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Ag Briefs - September, 2012 1
Z
Table of Contents
INSECTICIDE EFFICACY AGAINST WHITEFLY IN BROCCOLI, 2011
……………………………………………………………………… Eric T. Natwick - 2 -
INSECTICIDE EFFICACY AGAINST LETTUCE INSECTS, 2011
……………………………………….……………………………. Eric T. Natwick - 6 -
INSECTICIDE EFFICACY AGAINST BROCCOLI INSECTS, 2011 …………
……………………………………………………………………… Eric T. Natwick - 9 -
IT’S TIME TO CHECK YOUR SPRINKLER SYSTEM ………Khaled M. Bali - 11 -
2012 VEGETABLE CROPS GUIDELINES ….…………………………………… - 13 -
TRAIN THE TRAINER (SPANISH) PROGRAM ……………………………….. – 14 -
SAVE THE DATE! …………………………………………………………………. – 16 -
CIMIS REPORT AND UC DROUGHT MANAGEMENT PUBLICATIONS
………………………………………......…… Khaled M. Bali and Sharon Sparks - 17 -
Imperial County Agricultural Briefs
Features
September, 2012
From your Farm Advisors
Ag Briefs –September, 2012
2
INSECTICIDE EFFICACY AGAINST
WHITEFLY IN BROCCOLI, 2011
Eric T. Natwick
The objective of the study was to evaluate the efficacy of insecticides for control of Sweetpotato whitefly
(SWF): Bemisia tabaci (Gennadius) – biotype B on broccoli under desert growing conditions. All of the
insecticides applied to broccoli in the experiment described below provided whitefly control. However,
AdmirePro applied at 10 fl oz/acre as an in-furrow injection 2 inches below the seed at-planting followed by
two Movento foliar sprays at 5 fl oz/acre on 28 Sep and 28 Oct 2011 provided superior whitefly control
compared to other treatments and provided a plant growth response greater than all other treatments except
Durivo applied at 13 fl oz/acre applied at 10 fl oz/acre as an in-furrow injection 2 inches below the seed at-
planting followed by two Movento foliar sprays at 5 fl oz/acre on 28 Sep and 28 Oct 2011.
Broccoli ‘Castle Dome’ was direct seeded on 7 Sep 2011 at the University of California Desert Research and
Extension Center, El Centro, CA into double row beds on 40 inch centers. Stand establishment was achieved
using overhead sprinkler irrigation and irrigated via furrow irrigation thereafter. Plots were four beds 13.3 ft
wide by 40 ft long and bordered by one untreated bed. Five replications of each treatment were arranged in a
RCB design. Insecticidal compounds, formulations and application rates are provided in the tables. The in-
furrow, at-planting application of AdmirePro and Durivo were injected 2 inches below the seed into the soil
using 20 gpa at 35 psi on 7 Sep 2011. All other insecticide treatments were foliar sprays applied with a Lee
Spider Spray TracTractor 4-row sprayer with three TJ-60 11003VS nozzles per row that delivered a directed
spray application at 25 psi and 50.3 gpa on 28 Sep and on 28 Oct 2011. An adjuvant, Dyne-Amic (Helena
Chemical Co.) was added at 0.1% vol/vol to each foliar spray mixture. Numbers of SWF adults were counted
on a leaf from 10 plants per plot in each replicate and data were recorded on the dates listed in Table 1.
Numbers of SWF eggs and nymphs were counted within a leaf disk of 1.65 cm2 on a basal leaf from 10 plants
per plot in each replicate and data were recorded on the dates listed in Tables 2 and 3. Plant height was
measured in cm on 22 Nov 2011 and results are shown in Table 4. Data were analyzed using ANOVA.
Differences among means on each sampling date and in each experiment were determined using Least
Significant Difference Test (P≤0.05).
The SWF population level was high when this project was started in Sep 2011, but whitefly number,
particularly adults, were twice diminished by heavy rain, hail, and high winds on 13 Sep and on 3 Oct 2011.
None of the treatments had significantly (P≤0.05) fewer SWF adults than the check on 26 Sep, except the
treatment with AdmirePro (Table 1). None of the insecticide treatments had fewer SWF adults on 5 Oct, on 18
Oct, or on 27 Oct. All insecticide treatments had significantly fewer SWF adults than the check on 31 Oct, on 9
Nov and on 18 Nov with the exception of the treatment of Durivo followed by Movento on 31 Oct.
There were no differences (P≤0.05) among the treatment for numbers of SWF eggs on 26 Sep and on 31 Oct
(Table 2). All insecticide treatments had significantly fewer SWF eggs compared to the check on 5 Oct and 18
Nov. Only AdmirePro followed by Movento had significantly fewer SWF eggs compared to the check on 18
Oct. None of the insecticide treatments had fewer SWF eggs than the check on 27 Oct. The treatment of Durivo
Ag Briefs –September, 2012
3
followed by Movento and treatment of Oberon had significantly more SWF eggs than the check on 27 Oct. On
9 Nov only the treatment of AdmirePro followed by Movento and treatment of Durivo followed by Movento
had significantly fewer SWF eggs than the check. There were no differences (P≤0.05) among the treatment for
numbers of SWF nymphs on 26 Sep (Table 3). All insecticide treatments except the Oberon treatment had
significantly fewer SWF nymphs than the check on 5 Oct and on 18 Oct. Only AdmirePro followed by Movento
had significantly fewer SWF nymphs compared to the check on 27 Oct. Only the treatments of AdmirePro
followed by Movento and Durivo followed by Movento had significantly fewer SWF nymphs compared to the
check on 31 Oct and 9 Nov. All of the insecticide treatments had significantly fewer SWF nymphs than the
check on 18 Nov. Only the insecticide treatments of AdmirePro followed by Movento and Durivo followed by
Movento had significantly taller plants than the check on 22 Nov. No phytotoxicity symptoms were observed
following any of the insecticide treatments.
Table 1.
SWF adults per leaf
Treatment Oz/acre 26 Sep 5 Oct 18 Oct 27 Oct 31 Oct 9 Nov 18 Nov
Movento 5.0 16.46 a 0.70 51.56 a 25.94 ab 17.64 c 18.10 b 12.36 c
AdmirePro*
f/b Movento
10.0
5.0 3.78 b 0.44 32.18 b 17.61 b 10.36 d 6.92 c 16.56 bc
Durivo*
f/b Movento
13.0
5.0 12.66 a 0.64 54.92 a 32.82 a 23.72 ab 8.90 c 21.36 b
Oberon 8.0 13.58 a 0.48 52.18 a 17.54 b 19.40 bc 14.26 b 16.22 bc
Check -------- 12.22 a 0.40 42.48 ab 24.04 ab 26.70 a 24.54 a 30.84 a
*Preplant injected 2 inches below seed followed by (f/b) Movento.
Means within columns followed by the same letter are not significantly different; P>0.05, LSD.
Ag Briefs –September, 2012
4
Table 2.
SWF eggs per cm2 of broccoli leaf
Treatment Oz/acre 26 Sep 5 Octz 18 Oct 27 Oct 31 Oct 9 Nov
z 18 Nov
z
Movento 5.0 205.01 36.47 bc 94.46 ab 37.41 ab 28.42 18.53 a 5.59 b
AdmirePro*
f/b Movento
10.0
5.0 129.47 18.93 c 31.68 c 29.65 b 14.46 5.58 c 1.94 c
Durivo*
f/b Movento
13.0
5.0 222.51 30.87 c 89.79 ab 43.65 a 20.46 10.18 bc 4.33 bc
Oberon 8.0 200.61 74.98 b 103.08 a 45.58 a 37.83 15.10 ab 3.44 bc
Check -------- 220.19 152.56 a 83.36 b 29.95 b 28.00 17.48 a 15.56 a
*Preplant injected 2 inches below seed followed by (f/b) Movento.
Means within columns followed by the same letter are not significantly different; P>0.05, LSD. z Log transformed data used for analysis and actual means reported.
Table 3.
SWF nymphs per cm2 of broccoli leaf
Treatment Oz/acre 26 Sep 5 Oct 18 Octz 27 Oct 31 Oct 9 Nov 18 Nov
Movento 5.0 11.07 26.46 bc 6.10 bc 71.81 a 51.18 ab 32.61 ab 20.59 b
AdmirePro*
f/b Movento
10.0
5.0 6.52 8.82 c 3.45 c 37.44 b 18.00 c 10.06 c 3.87 c
Durivo*
f/b Movento
13.0
5.0 8.25 19.10 bc 5.66 bc 62.13 a 34.06 bc 26.08 b 25.73 b
Oberon 8.0 7.62 36.99 ab 8.69 ab 59.16 a 45.75 ab 31.26 ab 14.46 bc
Check -------- 11.14 51.32 a 14.42 a 65.81 a 67.92 a 43.66 a 54.50 a
*Preplant injected 2 inches below seed followed by (f/b) Movento.
Means within columns followed by the same letter are not significantly different; P>0.05, LSD. z Log transformed data used for analysis and actual means reported.
Ag Briefs –September, 2012
5
Table 4.
Height of broccoli plants in cm
Treatment Oz/acre 22 Nov
Movento 5.0 36.36 b
AdmirePro*
f/b Movento
10.0
5.0
48.69 a
Durivo*
f/b Movento
13.0
5.0
44.14 a
Oberon 8.0 38.57 b
Untreated Check -------- 34.12 b
*Preplant injected 2 inches below seed followed by (f/b) Movento.
Means within columns followed by the same letter are not significantly different; P>0.05, LSD.
Ag Briefs –September, 2012
6
INSECTICIDE EFFICACY AGAINST LETTUCE
INSECTS, 2011
Eric T. Natwick
The objective of the study was to evaluate the efficacy of soil insecticide injections applications of for control of
worm pests (Beet armyworm (BAW) Spodoptera exigua (Hübner) and Cabbage looper (CL), Tricholusia ni
(Hübner)) and Sweetpotato whitefly (SWF), Bemisia tabaci (Gennadius) – biotype B on iceberg head lettuce
under desert growing conditions. Head lettuce (MOHAWK M.I.) was direct seeded on 7 Sep 2011 at the
University of California Desert Research and Extension Center, El Centro, CA into double row beds on 40 inch
centers. Stand establishment was achieved using overhead sprinkler irrigation, and irrigated via furrow
irrigation thereafter. Plots were four beds 16.7 ft wide by 75 ft long and bordered by one untreated bed. Four
replications of each treatment were arranged in a RCB design. Insecticidal compounds, formulations and
application rates along with treatment dates are provided the tables. The in-furrow, at-planting application of
Admire Pro and VERIMARK 20 SC were injected 2 inches below the seed in 20 gpa H2O at 35 psi on 7 Sep
2011. VERIMARK is an insecticidal compound under development by DuPont and is not registered for use on
crops in CA or USA at the time of publication. Insecticide treatment rates are listed in Table 1. Numbers of
SWF eggs and nymphs were counted within a leaf disk of 1.65 cm2 on a basal leaf from 10 plants per plot in
each replicate and data were recorded on the dates listed in Table 2. The numbers of larval worm pests (BAW
and CL) were counted and recorded form ten plants in each replicate; results are included in Table 3. Plant
growth measurements of height and diameter were measured in cm on 26 Oct and results are reported in Table
4. Data were analyzed using ANOVA. Differences among means on each sampling date and in each experiment
were determined using Least Significant Difference Test (P=0.05).
The SWF population level was high at during stand establishment but numbers were twice reduced by hail and
rain storms on 13 Sep and 4 Oct. Both of the insecticide treatments of VERIMARK 20 SC and Admire Pro had
significantly (P=0.05) fewer SWF adults than the check on 24 Oct but there were no differences among the
treatments for mean numbers of SWF adults during the first three sampling dates (Table 1). Both of the
insecticide treatments of VERIMARK 20 SC and AdmirePro had significantly fewer SWF eggs than the check
on 27 Sep and 5 Oct, but there were no differences among the treatments for mean numbers of SWF eggs on 18
Oct (Table 2). There were no differences among the treatments for SWF nymphs on 27 Sep, both insecticide
treatments had significantly fewer SWF nymphs than the check on 5 Oct and both insecticide treatments has
more SWF nymphs than the check on 18 Oct (Table 2). There were no differences among the treatments for
numbers of worm pest larvae (CL and BAW) on any of the sampling dates (Table 3). The VERIMARK 20 SC
treatment was significantly taller than the check on 26 Oct, while the AdmirePro treatment was not significantly
taller than the check nor significantly shorter than the VERIMARK 20 SC treatment (Table 4). Both of the
insecticide treatments had wider diameter of the plant canopies than the check plants.
Ag Briefs –September, 2012
7
Table 1.
SWF adults per lettuce leaf
Treatment Oz/acre 27 Sep 5 Oct 17 Oct 24 Oct
VERIMARKz 20 SC 13.6 7.25 0.10 1.95 1.20 b
Admire Pro 10.0 10.55 0.25 2.58 1.48 b
Check ---- 10.45 0.08 2.45 3.00 a
Means within columns followed by the same letter are not significantly different, ANOVA; LSD (P<0.05). zVERIMARK is an insecticidal compound under development by DuPont and is not registered for use on crops
in CA or USA at the time of publication.
Table 2.
Treatment
oz/acre
Whitefly Eggs and Nymphs on Lettuce
Whitefly Eggs per cm2 Whitefly Nymphs per cm
2
27 Sep 5 Oct 18 Oct 27 Sep 5 Oct 18 Oct
VERIMARKz 20 SC 13.6 53.73 b 13.21 b 1.80 7.70 0.68 b 0.49 a
Admire Pro 10.0 41.98 b 16.80 b 3.09 9.36 2.15 b 0.45 a
Check ---- 95.82 a 24.95 a 3.27 14.47 5.52 a 0.19 b
Means within columns followed by the same letter are not significantly different LSD; P = 0.05. zVERIMARK is an insecticidal compound under development by DuPont and is not registered for use on crops
in CA or USA at the time of publication.
Ag Briefs –September, 2012
8
Table 3.
Wormz pests per lettuce plants
Treatment fl oz/acre 27 Sep 5 Oct 17 Oct 24 Oct 7 Nov
VERIMARKx 20 SC 13.6 0.03 0.00 0.00 0.05 0.00
Admire Pro 10.0 0.08 0.00 0.50 0.35 0.10
Check ---- 0.05 0.00 0.08 0.13 0.00
Means within columns followed by the same letter are not significantly different, ANOVA; LSD (P<0.05). xVERIMARK is an insecticidal compound under development by DuPont and is not registered for use on crops
in CA or USA at the time of publication. z Worm pests were CL and BAW
Table 4.
Treatment Oz/acre Height and Diameter of Lettuce Plants in cm
Height Diameter
VERIMARKz 20 SC 13.6 11.68 a 21.95 a
Admire Pro 10.0 10.39 ab 22.25 a
Check ---- 8.03 b 18.64 b
Means within columns followed by the same letter are not significantly different LSD; P = 0.05. z VERIMARK is an insecticidal compound under development by DuPont and is not registered for use on crops
in CA or USA at the time of publication.
Ag Briefs –September, 2012
9
INSECTICIDE EFFICACY AGAINST
BROCCOLI INSECTS, 2011
Eric T. Natwick
The objective of the study was to evaluate the efficacy of insecticides for control of various insect pests {Beet
armyworm (BAW) Spodoptera exigua (Hübner), Cabbage looper (CL), Tricholusia ni (Hübner), and
Sweetpotato whitefly (SWF), Bemisia tabaci (Gennadius) – biotype B} on broccoli under desert growing
conditions. Broccoli (Castle Dome) was direct seeded on 7 Sep 2011 at the University of California Desert
Research and Extension Center, El Centro, CA into double row beds on 40 inch centers. Stand establishment
was achieved using overhead sprinkler irrigation, and irrigated via furrow irrigation thereafter. Plots were four
beds 16.7 ft wide by 75 ft long and bordered by one untreated bed. Four replications of each treatment were
arranged in a RCB design. Insecticidal compounds, formulations and application rates along with treatment
dates are provided the tables. The in-furrow, at-planting application of Admire Pro and VERIMARK 20 SC
were injected 2 inches below the seed in 20 gpa H2O at 35 psi on 7 Sep 2011. VERIMARK is an insecticidal
compound under development by DuPont and is not registered for use on crops in CA or USA at the time of
publication. Insecticide treatment rates are listed in Table 1. Numbers of SWF eggs and nymphs were counted
within a leaf disk of 1.65 cm2 on a basal leaf from 10 plants per plot in each replicate and data were recorded on
the dates listed in Table 1. The numbers of larval worm pests (BAW and CL) were counted and recorded form
ten plants in each replicate; results are included in Table 2. Data were analyzed using ANOVA. Differences
among means on each sampling date and in each experiment were determined using Least Significant
Difference Test (P=0.05).
The SWF population level was high at during stand establishment but numbers were twice reduced by hail and
rain storms on 13 Sep and 4 Oct. Both of the insecticide treatments had significantly (P=0.05) fewer SWF
adults than the check on 27 Sep but there were no differences among the treatments for mean numbers of SWF
adults 5 Oct, following a severe hail storm (Table 1). Only the AdmirePro treatment had significantly fewer
SWF adults than the check on 18 Oct. There were no differences among the treatments for SWF eggs on any of
the sampling dates. There were no differences among the treatments for SWF nymphs on 27 Sep, but both
insecticide treatments had significantly fewer SWF nymphs than the check on 5 Oct and on 18 Oct. There were
no differences among the treatments for numbers of worm pest larvae (CL and BAW) on 27 Sep, 5 Oct and 17
Oct (Table 2). The VERIMARK 20 SC treatment had significantly fewer worm pest larvae than the check on
24 Oct while the AdmirePro treatment had significantly more worm pest larvae than the check.
Ag Briefs –September, 2012
10
Table 1.
Treatment oz/acre
SWF adults, eggs and nymphs on Broccoli
Whitefly adults/leaf Whitefly eggs/cm2 Whitefly nymphs/cm
2
27
Sep
5
Oct
18
Oct
27
Sep
5
Oct
18
Oct
27
Sep
5
Oct
18
Oct
VERIMARKz
20SC
13.6 1.98 b 0.02 5.43 a 197.3 31.1 54.5 19.0 3.62 b 0.39 b
Admire Pro 10.0 1.67 b 0.02 3.01 b 96.9 30.9 41.8 17.5 4.18 b 0.91 b
Check ---- 2.81 a 0.02 5.31 a 138.1 58.0 65.0 43.4 19.74 a 2.33 a
Means within columns followed by the same letter are not significantly different LSD; P = 0.05. z VERIMARK is an insecticidal compound under development by DuPont and is not registered for use on crops
in CA or USA at the time of publication.
Table 2.
Wormz pests per 10 broccoli plants
Treatment Oz/acre 27 Sep 5 Oct 17 Oct 24 Oct
VERIMARKx
20 SC
13.6 0.00 0.00 0.50 1.00 c
Admire Pro 10.0 1.25 0.00 0.25 3.75 a
Check ---- 0.25 0.00 0.75 2.00 b
Means within columns followed by the same letter are not significantly different, ANOVA; LSD (P<0.05). x VERIMARK is an insecticidal compound under development by DuPont and is not registered for use on crops
in CA or USA at the time of publication. z Worm pests were CL and BAW
Ag Briefs –September, 2012
11
IT’S TIME TO CHECK YOUR SPRINKLER SYSTEM
Khaled M. Bali
Fall is a great time to check your sprinkler irrigation system to insure maximum efficiency and to conserve
water. Sprinkle irrigation is mainly used for seed germination and for irrigating vegetable crops in the Imperial
Valley. Hand-move systems are commonly used in the Imperial Valley and throughout California. Sprinkle
irrigation was mainly used in the Valley for seed germination, however, in the last few years, more growers
have been using sprinkler irrigation to germinate and grow vegetable crops in the Valley. Sprinkle irrigation is
suitable for most vegetable crops in the Valley.
One of the advantages of sprinkler irrigation over surface irrigation is the ability to apply water uniformly at
low rates. Application rates for commercial crops vary from 0.10 to 0.30 in/hr. The application rate depends on
nozzle size, sprinkler spacing, and operating pressure. Frequent irrigations of low application rates are needed
on light or sandy soils. The application rate should not exceed the basic intake or infiltration rate on heavy soils
to prevent surface runoff. Table 1. can be used for maximum application rate values for hand-move systems.
The application rate of the system should not exceed the values presented in Table 1 to prevent runoff.
Reducing or eliminating surface runoff increases the efficiency of the system (water and energy savings). In
general, soil infiltration rates decreases after the initial irrigation. If water is filling up your runoff ditch and you
have runoff in your drop box, it is time to turn the system off.
The amount of water applied with a sprinkler system depends on the application rate and on the length of
irrigation event. The application rate needs to be determined first before any irrigation-scheduling question can
be answered. Application rate can be simply determined using the catch can method or a simple procedure in
which you run your system for a specific period of time (15 to 60 minutes), determined the amount of water that
has been used (using a flow meter) and then calculate the application rate. The application rate (AR) can be
calculated from
AR= 720 V/(T A)
Where AR is the application rate (inches per hour), V is the volume of water applied (acre-feet), T is the time of
application (minutes), and A is the area of application (acres).
Example: What is the application rate of a sprinkler system where 0.5 ac-ft of water was applied over 40 acres
in 60 minutes.
V= 5 ac-ft
T= 60 min.
A= 40 ac.
AR= 720 x 0.5/(60 x 40)
AR= 0.15 in/hr
If you need to apply 0.75 inches of water to meet the crop water demands over a specific period of time, then
you need to run the system for 5 hours (0.75 inches/ 0.15 inches per hour). Irrigation time should be adjusted to
account for irrigation efficiency/uniformity. Note that if you change the spacing between sprinklers and/or
laterals, the application rate needs to be adjusted to account for the new configuration.
Ag Briefs –September, 2012
12
To prevent leaching of nutrients, apply no more than 1 to 1.2 inches per application, if you exceed 1” per
application, you maybe leaching nutrients out of the root zone. If you are applying fertilizers with the irrigation
system, apply the fertilizer toward the end of the run time to prevent leaching of nutrients. For example if you
are planning to irrigate for 6 hours and apply fertilizers, run the system for 3 hours then inject the fertilizer
toward the end of the run (for 2 hours), then use the last hour to flush the fertilizer from the system.
Sprinkler Irrigation check list:
- Flow meter- to estimate the average depth of application and total applied water over the season
- Pressure gage: to monitor pressure and maintain the system pressurized within the range recommended
by the manufacturer of the system. Low pressure results in poor distribution uniformity and under
irrigation. High pressure results in over irrigation and wastes water and energy.
- Match application rate with crop water use or CIMIS (California Irrigation Management System)
reference evapotranspiration (ETo) during early crop stages.
Table 1. Maximum application rates for sprinklers (Slope less than 5%)
Soil Texture Maximum Application Rate (in/hr)
Sandy soils 1.50
Sandy loam soils 0.75
Silty loam soils 0.50
Clay and clay loam soils 0.15
Ag Briefs –September, 2012
13
2012 GUIDELINES TO PRODUCTION COSTS AND PRACTICES
IMPERIAL COUNTY- VEGETABLE CROPS
Khaled M. Bali
The new 2012 Guidelines to Production Costs and Practices in Imperial County - Vegetable Crops are
now available from the UC Cooperative Extension, Imperial County office. The information presented in the
vegetable crops guidelines allows one to get a "ballpark" idea of field crop production costs and practices in the
Imperial County. Most of the information was collected through verbal communications via office visits and
personal phone calls. The information does not reflect the exact values or practices of any one grower, but are
rather an average of countywide prevailing costs and practices. Exact costs incurred by individual growers
depend upon many variables such as weather, land rent, seed, choice of chemicals, location, time of planting,
etc. No exact comparison with individual grower practices is possible or intended. The budgets do reflect,
however, the prevailing industry trends within the region.
The cost of the Guidelines to Production Costs and Practices for Imperial County Vegetable Crops circular
(104-V) will be $25. This includes a hard copy of the Guidelines, electronic version on a CD or USB thumb
drive (Text in PDF and budget files in Excel format) and shipping cost. The publication is available from the
UCCE. If ordering by mail, please make checks payable to: UCCE-Imperial County and mail to Annette Tietz,
UCCE, 1050 E. Holton Rd. Holtville, CA 92250. Please specify if you want a CD or USB thumb drive in
addition to the hard copy. Please feel free to call (760-352-9474) or email ([email protected]) if you have
any questions.
Ag Briefs –September, 2012
17
CIMIS REPORT AND UC DROUGHT MANAGEMENT PUBLICATIONS
Khaled Bali and Sharon Sparks*
California Irrigation Management Information System (CIMIS) is a statewide network operated by California Department
of Water Resources. Estimates of the daily reference evapotranspiration (ETo) for the period of July 1 to September 30
for three locations in the Imperial County are presented in Table 1. ET of a particular crop can be estimated by
multiplying ETo by crop coefficients. For more information about ET and crop coefficients, contact the UC Imperial
County Cooperative Extension Office (352-9474) or the IID, Ag Water Science Unit (339-9082). Please feel free to call
us if you need additional weather information, or check the latest weather data on the worldwide web (visit
http://tmdl.ucdavis.edu and click on the CIMIS link).
Table 1.Estimates of daily Evapotranspiration (ETo) in inches per day
Station
July
August
September
1-15
16-31
1-15
15-31
1-15
16-30
Calipatria
0.39
0.38
0.35
0.32
0.30
0.27
El Centro (Seeley)
0.38
0.37
0.32
0.29
0.29
0.26
Holtville (Meloland)
0.39
0.38
0.34
0.31
0.30
0.27
* Irrigation Management Unit, Imperial Irrigation District.
Link to UC Drought Management Publications
http://ucmanagedrought.ucdavis.edu/