tipburn and other joys

The heatwave is bringing August to the North Country a couple of weeks earlier than usual.  The dreaded scourge of tipburn is making its insidious way across the farms up here.  In many cases you can't even see the damage because it happens as the plant is growing, and new growth covers up the damage.  An individual consumer cutting a head for a salad will pick off the spot and probably not complain, but the big lettuce processors have a fit, since their machines are not nearly as acute as a human eye and the necessity for speed when you are processing many tons of lettuce per hour makes it nearly impossible to get rid of the problem.  So, many hours are wasted debating and scoring percentages of tipburn which is more of an art than a science.  The other problem with the heat is the labor slowdown.  It's not easy spending 8-10 hours stooped over in 95 degree heat harvesting lettuce.  Hell, it's not easy standing in the shade in this kind of weather.