Clemson Extension Agents Provide Crop Updates

Weekly Field Update

Clemson Extension agents provide updates in The South Carolina Grower this week about the status of various crops being produced throughout the state.

Coastal Region

Anna Sara Hill

• The temperatures have been all over the place this month, ranging from below freezing several nights to daytime temperatures in the 70’s, and everything in between. Looks like we will see another warming trend this coming week. Watch the forecast and stay vigilant about frost protection as we still have potential for freezing through March. 
• Around the area, growers are prepping fields, taking soil samples, applying lime and disking fields. Watermelon and vegetable growers have started fumigating and laying plastic. It is also time to treat with pre-emergence herbicides. 
• Peaches in the area were just starting to break buds last week. Pruning is well underway and the last dormant oil sprays were put out early last week, just before the weather turned cold again. 

Zack Snipes

• We had a cool week last week but lots of bright sunny days. We have a bright and slightly warmer week ahead which should really push spring crops. Spring onions, lettuce, collards and strawberries are all coming along and will really flush this week. 
• Make sure to get out in the fields and scout for insects and diseases. Now is the best time to curb later season problems. I haven’t seen too many issues lately but suspect spider mites, aphids, and many diseases will increase in the next few weeks.
• I have seen both thrips damage and botrytis damage to spring onion lately. 
• We should have already gotten out our boron and fungicides on our strawberry crop this past week. We should be covering them during cold events from now on to protect blooms. I would start running liquid fertilizer to them this week. I think we will see a tremendous jump in plant size and blooms this week. 

Midlands

Sarah Scott

• It’s the time of year where the weather can’t decide which season we’re in, and our warm days faded into freezing nights this past week.
• Warm temperatures and pruning have signaled the peach trees to move out of dormancy. Many peach trees are in the bud swell phase, while some of our earlier varieties are entering into pink and even first bloom stage. With temperatures falling well below freezing two nights in a row, the question is raised as to whether we should be worried about the crop. If you go by this critical temperature chart from Utah State, we are going to be fine. Peach trees in pink stage would need to be in temperatures below 15 degrees Fahrenheit for several hours to show up to 90% damage/bud loss. The temperatures reached last week may have nipped the earliest blooms on the trees, but at this point, that would serve as natural thinning and cause no real damage. Peach trees can yield a good crop with only 15% bud survival. Warm weather in the forecast for this week will cause trees to move quickly into their bloom stage, and at that point, we will be watching the temperatures more closely.
• Strawberries were tucked in under row covers to protect them from the 20-degree nights. As covers come off and temperatures rise, we will keep a close eye out for spider mites and other issues.

Pee Dee

Brittney King

• Most strawberry fields were covered last week as the Pee Dee experienced a few nights with freezing temps. Plants are beginning to push blooms, so growers are trying to protect the flowers. The biggest issue I am seeing is plants struggling to size up due to Neopestalotiopsis (neo). I have also seen a good number of plants collapsing from J-rooting. Nothing can be done about that now. Continue scouting for spider mites as we head into warmer weather next week, and stay on top of your preventative sprays for neo like Thiram and Switch. 
• Leafy greens are progressing well. Be sure to continue scouting for signs of black rot and/or insect damage.
• Pruning operations for blueberries are underway, and some of the earlier varieties are starting to show buds, but overall health looks great.
• Onions are growing well so far, but make sure to watch for any leaf spots and manage your fertility. Late-season fertilizer applications can lead to rot and shortened shelf life, so make sure to pull back on fertility prior to harvest.  

Upstate

Andy Rollins

• Plum, peach and blueberry all have some varieties that have entered bud swell stage and have become more susceptible to freezing temperatures. We hit 16 to 17 degrees F last week. Plums at this stage start taking damage at 14F; peaches 18F; and blueberries 15F. Plums were further out than peaches and were not hurt at all, thankfully. Peaches only had a few varieties that had started bud-swell on the furthest branches. Some early Southern highbush blueberry varieties in the Upstate did have some damage. They were slightly past bud swell into the tight cluster stage.
• We are still pruning all our fruit plants. On peaches, we are finding San Jose scale. Growers should prune, then spray with oil this week with a minimum of 100 gallons of solution per acre. Most varieties are still in the dormant stage and should be using 3% mineral oil with two pounds MCE copper. If applied at bud-swell stage, growers need to reduce oil percentages to 1.5% or 1.5 gallons per 100 gallons of water to reduce damage to buds. The copper is applied to help keep bacterial canker/Pseudomonas sp. population at bay. Some growers used to use lorsban/chlorpyrifos to assist controlling scale, but limited supply and labeling issues have restricted this.