5.15.20 GDD update

No bud break at the Lamb homestead – all 6 trees.  But it was a nice excuse to go out for a ramble before the rain.

 

And a little disease note – for needlecast on Douglas fir.  How to cut down from 4 spray applications to 2.  From Brian:

Skip the early spray!  Wait until there’s an average of 1 to 1 ½ inch of growth for the first spray.  Then go 10 days later for the second spray. That should be all you need if you get good coverage with both sprays

 

Brian used the highest label rate for his applications to manage needlecasts on Douglas fir   (Since different products have different labeled rates – and different numbers of applications allowed – you need to check the label of the product you are using>)

 

GDD                                       May 15                 May 20

 

Champlain                           31                           59

Geneva                                61                           87

Riverhead LIHREC             136                         155

 

Looks like things might speed up in development – both plants and pests.

 

This is an important time for pest management – before and during bud break.

 

Dormant oil applications

  • Don’t spray blue spruce and other ‘blue’ cultivars, Douglas fir and spruce can be sensitive
  • Temperature between 40 and 85F, with night temperatures above 32F
  • At least 92% unsulfonated residues (check the label)
  • Good coverage essential – contact effect only, no residual
  • Keep the tank agitated

 

Remember to scout for these before making applications – you want to make sure the pest is there AND at the right stage

Cooley spruce gall adelgid                            22-91 GDD

Spruce spider mite eggs                                7-121 GDD

Balsam twig aphid eggs                                 58-120 GDD

Balsam woolly adelgid crawlers                  (haven’t found information for this one)

Eastern spruce gall adelgid                           22-170 GDD

Elongate hemlock scale                                 7-120 GDD