UConn Extension Vegetable IPM Pest Message & Reports from the Farm, Friday July 24th, 2015 [Comments or answers in brackets are provided by Jude Boucher, UConn Extension] Note: there will be no pest message next week, so the next update will be on Friday Aug. 7 th. We are currently under a late blight alert on tomato and potato, a fall armyworm alert for sweet corn, and a downy mildew alert for basil. Also, powdery mildew is starting for pumpkins and winter squash. Watch for downy mildew on cucurbits in the coming weeks (none detected yet) - it can be easily detected on cucumbers]. Downy mildew on cucumber Steve Bengtson, Cold Spring Brook Farm, Berlin, CT CEW moths are still very low, in fact, the last two times traps were checked there were no moths. We are currently not spraying silking corn. ECB are also very low with only 1 moth found in the Z trap this week. This is up from a total of 0 last week. FAW trap had 12 moths this week. Up from 0 last week. Scouting 4 fields of young corn resulted in infestations ranging between 4% to above 40%. Fields above 10% infestation will be sprayed with our boom sprayer tomorrow using Coragen. Peppers have been sprayed with Dimethoate after finding stings last week and capturing 5 PM flies in the last 10 days. All tomatoes were sprayed with Ranman and Initiate on Thursday to prevent late blight. I added some Coragen to help control the tomato fruit worm that have been showing up in some harvested fruit. [Whatever is causing holes in the fruit, it is not tomato fruit worm, aka corn earworm, since there are none in the pheromone traps/on your farm. Maybe variegated cutworms? The Coragen will get them]. Pepper fields were spot treated with a backpack sprayer using Gramoxone to control weeds in the walkways. Burn down was noticed within hours of application. All crops are growing well but are being irrigated on a regular basis due to extremely dry conditions.
Allan Popp, Green Farms, Easton, CT? I just lost all my basil to DM. Black/gray fuzz under leaf, plants look like N deficient. My wife said plants in the front of the raised bed didn't look right on Monday, by Wednesday 4 raised bed were completely infected. I ll try to send pics. [Growers should harvest their basil and get it in CSA boxes this week. A fungicide trial in FL last year showed that the most effective products were Revus, Ranman and Quadris, while they got at least some control with ProPhyt. Our UConn diagnostician, Joan Allen conducted an organic fungicide trial at multiple sites a few years back and found that Oxidate and Milstop lowered disease ratings compared with control plots at both sites, while Actinovate, Serenade and Trilogy resulted in lower disease at one site, but not both.] Downy mildew of basil, photos by Allen Popp Fred Monahan, Stone Gardens Farm, Shelton, CT ECB= 0 moths in traps. CEW= 0 moths in traps. Cherry peppers have pepper maggot stings in them. [He will make a single dimethoate or Orthene application to prevent damage and keep the number of flies down on his farm.] Powdery Mildew is being held back with Bravo/phosphoric acid and it s working great on all cucurbits. I use the same mix for early blight and Septoria and it s working great on tomatoes too. I scouted the tomatoes well for late blight after the alert the other day and found none, so I did not add anything for late blight. Eggplant had leaf hopper, I hit them with Grizzly (generic Warrior) and Hook [spreader-sticker]. [The threshold for PLH on eggplant is 1-1.5 per leaf] When I sprayed the potato beetle on potatoes with Radiant it worked pretty well, but when I sprayed the same beetles on eggplant, I added Hook and it completely wiped out the beetles. So when I sprayed the potatoes the other day, when populations had built up again, I sprayed with Agri-Mek and Hook and it completely wiped them out, so it seems like adding the Hook
really makes a difference. [The Radiant label calls for the use of an adjuvant for certain pests like CPB. Always check the label for recommended adjuvants that may improve performance]. We harvested our garlic this week. We spread it out on the benches in one of the greenhouses and flip it over every day for a week to cure it before we cut the stalks and grade it. I am planting my last corn today. We always take a chance and plant some late corn for mid-late Oct. It is on top of a hill that usually does not get a good frost until Nov. It is not unheard of for us to be picking into November. [One of the benefits of being close to the L.I. Sound]. Gypsy moths, photo from Wikipedia Corn earworm moth [Fred and others have gotten confused by the large number of gypsy moths in their traps. Note that they both have black spots on the front wings, but the GM is larger, darker, and has featherlike antennae]. Jamie Jones, Jones Family Farms, Shelton, CT My father and I were talking and a bit nervous because the pumpkins look so good. No major issues yet. Timely rains, few insects, weeds as always, but our crews are keeping after them. Flowering has started on the early plants and have seen some fruit set, but know this heat won t be good, doesn t look to last too long though. Watching for powdery, and ready for first spray, but haven t started yet. Most of our challenges have been with berry crops, starting with the cold winter, but overall feel fortunate they have come through pretty good. Ian Gibson, Well Stone Farm, Higganum, CT. I m finding my first tomato horn worms of the season on tomatoes and am planning to use B.t. to control them. [THW can build up on some plantings and cause damage. Scout by looking for the frass or manure on the plastic under the plants, then try to find the cateripillar. It gets easier to spot them once you find the first one and your search image is locked in. They used to use that slanted-white-lines pattern as camouflage on battle ships to break up the shape on the water surface before radar and sonar were invented]. Tom Scott, Scott s Yankee Farmers, E. Lyme, CT I didn t find any CEW moths this week and am not spraying silking corn.
I did find some powdery mildew in my winter squash and pumpkin field and will put on my first spray for these fall cucurbits. Jude Boucher, UConn Plant Science Research Farm, Storrs, CT No CEW moths in the pheromone trap this week. 14 SVB in trap last week. Late blight on tomatoes in Litchfield County this week. Left- stem lesion, right leaf lesion (note white sporulation on green tissue immediately around leaf lesion). LB also found in Ulster County NY this week. Growers who choose not to protect their tomatoes and potatoes at this time are risking the most profitable crop on their farm. Since this disease can destroy an entire field in a week, ask yourself what would happen if we suddenly had a week of rain and you couldn t get in to spray until next week. Earl Skokan, Stillwater Farm, Torrington, CT [reported by JB] We found Plectosporium in his summer squash planting. He will remove the infected plants and a few healthy plants adjacent to them, and apply Bravo. Group 11 fungicides such as Cabrio and Quadris are even more effective on this disease, but you should alternate between chemical families for resistance management. Josh Vincent, Vincent Farms, W. Suffield, CT [reported by JB] 0 CEW moths in two traps/fields. 25 moths in FAW trap. No infestation in mid-whorl to pre-tassel stage corn, but eggs may be hatching soon. He will re-scout next week. 12 ECB moths in traps. The threshold for peppers is to spray one week after capturing 7 or more borer moths per week. It takes two weeks after capturing 7 moths before you would find any larvae in the fruit, so this threshold is actually a conservative threshold meant to minimize spraying and eliminate fruit damage. Josh will make his first pepper spray for borers next week and keep them protected through most of the second generation moth flight while they are laying eggs. Different products have longer or shorter effective residual periods. Coragen will provide at least 2 weeks of protection, the insect growth regulator Intrepid and the insecticide Orthene will last for 10 days, Avaunt, Radiant and Entrust will last a week, while B.t. products will only last for 1-2 days and need to be applied multiple times each week during egg hatch. We found powdery mildew in one of his winter squash fields. He will make his first application this week with Vivando for powdery mildew and Bravo for fruit rots like black rot, Plecto and
scab. The next application will follow in 10 days using a different family of mobile fungicide (i.e. Torino, Quintec or Procure) for powdery to help prevent resistance. Organic growers can use sulfur to delay the development of powdery mildew and improve yields. His second planting of eggplant had a lot of young CPB larvae. He will clean these up this week, using a different resistance family than he used on the first generation in his early planting. Willy Dellacamra, Cecarelli Farm, Northford, CT [reported by JB] 0.2 CEW moths in the trap we checked. This leaves them on a 6-day spray schedule. Note: this was the only CEW moth we found at any farm this week. 5 FAW moths in trap. 52-60% of the plants were infested in early whorl to late whorl stage corn. No FAW were found in his pre-tassel stage corn right across the road. This insect really prefers to lay its eggs in very small (6-12 tall corn), but can infest older corn if abundant or when that is all that is around. Note: Long Island reported trap counts as high as 332 moths this week, with most traps between 62 and 163 moths. We have never seen counts that high in CT. Things may get worse before they get better for this pest. O ECB moths in traps. Steve and Ben Berezc, The Farm, Woodbury, CT [reported by JB] 13 FAW moths in the pheromone trap and 26% infestation in young whorl stage corn. Corn plantings with more than 10% of the plants infested should be treated. Zero CEW moths in two traps. The recommendation is not to spray silking corn at this time. Some onions had a little rot just under the first scale. Joan Allen at the UConn diagnostic lab found some bacteria present, but was not able to match it to any known disease. Liz Cecarelli, Eve s Garden, Bethany, CT [reported by JB] Liz wanted me to print a correction: she did use her own transplants for her peppers, but did bring ornamental peppers from FL into her ornamental greenhouse [which could have been a source of a Southern pest like pepper weevil]. She has still not been able to find any of the insects causing the weevil-like damage. Jonathan Griffin, Oxen Hill Farm, W. Suffield, CT [reported by JB] We found blossom end rot and a few pepper maggot stings in his Granby field. He will try to water on a regular basis to minimize BER, and make an application of Seduce for the pepper maggot. 28% of his young early whorl stage corn was infested with FAW. Entrust or a B.t. product like XenTari will control FAW on organic farms. Hopperburn is showing up on his potatoes, especially his russets. He is beginning to be a believer in row covers for this pest. I will try to get some pictures of the yields of a single protected and unprotected plant to share with you. It s quite impressive what leafhoppers can do to the yields. Michaele Williams, Bishop s Orchard, Guilford, CT [reported by JB]
Onions had 4-36 thrips per plant, but some leaves had 30. The threshold is 3 per leaf. The Assail didn t seem to hold the number down, so she will try Radiant with a wetting agent to get the product down between the leaves where the thrips hide. Onion thrips (yellow) hide down between the leaves Daren Hall, George Hall Farm, W. Simsbury, CT [reported by JB] Onions had many (>40) thrips per plant and sometimes per leaf. He will harvest to avoid damage. Phytophthora had run the full length of the field in one planting of summer squash. He will be working to improve water management and eliminate standing water after storms. Since my last visit, he used a sub-soiler to break up the plow pan and improve the drainage between all rows of plants in a second field. Tomatoes had Septoria leaf spot. He will try Oxidate and then copper. That s all for this week. I ll send another update on Friday, August 7th.