Abstract

The aim of the present study is to assess the effects of different irrigation blades on the growth and yield of cauliflower cv. Verona CMS. The plants were cultivated in Red-yellow Latosol during the dry period (winter-spring 2014 and 2015), in the Cerrado-Amazon transition region, Middle-Northern of Mato Grasso State, Brazil. The reference evapotranspiration (ETo) was recorded through the Class A pan method by using tank coefficient of (Kp) 0.7795. We assessed the blades of 40, 60, 80, 100 and 120% evapotranspiration of the culture (ETc) by taking into account the cultivation coefficients (Kc) of 0.70 and 0.95 in the vegetative and reproductive phases. With regard to the morphometric variables of the plants (height, stem diameter and number of leaves) there were no significant interactions between assessment time (days after planting) and irrigation blades throughout the crop years. The hydric response functions presented higher yield at repositions from 80% to 100% of ETc. Variations in the irrigation blade did not influence the thermal demands for the inflorescence differentiation period or the inflorescence shape. Increased irrigated blade reduced water use efficiency: 7.4 and 12.4 kg of fresh mass per m³ of irrigated water.

Key words: Irrigation management, water response function, degree-days, evapotranspiration.