Management of water deficit in the irrigated production of the green pepper¹

ABSTRACT

Information on irrigation management is essential for achieving satisfactory results when cultivating the green pepper. The aim of this study, therefore, was to evaluate the effects of water deficit, which varies according to phenological stage, on the production, growth and physiology of a crop of green peppers. The experimental design was completely randomised, with seven treatments, four repetitions, and plots comprising two plants. The treatments consisted of replacing the water demand during phenological phases I, II, III and IV (in terms of percentage ETc): T1 - 100%/I, 100%/II, 100%/III and 100%/IV; T2 - 100%/I, 75%/II, 100%/III and 75%/IV; T3 - 100%/I, 75%/II, 75%/III and 75%/IV; T4 - 100%/I, 75%/II, 75%/III and 50%/IV; T5 - 100%/I, 50%/II, 75%/III and 50%/IV; T6 - 100%/I, 50%/II, 50%/III and 50%/IV; T7 - 100%/I, 50%/II, 50%/III and 25%/IV. The plants were grown in the field under drip irrigation. The following variables were analysed: plant height; stem diameter, leaf area, shoot dry weight, number of fruits per plant, soluble solids, fruit length, fruit diameter, fruit weight, productivity, relative chlorophyll index, gas exchange, and water use efficiency. Compared to T1, management based on T2, T3 and T4 did not reduce expression of the vast majority of the vegetative variables or of gas exchange. The water deficit from T2 can be employed without any significant reduction in productivity and affords water savings of 12.5% in relation to T1. T1 and T2 give the highest values for water use efficiency. Management based on T1 and T2 is therefore recommended for cultivating the green pepper under field conditions.

Key words:
Capsicum annuum L; Gas exchange; Irrigation