Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu
Vine crop growers have commented that they are having a hard time keeping enough moisture in their beds. Certainly, irrigation system concerns need to be accounted for (emitter volume, emitter spacing, length of run, etc.). However, high evapotranspirational demand (water taken up by the plant and evaporated from the soil) may make providing enough irrigation water a challenge.
This is particularly the case when there are high temperatures and clear skies during June and early July when day lengths are long and when plant water uptake is peaking. In 2012 during this period we have had consistently higher solar radiation and higher evapotranspirational demand compared to 2011.