In areas with limited water supplies, certain management decisions must be taken into consideration when determining crop selections. The first thing that should be considered is the quantity of water available for irrigation. The second thing to consider is the capacity of the available irrigation system to deliver the water volume required to meet peak crop demands. Therefore, one should only attempt to grow crops that have a demand which can be met by the available water supply and the delivery capacity of his irrigation system. The average water requirements of selected vegetable produced in Texas are shown on the Water Requirements document.

The Water Requirements page also contains information depicting the critical need stages for vegetables. In general, crops from which leaves are harvested, especially those with short growing periods, need a generous supply of available water from planting to harvest. Plants that develop heads need a uniform, adequate water supply especially during head enlargement. Root, tuber and bulb crops require the greatest volumes during tuber set and during periods of enlargement of these plant parts. Crops from which fresh or dry seeds, pods, or ears are harvested need an adequate water supply at flowering (or tasseling) and fruit set. These crops also need an adequate water supply during fruit, seed, pod, or ear development to prevent fruit cracking and malformed ears or pods.

Deficit irrigation, a technique which utilizes less that the optimum quantity of water to produce a crop, is becoming increasingly more important in regions of limited water availability. This technique can enable successful crop production with limited quantities of water. However, when using this technique, as much water as possible should be held in reserve for application during the critical stages of that crop. Limiting water during these stages can have disastrous results from a yield and quality standpoint.

Adapted from the original publication by Frank J. Dainello, PhD, Extension Horticulturist – Commercial Vegetable Crops, Department of Horticultural Sciences, Texas A&M University

Publication updated April 2011