Search Results for: corn borer

August 9, 2017

Vegetable IPM Update: Week Ending 8/9/2017

Note:  Due to technical difficulties, only sweet corn related maps and information will appear in this edition of the IPM Update.  We hope to resume full coverage next week.

Kris Holmstrom and Joe Ingerson-Mahar

Sweet Corn

European corn borer (ECB) adult numbers have again subsided, and no map will appear here.  As with last year, the second flight of ECB in New Jersey is low and sporadic.  While we are beginning to see limited feeding from this pest, it is relatively insignificant compared to fall armyworm (FAW) feeding that is now occurring on whorl stage sweet corn.  Insecticide applications should be made when 12% or more plants exhibit signs of ECB and/or FAW feeding.  FAW is, and will remain the dominant pest of vegetative stages of sweet corn for the remainder of the season.  Damage is extensive in the southern most counties, while it has increased only slightly over the past week in central and northern NJ.

Corn earworm (CEW) catches have gotten slightly more consistent in blacklight traps around the southern half of the state, while pheromone trap catches have risen dramatically in some areas (see CEW blacklight and pheromone trap maps).  Growers now treating silking sweet corn should adhere to silk spray schedules to limit damage.

The following are recommended silk spray schedules by region:

South – 3 days

Central – 4-5 days

North – 5-6 days

With frequent rains, the incidence of rust is increasing in some sweet corn plantings.  Additionally, northern corn leaf blight has also been discovered in the northern counties.  These diseases can be economically significant, particularly if they first appear in whorl stage plants.  Should this situation occur, growers need to consider fungicide applications to limit damage.  See the latest Commercial Vegetable Production Recommendations for suitable fungicides on this crop.

Filed Under: Vegetable Crops
August 2, 2017

Veg IPM Update: Week Ending 8/02/17

Sweet Corn
European corn borer (ECB) catches remain low, but are occurring in some locations with greater intensity (see ECB map at left).  This is the early part of the second flight.  In recent years, this flight has been very sporadic.  ECB feeding in NJ sweet corn plantings is still nearly non-existent at this time, but should appear again within a week, although it may be obscured by fall armyworm (FAW) feeding.  Check 5 plants each in 10 random locations for a 50 plant sample.  Look  for “shot-hole” injury, and  consider treating when the number of infested (from ECB or FAW) plants in a 50 plant sample exceeds 12%.  As infested plants proceed to the pre-tassel stage, live larvae and damage may be found in the emerging tassels.  Once plants hit full tassel, ECB larvae will move downward on the stalk and re-enter the plant near the area where ears are forming.  This can result in direct injury to the ear.  Growers should consider an insecticide application at the full tassel stage to target ECB larvae as they migrate downward.  This application can eliminate larvae that have escaped any earlier insecticide applications. [Read more…]

Filed Under: Vegetable Crops Tagged With: ,
July 26, 2017

Veg IPM Update: Week Ending 7/26/17

Sweet Corn
European corn borer (ECB) catches are still low, but catches are beginning to occur in more locations now (see ECB map at left).  This is an indication that the second flight is beginning.  ECB feeding in NJ sweet corn plantings is nearly non-existent at this time, but will appear again within 1-2 weeks.  Check 5 plants each in 10 random locations for a 50 plant sample.  Look  for “shot-hole” injury, and  consider treating when the number of infested plants in a 50 plant sample exceeds 12%.  As infested plants proceed to the pre-tassel stage, live larvae and damage may be found in the emerging tassels.  Once plants hit full tassel, ECB larvae will move downward on the stalk and re-enter the plant near the area where ears are forming.  This can result in direct injury to the ear.  Growers should consider an insecticide application at the full tassel stage to target ECB larvae as they migrate downward.  This application can eliminate larvae that have escaped any earlier insecticide applications. [Read more…]

Filed Under: Vegetable Crops Tagged With: ,
July 19, 2017

Veg IPM Update: Week Ending 7/19/17

Sweet Corn
European corn borer (ECB) catches continue to be very low, and no map will appear in this edition.  There have been a few traps that have begun to record minor increases, however.  ECB feeding in NJ sweet corn plantings is also low.  Check 5 plants each in 10 random locations for a 50 plant sample.  Look  for “shot-hole” injury, and  consider treating when the number of infested plants in a 50 plant sample exceeds 12%.  As infested plants proceed to the pre-tassel stage, live larvae and damage may be found in the emerging tassels.  Once plants hit full tassel, ECB larvae will move downward on the stalk and re-enter the plant near the area where ears are forming.  This can result in direct injury to the ear.  Growers should consider an insecticide application at the full tassel stage to target ECB larvae as they migrate downward.  This application can eliminate larvae that have escaped any earlier insecticide applications. [Read more…]

Filed Under: Vegetable Crops Tagged With: ,
July 12, 2017

Veg IPM Update: Week Ending 7/12/17

Sweet Corn
European corn borer (ECB) catches remain very low, and no map will appear in this edition.  Feeding in NJ sweet corn plantings is also low, with remaining larval infestations only on pre-tassel stage corn in the northern counties.  Check 5 plants each in 10 random locations for a 50 plant sample.  Look  for “shot-hole” injury, and  consider treating when the number of infested plants in a 50 plant sample exceeds 12%.  As infested plants proceed to the pre-tassel stage, live larvae and damage may be found in the emerging tassels.  Once plants hit full tassel, ECB larvae will move downward on the stalk and re-enter the plant near the area where ears are forming.  This can result in direct injury to the ear.  Growers should consider an insecticide application at the full tassel stage to target ECB larvae as they migrate downward.  This application can eliminate larvae that have escaped any earlier insecticide applications. [Read more…]

Filed Under: Vegetable Crops Tagged With: ,
July 5, 2017

Veg IPM Update: Week Ending 7/05/17

Sweet Corn
European corn borer (ECB) catches continue to be extremely low, and no map will appear in this edition.  Feeding in NJ sweet corn plantings is highly variable, but with second and third plantings now reaching the silk stage, we find that later plantings have much less damage.  Check 5 plants each in 10 random locations for a 50 plant sample.  Look  for “shot-hole” injury, and  consider treating when the number of infested plants in a 50 plant sample exceeds 12%.  As infested plants proceed to the pre-tassel stage, live larvae and damage may be found in the emerging tassels.  Once plants hit full tassel, ECB larvae will move downward on the stalk and re-enter the plant near the area where ears are forming.  This can result in direct injury to the ear.  Growers should consider an insecticide application at the full tassel stage to target ECB larvae as they migrate downward.  This application can eliminate larvae that have escaped any earlier insecticide applications. [Read more…]

Filed Under: Vegetable Crops Tagged With: ,