Northern wild rice, Zizania palustris, is a vital natural resource in Michigan. Because of human development of its habitat and displacement by invasive species, northern wild rice is declining across its natural range. We have studied the stratification needs and percent germination of wild rice for two years because we are attempting to restore rice populations in central Michigan to their former range and abundance, which will help develop a culture of wild ricing here.
To restore the populations of wild rice in central Michigan, one needs seed that is vigorous, large-grained, and has similar dormancy requirements to local rice. This type of seed may be what is found in Lac Vieux Desert (LVD) on Michigan-Wisconsin border, as we already know that it is large-grained, and the fact that it is a dense population hints that it is vigorous. To determine whether LVD rice would be good for reseeding central Michigan, we compared the stratification requirements of samples from LVD and central Michigan (Martiny Lakes) and recorded germination rates to determine if they were suitably high for restoration.
Results/Conclusions
The results from the two years were very different. In year one, the Martiny seeds did not begin to germinate until after 22 weeks of stratification and did so at very low rates, while the LVD seeds germinated after 14 weeks with much higher rates throughout the experiment. This could be taken to mean that southern seeds (Martiny) need more stratification than northern seeds (LVD), but the results from year two proved this false. Both populations had very high germination rates starting in the sixteenth week of stratification, and continued throughout the experiment. 2008 was a highly productive rice crop in the Martiny Lakes, while 2009 was a bust in the same site sampled for our research. Correlating the low germination rates at Martiny with the subsequent bust year that followed a boom year suggests that the rice knew to stay dormant. Perhaps it did not want to let all the seed germinate when nutrient levels were low due to the nutritional demands of the 2008 rice crop. We are investigating the phenomenon to determine if rice germination rates in the lab can be combined with rice crop abundance from previous years to predict future rice crops. Overall we found that LVD seeds did have high germination rates over two years, fulfilling the second requirement for restoration worthy seeds.