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

Abstract

The adoption of quinoa as a potential food crop in semi-arid Zimbabwe is threatened by poor seed establishment. A 4 x 3factorialexperiment arranged in a completely randomised design (CRD) was carried out to establish the effects of irrigation frequencies and different soil types on germination and early growth of quinoa. Three soil types (sand, loam, and clay) and four irrigation frequencies (after every 1, 2, 3,and 4days) were used. Measurements taken included days to 50% emergence, germination percentage, mean germination time,germination rate index, coefficient velocity of germination, seedling height, final crop stand,and root density. Analysis of variance (ANOVA) was done using GenStat 18thEdition 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). Sandy soil irrigatedon1-day intervals recorded the highest germination percentage (96.7%), while clay irrigated on 3-dayintervalsrecorded the lowest (41.7%)final germination percentage respectively. Seeds planted in sand and clay recorded the shortest (3.25) and longest (4.5) mean germination time (days) respectively. Loamy and sandy soils irrigated on3-day intervals and 1-day intervals recorded the lowest (29.4%) and highest (70.4%) germination rate index respectively. Loam soil irrigated on1-dayand 4-day intervals recorded the highest (16.37cm) and shortest (9.3cm)seedling height. Loam soil irrigated on2-dayand sandy soil irrigated on3-dayintervalsrecorded the lowest (3.07cm/cm3) and the highest (21.23cm/cm3) root length densities respectively. Sand irrigated on1-day intervals recorded the highest (85%) crop stand. Findings concluded and recommended planting and frequently irrigating quinoa in sandy soils for better crop establishment.