A message from Ben. Fulton County Agricultural News & Events March 2017

Transcription

1 Fulton County Agricultural News & Events March 2017 A message from Ben Cooperative Extension Service Fulton County 2114 S 7th Street Fulton KY Phone: (270) Fax: (270) extension.ca.uky.edu Spring has not sprung, but it sure feels like it. I am not complaining because as we all know that just in a minute, it will change. The rains have recharged the ground from the dry fall we had, and the rivers have been low most of the winter, but with the warm temperatures, snow, and ice melts from the northern tier of the country there are reports of a high river (40ish feet) in mid- March. This could cause issues with the spring planting season if we get a lot of rain, which is quite possible. Based off Table 1 in the article titled Winter Wheat at Advanced Growth Stages, there is a 90% chance of a freeze between March rd based off the Mayfield and Murray weather data. With the warm temperature, it is very tempting to want to get a jump on planting season, as some are in other states, but we do not recommend planting corn until April 1 st. As you begin the crop season, and start to put into place all of the new ideas and topics that you have read about and seen, think about the data presented and look at the numbers. Then, ask yourself, is it economically and financially feasible to implement on YOUR OPERATION? I encourage you to take time and read through this newsletter for current information in the agriculture field and upcoming dates of meetings and field days. Like us on Facebook. Ben Rudy Fulton County Extension Agent for Agriculture & Natural Resources UPCOMING EVENTS March 1 IPM Training, Princeton, Ky 3-4 Farm and Gin Show, Memphis, TN 8 Wheat School (Part 1), Princeton, Ky April 26 Wheat School (Part 2), Princeton, Ky May 9 Wheat Field Day, Princeton July 27 UK Corn, Soybean, and Tobacco Field Day, Princeton

2 Winter Wheat at Advanced Growth Stages due to Warm Winter in KY Carrie Knott, Extension Agronomist-Princeton, University of Kentucky Lloyd Murdock, Emeritus Extension Soil Specialist, University of Kentucky Edwin Ritchey, Extension Soil Specialist-Princeton, University of Kentucky Unseasonably warm temperatures in KY since wheat planting (October 15, 2016) may become a major challenge to wheat yield and profitability this year. Since Oct 15, 2016, KY has accumulated about 2000 GDD growing degree days (GDD) or heat units. In most years, only about 1500 GDD are accumulated by mid-february, while 2000 GDD are typically accumulated around the end of March in KY. These extraordinarily warm days and large number of GDD have resulted in wheat crops that are at a more advanced growth stage for this time of year. Typically, most of KY wheat in mid-february is beginning to break dormancy and initiate active growth: Feekes 3, Green-up. However, there are several reports in KY that wheat is jointing (Feekes 6; Figures 1 & 2). This is very concerning because at jointing (Feekes 6) the growing point (developing wheat head) is above the soil surface and is vulnerable to damage, including freeze damage. The risk of freeze damage is quite high because throughout KY there is still at least a 6 to 9 week window that a freeze typically occurs (Table 1). Figure 1. Wheat Plant at jointing (Feekes 6). Considerations: For wheat crops that have not received any nitrogen, consider a single nitrogen application as late as Feekes 6 or 7 growth stage. Delaying nitrogen application may reduce plant growth and the risk of freeze damage. Research in KY has shown that with sufficient tillers, nitrogen application can be delayed as late as Feekes 6 or 7 with little or no yield reduction. Normally nitrogen is applied by Feekes 5 or 6 to maximize yield. With the accelerated growth this year, delaying nitrogen application until Feekes 6 Figure 2. Wheat plant at jointing with or 7 could retard wheat development and provide dissected wheat head. additional freeze protection, depending on when a freeze occurs. Yield will be reduced if nitrogen application is delayed beyond Feekes 7, such as delays due to weather or field conditions. For wheat crops at jointing, Feekes 6, that have already received nitrogen applications, there is nothing that will protect the crop from freeze damage. The best approach is to

3 consider delaying the second nitrogen application until Feekes 6 or 7, potentially reducing the severity of freeze damage. Freeze injury occurs when temperatures fall to 24 F or below for 2 or more hours at the jointing growth stage: Feekes 6. If freezing temperatures remain above 24 F there is only a slight risk of freeze damage. In Western KY, the wheat crop does not appear to be as advanced as other areas of the state. Last fall there was a considerable drought that may have resulted in dormant wheat in the fall (due to lack of water) when other areas of the state wheat was actively growing. These areas will likely be most profitable following normal wheat management recommendations. Be prepared to scout fields much earlier than usual for insects and plant diseases. The warm winter temperatures have also resulted in greater insect populations in KY, specifically cereal aphid species, which may increase the incidence of barley yellow dwarf virus. Table 1. Probabilities for the date of the last spring freeze (32 F) in Kentucky based upon data from 1981 to 2010 (Arguez et al., 2010 provided by S. Foster, State Climatologist for Kentucky). Probabilities that the last spring freeze will occur on or after the date listed. For example, for 90% probability the last spring freeze will occur on or later than the date listed 90% of the time (nine out of ten years), while at the 10% probability level the last spring freeze will occur on or later than the dates listed 10% of the time (one out of ten years). Kentucky Location Date of Last Spring Freeze (32 F or less) in Kentucky by Probability Level 90% 50% 10% Ashland 6-Apr 24-Apr 10-May Bardstown 30-Mar 14-Apr 29-Apr Bowling Green 25-Mar 9-Apr 25-Apr Covington 2-Apr 16-Apr 2-May Danville 27-Mar 11-Apr 27-Apr Glasgow 29-Mar 13-Apr 27-Apr Henderson 24-Mar 8-Apr 23-Apr Hopkinsville 24-Mar 10-Apr 24-Apr Leitchfield 14-Apr 28-Apr 15-May Lexington 29-Mar 14-Apr 29-Apr Mayfield 23-Mar 9-Apr 23-Apr Monticello 3-Apr 20-Apr 5-May Murray 17-Mar 2-Apr 18-Apr Nolan River Lake 3-Apr 20-Apr 7-May Princeton 29-Mar 13-Apr 29-Apr Russellville 25-Mar 11-Apr 29-Apr Shelbyville 16-Apr 29-Apr 14-May Somerset 3-Apr 20-Apr 6-May

4 Wheat: Earlier Aphid Occurrences May Be a Consequence of the 2017 s Warm Winter Raul Villanueva, Extension Entomologist, University of Kentucky In Kentucky there is a complex of aphid species that feeds on wheat. The bird cherry oat, the English grain (Fig.1), the greenbug, and the corn aphids are the most important species. Their role as vectors of plant viruses, particularly Barley Yellow Dwarf Virus (BYDV), branded them as the key pest on wheat grain production. These aphid species overwinter as nymphs, and can be active when temperatures are above 45⁰ F. It is known that BYDV infections are more damaging when they occur in early growth stages of the wheat plant. Thus, aphids have more opportunities to infect young plants under this climatological circumstances. Figure 1. Pictures of the bird cherry oat aphid and a winged English grain aphid found in wheat fields in February (Photo credits Yaziri Gonzales). Also, uncharacteristically warm temperatures (above 50⁰ F) were present during most days of November (Fig. 2). Based on historical records and comparing mean temperatures for the bimonthly periods November December 1976, 1996, and 2016; and January-February 1977, 1997 and 2017 (periods were separate to facilitate the analysis). We can notice that mean temperatures (linear regression analysis) for 2016 and 2017 were higher than the previous year for the same periods, respectively (Fig. 2). It may be possible that the continuous alterations on the climatological events are influencing these warmer temperatures (more frequent rains, storms out of the normal patterns, sudden ice storms, etc.) as shown on these 20-year intervals. Figure 2. Temperatures (40⁰ F) for the months of November-December 1976, 1996, and 2016; and January-February 1977, 1997, and Regression lines shown that temperatures for 2016 and 2017 were higher than for the previous years. (Figure was generated with temperatures of of Princeton, KY obtained from:

5 Given the circumstances mentioned above, the warm winter in all likelihood will accelerate the development of both plants, and insects. To predict the biological events of organisms, accumulated degree days (AcDD) is used. The DD is based on temperatures above threshold temperatures that are specific for each organism. For wheat and aphids these are 45⁰ and 40⁰ F, respectively. These biological events re in turn used to schedule particular activities such as scouting and synchronizing insecticide sprays. For aphids and wheat, the AcDD starts on January Table 1 shows the AcDD for wheat and aphids from 2011 to 2017 for three counties of Kentucky. AcDD for 2017 are ahead of the AcDD of previous years. Table 1. Accumulated degree days for wheat and aphid species for Caldwell, Monroe and Fayette Counties in Kentucky from January 1 to February 20, 2011 to (Data source: For wheat, the AcDD is far ahead compared to all the previous years, and that could set up wheat fields for freeze damage later in case an eventual freeze takes place. A later freeze on March or April can also affect insects. However, Dr. Michaud (Biocontrol Specialist) from the University of Kansas declared that earlier biological control organisms such as ladybug eggs and parasitoids can be disrupted by a cold front, and their recovery can be slower compared with insect pests. Other pests such as Hessian fly maggots that are in root system of volunteer wheat or other plants also can be a problem. They can continue feeding as long as temperatures are above 40⁰ F. For this pest a chemical control would not work. However, for Hessian flies or BYDV there are resistant varieties that growers should have been using to reduce pest damages. We have been sampling for aphids here at the UK s Research and Education Center and other counties (Lyon, Trigg, Christian) and no aphids were found so far. However, we found aphids in early or late when? December. No aphids were found from mid-december to mid-february. However, aphids were found in low numbers after February 15 (when temperatures were >65⁰ F). Most of these aphids were nymphs although we had some adults and winged aphids. A question still remains about to spray or not to spray. There are many factors to consider but the most important is the economic value of the crop. The best alternative here is to continue monitoring for the presence of aphids and if the tallies are above the threshold levels indicated in Table 2, an insecticide spray need to be considered.

6 Table 2. The number of aphids per foot of wheat row required to support an insecticide application for management of BYD For more information check the following URL: Predicting Insect Development Using Degree Days: Aphids and Barley Yellow Dwarf (Byd) in Kentucky Grown Wheat: Using Correct Nozzles Correctly: Thoughts on the Additional Nozzles Added to XtendiMax Label Larry Steckel, Extension Weed Specialist, University of Tennessee The fifth blog on stewardship of XtendiMax and Engenia on Xtend crops will revisit nozzles. Just this past Friday (Feb 10) the EPA approved the use of 20 other nozzles and/or orifice sizes besides the TTI for XtendiMax. The additional nozzles on the list are good with respect to having more options but keep in mind that the nozzles are only approved if used at the designated operating pressures listed on that website. As a result I do not think we should be moving from Spraying Systems TTI nozzles to their AI nozzles. The reason for that is the operating pressure for AI11002, AI8002 and AI8005 must be between 30 and 40 psi to stay on label. I fear as folks get into a hurry (which we all know will happen at some point) and increase their speed, it will result in operating pressures that ramp up well above 40 psi. These higher pump pressures will cause those AI nozzles to produce a lot of fine droplets that will readily drift. I am not sure how many AI nozzles are still out there but these would be the last choice I would consider out of the nozzles on that list. Similarly, other nozzles on that list that are only labeled to be used at a narrow pressure range, like the Lechler ID nozzles, would also concern me. The Lechler nozzles are only approved to be used between 30 and 40 psi which is hard to do if you are in a hurry or indeed just trying to spray some of our rolling hilly fields. On the other hand, I was glad to see the Greenleaf TADF and TDXL nozzles were added as we have evaluated them for several years and they have proven to be good nozzles. Moreover, they have a pretty good pressure range they can be operated at and still be on label. Finally, I was very happy to see that the Wilger DR11010, was added. This non-air induction nozzle will let those sprayers using the Pulse Wide Modulation (PWM) system, like the Aim Command, to run as intended with solenoids and not pump pressure controlling the flow rate. I am a believer in the PWM sprayers as the pressure remains constant even at higher speeds which can greatly help mitigate drift. Before the DR nozzle was cleared, the only choice folks running PWM systems had was to shut the PWM system off and use an air induction tip. Though that is workable, now they have the

7 PWM option when spraying XtendiMax. Unfortunately, that is not yet the case for Engenia. Hopefully, that will change before we go to the field. Please keep a close eye on the Engenia and/or XtendiMax websites as new surfactants, herbicides and nozzles are being added fairly quickly. What is not labeled today may be tomorrow. Engenia XtendiMax Timely Tips Dr. Roy Burris, Beef Extension Professor, University of Kentucky Spring-calving Herd Get ready for calving season this month! Replacement heifers should be gaining adequately to reach target breeding weights by May 1. Be sure that their feeding program is adequate for early breeding. Overall condition of the cow herd should be evaluated. Cows losing weight now are more likely to have weak or dead calves. These cows will likely be a poor source of colostrum milk for the newborn calf. Feed cows, if necessary to keep them in good body condition. Have calving equipment, supplies and labor ready for the spring calving season. Some supplies which may be needed are: eartags and applicator (put numbers on eartags now), tattoo pliers and ink, record book, scales for calf weights, iodine for calves' navels and colostrum supplement. Calving equipment (puller and chains, etc.) and facilities should be ready and clean. Heifers should begin head-start calving in early February. Move them to a clean, accessible pasture, away from cow herd and near facilities so that calving assistance can be given. Cows may start calving later this month. Signs of calving are relaxation of pelvic ligaments, enlargement and swelling of the vulva, and enlargement of the udder. Expect calving difficulty if (1) calf's head and two feet are not visible, (2) only the calf's tail is visible, and (3) the cow has been in labor for 1½ hours. Be sure calf is being presented normally before using calf puller. Recognize situations that are beyond your capability and seek professional help as early as possible. Calves that aren t breathing should receive assistance. Try sticking a straw in nostril to stimulate a reflex or try alternate pressure and release on rib cage. Commercial respirators are also available. Calves should consume colostrum within 30 minutes of birth to achieve good immunity. Record birthdate, cow I.D., and birthweight immediately (use your Beef IRM calendar). Identify calf with eartag and/or tattoo. Registered calves should be weighed in the first 24 hours. Male calves in commercial herds should be castrated and implanted as soon as possible. Sub-zero weather can mean death for newborn calves. During extremely cold spells, bring the cow(s) into a sheltered area as calving approaches to protect the calf. Be prepared to warm-up and feed newborn, chilled calves. Calving in mud can also cause problems. Separate cows that calve away from dry cows and increase their feed. Increase feed after

8 calving to pounds of high quality hay. Concentrate (3-4 lb. for mature cows and about 8 lb. for first-calf heifers) may be needed if you are feeding lower quality hay. Supplementation may have a beneficial effect on date and rate of conception. The most important time to feed a beef cow is after calving. Thin cows don't come into heat very soon after calving. We must have cows in good condition, if we plan to breed them early in the season for best pregnancy rates, especially on high-endophyte fescue pastures. Watch for scours in newborn calves. Consult your veterinarian for diagnosis, cause, and treatment. Avoid muddy feeding areas so that cows' udders won't become contaminated and spread scours. Don't confine cows to muddy lots. Start looking for herd sire replacements, if needed. Fall-calving Herd Consider creep feed or creep grazing (wheat, etc.) to supply extra nutrition to fall-born calves which may have to depend solely on their dam s milk supply for growth. They are not getting much except their dam s milk now (i.e. there is nothing to graze). February/March is the worst time of the year for fall-born calves. Breeding season should end this month maybe Valentine s Day. Remove bulls and confine them so that they regain condition. Provide windbreaks or clean shelter for calves. General Provide water at all times. Watch for frozen pond hazards. If cattle are watering in a pond, be sure to keep ice chopped to keep cattle from walking on the ice and, possibly, breaking through. Keep automatic waterers working. Increase feed as temperature drops. When temperature falls below 15 degrees, cattle need access to windbreaks. For each 10 degree drop below 15 degrees, add three pounds of hay, two pounds of corn, or six pounds of silage to their rations. You should be feeding a mineral supplement with adequate magnesium to prevent grass tetany (~ 15% Mg) now. The Hi-mag UK Beef IRM mineral can be used now. Control lice. Watch for signs such as rubbing. Begin pasture renovation. You can overseed clover on frozen or snow-covered pastures. If you would like to receive this newsletter electronically, please me at ben.rudy@uky.edu

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