Copper resistance in bacterial leaf spot of tomato and pepper crops has been detected at a high level in New Jersey the past few summers. While not surprising, copper resistance has been known to develop for decades now. Copper applications for the control of bacterial diseases in many crops has been a mainstay for decades now and is often applied in weekly protectant fungicide programs. With help from Dr. Nrupali Patel and Dr. Don Kobayashi, bacteriologists in the Department of Plant Biology located on the New Brunswick campus, a (NJ-VGA funded) survey was initiated to determine which species of bacterial leaf spot are most prevalent in New Jersey tomato and pepper crops. Bacterial leaf spot can be caused by four species of Xanthomonas: X. euvesicatoria, X. vesicatoria, X. perforans, and X. gardneri. Currently, there are four races of BLS found in tomato (T1-T4; one for each of the 4 species stated above) and eleven races found in pepper (0-10). Differential tests in southern New Jersey using various bell pepper lines over the past 15 years has suggested that the number of races of BLS in pepper has increased over time; with all races present in the State to date. Lab testing results from samples collected from the small number of NJ vegetable farms the last three summers has shown the presence of X. euvesicatoria in pepper, as well as X. euvesicatoria and X. perforans in both tomato and pepper in the state, with ~60% of all samples testing positive for copper resistance.
Bacterial leaf spot, copper resistance, hot water seed treatment, and viruses
Bacterial leaf spot control and copper resistance in pepper and tomato
Copper resistance in bacterial leaf spot of tomato and pepper crops has been detected at a high level in New Jersey the past few summers. While not surprising, copper resistance has been known to develop for decades now. Copper applications for the control of bacterial diseases in many crops has been a mainstay for decades now and is often applied in weekly protectant fungicide programs. With help from Dr. Nrupali Patel and Dr. Don Kobayashi, bacteriologists in the Department of Plant Biology located on the New Brunswick campus, a (NJ-VGA funded) survey was initiated to determine which species of bacterial leaf spot are most prevalent in New Jersey tomato and pepper crops. Bacterial leaf spot can be caused by four species of Xanthomonas: X. euvesicatoria, X. vesicatoria, X. perforans, and X. gardneri. Currently, there are four races of BLS found in tomato (T1-T4; one for each of the 4 species stated above) and eleven races found in pepper (0-10). Differential tests in southern New Jersey using various bell pepper lines over the past 15 years has suggested that the number of races of BLS in pepper has increased over time; with all races present in the State to date. Lab testing results from samples collected from the small number of NJ vegetable farms the last three summers has shown the presence of X. euvesicatoria in pepper, as well as X. euvesicatoria and X. perforans in both tomato and pepper in the state, with ~60% of all samples testing positive for copper resistance.
Controlling Septoria Leaf Spot and Bacterial Leaf Blight in Parsley
Septoria leaf spot (SLS) in Parsley can cause significant losses in fields where it has become established. Like other Septoria’s, the leaf spots produced on parsley look much like the leaf spots produced on tomatoes and other crops. Septoria leaf spot overwinters from year to year on infected debris so long crop rotations of 2 or more years are important to help reduce disease pressure. During the season, SLS will spread rapidly with each subsequent rainfall and/or overhead irrigation event. Therefore, early detection and preventative fungicide applications are key to successfully controlling SLS. There have been a few new fungicides labeled for SLS control in the past few years.
Septoria leaf spot of Parsley
Vegetable Disease Update: 08-24-23
- Cucurbit downy mildew has been reported on pumpkin, butternut squash, spaghetti squash, cucumber, and cantaloupe in New Jersey. For more information on CDM control please click here.
- Pepper anthracnose is being reported in New Jersey. For more information on controlling anthracnose fruit rot please click here.
- Basil downy mildew has been reported in New Jersey.
- There have been no reports of Late blight in potato or tomato in the region to date. To follow the progress of Late blight in the US please click here.
- Bacterial leaf spot has been reported in pepper. More more information on BLS control please click here. Rutgers is surveying tomato and pepper fields throughout the state this summer to help determine the makeup of the bacterial population and for copper resistance development.
- Powdery mildew has been reported in cucurbit crops. For more information on the control of CPM please click here.
- For information on diagnosing important diseases in pepper, tomato, and cucurbit crops please click on links.
- The 2022/2023 Commercial Vegetable Production Recommendations Guide is available for free online or for sale in hardcopy form at many County offices.
- For a quick review on managing fungicide resistance development using tank mixes and fungicide rotations, and information on FRAC group 4, FRAC group 7, and FRAC group 3 and FRAC group 11 fungicides please click on hyperlinks.
Vegetable Disease Update: 07-29-23
- Basil downy mildew has been reported in New Jersey.
- Rhizoctonia root rot has been reported in tomato and other vegetable crops.
- Phomopsis and Phytophthora fruit rot has been reported in eggplant.
- Collar rot has been reported on tomato. For more information please click here.
- Pythium cottony leak has been reported on pepper. For more information on controlling Pythium and Phytophthora please click here.
- Pepper anthracnose has been reported in southern New Jersey. For more information on controlling anthracnose fruit rot please click here.
- Cucurbit downy mildew has been reported on cucumber and cantaloupe in New Jersey with more being reported on the East Coast and Ontario, Canada. For more information on CDM control please click here.
- Blackleg has been reported on potato in New Jersey.
- There have been no reports of Late blight in potato or tomato in the region to date. Late blight has been reported in Ontario, Canada. To follow the progress of Late blight in the US please click here.
- Bacterial leaf spot has been reported in pepper. More more information on BLS control please click here. Rutgers is surveying tomato and pepper fields throughout the state this summer to help determine the makeup of the bacterial population and for copper resistance development.
- Powdery mildew has been reported in cucurbit crops. For more information on the control of CPM please click here.
- Southern blight has been reported on pepper.
- Bacterial canker has been reported in tomato. For more information on diagnosing important tomato diseases please click here.
- For information on diagnosing important diseases in pepper, tomato, and cucurbit crops please click on links.
- The 2022/2023 Commercial Vegetable Production Recommendations Guide is available for free online or for sale in hardcopy form at many County offices.
- For a quick review on managing fungicide resistance development using tank mixes and fungicide rotations, and information on FRAC group 4, FRAC group 7, and FRAC group 3 and FRAC group 11 fungicides please click on hyperlinks.
Vegetable Disease Update: 07-22-23
- Collar rot has been reported on tomato. For more information please click here.
- Pythium cottony leak has been reported on pepper. For more information on controlling Pythium and Phytophthora please click here.
- Pepper anthracnose has been reported in southern New Jersey. For more information on controlling anthracnose fruit rot please click here.
- Cucurbit downy mildew has been reported on cucumber and cantaloupe in southern New Jersey with more being reported on the East Coast and Ontario, Canada. For more information on CDM control please click here.
- Blackleg has been reported on potato in New Jersey.
- There have been no reports of Late blight in potato or tomato in the region to date. Late blight has been reported in Ontario, Canada. To follow the progress of Late blight in the US please click here.
- Bacterial leaf spot has been reported in pepper. More more information on BLS control please click here. Rutgers is surveying tomato and pepper fields throughout the state this summer to help determine the makeup of the bacterial population and for copper resistance development.
- Powdery mildew has been reported in cucurbit crops. For more information on the control of CPM please click here.
- Southern blight has been reported on pepper.
- Bacterial canker has been reported in tomato. For more information on diagnosing important tomato diseases please click here.
- For information on diagnosing important diseases in pepper, tomato, and cucurbit crops please click on links.
- The 2022/2023 Commercial Vegetable Production Recommendations Guide is available for free online or for sale in hardcopy form at many County offices.
- For a quick review on managing fungicide resistance development using tank mixes and fungicide rotations, and information on FRAC group 4, FRAC group 7, and FRAC group 3 and FRAC group 11 fungicides please click on hyperlinks.
