It was pointed out by a neighbor that our tomatoes were all diseased and would not yield what we wanted. The leaves were turning a reddish tint (a closer look showed tiny red bugs.) So we succumbed to chemicals. We bought some insecticide and borrowed a sprayer from a colleague. We added 20-25 ml of the stuff to 10 L of water. All we did was pump and spray. Not our proudest moment since we have been working hard on our compost and wanted to be chemical free.