Canker is the most destructive of the bacterial diseases affecting tomato with greater potential to kill plants than bacterial speck or spot. Fortunately there has been very limited occurrence on Long Island in recent years. It has been seen occasionally in some commercial production fields, often on farms where seen before, and a garden.
Meg McGrath, a Cornell University plant pathologist based at the Long Island Horticultural Research and Extension Center, is an internationally recognized researcher, sought-after speaker, and well-versed in the solutions to devastating plant diseases.
And for growers with trouble on their hands, she’s available at a moment’s notice.
These qualities and more have earned McGrath an Excellence in IPM award from Cornell University’s New York State Integrated Pest Management Program (NYS IPM).
McGrath’s expertise spans the gamut of IPM strategies and tactics that both organic and conventional growers use to combat disease pests such as late blight and downy mildew. “Meg embraced the concepts of integrated pest management from the beginning of her career,” says colleague Margery Daughtrey. “She does a splendid job of bringing her discoveries to the practical level for growers in dozens of presentations annually.”
But it’s her help in the field that farmers value the most — help that’s delivered with a welcome dose of levity. “Meg’s funny,” says Marilee Foster at Foster’s Farm in Sagponack. “She’ll say ‘I’m sorry, I’m a plant pathologist. I like to study sick plants.’” When a nearby outbreak of late blight threatened Foster’s organic heirloom tomatoes, Meg came to help scout — “arriving early so we’d have the visual benefit of dew,” Foster says.
When they found a handful of plants with symptoms, McGrath reviewed Foster’s alternatives, but none were suited for organic crops. The strategy they hit on together? Using a handheld weed-flamer to take down suspect plants. “Blight can’t handle temperatures much above eighty degrees,” Meg told Foster. “And it might feel good!” Which, Foster agrees, it did.
Meg focuses on core IPM principles — principles such as careful identification so you don’t treat a disease the wrong way, or changing a crop’s environment to outsmart its pathogens. “She helps Long Island growers deal with the limited availability of products they can use to manage pests, given the island’s heightened groundwater concerns,” says Jennifer Grant, director, NYS IPM. “It’s not every day you find someone who brings such warmth and knowledge to a position that means so much to so many farmers’ livelihood.”
Marilee Foster echoes that. “I have long admired the energy and curiosity Meg brings to farmers in eastern Long Island. We are lucky to have her working with us, for everyone.”
McGrath received her award on January 18 at the 2017 Empire State Producers Expo in Syracuse, New York. Learn more about integrated pest management at nysipm.cornell.edu.
Symptoms of Phytophthora blight on eggplant include leaf spots that can be large, fruit rot, crown rot, and dieback of the growing tip. Plants with the last two symptoms often die.
This disease has been more commonly found in cucurbit crops (especially pumpkin and squashes) and peppers. Other susceptible crops are tomato and snap bean.
Bloat (aka stem and bulb) nematode was confirmed on garlic four times on Long Island between 2010 and 2016. This nematode (Ditylenchus dipsaci) occurs where contaminated cloves were planted. It can survive in soil for at least 4 years. Dry soil favors survival.
Above ground symptom is yellowing of foliage and plant stunting, which has been noticed in late spring. Twisting of foliage can also occur. These symptoms are due to the nematode feeding on roots. All roots may be gone. Rot often doesn’t extend far into the bulb unless other organisms, in particular soft rot bacteria, are present.
White mold (aka timber rot) has been observed occasionally on Long Island in tomatoes growing in the field and in high tunnels. Other crops observed affected in the area include pepper, lettuce, and cabbage.
Diagnostic feature for white mold is the black, hard structures resembling rat droppings the pathogen forms on or in diseased tissue (sclerotia). These are inside tomato stems that are white and dry because of the disease. Sclerotia are how the pathogen survives for many years. It is worthwhile, especially in high tunnels, to remove affected plant tissue and thus the pathogen’s survival structures.
Beans are not as commonly affected by Phytophthora blight as other crops, notably cucurbit crops and peppers. Beans have not been recognized as a host for the pathogen (Phytophthora capsici) for very long. First report was 2003 in Michigan. In 2008 the disease was confirmed on Long Island, and subsequently was observed in upstate New York. Symptoms can be limited to pod rot. Varieties producing long pods touching the soil are most likely to be affected. Blight affecting whole plants has been observed in low areas of fields following rainstorms that resulted in standing water.
Sunscald damage to fruit can occur when exposed to sunlight as a result of loss of leaves. The potential for this to happen increases substantially in the fall because leaves have died and heavy dews common in the fall can exacerbate the problem. Pumpkin and winter squash fruit are especially prone to sunscald. Affected fruit are seen every year on Long Island in fall.
Symptoms are small brown leaf spots, sometimes with characteristic tan centers and tiny black round structures (pycnidia) where the pathogen’s spores are produced. Tiny, dark brown spots (usually less than ¼ inch in diameter) also develop with bacterial leaf spot, therefore it is important to look for the diagnostic pycnidia in the spots to distinguish these diseases.