HIGHLIGHTS:
Irrigation with brackish water (5.0 dS m-1) negatively affects the agronomic performance of millet.
Millet has significant decreases in growth with decreasing irrigation frequency beyond two days.
The combination of salt and water stresses compromises the forage potential of millet due to the decrease in biomass.
ABSTRACT
The semi-arid region faces problems related to water deficit and the presence of brackish water that compromise crop performance. Therefore, irrigation frequency can enhance the growth of agricultural crops of interest even under salt stress conditions. In this context, the objective of the present study was to evaluate different irrigation frequencies with water of higher and lower salinity on the agronomic performance of millet. The experiment was conducted from September to November 2020, in the experimental area of the Auroras Seedling Production Unit, belonging to the Universidade da Integração Internacional da Lusofonia Afro-Brasileira, Redenção, Ceará, Brazil. The experimental design used was completely randomized in a 4 × 2 factorial arrangement, with five repetitions. The first factor corresponded to four irrigation frequencies (F1 - daily irrigation; F2 - irrigation every two days; F3 - irrigation every three days; F4 - irrigation every four days) and the second factor consisted of two levels of electrical conductivity of irrigation water (0.3 and 5.0 dS m-1). Salt stress (5.0 dS m-1) negatively affected leaf area, plant height, stalk diameter, panicle length, and leaf, stem, panicle, and total dry mass of millet, under daily and four-day irrigation frequencies. Increasing the interval in irrigation frequency to beyond two days negatively affects the agronomic performance of millet crop, regardless of the electrical conductivity of water used (0.3 or 5.0 dS m-1). Under salt stress conditions, adopting irrigation frequencies between two and three days can be a viable alternative for irrigation management in pearl millet crop.
Key words:
Pennisetum glaucum
; abiotic stresses; salinity; irrigation management
Thumbnail
Thumbnail
Thumbnail
Thumbnail
Thumbnail
Thumbnail
** - Significant at p ≤ 0.01 by F test; Lowercase letters differentiate at the same frequency of irrigation, and uppercase letters differentiate at the same salinity level the frequencies of irrigation by the Tukey test (p ≤ 0.05)
* - Significant at p ≤ 0.05 by F test; Lowercase letters differentiate the means by the Tukey test (p ≤ 0.05)
* - Significant at p ≤ 0.05 by F test; Lowercase letters differentiate at the same frequency of irrigation, and uppercase letters differentiate at the same salinity level the frequencies of irrigation by the Tukey test (p ≤ 0.05)
* - Significant at p ≤ 0.05 by F test; Lowercase letters differentiate at the same frequency of irrigation, and uppercase letters differentiate at the same salinity level the frequencies of irrigation by the Tukey test (p ≤ 0.05)
** - Significant at p ≤ 0.01 by F test; Lowercase letters differentiate at the same frequency of irrigation, and uppercase letters differentiate at the same salinity level the frequencies of irrigation by the Tukey test (p ≤ 0.05)