Category Archives: Irrigation

Cotton Irrigation At Squaring

Some of our pivots have not been running these past few weeks thanks to steady rainy days. For being so dry at planting, this is hopefully going to get us off to a good start in the field. Below is a photo of rep 2 from our variety trial. We have some plants squaring already.

Remember, stressing cotton during squaring has more negative effects than we realize. Cotton does not rebound if stressed from no irrigation through squaring. Last year, we lost so many squares from drought stress. This is something UGA Extension Irrigation Specialist Dr. Wes Porter says we have to be careful about.

Data on this using the UGA Checkbook Method where pre-bloom irrigation was eliminated found no difference in non-irrigated cotton. The reason for this is that cotton grows vegetatively and reproductively at the same time. During its vegetative growth, cotton is setting nodes. If it is stressed during this time, less nodes are set.


Dr. Porter has been looking at soil moisture sensors and the irrigation apps we can download on our phone. Research does show that the Smart Irrigation App is keeping us from putting out more water than is needed during both drought and rainfall situations. This is interesting because these apps do not monitor soil moisture, and the Smart Irrigation App is no charge to download. We go one step further when we use soil moisture sensors.



I saw some ants crawling up some plants. I then checked for aphids. The ants eat the ‘honeydew’ produced by the aphids, called ‘farming aphids.’ UGA Extension Entomologist Dr. Phillip Roberts says there are some aphid hot spots that may develop in fields now. We just need to watch.

Aphids under leaf of squaring cotton

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Plant Bugs


Tarnished Plant Bugs

We will now begin scouting for tarnished plant bugs. TPB have piecing/sucking mouthparts (like stinkbugs). Adults have a yellowish triangle behind the thorax with 5 distinct black dots. We want to retain 80% of our squares. Sometimes, less retention can occur even when plant bugs are not present. We need to monitor both square retention and plant bugs. Plant bugs are mobile and can move in and out of fields fast. They can be present and not causing square loss. Here is a threshold from UGA Extension Entomologist Dr. Phillip Roberts:


Adult Plant Bug - Photo by Jenna Brock

Adult Plant Bug – Photo by Jenna Brock

Plant Bug Nymph

Plant Bug Nymph

At cotton scout school this week, Dr. Roberts showed us plant bugs and other insects he is seeing at this time. Colquitt Ag Agent Jenna Brock is seeing some and also some reported by Jodie Stringer down here. I ran a sweep net through one field, and did not see any plants bugs. In a field where I looked, I did find a bigeyed bug. These are not problem insects. They actually feed on small caterpillars and eggs. Minute pirate bugs look somewhat similar and are beneficial also.

Bigeyed Bug

Bigeyed Bug



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Filed under Cotton, Entomology, Irrigation

Early Season Irrigation In Peanuts

We have been getting sporadic rainfall and periods of hot and dry weather. The early rainfall was good, but then the periods of hot dry weather have really hurt some of the dryland crops and caused some pivots to be operated near continually. Here is some information from UGA Extension Irrigation Specialist Dr. Wes Porter:

Ideally, peanut planting has finished up, and crops should be emerged and growing well. If you were able to take advantage of the early warm weather and get peanuts planted in the April throuh early May time frame, you are moving into peak water requirements in about a month. You are currently (throughout the month of June) around requiring 1 to 1.75 inches per week. If you missed the first window and have just finished up planting your peanuts in the month of May, then you are still at a low water use stage. You are ranging somewhere between 0.2 and 0.8 inches required per week.

Overwatering can hurt just as much as under-watering. Focus on keeping a record of local rainfall events and especially your irrigation applications. Just blindly irrigating a set number of times per week throughout the season will not aid you in properly meeting your requirements for the crop. Irrigating blindly will also not help in maximizing yield potential nor profit potential. Remember this requirement is IRRIGATION and RAINFALL. Irrigation may not even be required in the first few weeks.

Good record keeping and a sound irrigation scheduling strategy can aid significantly in increasing profitability in multiple ways, including reductions in irrigation applications, correlating to reductions in energy requirements, and potentially increases in yield.


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Irrigating Corn

Corn-V8-V10 002

Much of our corn is approaching the V6 to V7 growth stage. We really need rain at this time. This is an important time in development as corn is setting yields. Our water management is critical at this time. Here is a look at corn growth and development.


Thanks to Mitchell County Ag Agent Andy Shirley for sharing the checkbook method from the 2016 UGA Corn Production Guide on his blog with Mitchell County Ag News. Many growers may be using moisture monitors or other technology to determine when and how much to irrigate.  If not, we need to consider using the checkbook method for scheduling irrigation. Below are tables:



Here is an example of how to use the checkbook method:


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Early Planted Corn Growing


Here is some of our earliest planted corn in the northeast part of the county. This corn is planted twin row at 8 inches.

Collar visible on fourth leaf

Collar visible on fourth leaf

Much of the corn is in the seedling stage with one or two leaves. But the oldest of this corn at v3. At this growth stage, the first three leaves are collared. This is how we tell our growth stage. Look for the collar on the back of the leaf sheath. All leaves are initiated at the growing point, which is still below ground. This is more important early on if temperatures were to drop. The photo on the right shows the collar.

Estimated Water Use

At this point, corn is using 0.07 – 0.09 inches of water per day. This is between 13 and 22 days after planting. Here is a table from the UGA Corn Production Guide showing the irrigation scheduling through checkbook method.


Leaf Tissue Sampling

At this stage, we may pull some leaf tissue samples to make sure we’re taking up our nutrients from pre-plant. Sidedressing is coming soon when corn is 12 to 16 inches tall. In terms of leaf tissue sampling, we consider anything less than 12 inches seedling stage. We need to sample all above ground portions of the plant:


  1. Seedling stage (less than 12″) – All the above ground portion
  2. Prior to tasselling – The first fully developed leaf below the whorl
  3. From tasselling and shooting to silking – The entire leaf at the ear node (or immediately above /below it)

*We need 15 – 20 samples at each stage.

We have not been able to get in the field this week with rain last weekend.  I’ve driven on a pasture and around woods edge making calls the last two days, and you can still hear the water under the tires. With projected rain coming, it’ll be another few days before fields dry out. We had a good sunny day yesterday, but it takes a few sunny days to dry things out. Some reports of rain 5 inches. Here is picture from yesterday.


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Winterizing Irrigation Systems

From Gary Hawkins, Ph.D. Water Resource Management Specialist Crop and Soil Science Department, UGA.

‘Twas the night before harvest, when all through the fields not a creature was stirring, not even a mouse.
 The harvesters were greased by the farmer with care,
 in hopes that good harvest soon would be there.

But before you “spring from your bed to see what’s the matter or settle in for a long winters nap”, take some time to think about your irrigation system and get it ready for a long winter’s nap as well.

Now that the harvest is over, have “irrigation geysers” been dancing in your head? Where were they? Which ones needed to be repaired and which nozzles were worn? At this time of the year, I realize you are tired, want to go to the house for a nap and dream of next years planting, but prepare your irrigation system now so it will also be ready for the spring. Water is a commodity that is needed by the plants to produce the crop you dream of and getting the water to the fields is the purpose of the irrigation system.

So before you whistle and shout them by name: “Now Case! Now Valley!
 Now, John and Deere!
 On, Reinke! On, Rainbird!
 On, Cotton and Peanut!
 To the top of the Field!
 To the top of the shed!
 Now Winter -ize! Winter -ize! Winter -ize! all!”

-Get everything winterized prior to settling in so next year will be a good year on many different fronts. In the Regional Water Plans (can be found at there are many activities suggested by the Water Councils to help conserve water in the specific water regions and in the State of Georgia.

In the Southern portion of Georgia some of these are:

  • Continue to improve agricultural water use efficiency through innovation.
  • Implement water conservation practices.
  • Improve implementation of nonpoint source controls.
  • Conduct irrigation audits By winterizing your irrigation system you can improve your irrigation system efficiency, increase uniformity and better utilize water resources.

Through the process of conducting an irrigation audit this time of the year when it is easy to get into the field, around the pivots and under them for repairs you are also performing the check of your irrigation systems efficiency required by the Flint River Drought Protection Act (

After efficiency and uniformity tests are “nestled all snug in their beds,” winterize your system. Briefly, that is the process of removing water from the spots prone to freeze in the winter, cleaning the engines, and preparing the system for a new beginning in the spring. A complete checklist for both center pivot and drip systems can be found in the “Winterizing your Irrigation System” publication (

So, before you exclaim “Happy Harvest, to all and to all a good winter”, get your irrigation systems ready for the winter so when you start the Deere or Case or IH for planting in the spring, the irrigation system will also be ready to provide the water needed for a good harvest next year while efficiently and uniformly applying the water resources needed for growth.

Remember to check in with the weekly Water Blog where we will put articles and links to water related issues across Georgia and the world. I hope you have a Merry Christmas and a very Happy Holiday Season!

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Fall Broccoli Close To Harvest

Broccoli-EmeraldCrown 032

We have a few vegetables planted  in the county this fall. Here is Brandon Barnes with some bare ground broccoli that was transplanted back in October. This variety is Emerald Crown which is a mid-season variety in Georgia and North Carolina. The heads are coming on now, and some will probably be ready to pick in a week to ten days. The overall plants and color look good across the field. He has a pivot in this field, and we want to make sure we’re putting on an inch more or less of water each week.

Broccoli-EmeraldCrown 029

Caterpillars are a common insect pest of cole crops. We have been checking for diamond back moths which is part of the cabbageworm complex. Populations are low in the field right now which is good since management is a challenge with resistance. When scouting, we note the ‘window pane’ effect that is common from diamondback moth feeding.

Broccoli-DiamondBackMoth 005

Some disease is showing up but not causing real problems. Alternaria is usually observed with concentric ring on a leaf. Another pathogen we may check for is black rot, which is a bacteria in the Xanthamonus genera. Below is a photo of black rot in red cabbage. With black rot you generally see yellowing at the leaf margin, and you will see ‘black veins’ running through the yellow/necrotic area through the light. Lesions are usually characteristic of V-shape. Upcoming cool nights will hold back the bacterium.  So far, a good fungicide program has proved to be effective.

RedCabbage-BlackRot 012

Black Rot of red cabbage


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Mid-Season Peanut Irrigation

Here is an update from UGA Extension Irrigation Specialist Dr. Wesley Porter:

Our ample rainfall seemed to stop early later in May and into June. With the lack of rainfall we also had an excess of heat. Typically, peanuts do not require much water early in the season, but the lack of rainfall and extreme continual heat may have pushed some producers to turn their pivots on.  I would say this was a good decision and recommended practice. We had depleted much of our non-irrigated soil moisture due to the hot and dry period. 

As of June, we have began to pick up some rainfall from scattered mid-afternoon thunderstorms.  These rains are beneficial and very welcome. However, high intensity rainfall does not do a very good job of refilling your soil water profile. Do not bank fully on these high intensity events to fully provide the required water you need.

Based on the split planting of peanuts due to the warm early season weather we will be moving into one of two stages during July, either ramping up to peak water use and then dropping off, or just getting ready to move into peak water use.  The graphic below should give us an idea of where we will stand for the 4 weeks of July.  Keep track of rainfall, and supplement it with irrigation. On rainfall events from 0.25” to 1” it is good to assume a 90% efficiency, and on events over 1” it’s probably safest especially if it is a high intensity event to assume around a 75% efficiency.  Make sure not short yourself on soil moisture as this can be detrimental. Overwatering can hurt just as much as under-watering too.  Remember this requirement is IRRIGATION and RAINFALL!  Irrigation may not even be required in the first few weeks!


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Filed under Irrigation, Peanuts

Pre-Bloom Irrigation In Cotton

Cotton-Irrigation 007

We’ve had some rain the past few days and even some in the northwest part of the county that is usually dry. Today I was in the central part of the county and fields were still wet from rain yesterday. Although irrigation requirement is higher for blooming cotton than for pre-bloom cotton, stressing cotton during squaring has more negative effects than we realize. Cotton does not rebound if stressed from no irrigation through squaring. UGA Extension Cotton Agronomist Dr. Jared Whitaker conducted research on this using the UGA Checkbook Method where the pre-bloom irrigation was eliminated and they had no difference in non-irrigated cotton. The reason for this is that cotton grows vegetatively and reproductively at the same time. During its vegetative growth, cotton is setting nodes. If it is stressed during this time, less nodes are set. Below is a graph showing the research and UGA Checkbook Method.



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Pecan Irrigation Schedule

The intense heat has arrived in South Georgia with high’s in the upper 90’s. This is also nut sizing period and water demand increases.  Below is information on irrigation from UGA Extension Horticulturalist Dr. Lenny Wells:

Through June, pecan trees benefit from irrigation but only need a fraction of the amount they require as the crop begins to develop. This demand will continue to increase through the nut sizing period and peaks during the kernel-filling process in August and September. As a result, the irrigation schedule for pecan production should reflect the tree’s demand throughout the growing season. Our recommended irrigation schedule for mature pecan trees (age at which an economically significant crop can be harvested—usually 8-10 yrs and beyond) is found below:


Your maximum capacity to be applied in August and September is 3600-4000 gallons per acre per day within a 12 hour period. Percentages shown in the table above represent the percentage of this maximum capacity for each month. We are often asked, “Doesn’t a 60 year old orchard need more water than a 10 year old orchard?” The general answer is no. There is probably some wiggle room for certain situations, because many factors play into an orchard’s water demand – including the number of trees per acre, crop load, cultivar, nut size, hedging, etc. [For example, while an individual 10 year old tree’s water demand may not be as great as that for a 60 year old tree,  there are fewer trees per acre in an orchard full of 60 year old trees (if the orchard has been managed correctly), thus the water requirements per acre are about the same.] Hedging may change this somewhat and we are working to try and determine any differences in water demand for hedged vs. non-hedged trees under our conditions as this practice becomes more common in the Southeast.

For now, research has shown that the schedule above works for all bearing pecan trees grown under our conditions. In addition, it is a 38% reduction in the amount of irrigation water applied over the previously recommended schedule, with all the savings coming from April-July. Many are concerned that applying less water than we had applied previously in June and July would limit nut size. This is a very important question, because nut size rules the pecan market at this time. However, our work over a 3 year study – including 2 years with very dry weather during these two months – has shown no loss in nut size, yield, or quality for the above schedule compared to the old schedule. In fact, nut size was even a little larger for the reduced schedule. The requirement for June is a little more than 1,300 gal per acre per day. In July the requirement increases to 1600 gal per acre per day. While this represents less water, it is no small amount of water and is quite enough to size the nuts.

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