Increased Workload during COVID-19 2020 for Commercial Fruits and Vegetables Agent

March 11, 2021

crops in fieldI was also able to test out a new botanical omri (organically) approved botanical fungicide for use on peach for blossom blight.  I was able to perform two tests of this product on farm to see its effectiveness. I was able to test it at Glory Farms in York Co. SC on Downy Mildew of several leafy greens and this was under a protective structure. I was also able to test it on Blossom blight of peach at peach farm near Chesnee SC. Neither test was randomized. I will summarize my findings separately.  Glory Farms is an organic farm and had a problem in their spinach greens but upon investigating it was downy mildew and the disease was widely spread throughout multiple greens varieties and species and throughout the entire protected house. The disease was progressing rapidly. There weren’t many options for her organically and I wasn’t sure what I was going to recommend.  I remembered that I had the new product you had told me of EcoSwing but I had not considered it because my plans were to use it for peach.  After speaking with the company representatives, it was labeled and worth giving it a try even though this was more of a “rescue” kind of situation at that point.  On March 6, 2020 I sprayed the product myself on 4 rows of greens.  There were 2 rows of spinach 1 ½ rows of Arugula, and ½ row of Mustard. I mixed the product at a rate of 1 fl.oz./gallon of water and sprayed each 40 foot row with 1 gallon of product. In the worst areas on each row I made sure to leave a small 3 foot area of row unsprayed to be able to see the difference between sprayed and unsprayed easily. I had the grower inspect the plants for the next two days after application and there was no foliar damage from applying the product even though I had applied during the hottest part of the day. After 2 weeks, I returned to assess the results. I found that product was able to control this disease. My controls were completely destroyed with very few plants remaining in those entire blocks but my treated areas were fully intact albeit the disease wasn’t completely eradicated. I should have had actual stand counts before and after to better show this more accurately, but I only did estimates of % of full stand.  Spinach before treatment was estimated at 75% of a stand and 2 weeks later still retained 75% of a stand or possibly slightly higher. The Arugula and the mustard were in similar situations but started with slightly higher stands 85% and finishing with 85%. The untreated controls for spinach started with the 75% but ended up with less than 10% as did the arugula and mustard went from 85% down to less than 10% of a stand 2 weeks after application.
I also tested EcoSwing in the bloom of CaroKing variety peaches. The grower in this case sprayed twice with product during bloom.  I evaluated the bloom by taking bloom counts between the control and the treated row.  Unfortunately, the disease pressure was very low and, unknown to me at the time, I did not have a true untreated control. I had trees that had EcoSwing being compared to trees that had Bravo applied at the same interval. On each branch I just looked at the number of surviving blooms/fruit versus number total number of flowers present to try and compare. I wasn’t able to find anything that I knew for sure was blossom blight so this was an attempt to see if there were any differences between the two treatments. There were none.  The Bravo treated trees and the EcoSwing trees both had nearly identical numbers of surviving flower/fruit. Cold damage had also hurt this crop as well. It is a little more bud tender than many. Assessment was done on March 20th. Picture below shows one of the shoots I would take data on counting number of live flowers/fruit to total number of flowers/fruit per shoot.  I still have some product left over that was not used. Hopefully, this coming year I will have more time to plan a small protocol for evaluating it on peach or possibly strawberry.  I am thankful I now know more about this product and what it is capable of doing.

I tested two products (AKX‐835 / AKX‐244) for cold freeze protection claims as compared to a control early this spring.  Agro-K is a fertilizer company and have two proprietary products they allowed me to test for frost freeze protection.  They were applied according to there protocol with temperature recorders in each treatment and at different heights within the trees.  Treatments were not replicated but were randomized within a block of ‘Flavorich’ peach trees at a farm near Cooley Springs, SC.  Multiple applications were made of the products approximately 24 hours before each of the freeze events as directed from early bloom through end of bloom.  Fertilizers were sprayed thoroughly into the trees at approximately a 200 gal/acre total volume with the appropriate product at the suggested rate.  Bloom began shortly before February 26, 2020 when recorders were placed in the trees and first application made.  Our first freeze event in the bloom occurred on February 27th (27F low), 28th (25.5F low), 29th (28F low), March 1st (21.2F low).  Second application was made on March 6th and we had freezing temperatures on March 7th (24.8F low), 8th (29F low), and 9th (29.8F low).  These products never claimed to give this degree of protection in fact after talking with company representatives they didn’t expect the products to have worked at all.  I waited until after fruit had fully pollinated and fruit had grown to golf ball size but had not been thinned.  Dr. Guido Schnabel and I did random branch fruit counts on each of the treatments and the control.We found no significant differences between treatments even though there appeared to be a higher fruit load on the AKX-835 treatment.  The grower estimated only ½ bu per tree in the AKX-234 and 2 ½ bu per tree in the AKX-835 and the control treatment.  The control treatment was badly selected as it was an outside row receiving more sunlight which was exaggerated because the trees were planted in east to west orientation.  The control trees also bloomed about 1 week later than the rest of the block of trees.  I am glad I did this work with the assistance of the grower.  Further examination is planned for next year.

Planted onfarm muscadine trial with novel true seedless plants developed from Gardens Alive Nursery and also some plants from the breeding program at the University of Georgia, Dr. Patrick Conners program on a large muscadine farm near Inman, SC.  The purpose of establishing this test site was to expose the significantly sized grower some other options that are available to him.  I also plan on doing demonstrations on this site in the future and including other novel varieties that I receive from breeding programs that show promise.  This years work amounted to planting and multiple visits to prune, tie/train, fertilize and spray if needed to take care of these plants.  Many of these plants have reached the top wire and are now developing the cordons.  Some fruit data will be available next year.  Also with the help of a master gardener volunteer we were able to take diameter measurements at planting.  I will measure them again this winter to get a measure of how much each of them grew this year.  Bloom, fruit yield and fruit quality will all be measured next year.

Insect monitoring paid off in assisting all of the peach growers in the Chesnee area with critical information on whether or not their sprays were controlling a fruit worm that had done significant damage in previous years.  With the information we were able to provide we were able to save growers and the environment from ineffective sprays.  We also helped make recommendations as to rotations of insecticides that would be helpful for controlling this pest.

I remained vigilant this year on assisting growers with there on farm needs related to insect and disease problems as well as weed control problems and the like.   I am currently assisting many growers with planting of strawberry plants.  We have 1 new grower in the area and many others who have never used the type of plant they are having to use this year directly because of problems with getting strawberry plants due to COVID outbreaks in the strawberry plant growing regions.  It was a very different year but a very successful year for many of the farms.  Thank you so much for your continued support of Clemson Extension Service!


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