Effect of Irrigation Frequency on Yield and Yield Components of Quinoa (chenopodium quinoa) under Saline Condition

This study was done to investigate the effects of different irrigation frequency with tape system on quinoa yield and yield components in spring at Yazd.

The experiments were conducted as a randomized complete block design with different irrigation frequency (3, 7, 10, 14, 17 and 20 days) and in three replications. Electrical conductivity of irrigation water was 10 dS.m-1. At the end of the study, quinoa harvest was done manually and after drying, plant height, panicle length, panicle width, number of branch, number of panicle per plant, 1000-seed weight, dry biomass, grain yield and harvest index were measured and the effect of different irrigation frequency on these parameters were investigated.

The results showed significant effect of irrigation interval on all studied traits except panicle width and number of panicle per plant. The highest biomass (9.7 ton.ha-1), seed yield (3.2 ton.ha-1) and harvest index (39.14%) were observed in 10, 3 and 3 days irrigation interval, respectively. The lowest biomass (6.8 ton.ha-1), seed yield (1.7 ton.ha-1) and harvest index (25.2 %) was observed in 20 days irrigation interval. Results of correlation coefficients showed that seed yield was highly correlated with 1000-seed weight (r = 0.821**) and Panicle length (r = 0.711**).

Water use efficiency of quinoa varied from 0.24 to 0.62 kg m-3 at different treatments of applied water. According to this index, the optimum irrigation frequency of quinoa and the applied water volume by the drip irrigation system (tape) were about 14 days and 4350 m3 ha-1, respectively, which is recommended under conditions similar to the this study.