampling all four quadrants of each sample tree, again recording each instar. Percentage of scarred fruit due to citrus cutworm feeding was evaluated on 7 Sept on each of the sample trees within a 2 m vertical swath around the tree beginning approximately 20 cm above ground level and extending approximately 40 cm into the tree interior. In 1994, late Apr and early May temperatures at Lindcove ranged from relatively cool to warm, with daily maximums between 61°F and 90°F (mean of 72.5°F).

scholarly journals Citrus Cutworm Pesticide Efficacy Trials, 1993

1994 ◽  
Vol 19 (1) ◽  
pp. 51-51
Author(s):  
E. E. Grafton-Cardwell ◽  
C. A. Reagan ◽  
S. L. Vehrs ◽  
A. E. Eller ◽  
J. McClain
Keyword(s):  
Honey Bees ◽  
Post Treatment ◽  
Navel Orange ◽  
Single Tree ◽  
Efficacy Trials ◽  
Pvc Pipe ◽  
Orange Trees ◽  
Detrimental Impact

Abstract Insecticides for the control of citrus cutworm were evaluated in a commercial orchard on 28 year old navel orange trees (‘Washington’ on Troyer rootstock) in Terra Bella, California. The insecticides were applied on 21 and 22 Apr when citrus cutworm larvae were first emerging. Treatment applications were made with a Bean hand-sprayer at 450 psi, and approximately 300 gal/acre (3-4 gal/tree). Lorsban was applied after sunset to reduce the detrimental impact of the spray on honey bees in the orchard. ATI 720 F (Azadirachtin) was applied with a spray adjuvant (Kinetic). Each of 19 treatments were applied to 8 single tree replications. Treatments were assigned to trees based on pretreatment levels of citrus cutworm and the insecticide applications were made to alternate trees along three rows of citrus. All larval collections were accomplished by placing a canvas beating sheet (112 cm × 75 cm) under the outside foliage of the tree and vigorously striking the foliage with PVC pipe. Citrus cutworm larvae which fell on the canvas were counted and recorded by instar, then returned to the foliage. Pretreatment citrus cutworm larvae counts were made on 20 Apr by sampling the northwest and southeast quadrants of the tree. Post treatment counts were made on 29 Apr and 5 May by sampling all four quadrants of the tree, again recording each instar. Percentage of scarred fruit due to citrus cutworm feeding was evaluated on 1 Sep on each experimental tree within a 2 meter swath around the tree beginning 20 cm from the ground and extending 40 cm into the tree interior. In 1993, late April and early May temperatures ranged from relatively cool to warm, with daily maximums between 70 and 91° F (mean of 82.4° F).

Effect of transmission of exocortis dwarfing factors into Washington navel orange trees

1975 ◽  
Vol 15 (72) ◽  
pp. 136 ◽  
Author(s):  
MC Stannard ◽  
JC Evans ◽  
JK Long
Keyword(s):  
High Density ◽  
Normal Density ◽  
Navel Orange ◽  
Trifoliate Orange ◽  
Four Seasons ◽  
Washington Navel ◽  
Area Basis ◽  
Early Production ◽  
Orange Trees

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

scholarly journals EFFECT OF ENRICHED COMPOST TEA ON WASHINGTON NAVEL ORANGE TREES

2009 ◽  
Vol 34 (10) ◽  
pp. 10085-10094
Author(s):  
M. Mostafa ◽  
M. El-Boray ◽  
A. Abd El-Wahab ◽  
R. Barakat
Keyword(s):  
Navel Orange ◽  
Compost Tea ◽  
Washington Navel ◽  
Orange Trees

scholarly journals The Efficiency of Calcium Boron and Carpox-K Sprays on Fruit Quality of Washington Navel Orange Trees

2020 ◽  
pp. 23-31
Author(s):  
A. A. EL- Khwaga ◽  
F. M. Abd El- Latif ◽  
M. H. M. Baiea ◽  
S. F. EL- Gioushy
Keyword(s):  
Fruit Quality ◽  
Chemical Properties ◽  
Quality Parameters ◽  
Navel Orange ◽  
Fertilization Program ◽  
Washington Navel ◽  
Orange Fruit ◽  
Physical And Chemical ◽  
Orange Trees

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.

scholarly journals Winter Application of Low-biuret Urea to the Foliage of `Washington' Navel Orange Increased Yield

1994 ◽  
Vol 119 (6) ◽  
pp. 1144-1150 ◽  
Author(s):  
Anwar G. Ali ◽  
Carol J. Lovatt
Keyword(s):  
Foliar Application ◽  
Negative Impact ◽  
Irrigation Treatment ◽  
Poncirus Trifoliata ◽  
Optimal Time ◽  
Navel Orange ◽  
Total N ◽  
Soil Application ◽  
Washington Navel ◽  
Orange Trees

The objective of this study was to test whether a single winter prebloom foliar application of low-biuret urea would increase the yield of 30-year-old `Washington' navel orange trees [Citrus sinensis (L.) Osbeck] on Troyer citrange rootstock [C. sinensis `Washington' × Poncirus trifoliata (L.) Raf.]. All trees received a winter (November to January) soil application of urea (0.5 kg N/tree). Trees were maintained under irrigation or irrigation was withheld from 1 Oct. to 1 Mar. To determine the optimal time for foliar urea application, trees in both irrigation main plots received one application of low-biuret urea in mid-November, mid-December, mid-January, or mid-February applied at a rate of 0.16 kg N/tree. There was a set of control trees that only received the soil application of urea. Trees receiving foliar-applied urea in mid-January or mid-February, independent of irrigation treatment, had significantly greater yield and fruit number per tree each year than the control trees for 3 consecutive years. The number of fruit with diameters of 6.1 to 8.0 cm increased significantly as yield increased (r2 = 0.88). Withholding irrigation from 1 Oct. to 1 Mar. had a negative impact on yield. Annual winter application of low-biuret urea to the foliage did not significantly increase leaf total N at the end of 3 years.

Salinity, Stomatal Responses and Whole-Tree Hydraulic Conductivity of Orchard 'Washington Navel' Orange, Citrus sinensis (L.) Osbeck

1989 ◽  
Vol 16 (2) ◽  
pp. 169 ◽  
Author(s):  
J Lloyd ◽  
H Howie
Keyword(s):  
Vapour Pressure ◽  
Early Morning ◽  
Bulk Water ◽  
Navel Orange ◽  
Diurnal Patterns ◽  
Stomatal Responses ◽  
Water Potentials ◽  
Washington Navel ◽  
Orange Trees ◽  
High Vapour Pressure

Diurnal patterns in stomatal conductance and bulk water potentials were measured over a 6-month period for spring flush leaves on 24-year-old Washington Navel orange trees that had been irrigated with water containing either 5 mol m-3 NaCl or 20 mol m-3 NaCl for 5 years prior to measurements. During summer and autumn, at early morning measurement times, stomatal conductances of leaves on trees irrigated with 20 mol m-3 were significantly below those on trees irrigated with 5 mol m-3 NaCl. Lower values on high salinity trees were not attributable to more negative water potentials or lower turgor pressures but were apparently due to an inability of stomata on leaves from salinised trees to open in response to low vapour pressure deficits (VPDs). There was little effect of salinity on stomatal conductances during afternoon measurements when high vapour pressure deficits prevailed. Laboratory studies confirmed that stomata on salinised trees are less responsive to VPD than those from unsalinised trees. When measurements were made during winter months there was no effect of salinity on diurnal patterns of stomatal conductances but leaf water potentials were less negative for leaves of salinised trees during daylight hours. Hydraulic conductance (G) of trees to liquid water flow was greater for trees irrigated with 5 mol m-3 NaCl in summer, but seasonal reductions in G for trees irrigated with 5 mol m-3 NaCl occurred to a far greater extent than for trees irrigated with 20 mol m-3 NaCl. This may have been a consequence of a reduction in leaf areas of salinised trees during summer and autumn without concomitant decreases in root length.

Sign in / Sign up

Export Citation Format

Share Document