Monthly Archives: February 2017

Fertilizing Late Winter Forage

forage-3

We were months late getting our winter forage planted this year. We didn’t have many options because of this, so most winter forage is ryegrass. Most of it is looking good now and very green. We haven’t had too much rain to leach nutrients, and weather has been similar to a normal October/November. We typically put 50 lbs of N at planting, in winter, and again in spring. We will still be able to get in another few fertilizers if need, but probably one less than normal. At this time, we need to check small grains for deficiency and put on another 50 lbs when we see the lower leaves yellowing.

N deficiency in triticale

N deficiency in small grain

Last season, winter rains leached our nitrogen from the soil, and timeliness with winter fertilization was critical. UGA Forage Agronomist Dr. Dennis Hancock sent out information on ryegrass last year to address issues with heavy rains:

Ryegrass

Standard soil test recommendations are that one should put out 50 lbs of N/acre on ryegrass and small grains in late winter (late January – February) and another 50 lbs of N/acre on ryegrass in early spring (mid-March – mid-April). Applications of N at these rates are likely to result in more than 15-20 lbs of DM per lb of added N for the late winter application and more than 20-25 lbs of DM per lb of added N.  As a general rule of thumb, N response rates greater than 15-20 lbs of DM per lb of added N will result in an economical response.

The response to N (lbs of DM gained per lb of added N) has to be considered in context. To illustrate this, let us consider three scenarios:

Scenario 1) Ryegrass or small grains that have been slow to grow, either because of bad weather or N deficiency (and, sometimes, a late planting). These winter annual forage crops will often respond very aggressively to a winter application (20-30 lbs of DM per lb of added N assuming N rates are 40 – 60+ lbs of N/acre).  It is analogous to compensatory gains in growing livestock. It is the same basic principle: an organism that has had growth limitations will often grow at extraordinary rates whenever those factors are no longer limiting.

Scenario 2) Ryegrass or small grain plantings that have been growing strong. Winter annual forage crops in this scenario are unlikely to respond as aggressively to N at this time. For example, they may barely provide 15 lbs of DM per lb of added N during the few weeks following N application. However, this N is still crucial, as it keeps the plant growing at least at a healthy rate. Therefore, it is important to fertilize them at the same or nearly the same rates because they will need the fertility during the remainder of the season.

Scenario 3) Winter annual forages that have been moderate to severely damaged by disease (Helminthsporium leaf spot, grey leaf spot/blast, leaf rust, or barley yellow dwarf virus, etc.). These forage crops are unlikely to respond to N application. For example, tillers that are exhibiting physical symptoms of barley yellow dwarf (BYD) infection will die quickly, especially following a hard freeze. Therefore, if more than 30% of the tillers in a stand of oats have been damaged by barley yellow dwarf, those plants are unlikely to respond well to N. Each producer will have to determine if they are willing to take the risk, but if it were my oats, I doubt I would put any more N into those areas/fields.

Advertisements

Leave a comment

Filed under Fertility, Forages

Warm Winter And Pecans

UGA Extension Pecan Specialist Dr. Lenny Wells has an update on pecans:

We haven’t had much of a winter this year. We’ve only had 4 days where temperatures dipped below freezing in Tifton and the average temperature since November has been 57 degrees as opposed to 55 degrees last winter. We’ve also accumulated only 368 chill hours as opposed to the 559 chill hours we had by this time last year.

Nursery tree leafing out on 2/21/17 - Photo by Dr. Lenny Wells

Nursery tree leafing out on 2/21/17 – Photo by Dr. Lenny Wells

For many fruit trees, once buds have entered dormancy, they will be tolerant to temperatures below freezing and will not grow in response to mid-winter warm spells. These buds remain dormant until they have accumulated sufficient chilling units (CU) of cold weather. When enough chilling accumulates, the buds are ready to grow in response to warm temperatures. As long as there have been enough CUs the flower and leaf buds develop normally. If the buds do not receive sufficient chilling temperatures during winter to completely release dormancy, trees will develop various physiological symptoms associated with insufficient chilling.

Its really not clear how many chill hours pecans need, probably because there is so much variation from one variety to the next. It is reported that 300 -500 chill hours are required for Desirable, Mahan, Success, and Schley, while Stuart reportedly requires from 600-1000 (I think that’s a little high, myself). Interestingly, Terminal buds have lower chill requirements than lateral buds. So, after a cold winter you may have heavier crop loads because more lateral buds flower and get pollinated at the right time.

In general, pecans don’t need a lot of chill hours. At the southern end of its range in Mexico, you can have trees that receive less than 100 chill hours, and still produce nuts. The actual chilling requirement for pecans also varies with fall temperatures. If trees are exposed to cooler fall temps (less than 34 degrees F) the intensity of the bud’s rest is greater and the number of chill hours required for budbreak increases.   But, the colder the winter, the fewer the heat units in spring required to start budbreak. Heat units in spring strongly influence budbreak and drive the progression of the crop’s maturity. So, with a cold winter and warm spring you can actually get a pretty early budbreak.

We had a warm fall, therefore the intensity of the bud’s rest is weak and the number of winter chill hours required for budbreak will be lower. Indeed if you look around at the edges of fields and in the woods you will see red maples, red buds, and oaks budding out. Azaleas are blooming in the yards. And yes, some pecans are even budding out already as you can see from the pictures above. Unless we have a cool spell to slow things down I expect to see a lot of buds breaking within 2 weeks. What will this mean for the crop?

Well, the main thing is we have to hope and pray for a warm spring with no late freeze. Any late freeze down into the 20’s for any significant length of time after the shoots begin expanding, putting on catkins and female flowers will cause serious problems. The tissue would be burnt off by the freeze. The trees would shoot back out, and grow. We would lose that flower crop and some varieties would try to put on more flowers but most of those secondary flowers either wouldn’t develop into nuts or the nuts would be of very poor quality (because pollination would be off).

Beyond a late freeze, the most likely problem will be poor pollination. Because budbreak tends to be so sporadic, staggered, and non-uniform when you have low chill hours, the synchronization of female flowers with male flowers from the pollinators is usually off, leading to poor nut set and poor quality. The more cold snaps we have from here on out, the more non-uniform budbreak and flower development will be. So, from this point on we need it to stay warm.

Leave a comment

Filed under Pecans

2017 Pond Management Program

2017pondmeeting

Leave a comment

February 21, 2017 · 9:48 PM

2017 UGA Recommended Soybean Varieties

The to UGA Extension Agronomist Mark Freeman and UGA Extension Weed Scientist Dr. Eric Prostko, The following is the current list of UGA recommended soybean varieties for 2017. To make it on this list, a soybean variety must 1) perform, at least, at or above the 2-year average in yield across 6 Georgia locations (12-test average); 2) must not be susceptible to stem canker; and 3) other considerations include new herbicide tolerances or nematode resistances.

soybeanvarities-1

II. Coastal Plain and Piedmont (Late Planted)

soybeanvarities-2

 

Leave a comment

Filed under Soybeans

Citrus Grower’s Association Meeting – Feb 27

Mrs. Lindy Sevell, President of the Georgia Citrus Growers Association, is planning the associations first citrus meeting. If you are interested, here is some information below:

Date: The Georgia Citrus Association is planning its first annual meeting for February 27th. 

citrusLocation: UGA Tifton Campus Conference Center, 15 RDC Road

Tifton, Georgia 31794

Time: 9:00am – 3:00 pm

Potential Speakers:

  1. Dr. Wayne Hanna – new UGA releases
  2. Travis Murphy- Diversity of Crops
  3. Robert Sexton- packing of fruit
  4. Seald Sweet International – marketing & sales
  5. Mack Glass – practical experience of growing
  6. Chris Anglin – possible crop insurance

Tours:

UGA Grove

Tangerine/Lemon/Grapefruit Grove with Perennial Peanut Middles

Registration:

To register for this meeting use the link below. The cost is $15.00 per person. If you wish to join the citrus association at the same time it will be $65.00. Lunch is included. Registration closes February 20th.

https://www.eventbrite.com/e/georgia-citrus-association-annual-meeting-tickets-31756818499

Leave a comment

Filed under Citrus

Early Weed Control In Satsuma’s

UGA Extension Agent in Lowndes County, Jake Price, has this update on weed control:

The warm weather we have been experiencing is unbelievable. Usually we can depend on Jan and Feb for some cold temperatures. With these temps trees may be waking up early which is not good especially if we have a late hard freeze. Time to apply the first application of fertilizer is approaching as well (late Feb to early March). Also if you plan to use a preemergent herbicide, it will be wise to put that out very soon. Attached is the fertility recommendation for satsumas from Auburn University and a fact sheet on herbicides and leaf miners.

If you have been using the same herbicides/pesticides over and over, it will be smart to rotate other materials that are not in the same class. There are a couple of miticides that will also have efficacy on citrus leaf miners, (Ari-Mek and Micromite). Citrus leaf miners have not been damaging our first flush of new foliage so wait until after bloom to apply any insecticides. This will also be a more “bee friendly time to apply your pesticides”. This is usually around the first of May.

Pre-Emergent Weed Control

These herbicides should be applied to a fairly clean soil surface prior to emergence of weeds. In Georgia/North Florida late winter is a good time for the first application. At least two applications are needed per year. Common practice in Florida groves is to not use pre-emergence herbicides on newly planted trees although several herbicide labels below allow for their use.

Satsuma-PreEmergeWeedControl

Post-Emergent Weed Control

These herbicides are either systemic or contact herbicides. Systemic herbicides are translocated throughout the plant while contact herbicides kill plant parts in which they touch. Drift from systemic herbicides will likely cause more damage to trees.

Satsuma-PostEmerge-WeedControl

Mechanical Weed Control

The use of landscape fabrics around trees can help eliminate weeds. Also, the use of BH-10 (both hands, 10 fingers) can be used around trunks of small trees where cultivation or landscape fabrics are not applied. Cultivation or tillage can be used but at the risk of damaging fibrous root which can lead to invasion of pathogens or insects.

For more information, UF has a publication on 2015 Citrus Pest Management – Weeds.

Leave a comment

Filed under Citrus, Weed Science

2017 Pecan Spray Guides

2017pecansprayguideUGA Pecan Specialists Dr. Lenny Wells and Jason Brock gave their first of the season program for us in Thomasville yesterday. Dr. Wells updated us on hedging, spacing, and storm damaged trees. Mr. Brock talked to us about our fungicides and resistance issues.

Dr. Wells announced the newest pecan spray guides are now in. Lenny will not have them printed this year, but if you need us to print one for you, we can do that at the office.

Here is the link to the 2017 Commercial Pecan Spray Guide.

UGA Extension Specialist Dr. Lenny Wells presents at the 2017 Pecan Production Update

UGA Extension Specialist Dr. Lenny Wells presents at the 2017 Pecan Production Update

Leave a comment

Filed under Pecans