Archives for April 2015

April 28, 2015

Fruit IPM Report 4-28-2015

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Peach

Petal Fall Insect Complex: An OFM biofix was set for April 20 in southern counties. Treatments for the first flight will be due at 170-200 degree days after the first trap captures or “biofix.” According to the NEWA weather station in Upper Deerfield, we have had 49 degree days accumulate since 4/20. This timing usually coincides with late petal fall to shuck split, however we are a little late this year, since we have about 120 degree days to go until the first OFM treatment.

Since we are still waiting for the OFM timing, the initial petal fall spray will primarily target plum curculio, tarnished plant bug and other catfacing insects. Plum curculio is active, and will feed on blossoms and freshly set fruit. See last week’s newsletter and the Tree Fruit Production Guide for insecticide options. Given the current insect targets, Avaunt is one of the better materials for plum curculio (PC) at this time, and also covers Oriental fruit moth and tarnished plant bug. We are not concerned with BMSB at this time, so many of the other materials which are effective for BMSB can be saved for later in the season.
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Filed Under: Blueberry, Tree Fruit
April 27, 2015

Winter’s Continuing Legacy

Despite a winter we all want to forget, it never ends if you are a pathologist. Everywhere I look there is plant damage due to the extreme winter. Broad-leaved evergreens seemed to take it hard again this year, particularly some of the hybrid hollies. Frozen roots and heavy winds, along with the need to transpire on sunny winter days, left them in shambles. The injury was visible early and often.

Holly suffering from severe winter dessication. Photo: Richard Buckley, Rutgers PDL

Holly suffering from severe winter wind desiccation. Photo: Richard Buckley, Rutgers PDL

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Filed Under: Landscape, Nursery, & Turf, Plant Diagnostic Lab Tagged With: ,
April 23, 2015

Fruit IPM Report 4-24-2015

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Peach

Brown Rot: Blossom infections from the brown rot fungus can occur whenever pistils are exposed and a favorable climate exists. Infections can occur during any wetting period when temperatures are between 41 and 86°F. However optimum conditions for infection occur with wetting and temperatures in the mid 70’s. During long wetting periods (several days or more) blossoms can be infected regardless of temperature. Generally infections that occur when conditions are sub optimal are less severe. Blossoms and fruitlets will remain susceptible until the pistil desiccates (sometime between petal fall and shuck split).

Petal Fall Insect Complex: An OFM biofix was set in southern counties on 4/20. Treatments for the first flight will be due at 170-200 degree days after the first trap captures or “biofix.” This timing usually coincides with late petal fall to shuck split. Be sure all petals are off before applying insecticides. Imidan, Lannate, and synthetic pyrethroids (Asana, Ambush/Pounce, Danitol, Mustang/ Mustang Maxx, Warrior, Baythroid) are rated for control of petal fall insect pests. Diamide and diamide mixes are also labeled, and include Altacor, Belt, Voliam Flexi and Voliam Express, Belt and Tourismo, and the new diamide, Exirel. When used alone the diamides are only effective against Leps. such as OFM. Exirel is a second generation diamide and will also control PC, but must be used at the higher rate to do so. This makes it expensive to use. The spinosyn, Delegate is effective for OFM and other Leps, and thrips if they are present in nectarines. Experience has shown that the pyrethroids may be weak at lower rates against plum curculio (PC), especially in hot weather. If using any of the pyrethroids, use a high rate in order to control both OFM and PC. Rotate pyrethroids (IRAC group 3) and O.P.’s (IRAC group 1B) with different chemistries for resistance management. The key arthropod targets at petal fall are OFM, PC and various catfacing insects, primarily tarnished plant bug and native stinkbugs.
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Filed Under: Tree Fruit
April 23, 2015

Weather Alert from NJ Dept of Ag: Open Burn Approval

At the request of the NJ Dept of Agriculture, DEP Commissioner Martin today approved open burning and the use of smudge pots for tonight and Friday because of the extreme cold temperatures forecasted for those evenings. This approval mirrors the approval from 2012. Copies of the approval and restriction memo plus the list of Critical Temperatures for Frost Protection of Various Crops are attached.

Filed Under: Commercial Ag Updates, Fruit, Tree Fruit, Vegetable Crops
April 23, 2015

Damping-off: Important Early-season Pathogens

It is extremely important to know which pathogen is causing damping-off problems and which fungicide to properly apply. The key to controlling damping-off is being proactive instead of reactive. Always refer to the fungicide label for crop use, pathogens controlled, and application rates.

Damping-off is caused by a number of important vegetable pathogens and is very common during the spring. Damping-off can kill seedlings before they break the soil line (pre-emergent damping-off) or kill seedlings soon after they emerge (post-emergent damping-off). Common pathogens that cause damping-off include Pythium, Phytophthora, Rhizoctonia and Fusarium spp.

Control of damping-off depends on a number of factors. First, is recognizing the conditions which may be leading to the problem (i.e., weather/greenhouse growing conditions) and second, identifying the pathogen causing the problem.

Conditions Favoring Damping-off

Although all four pathogens are associated with damping-off, the conditions which favor their development are very different. In general, Phytophthora and Pythium are more likely to cause damping-off in cool, wet or overwatered soils that aren’t allowed to dry out due to cloudy weather or cooler temperatures. Conversely, Rhizoctonia and Fusarium are more likely to cause damping-off under warmer, drier conditions especially if plug trays are kept on the dry side to help reduce transplant growth. [Read more…]

Filed Under: Organic Production, Vegetable Crops
April 22, 2015

Controlling Septoria Leaf Spot in Parsley

Septoria leaf spot 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.

Parsley SLS

Parsley: Septoria Leaf Spot

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 keys to successfully controlling SLS. Unfortunately, very few fungicides are currently labeled making control difficult.

Parsley growers who have significant septoria leaf spot issues every year and have seen poor control in fields where FRAC code 11 fungicides have been used considerable in the past should consider no longer using them due to potential resistance issues. Fungicide programs should include Fontelis at a high rate (16.0 to 24.0 fl oz/A) tank mixed with a copper rotated on a weekly basis with Merivon (5.5 fl oz) plus copper. Fontelis has a 3 day PHI and a 72.0 fl. oz season max. Merivon has a 1 day PHI and 33.0 fl. oz season max. Organic farmers should use an OMRI-approved copper fungicide on a regular basis to help suppress septoria leaf spot.

Filed Under: Organic Production, Vegetable Crops Tagged With: ,