Archives for July 2015

July 27, 2015 A.Wyenandt, W.Kline, and J.Ingerson-Mahar

Potato | Tomato Disease Forecast 7-28-15

Potato Disease Forecasting Report

We will be tracking DSVs for Late blight development and calculating P-days for initiating the first early blight fungicide application.

The first late blight fungicide application is recommended once 18 DSVs accumulate from green row. Green row typically occurs around the first week in May in southern New Jersey. An early season application of a protectant fungicide such as mancozeb (Dithane, Manzate, Penncozeb) or Bravo (chlorothalonil) as soon the field is accessible is suggested. Please be vigilant and keep a look out for suspect late blight infections on young plants. No late blight has been reported in our region to date.

Remember the threshold for P-days is 300! Once 300 P-days is reached for your location early blight fungicide applications should be initiated. Growers who are interested in using this model should chose the location above that is closest in proximity to their farming operation and should regularly check the Cornell NEWA website (http://newa.cornell.edu/) where this information is compiled from. Click on Pests Forecasts from the menu, select your weather station, and click on tomato diseases, set accumulation start date and a table of daily and total DSVs will be generated.

Tomato Disease Forecasting Report

Disease severity values (DSVs) for early blight, septoria leaf spot, and tomato anthracnose development are determined daily based on leaf wetness (due to rainfall, dew) and air temperature.

On a daily basis DSV values can range from 0 to 4 where 0 = no chance for disease development to 4 = high chance for disease development.
DSVs are accumulated during the production season.

Fungicide applications are based on an individually determined DSV threshold. The first fungicide application for the control of these three diseases is not warranted until 35 DSVs have accumulated from your transplanting date. After that, growers can base fungicide applications on different DSV thresholds.

Filed Under: Disease Forecasting

July 24, 2015 Norman Lalancette

Brown Rot Management in a Wet Growing Season: Part II

In part I of this article series, we discussed the sources of inoculum for fruit infection by the brown rot pathogen, Monilinia fructicola (see July 21, 2015 article).

Air-blast application of fungicide to peach.

Although measures to reduce the inoculum from these sources were presented, these cultural controls alone only provide partial control. They are to be used in conjunction with other measures in an integrated program. And every facet of this program needs to be fine-tuned for optimum performance, especially in a wet growing season.
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Filed Under: Fruit, Tree Fruit

July 23, 2015 A.Wyenandt, W.Kline, and J.Ingerson-Mahar

Potato | Tomato Disease Forecast 7-24-15

Click to View | Download Report 7-24-15

Potato Disease Forecasting Report

We will be tracking DSVs for Late blight development and calculating P-days for initiating the first early blight fungicide application.

The first late blight fungicide application is recommended once 18 DSVs accumulate from green row. Green row typically occurs around the first week in May in southern New Jersey. An early season application of a protectant fungicide such as mancozeb (Dithane, Manzate, Penncozeb) or Bravo (chlorothalonil) as soon the field is accessible is suggested. Please be vigilant and keep a look out for suspect late blight infections on young plants. No late blight has been reported in our region to date.

Remember the threshold for P-days is 300! Once 300 P-days is reached for your location early blight fungicide applications should be initiated. Growers who are interested in using this model should chose the location above that is closest in proximity to their farming operation and should regularly check the Cornell NEWA website (http://newa.cornell.edu/) where this information is compiled from. Click on Pests Forecasts from the menu, select your weather station, and click on tomato diseases, set accumulation start date and a table of daily and total DSVs will be generated.

Tomato Disease Forecasting Report

Disease severity values (DSVs) for early blight, septoria leaf spot, and tomato anthracnose development are determined daily based on leaf wetness (due to rainfall, dew) and air temperature.

On a daily basis DSV values can range from 0 to 4 where 0 = no chance for disease development to 4 = high chance for disease development.
DSVs are accumulated during the production season.

Fungicide applications are based on an individually determined DSV threshold. The first fungicide application for the control of these three diseases is not warranted until 35 DSVs have accumulated from your transplanting date. After that, growers can base fungicide applications on different DSV thresholds.

Filed Under: Disease Forecasting

July 23, 2015 Dean Polk

Fruit IPM Report 7-22-2015

Peach

Oriental Fruit Moth (OFM): While overall pest pressure in peaches is very low for oriental fruit moth, we are at the proper time to treat if your farm has trap captures above 6 males per trap. Timing for third brood OFM applications are as follows:

OFM 3nd Generation Timing
		Insecticide Type
County/Region	Degree Days by 7/22 base 45	Conventional	Intrepid/IGRs	Diamides
Gloucester-Southern	2317	1st – 7/17-19, 2nd – 7/27-28	1st – 7/14-15, 2nd – 7/25-27	1st – 7/13-18, 2nd – 7/24-27
Hunterdon-Northern	2053	1st – 7/24-28, 2nd – about 8/5-7	1st – 7/22-24, 2nd – about 8/3-5	1st – 7/22-23, 2nd – about 8/3-5

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Filed Under: Blueberry, Fruit, Tree Fruit, Wine Grape

July 22, 2015 Kris Holmstrom and Joe Ingerson-Mahar

Veg IPM Update: Week Ending 7/22/15

Sweet Corn

Click to View

European corn borer (ECB) adult activity is starting to increase in parts of the state now. This is the beginning of the second adult flight. Areas of highest activity are currently along the Delaware Bay Shore and in central Morris County (see ECB map), but areas between should fill in over the next week.

As always, consider treating when the number of infested plants in a 50 plant sample exceeds 12%. Any planting remaining at or above threshold as it proceeds to full tassel should be treated, as this is the last stage at which ECB larvae will be exposed and vulnerable to insecticidal sprays.

See the 2015 Commercial Vegetable Recommendations Guide for insecticide choices.
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Filed Under: Vegetable Crops

July 22, 2015 Andy Wyenandt

Cucurbit Downy Mildew Reported: Watermelon & Butternut Squash in NJ ALERT – 7/22/15

Cucurbit downy mildew has been reported on watermelon (Warren County) and butternut squash (Hunterdon County) in Northern New Jersey. This is the first report on both crops this season. Downy mildew was confirmed on cucumber in New Jersey on July 9th.

All cucurbit growers should include downy mildew specific fungicide(s) in their weekly programs. For more information on the controlling downy mildew on all cucurbit crops please see the 2015 Commercial Fungicide Recommendations Guide. To track the progress of cucurbit downy mildew in the US please visit http://cdm.ipmpipe.org/