Pollen Beetle in OSR
- Thread starter pgilliat
- Start date
Loads of Pollen Beetle here and in many instances above published spray thresholds. Good crops have started flowering but late, backward or CSFB larvae infested crops (delete as appropriate) are stuck at 'green bud' and the cold weather will delay onset of flowering.
I don't know what the cold weather will do to beetles. I anticipate the beetles that have already located a crop will go about their business (albeit more slowly) and think migration will temporarily stop (or dramatically slow down) next week if the forecasts are to be believed.
I have never sprayed for pollen beetle before but the condition of crops (health/growth stage/potential) is so variable and is causing a real conundrum on best course of action. Obviously crops that have started flowering don't require a spray but there are 'late' crops stuck at green bud with some potential and it feels like intervention with an insecticide is probably justified (if beetle numbers exceed threshold). The crops riddled with flea beetle larvae will have to take their chances now until harvest with no/minimal inputs.
I don't know what the cold weather will do to beetles. I anticipate the beetles that have already located a crop will go about their business (albeit more slowly) and think migration will temporarily stop (or dramatically slow down) next week if the forecasts are to be believed.
I have never sprayed for pollen beetle before but the condition of crops (health/growth stage/potential) is so variable and is causing a real conundrum on best course of action. Obviously crops that have started flowering don't require a spray but there are 'late' crops stuck at green bud with some potential and it feels like intervention with an insecticide is probably justified (if beetle numbers exceed threshold). The crops riddled with flea beetle larvae will have to take their chances now until harvest with no/minimal inputs.
Have sprayed a block of good rape, heavily infested & going to stall because of cold nap. More forward-good speckle of yellow-left, greener checked for numbers and will be rechecked post easter.
Have seen people leave crops untreated and have been destroyed, when they should have been sprayed. Power of social media prognosticating about crops the vocal are not standing in can be really unhelpful.
Have only sprayed when these conditions prevail, green bud, warm spell to move beetle in to high numbers-then followed by a cold spell that will stall crop development and leave hungry beetles with no patience to wait for slowed flowering.
Have seen people leave crops untreated and have been destroyed, when they should have been sprayed. Power of social media prognosticating about crops the vocal are not standing in can be really unhelpful.
Have only sprayed when these conditions prevail, green bud, warm spell to move beetle in to high numbers-then followed by a cold spell that will stall crop development and leave hungry beetles with no patience to wait for slowed flowering.
Try to succeed
Member
I have 80-110 per plant. In some cases more. I had the same pressure two years ago. Agro was v relaxed and said don’t treat but I did as they were literally wiping my crop out. Neighbours who waited had masses of potential wiped out. Have sprayed a tankful this evening just before dark to limit damage. You can’t get away without insecticides with osr here, no matter how much I wish I could. There was no damage yday morning. This morning it is obvious, and in this cold spell coming it’ll just sit there getting hammered.
Hindsight
Member
- Location
- Lincolnshire
Which insecticide did you use?
Try to succeed
Member
Insyst 200g/ha
Try to succeed
Member
You’ll not be far away in Lincolnshire? What’s the pressure like there?
Chae1
Member
- Location
- Aberdeenshire
Hindsight
Member
- Location
- Lincolnshire
I had a look at a block of 200 hectares jus south of LIncoln yesterday. Pollen Beetle were there but most I saw was 2 or 3 in an the more forward yellow bud stems. Al lot of stems none at all. So one of those situations where could say I will come back after weekend for another look. Am going to have a look at another block later today when walk the dog.
- Location
- S E Glos
TLDR. However their conclusion (in the abstract and summary) that spring rape is as susceptible as winter rape, misses the point. Beetles come in to winter crops just before flowering so there is a short window of potential damage. When they appear however spring rape is much smaller, and they can be found looking for flower buds in these crops well before stem extension. Hence a much longer window of feeding and damage.
Thanks for that Ugo79
- Location
- Lincolnshire Wolds
Anyone used Steward (Indoxacarb)? Been recommended but will be £30/ha.
Seriously? Someone has recommended you spend £30/ha on pollen beetle? Is this right or a typo?!