cucumber curl is usually a result of lack of pollination. the female
flower needs to be pollinated @ 20 times to grow a long, straight
cucumber. there is obviously not much you can do about this other than
make sure you are not using any insecticides that will deter bees from
doing their job. the other thing you need to be sure of is that you
water regularly not intermittently. if there is a dry spell between
rains, make sure you get some moisture in the soil.