I am currently in a horticulture class as part of my classes, and my school is unique in that we have a greenhouse that is used and controlled by students. I have two questions and would be very appreciative if anybody could please help me. The first question is actually my teacher's. He has never seen what is happening to our hydoponic cucumbers' leaves before. They are curling under, and he has called everywhere trying to find the cause of this.
Nobody seems to know.
Also, as part of this class I am trying to find a natural insecticide which I can make myself and apply to my plants.