The literature concerning crop management experimentation using continuous variable designs (CVD) is reviewed. Some modifications and advantages and disadvantages of the CVD are discussed based on field trials with vegetable, grain, and root crops. The results for three experiments with cassava in Puerto Rico using the CVD are discussed. In the first, on a Udic Chromustert, the yield response to nitrogen levels was linear up to approximately 30 kg N/ha. In the second and third, on a Cumulic Haplustoll, there was little or no discernible response to nitrogen levels from 0 to 44 kg N/ha or to phosphorus levels from 0 to 37 kg P/ha. The CVD appears to be an efficient but underutilized technique that has merit for use in management trials for various crops, especially where space and funding are limiting factors.