Agricultural and Biological Research

Irrigation frequency and soil type influence germination and early growth of quinoa (Chenopodium quino Willd)

Paul Chaibva*, Cecil Mugala, Veronica Makuvaro, Ignatius Chagonda, Blessing Mirika Ndau and Tavagwisa Muziri

Poor seed establishment threatens the adoption of quinoa as a potential food crop in semi-arid parts of Zimbabwe. We used a 4 × 3 factorial experiment arranged in a Completely Randomised Design (CRD) to establish the effects of irrigation frequencies and different soil types on quinoa germination and early growth. We used three soil types (sand, loam, and clay) and four irrigation frequencies (after every 1, 2, 3, and 4 days). Measurements included days to 50% emergence, germination percentage, mean germination time, germination rate index, and the coefficient velocity of germination, seedling height, final crop stand, and root density. An Analysis of Variance (ANOVA) was done using GenStat 18th Edition and mean separation was done using the Least Significant Difference (LSD) at a 5% significance level. There was an interaction between irrigation frequency and soil type on days to 50% emergence (p<0.05), germination percentage (p<0.05), germination rate index (p<0.05), seedling height (p<0.05), root length density (p<0.05), seedling crop stand (p<0.05). Shorter irrigation frequencies on all soil types had higher final germination percentages than longer irrigation frequencies. Seeds planted in sand recorded the shortest mean germination time (3.25 days), with no significant differences between clay and loam. Sand irrigated at 1-day intervals recorded the highest (70.4%) germination rate index, while other longer frequencies had the lowest. Loam and sand irrigated at 1-day intervals and loam irrigated at 2-day intervals recorded the highest seedling height. Sand irrigated at 2-day and 3-day intervals had the highest root length densities, while clay and loam soil irrigated at 1-day intervals and loam irrigated at 2-day intervals recorded the lowest root length densities. Sand irrigated at 1-day intervals recorded the highest (85%) crop stand. We recommend planting and frequently irrigating quinoa in sandy soils for better crop establishment.