Water Management in Horticultural Crops

Introduction

• It is necessary to conduct field experiments for precise data on crop water requirements. In view of the difficulties associated with direct measurement of crop water requirements, some methodologies have been developed to predict the water requirements, primarily, based on climatological factors. The FAO group of scientists screened 31 empirical formulae for predicting the ET and recommended four for use under different climatic conditions.
1. Blaney – Criddle method
2. Radiation method
3. Modified Penman method
4. Pan evaporation method
 
• Three major steps involved in the estimation of ET are
• Estimation of PET or reference evapotranspiration (ETo)
• Determination of crop coefficient (kc)
• Making adjustments to location specific crop environment
• The choice of prediction method for the determination of ETo is primarily determined by the available climatic data.