Effects of seed soaking with biogas slurry on seed germination and seedling growth of Tagetes erecta

Abstract

Objective: The experiment was conducted to study the effect of soaking seeds with biogas slurry on seed germination and growth of Tagetes erecta so that we can provide theory base for cultivation management of T. ercta. Method: In order to find the best combine of biogas slurry concentration (25%, 50%, 75%, 100%) and soaking time (2, 3, 4, 5 h), completely randomized design was selected, germination percentage, seedling height, root length, root activity, content of chlorophyll (a, b) and MDA were analyzed and principle component analysis was adopted. Result: Both soaking for 5 h in 25% biogas slurry and soaking for 4 h in 50% biogas slurry had the highest germination percentage (81.3%). Soaking for 5 h in 50% biogas slurry had the longest root, and soaking for 4 h in 50% biogas slurry had the highest root activity. They were significant higher than other 19 treatments. Soaking for 5 h in 50% biogas slurry had the highest content of chlorophyll a, chlorophyll b, chlorophyll (a + b) and ratio of chlorophyll a/chlorophyll b. It was significant higher in these index, except b, than other 19 treatment. Soaking for 5 h in 25% biogas slurry had the low-est MDA content (0.028 0 μmol·L-1), then was Soaking for 4 h in 50% biogas slurry (0.028 6 μmol·L-1 in MDA content). Conclusion: Appropriate biogas slurry concentration combined with seed soaking time can improve the germination and growth of T. erecta. As a whole, soaking for 5 h in 50% biogas slurry had the best effects on germination and growth in seedling stage for T. erecta.