Search Results for: corn borer

Sweet Corn 

 European corn borer (ECB) moth catches are very low, but showing signs of increase on the Cape May/Cumberland Co. border (se ECB map) .  Most larval infestations, have passed.  Be sure to begin monitoring plantings for ECB feeding while they are still in the whorl stage.  Consider treating when the number of infested plants in a 50 plant sample exceeds 12%.  Feeding in the whorl stage will appear as numerous small holes (called “shot-hole”) on leaves, with damage present on consecutively younger leaves. As plants progress to pre-tassel and beyond, droppings and  larvae may be found in or on the emerging tassels.  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.    [Read more…]

Sweet Corn 

European corn borer (ECB) moth catches remain very low now.  Only scattered individuals are now being captured, and growers are managing residual infestations.  At the present, the highest adult activity is in Salem county, although it is quite low even there (see ECB map).  Larval feeding ranges from single digits to above 20% in areas where IPM personnel are operating.  Be sure to begin monitoring plantings for ECB feeding while they are still in the whorl stage.  Consider treating when the number of infested plants in a 50 plant sample exceeds 12%.  [Read more…]

Sweet Corn

European corn borer (ECB) moth catches remain very low now.  The first flight is over, and growers are now managing subsequent infestations, which are generally lower than normal.  Present adult activity is too low to generate a map image (<0.5 moths/night in all traps).  Larval feeding ranges from single digits to above 20% in areas where IPM personnel are operating, although many plantings still have no detectable feeding at all.  Be sure to begin monitoring plantings for ECB feeding while they are still in the whorl stage.  Consider treating when the number of infested plants in a 50 plant sample exceeds 12%.  Feeding in the whorl stage will appear as numerous small holes (called “shot-hole”) on leaves, with damage present on consecutively younger leaves. As plants progress to pre-tassel and beyond, droppings and  larvae may be found in or on the emerging tassels.  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.    Insecticides that are acceptable in organic production include the spinosyn based material Entrust (IRAC-5) and Dipel (IRAC-11a).  The 10G formulation of Dipel is particularly useful when granules can be dropped or broadcast such that they get into the whorls of corn plants.  Other effective insecticides include Coragen (IRAC 28), and the synthetic pyrethroids (IRAC 3).  See the 2016 Commercial Vegetable Recommendations Guide for a more complete list of insecticides.

The highest nightly ECB catches for the previous week are as follows:

In addition, several low-level infestations of fall armyworm (FAW)  were discovered this week.  These were in Hunterdon and Middlesex counties, but it is likely that there are other light infestations throughout the state.  These infestations have not exceeded 4% in the whorl stage, and are likely the result of a few FAW moths arriving in advance of weather fronts.  This is somewhat early for FAW infestations in NJ, and we would expect to see little injury until mid-July.  FAW feeding is much more obvious than that of ECB larvae, with large ragged holes and conspicuous droppings found in the whorl.  FAW is resistant to synthetic pyrethroid insecticides (IRAC 3), and can be effectively managed with insecticides such as Radiant/Entrust/Blackhawk (IRAC 5) or Coragen/Besiege (IRAC 28).  Consider treating if damage from ECB and/or FAW reaches 12%.  [Read more…]

Sweet Corn

European corn borer (ECB) moth catches are very low now.  The first flight is largely over, and as is common, feeding signs in the field have increased as eggs hatch.  Present adult activity is largely confined to Gloucester and parts of surrounding counties (see ECB map).  Larval feeding ranges from single digits to 40% in areas where IPM personnel are operating, although many plantings still have no detectable feeding at all.  The highest feeding percentages are currently in Mercer and parts of Morris counties.  Be sure to begin monitoring plantings for ECB feeding while they are still in the whorl stage.  Consider treating when the number of infested plants in a 50 plant sample exceeds 12%.  Feeding in the whorl stage will appear as numerous small holes (called “shot-hole”) on leaves, with damage present on consecutively younger leaves. As plants progress to pre-tassel and beyond, droppings and  larvae may be found in or on the emerging tassels (see photo at right).  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.    Insecticides that are acceptable in organic production include the spinosyn based material Entrust (IRAC-5) and Dipel (IRAC-11a).  The 10G formulation of Dipel is particularly useful when granules can be dropped or broadcast such that they get into the whorls of corn plants.  Other effective insecticides include Coragen (IRAC 28), and the synthetic pyrethroids (IRAC 3).  See the 2016 Commercial Vegetable Recommendations Guide for a more complete list of insecticides.  [Read more…]

Sweet Corn

Catches of European corn borer (ECB) have declined through much of the state.  Remaining areas of highest activity include parts of Monmouth, Mercer and Salem counties (see ECB map).  ECB infestations are now rising in sweet corn plantings, but are well below normal levels.   Feeding ranges from single digits to 20% in areas where IPM personnel are operating, but many plantings have no detectable feeding at all.  Be sure to begin monitoring plantings for ECB feeding while they are still in the whorl stage.  Consider treating when the number of infested plants in a 50 plant sample exceeds 12%.  Feeding in the whorl stage will appear as numerous small holes (called “shot-hole”) on leaves, with damage present on consecutively younger leaves. As plants progress to pre-tassel and beyond, the actual larvae may be found in or on the emerging tassels (see photo).  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. Often, early sweet corn plantings suffer from “split set”, in which germination does not occur in a uniform

Sweet corn tassel with ECB larvae.
Photo: Kris Holmstrom

fashion. The result is a planting where all plants do not reach full tassel at the same time.  This situation may require an extra tassel spray if there are several days difference in the time full tassel is reached on a significant number of the plants.  Insecticides that are acceptable in organic production include the spinosyn based material Entrust (IRAC-5) and Dipel (IRAC-11a).  The 10G formulation of Dipel is particularly useful when granules can be dropped or broadcast such that they get into the whorls of corn plants.  See the 2016 Commercial Vegetable Recommendations Guide for more insecticide choices.

The highest nightly ECB catches for the previous week are as follows:

  [Read more…]

Sweet Corn

European corn borer (ECB) adult catches have declined, and are now quite low throughout the state.   The most consistent catches at this time range from southwestern Burlington County through Cumberland County (see ECB map).  The earliest sweet corn plantings are now silking in southern NJ, and are approaching full tassel in some northern sites.  Feeding percentages are still very low (to 4% in central counties), but growers should expect that eggs are now hatching, and larval infestations could appear on all corn whorl stage and older.  Be sure to begin monitoring the earliest plantings for ECB feeding while they are still in the whorl stage. Consider treating when the [Read more…]