Late blight (US23) was confirmed on tomato in a small, retail greenhouse operation in western Maryland (Garrett Co.) today. This is the first report of Late blight on tomato or potato this growing season. US23 has been the most prevalent genotype found in the region the last few years and can infect tomato or potato. While the current report not an immediate threat to NJ, all tomato and potato growers should scout fields on a regular basis as long as wet weather pattern continues. At this time, general protectant fungicide programs that have been initiated will help protect against Late blight. Importantly, in order for Late blight to appear this early in our region it must either have survived on an infested potato tuber left in the field or in a cull pile. For more information on the control of late blight please see the 2016 Mid-Atlantic Commercial Production Recommendations Guide.
Vegetable Crops Edition
Seasonal updates and alerts on insects, diseases, and weeds impacting vegetable crops. New Jersey Commercial Vegetable Production Recommendations updates between annual publication issues are included.
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Basil downy mildew – 24c’s granted for Subdue Maxx and Heritage use in greenhouse
Special local needs labels (24c) have been granted for the use of Subdue Maxx (mefenoxam, 4) and Heritage (azoxystrobin, 11) for downy mildew (Peronospora belbahrii) on basil transplants grown for resale to consumers in New Jersey. Micora (mandipropamid, 40) also has a supplemental label for the control of basil downy mildew in the greenhouse. In order to use these fungicide, growers must have in their possession the 24c labels. Please see label for specific rates, REI’s, and PHI’s. Please here click on Subdue Maxx, Heritage, or Micora for links to the 24c label.
Pest Alert: Probable Allium Leafminer infestations found in NJ
Allium leaf miner oviposition scars- garlic.
Leaf mine on onion
Allium leafminer oviposition scars on onion
Two probable infestations of allium leafminer have been discovered. One of these was on the Hunterdon/Warren County border involving overwintered garlic and onions planted this spring. The second, a very minor infestation, was found near Princeton in Mercer County on overwintered chives. While we await word from USDA as to where specimens should be sent for final confirmation, the signs of infestation are very characteristic of allium leafminer, and larvae and eggs were found in association with the egg laying scars (oviposition scars) on the leaves of onions and garlic. Both of these infestations appear to be very recent, with larvae in very early growth stages. [Read more…]
Vegetable Disease Briefs – 5/11/16
- Rhizoctonia root rot has been found on newly emerged cucurbit seedlings. The cool, cloudy weather has significantly slowed emergence and transplant growth the past few weeks. The longer it takes for emergence and transplants to establish themselves, the more likely they are to pick up pre- and post-emergent damping-off diseases such as Rhizoctonia or Pythium.
- Botrytis is being reported in greenhouse tomatoes and in strawberries fields. The weather the past few weeks has been ideal for its development in a multitude of crops. Growers need to scout on a regular basis and incorporate Botrytis specific fungicides into their weekly maintenance sprays as long as the current weather pattern remains the same.
- Transplant health – transplants that have yet to be put in the field and that are showing signs of stress via the lack of fertility and water to keep them to size can become predisposed to a multiple of opportunistic fungal and bacterial pathogens. Growers need to pay close attention to and adjust fertility and watering programs on a daily basis and consider preventative fungicide applications.
Veg IPM Update: Week Ending 5/11/16
Mites and feeding signs on lower leaf surface. Aphids also present.
Two-spotted spider mite (TSSM) infestations have recently been discovered in high tunnels.
TSSM feeding results in small white pin-spots on the upper leaf surface (see photos). Mites are actually underneath leaves. These pests can increase dramatically in the warm, dry environment of the tunnel.
Check 5 plants each in 5 separate locations in the tunnel. Inspect the entire plant, and be sure to check the underside of leaves that display the whitish mite feeding. If mites are found, it is best to immediately treat. TSSM is much more easily managed, when the problem is addressed at low levels. If allowed to spread throughout the tunnel, TSSM will be much more difficult to control.
See the 2016 Commercial Vegetable Production Recommendations – Pest Management section for materials that are labeled for use in greenhouse structures, including those that are OMRI approved.
[Read more…]
Using Orondis Gold 200
Orondis (oxathiapiproplin, U15) targets the oxysterol binding protein that is a part of the cell wall. The active ingredient inhibits growth of the fungus as well as sporangia production and zoospore germination. Orondis has a low solubility (i.e., locally systemic), is translaminar; and will protect new growth. Orondis is currently sold as a co-pack with either mefenoxam (Orondis Gold), chlorothalonil (Orondis Opti), or mandipropamid (Orondis Ultra). Growers will be required to tank mix Orondis with its partner during 2016 season. In 2017, the partners will be formulated together. Orondis has different use rates and restricted seasonal use. The rates for Orondis and it counterpart will differ by crop, pathogen, and desired use (drip vs. foliar). Unfortunately, because of its registration date, Orondis was not included the 2016 Mid-Atlantic Commercial Vegetable Production Guide.
Orondis Gold 200 (oxathiapiprolin [OXTP] + mefenoxam, U15 + 4) — Growers using Orondis Gold will need refer to the Orondis Gold 200 (OXTP) label and the Orondis Gold B (mefenoxam) label.
Orondis Gold 200 targets damping-off caused pythium and/or phytophthora in cucurbits and fruiting vegetables (pepper, tomatoes, eggplant), and leafy vegetables (excluding brassica’s).
