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001797 reports that a '0 percent increase in precipitation could increase the runoff by as much as 50 percent. Asked if irrigation Vlill increase humidity significantly, he stated there is too much turbulence in the atmosphere for irrigation to keep moisture content up over a large area. He suggested irrigation practices might need to be regulated to give more consideration to wind, temperature, and humidity conditions and thereby become more efficient. In summary, he indicated we need to work with our climate and not against it when we are developing a plan for the most efficient use of water resources. Dr. Edward Kanemasu's comments dealt with where the largest advances can be expected in the reduction of evapotranspiration during the next 30 years. He stated the largest portion of the water lost from the soi I profi Ie is due to evapotranspiration-oat least in the major part of the agricultural lands in Kansas. There is a small amount of drainage which may satisfy the leaching requirements. The evapotranspiration may be divided into soil evaporation from vegetative surfaces. After a vegetative cover has been establ ished, most of the evaporation loss is from the plant leaves. Hence, it seems logical that we should concentrate On reducing the transpirational losses that depend on both micrometeorological conditions and physiology of plants. He indicated that to obtain mOre efficient use of our water, we would like to increase the dry matter accumulation per unit mass of water. A useful and indicative parameter is photosynthesisltranspiration (PIT). The larger the PIT ratio, the more efficient is the plant. We can increase this ratio by modifying the boundary layer resistance (Ra), stomatal resistance (Rs), or mesophyll resistance (Rm). Also by genetically altering the physiological and morphological characteristics of the plant, we hope to select economic plants to be more efficient users of our water resources. He illustrated this point by the use of two equations: (a) Transpiration T ~ 6 Humidity Ra + Rs (b) Photosynthesis P ~ tJ C02 Ra + Rs + Rm Where Ra--boundary layer resistance Rs--stomatal resistance Rm--mesophyl \ resistance 7.