Lowndes County Agent Jake Price has put together another citrus program for Monday, April 25th at the Lowndes County Extension Office. The main topic of discussion is forming a citrus growers association. There will be a $15 registration for a meal, so RSVP by April 20th.
Category Archives: Citrus
We had a few frosts this week. With record warm temperatures in December, this cold is going to help some of our winter crops claim some chill hours. We’ve also been having plenty of rain as El Nino was predicted. Here are some screen shots of rain, temperatures and chill hours from the Dixie weather station from www.georgiaweather.net. You can see how much lower chill hours are as were last winter this far. The ’12 to ’13 winter was also warm.
Our forage crops look okay and hearing some good reports. We need to watch some of our forage now as cool temperatures are going to come back this weekend and next week. Oats, of course, are more susceptible to the cold damage. Some cattlemen are fertilizing forage after heavy grazing to encourage new growth. Ryegrass is one of our small grains that has 3-way split, with one fertilization through the winter. Everything else we fertilize once at planting and then before spring to encourage more tiller growth. We may want to be careful with management inputs during these upcoming cold hits. Below is the forage recommendation fact sheet from the UGA Soil Test Handbook:
Here are some oats I looked at today. Overall, they look good. Fields are wet and we need to watch for compaction. And we need to watch our grazing. To determine when to pull cows off, we look at the node or joint inside the stem of the plant. This is the growing point, and it feels like a bump or bee bee inside the stem. We don’t want them to graze lower than the growing point. In the picture below the joint is between my thumb and the roots.
I also see a little crown rust showing up. These orange/red pustules on the leaf resemble that of aphid feeding. The rust pustules will rub off on your finger. They are also raised above the leaf.
Crown rust will cut back on yield even in grazing, so we have to graze heavily when rust is seen so we remove the leaf tissue where spores land.
Some crops are not going to appreciate the cold. Thomas County has 2,500 citrus trees in commercial production now – mostly Satsumas. The biggest challenge for citrus north of Florida is cold protection. Certain plants handle cold more than others. Satsumas have the greatest degree of cold hardiness. Bearing satsumas can withstand temperatures as low as 19º to 20ºF without considerable wood damage. (Citrons, lemons and limes, on the contrary, are most easily killed by freezing temperatures – as low as upper 20s.)
I took a picture of these satsumas Tuesday morning. The temperature that morning was 29 degrees. Once temperatures get down to 24 and 25, they will cut on the irrigation as a form of cold protection. Previous cool weather allowed the plants for some cold acclimation. Cold acclimation is very important for citrus. The sudden, hard freezes in November 2014 hurt us so much more, because plants were essentially not ready for the cold. A few nights in the upper 20s is good for our citrus.
Cold damage always takes some time to show up. Lowndes County Agent, Jake Price, gave a good talk on cold damage at the Satsuma meeting this week. There are a few types of cold damage we may see. Sometimes damage occurs on the leaves only. If damage is on the stem, it is worse. If the plant incurs cold damage on the leaves, it may drop those leaves. This is a good sign since the plant has to be alive to drop the leaves. If cold damage occurs and leaves do not drop, this is not good news. Here are some pictures of cold damage. The darker green is cold damage:
There is more and more interest in planting Satsumas in Georgia. They are a very tasty orange that is self-fruitful and ripens its fruit well ahead of any freeze problems (September to November). Although Satsuma’s have the best cold hardiness of citrus, they still need cold protection and irrigation. Fellow county agent, Jake Price in Lowndes County is researching varieties of Satsuma’s that do best in South Georgia. Here are about 100 new Satsuma trees recently planted after cold killed most this winter. These varieties are Owari and Sharanui.
I was asked to check on the leaves which were curling up as a result of a leafminer. The leafminers are either a fly or a moth. This is common in citrus and doesn’t cause much of a problem unless damage is very heavy. In a commercial field, treatment is still recommended. Eggs are laid on new leaves and the larvae mine underneath the cuticle of the leaf. The leaf will most times curl if damage is severe.
We can use imidacloprid to treat for leafminers. We can spray on the foliage which will stay for some time. Imidacloprid, like pyrethroids photodegrades. We can also drench imidacloprid into the soil which is taken up by the roots and provide longer control. UGA Extension Entomologist Dr. Will Hudson has this to say about drenching:
The drench rate for Admire (a 4.6 lb/gal formulation) varies according to the tree size, but it ranges from 10-20 trees per fluid oz. (14 oz/acre). The amount to add to a bucket depends on how many trees will be treated with that batch. You probably need to pour 1-2 qt. per tree, depending on the size (I use 2 gal per tree for pecan trees 8-10 inches DBH). So, decide how many trees will be drenched, and add 0.05 fl. oz. per 3′ tree. For the 2 lb material, the label suggests 3-6 ml per inch DBH (5 ml = 1 tsp) or about 1 tsp per 3′ tree.
I also saw some white flies. That along with the big Orange Dog caterpillars are some things we need to look for now. The Orange Dog caterpillar eggs will be orange under the leaves.