I have a lodgepole pine that is growing in a pot, every year the needles get a yellow stripe. I have sprayed with insecticides and fungicides but the problem persists. Can anyone identify this problem and provide a solution. Thank you.
More likely a nutrient imbalance or deficiency in the limited quantity of soil in the pot. Try repotting with fresh soil, and give it a dose of fertiliser regularly. Or plant it out into the ground so it can spread its roots widely to get the nutrients it needs. Never use insecticides or fungicides without a specific diagnosed need.
You might like to scroll down the list of links to the pine ones (on the "Plant Name Begins with P" page) to see if anything fits. http://plant-disease.ippc.orst.edu/plant_index.aspx?title=disease
