Posts Tagged ‘peaches’

Fruit Crop Insects – July 27, 2012

Friday, July 27th, 2012

Joanne Whalen, Extension IPM Specialist;

Spotted Wing Drosophila
Over the past couple of weeks, we have started to find spotted wing drosophila adults in traps placed in 6 locations throughout the state. The following new publications were recently developed by specialists at Penn State University and the University of Maryland.

Spotted Wing Drosophila, Part 1: Overview and Identification
Spotted Wing Drosophila, Part 2: Natural History
Spotted Wing Drosophila, Part 3: Monitoring
Spotted Wing Drosophila, Part 4: Management

Brown Marmorated Stinkbug
Emergency Exemption (Section 18) for BMSB Control in Apple, Peach, and Nectarine – On Friday, July 20, 2012, the EPA approved our Sect 18 request for the use of the pesticide bifenthrin on apples, peaches, and nectarines to help manage populations of the brown marmorated stink bug. The only bifenthrin products allowed under this Sect 18 are Brigade WSB (FMC’s product), Bifenture EC and Bifenture 10DF (United Phosphorus, Inc. products). Please see the attached copy of the approval letter from EPA for use directions, rates and restrictions: You will also need a copy of the label before making any applications. The Section 18 label for Brigade is available online: Please contact Dave Pyne at the Delaware Department of Agriculture or Joanne Whalen for more information.

Section 18 for Brown Marmorated Stink Bug (BMSB) Management on Stone and Pome Fruit Approved

Friday, July 6th, 2012

Joanne Whalen, Extension IPM Specialist;

Our Section 18 request for the use of dinotefuran (Trade Names: Venom from Valent U.S.A. Corporation; Scorpion from Gowan Company, LLC) to control BMSB on stone and pome fruits has been approved by EPA. This use expires on Oct 15, 2012. Please refer to this link: for more information on use rates and restrictions. You should also have a copy of the label in your possession before making an application so please contact either David Pyne at the Delaware Department of Agriculture ( or Joanne Whalen ( for more information. 

Weather Worries for Fruit Growers

Thursday, March 29th, 2012

Gordon Johnson, Extension Vegetable & Fruit Specialist;

Peaches, plums, and apricots have bloomed, several weeks ahead of normal. Strawberries have been blooming for weeks in plasticulture systems. These fruit crops are at great risk of losses due to freeze events. Other fruit may also flower early and be at risk. For example, pears are in bloom now and cherries and blueberries are starting to bloom.

Normally, the average date of the last frost in Delaware is somewhere between April 20-25. We still have four weeks of worry ahead for our fruiting crops.

For all these fruit crops the most susceptible stage of injury is when flowers have just opened. Closed buds have higher cold tolerance as do small fruit. For most fruits, critical temperature for losses after fruits have formed is 28° F.

 Plasticulture strawberries blooming 3- 29-2012.

Frost and freeze protection methods vary with fruits and the type of freeze expected. Advective freezes occur with freezing temperatures and high winds. This is the most difficult to protect against. For strawberries, two layers of floating row covers may be the most effective strategy for advective freezes. Double covers have been shown to be more effective than single heavy covers in this case. Irrigation along with double covers can provide even more protection if done properly.

Radiational freezes occur on cold, still nights. In this case cold air is near the ground and warmer air is above. Wind machines and helicopters have been successfully used to stir the air and raise the temperatures in orchards in this case. Row covers in strawberries will protect against radiational freezes too.

Irrigation has also been successfully used for frost protection but it has to be done properly. How irrigation works is that as ice forms on plants heat is released. The key is to keep ice formation occurring through the night and continue through melt in the morning. Remember that initially, until ice starts forming, there will actually be evaporative cooling of the plant. The latent heat of fusion (water freezing) will release heat (approximately 144 BTUs/lb of water), whereas evaporative cooling will absorb heat from the plant (absorbing approximately 1,044 BTUs/lb of water) and lower plant temperatures. Therefore, irrigation must start well above critical temperatures. Also, the volume of water needed needs to be matched with the expected temperature drop and wind speed. In addition, uniformity of water application is critical. This is difficult to do in high wind situations.

This past week temperatures dropped below freezing in parts of Delaware on three nights, with some areas in the mid-twenties. NOAA has predicted an increased risk for lower than normal temperatures in the Mid-Atlantic region for the next 2 weeks.

Update on Brown Marmorated Stink Bug on Tree Fruit – August 12, 2011

Friday, August 12th, 2011

Joanne Whalen, Extension IPM Specialist;

Please refer to the most recent update from Tracy Leskey, USDA-ARS regarding BMSB activity in tree fruit at:

The photo above, courtesy of Gordon Johnson, is of BMSB damage to peach fruit.

Section 18 for Brown Marmorated Sting Bug (BMSB) Management on Stone and Pome Fruit Approved

Friday, July 1st, 2011

Joanne Whalen, Extension IPM Specialist;

This week we received the letter from EPA that they approved our Section 18 request for the use of dinotefuran (Trade Names: Venom from Valent U.S.A. Corporation; Scorpion from Gowan Company, LLC) to control BMSB on stone and pome fruits. This use expires on Oct 15, 2011. Please refer to for more information on use rates and restrictions. Both labels are also available so please contact either David Pyne at the Delaware Department of Agriculture ( or Joanne Whalen ( for more information.


Update on Brown Marmorated Stink Bugs in Orchards

Friday, May 27th, 2011

Joanne Whalen, Extension IPM Specialist;

Tracy Leskey (USDA/ARS) provided the following report: “It appears that the beginning of Brown Marmorated Stink Bug (BMSB) immigration and dispersal into commercial orchards has begun in earnest in both WV and MD. Crews out scouting reported large numbers of BMSB in managed peach trees. Not surprisingly, bugs were most dense in the peripheral zone of the plots bordering wild habitat, but not necessarily anywhere near structures. Estimates of bug density were in the vicinity of 3 bugs per tree in border rows, and feeding injury was very fresh but clearly evident.”

See the article titled ‘Brown Marmorated Stink Bugs Damaging Peaches and Apples in WV, NJ, MD and VA’ in WCU 19:9 for more information and photos of damaged fruit.


Brown Marmorated Stink Bugs Damaging Peaches and Apples in WV, NJ, MD and VA

Friday, May 20th, 2011

Joanne Whalen, Extension IPM Specialist;

Over the past week, we received reports of Brown Marmorated Stink Bug adults being found in peaches and apple trees in West Virginia, NJ, Western Maryland and Virginia. So far, we have not heard of reports on the Eastern Shore but it is important that you scout orchards for activity. Reports from Dr. Tracy Leskey (USDA/ARS in WVA) indicated that the feeding in peaches was concentrated in the upper third of the canopy – and in some situations it appears that this is also the case with our native green and brown stink bugs. Please see the photos (courtesy of Dr. Tracy Leskey) of damage to young peaches online at


Peach Pruning Best in March-April

Thursday, March 4th, 2010

Gordon Johnson, Extension Fruit & Vegetable Specialist;

Research has shown that peach tree pruning is best done in March or April.

In past years with mild winters, there has been a tendency to prune on the early side. With the snow and cold weather in 2010 this has not been as much of an issue this year.

Pruning is done to remove suckers, manage fruit loads, manage vigor, manage tree shape, increase light penetration, and remove damaged or weak wood.

Pruning earlier than March increases the risk of cold injury to buds because trees are stimulated metabolically by the pruning. It is advised to only do pruning to remove dead or damaged wood during the winter.

As trees start to become active in March, there is little or no increase in cold injury to buds by pruning. Sucker removal and removal of weak fruiting branches can be done at this time, along with managing the shape and openness of the tree. While selective removal of excess fruiting material can be done, the full fruiting potential cannot be evaluated until plants start to bloom. In addition, winter injury or poor plant vigor cannot be determined accurately in March. This may lead to excessive pruning of weaker trees that could be detrimental.

You can also prune peaches when plants start to bloom through the month of April. This allows for better assessment of fruiting potential and selective thinning of fruiting wood to manage crop loads. It also stimulates plants to produce more growth. In peach orchards where reduced plant vigor or damage is suspected, delaying pruning to late April or early May will allow for accurate assessment of tree status so that pruning can be matched to the level of vigor or extent of damage.

Summer pruning (July) can be beneficial, especially in trees with excessive growth. However, because peaches fruit the following year on wood produced this year, any removal of this year’s growth will reduce fruiting wood for next year. Therefore, take care not to do excessive summer pruning. August pruning is not recommended on trees still in fruit but can be done on earlier cropped trees or non-bearing trees.

Avoid peach pruning from September through February and mid-May through June.

For a good article on the subject by Jerome Frecon, Agricultural Agent at Rutgers University, go to

Cold Temperature Damage in Fruit Crops

Friday, May 1st, 2009

Gordon Johnson, Extension Ag Agent, Kent Co.;

We have seen considerable cold temperature damage to fruit crops in parts of Delaware and the Eastern Shore of Maryland. In particular, certain mid-season peach varieties have severely reduced crops; some varieties will not have enough fruit to warrant harvest, and other varieties will have a reduced crop. Early peaches and those up to the Red Haven season have better sets and will need to be thinned. Later peaches also have better sets.

Matted row strawberries that were uncovered have suffered anywhere from a 15% to over 50 % loss of flowers due freeze damage in some areas. Brambles (raspberries and blackberries), have also had significant winter damage to canes resulting in the need for additional pruning back of dead material.

These losses can be attributed to three cold weather events. On March 3 and 4, low temperatures were near 0°F in some areas. The second damaging event was on March 25 where temperatures dropped to 22°F and the third event was on April 13 where low temperatures reached 26°F in some areas.