Monthly Archives: April 2020

After several inches of rain last week an interesting observation was made where peanuts were recently planted.  Snails were present in high numbers in this conventionally tilled field.  Normally, we would expect to find them in fields with more plant residue.  Recent tillage and rain likely made the snails more noticeable.  Dr. Abney says that the snails do not usually feed on live plants, just decomposing plant material, so they don’t pose a threat to the crop until harvest (if they make it into the combine).

There is little information available on snail control in peanuts, but some recommend tilling to disturb the soil and prevent populations from increasing.  However, this may not be an option for growers implementing conservation tillage practices.

For essentially two decades, Georgia farmers have battled glyphosate-resistant
Palmer amaranth. Its impact on Georgia agriculture is so high it is simply immeasurable. As many lessons have been learned from our past, weed management decision making has vastly improved at all levels across Georgia. However there are great concerns with overuse of many herbicide chemistries especially dicamba and the PPO herbicides (examples such as Reflex, Cobra, Ultra Blazer, Valor, etc). With Georgia research, observations of pigweeds responding to dicamba applied by researchers has noted some plants dying while others show few symptoms (all plants of the same size and coverage). There is no question that this is a sign of trouble. Dr. Larry Steckle recently published an article addressing a similar concern with dicamba.

The picture above shows “Response of Palmer amaranth to 0.5 lbs/A of Dicamba: 2001 collected seed Left and 2019 collected seed Right. 11 days after application”.

What about the PPO herbicides? Although it is complex for a scientist to be able to say a weed is resistant to a specific herbicide, we now have the data required to make that statement. Palmer amaranth resistant to topical applications of PPO herbicides are in Georgia.

The photo (above) of plants dead (left) are from a known sensitive population treated with Reflex at 24 oz/A plus surfactant in the greenhouse. The plants surviving (right) were treated at the same time with 240, yes 240, oz/A of Reflex plus surfactant; plants were also not controlled with Cobra or Ultra Blazer at enormous rates. It is important to note, the world of weed control in Georgia is not ending as most growers are making and implementing sound management programs. However, there are a few that need a wakeup call………..hopefully this information will fulfill that need!!! Make good decisions, use cover crops or tillage, start clean, two residual at-plant herbicides, make sure your program includes at least 5 different classes of herbicide chemistry AND PULL OUT ESCAPES! Also stay in touch with your local extension for the best management programs.

Using Pesticides Wisely Training moved to online delivery April 21-23, 2020

The University of Georgia (UGA) and Georgia Department of Agriculture (GDA) dicamba training program will complete the 2020 sessions using online webinar delivery of materials. The decision of the U.S. EPA requires only applicators who were not trained in 2019 to be trained in 2020. Online sessions remove the limitations of meeting room capacity, thus growers can register for the date and time which works best for their schedule. Please note that each session has its own registration link, so it is important to use the link that matches your preferred time. Registration information will require that you enter your address, phone number, email and pesticide license number (a license is not required for 2,4D application, just type in N/A). The meeting link will be emailed to registrants prior to the session. Using Pesticide Wisely (UPW) will last about 1 hour and 30 minutes. Participants will be able to submit questions using a chat box or over phone. Attendee’s names will be placed on a list posted to the Georgia Department of Agriculture’s auxin website at http://www.agr.georgia.gov/24c.aspx. Please allow up to 21 days after the training date for names to be posted. This list will serve as the official training record as attendance verification.
Date and Time:  April 21, 10:00 am

Host Agent:  Bill Tyson, Bulloch County,

Host’s Number:  912-871-6130

Registration Link:  https://zoom.us/webinar/register/WN_QQLSPi7aTiq869rhy9Gi8A
Date and Time:  April 22, 10:00 am

Host Agent:  Raymond Joyce, Laurens County

Host’s Number:  478-272-2277

Registration Link:  https://zoom.us/webinar/register/WN_6ZdJp262SkyG19nQFH_vtw
Date and Time:  April 23, 10:00 am

Host Agent:  Brian Cresswell, Early County

Host’s Number: 229-723-3072

Registration Link:  https://zoom.us/webinar/register/WN_RtsRK88CQlq7QF35lxJL_A
Date and Time:  April 23, 6:00 pm

Host Agent:  Justin Hand, Tift County

Host’s Number: 229-646-1413

Registration Link:  https://zoom.us/webinar/register/WN_42CPH2-8QkWcVtZ459fgNg

If you have any questions call/text Sydni Barwick (2292258952).

Getting ready to plant peanuts should also mean getting ready to manage thrips and Tomato Spotted Wilt (TSWV). Three of the most important and easy to adjust thrips/TSWV management tactics are choosing the right cultivar, considering planting date, and deciding on an at-plant insecticide. Most will plant GA-06G in 2020, but those who do not need to be certain that the cultivar they choose has good resistance to TSWV. The warm spring we are experiencing will almost certainly result in more peanuts being planted early. Any peanuts planted before May 10 are at increased risk of thrips injury and TSWV infection. Planting some of the crop after May 10 will help hedge against the risk of losses to TSWV. There are only a few options for controlling thrips with insecticides, and nothing much has changed in the last few years. Growers can use phorate (Thimet), imidacloprid (Admire Pro and others), or aldicarb (Ag-Logic) in the furrow at planting. Phorate is the only insecticide that has been proven to reduce the risk of TSWV infection in peanut. The convenience and ease of applying liquid imidacloprid has driven an increase in the popularity of this active ingredient in some parts of the state. Those who are planting early (before May 10) need to know that imidacloprid in furrow will not reduce the risk of TSWV. Those who choose not to use insecticide at planting need to scout for thrips as soon as plants begin to
emerge. Acephate (Orthene) applications should be applied before heavy thrips injury occurs. In the final run up to what promises to be a wide-open planting season, making sure all application equipment is properly calibrated can save money and help ensure optimal performance of pest control products.

The three main problems we want to watch for following severe wind events in corn are greensnap, root lodging, and pinching.

• Greensnap is when the plant breaks at some point along the mainstem.  This is most likely to occur in plants that have reached or exceeded the V8 growth stage, but should still be scouted for in younger plants.  Most often, plants that have “greensnap” may not recover and potential yield losses may be correlated to the percent stand reduction.
• Root lodging from strong winds is most often found in plants that have surpassed the V13 growth stage and are nearing tassel.  The roots on the windward side of the plant will be uprooted/exposed while the roots on the opposite side of the plant will be buckled below the soil surface.  While this issue tends to effect more mature/heavier corn plants it should not be completely ruled out in younger corn plants.  Past research has shown that root lodged plants can recover vertical growth, through “goosenecking”, without significant yield loss if the damage no later than 10 days prior to tasseling.
• Pinching is similar to greensnap but instead of actually breaking, the mainstem folds, or pinches.  Corn plants will remain alive and can recover upright growth but yield loss may occur due to decreased efficiency in nutrient and water flow within the plant.

Overall, most of the corn in the state is young enough that it should recover without significant yield loss concerns.  If you do find instances of greensnap, root lodging, or pinching, carefully consider the percent or stand affected, the original yield goal, value of inputs already applied, and potential yield loss from a later planting date prior to making any replant decisions.

Silverleaf whitefly (SLWF) is a sporadic and localized pest of cotton in Georgia. There are reasons for this localized infestation pattern and it is important we understand why this occurs. In Georgia SLWF infestations are most common in areas where both cotton and vegetable production occur. In these areas crops which serve as reproductive hosts are grown 12 months a year. SLWF infests brassica crops in the winter months, move to cucurbits in the spring, move to cotton in the summer, move to cucurbits in the fall, and back to brassica crops during the winter. This is a simplified view of movement and buildup of SLWF during the year. SLWF actually has many different hosts (both wild hosts and cultivated crops), but the crops mentioned are the drivers in SLWF population dynamics. What we do know is that it is important for all of agriculture to properly manage SLWF. Failure to properly manage SLWF in a crop will have negative consequences on the next crop SLWF infests. More information on SLWF and management can be found in the publication “Cross-Commodity Management of Silverleaf Whitefly in Georgia” (https://secure.caes.uga.edu/extension/publications/files/pdf/C%201141_1.PDF).
There are several risk factors influencing SLWF populations during the year. One important factor is winter weather. SLWF survive the winter months on both cultivated and wild host plants. Mild winters favor survival of SLWF. Although temperatures rarely are low enough in South Georgia to kill SLWF outright, freezing temperatures which kill host plants infested with immature SLWF effectively kills immature SLWF on those plants. Cold temperatures also slow development of SLWF. Higher survival and reproduction during winter months leads to higher populations in the spring and the opportunity for populations to rapidly build to damaging levels. To date we have only had 6 days in Tifton when the low temperature was below 32 degrees. When reviewing weather data for the last 15 years, this winter was tied for the fewest days below freezing. What does the lack of cold temperatures mean for cotton? The mild winter suggest our risk for SLWF in cotton is elevated. This does not mean we will have a SLWF problem in cotton, but we cannot ignore the lack of cold temperatures. Spring and summer weather will be the primary factor affecting SLWF populations from this point forward. Hot and dry conditions will favor SLWF population buildup. If you are in an area prone to have SLWF, NOW is the time to manage risk factors we can control.

Variety Selection: hairy leaf cottons are preferred by SLWF compared with smooth leaf cottons. There is a direct correlation of SLWF infestations in cotton based on the degree of leaf hairiness. Risk of SLWF is greatest on hairy varieties > light hairy > semi-smooth > smooth varieties. Smooth leaf varieties are the least preferred by SLWF. Plant Smooth Leaf Varieties

Planting Date: the risk of SLWF problems increases as planting dates are delayed. SLWF complete a generation in about 2 weeks during summer months and populations can increase rapidly. The impact of SLWF on yield is dependent on the growth stage of cotton when SLWF infest the crop. Potential yield loss is greater when infestations appear during squaring or early bloom compared with late bloom. The duration or time of control required to protect yield and quality from SLWF is also dependent upon
planting date. April and early May planted cotton is at lower risk for SLWF problems compared with late May and June planted cotton. Avoid Late Planting

Location (proximity of SLWF infested crops): crops produced in a given area can be viewed as sources and sinks for SLWF populations. Spring vegetable and melon crops are a source of SLWF infesting cotton. In the fall cotton is a source of SLWF infesting fall vegetables. The nearness of cotton to a SLWF infested field increases the risk of SLWF. Minimize Planting Cotton Next to SLWF Infested Crops. If planting cotton near SLWF infested crops, be sure to avoid late planting and use a smooth leaf variety. Destroy SLWF host crops immediately after harvest; this includes vegetable and melon crops in the spring and cotton (timely defoliation and harvest) and other crops in the fall.