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.
- Following additional rainfall over the holiday weekend, sanitation will be critical in strawberries to remove water-soaked and diseased berries. Maintain fungicide applications for gray mold and anthracnose prevention. Keep scouting for spider mites.
- Blueberries are approaching the end of harvest with excellent quality.
- Blackberries are ripening well with the first pick occurring over the weekend.
- Brassica crops look good, but we are observing increasing numbers of diamondback moths. Remember to rotate modes of action to prevent resistance development. Adding an organosilicon spreader such as Silwet can effectively improve coverage.
- Cucurbit crops are developing well, with early crops approaching harvests in a few weeks. Squash bugs remain in high populations. Given the cool, damp conditions, gummy stem blight and downy mildew are expected to increase. If you have used tebuconazole, switch to another active ingredient, such as difenoconazole (Inspire Super), to prevent further sensitivity shifts to tebuconazole. For downy mildew, remember to restrict Orondis applications to one-third of the total number of applications. So, if you make three downy mildew applications, one can be Orondis.
- Squash and cucumbers are coming to harvest with good volumes and quality.
- Tomatoes and peppers are looking good with a good fruit set. Bacterial spot will continue to be a risk given rainfall and wet, cool weather. Monitor for thrips by tapping flowers against plain paper and looking for adult thrips.
- Lots of rain over the past week will cause disease pressure to be high, as many fields have standing water.
- Strawberries are still being harvested. Cool night temps are helping extend the season some, but disease pressure is getting heavy with wet weather. We are seeing some leather rot on berries and anthracnose.
- We are in a lull for peach harvesting due to early varieties being damaged by cold events in March. Mid-June varieties should be heavy enough for packing sheds to begin running again. Brown rot and bacterial diseases are heavy this year due to ideal winter inoculation conditions and reduced spraying schedules.
- We’re finding spotted cucumber beetle in white potatoes. These beetles, along with their striped cousin, are really not much of a problem on their own. Unfortunately, they both can transfer bacterial wilt (Erwinia tracheiphila) from their feces into cucurbit plants like watermelon and cantaloupe. Scout and be aware of these pests.
- We began planting sweet potatoes in the Upstate.
- Strawberry production is continuing, although rains have caused much damage to ripe fruit. Overripe and water-damaged fruit have brought on some sap beetle issues also.
- Peaches are still very slim in the upstate. We will have some coming later this summer.
- Tomatoes are being harvested in greenhouses and high tunnels.
- Muscadines still haven’t started blooming, but flower buds are present. The grape crop took some damage from the December arctic blast. Cordons further away from the trunk have more damage, and many had to be cut back. They are now being fertilized a little more than normal to re-establish them.