The name intermediate wheatgrass comes from the perennial grass Thinopyrum intermedium. It belongs to the Triticeae family of Pooideae and is native to Europe and Western Asia. Its seed heads and ear structures are similar to common wheat. However, there are some significant differences between the two species. To learn more about the differences between them, read on. This article will cover these differences and give you an idea of which one is right for your garden.
Fertility
A study to determine the fertility of intermediate wheatgrass germplasm used a standardized procedure to rate spikelet position, floret size, and seedset composition. The study used a seed size evaluation method developed by Trupp and Slinkard, with seed sizes ranging from 3.6 g/1000 seeds to 7.2 g/1000 seeds. The results showed that there was sufficient variation among germplasm to meet the criteria for fertility assessment.
A wide distribution of plants for fertility suggests that significant improvement is possible in ill-performing four grass varieties. One cultivar, ‘Luna’, performed similar to dough-forming wheat in farinograph tests, while another cultivar, ‘Oahe,’ was less favorable. Fertility of intermediate wheatgrass may be dependent on the cultivar, but the variability could be sufficient to suit different culinary purposes.
A similar situation was observed for bromegrass and intermediate wheatgrass florets. In both cases, floret position correlated with seed set. Similarly, Mackay (10), who reported similar results, observed that crested wheatgrass florets were more fertile. Sterile florets in intermediate wheatgrass had a high percentage of seeds, but was distributed throughout the spikelet, not just at the terminal floret. This suggests that both genetic and cytological factors may contribute to seed failure in intermediate wheatgrass.
Intermediate wheatgrass has been grown for several decades in Western Canada as a forage grass. Now, it is being tested for grain production in the Prairies, thanks to new research by Doug Cattani and other researchers. The results of this study will help farmers avoid the fussy weather conditions and bolster their bottom lines, which have been slashed by low prices for organic wheat. But there are limitations.
Seed size
Although closely related to pubescent and tall wheatgrass, the difference in seed head structure and seed yield makes this plant different. The seed size of intermediate wheatgrass is much smaller than that of pubescent wheatgrass. Seed fertility is measured as the number of fertile florets per seed head and the number of tillers per plant. Seedhead fertility is the number of florets in a seedhead divided by the number of seeds.
The seed size of intermediate wheatgrass varies considerably among populations. While wheatgrass seeds are relatively small, commercially produced seed from this plant can grow to be more than two feet in diameter. Because the plant’s roots are quite extensive, it can be planted in low-lying regions, though this is not recommended as it needs higher levels of moisture. Depending on the variety, seeds of intermediate wheatgrass can be used as groundcover in lawns, pastures, and other areas.
The re-growth rate of intermediate wheatgrass is slow, and this makes it best for single-crop haying situations. It also responds well to irrigation. For a single-crop situation, the seed size of intermediate wheatgrass can reach a height of three inches, comparable to orchardgrass. In multiple cutting situations, however, the yield of intermediate wheatgrass is not as high as that of orchardgrass.
The results show that seedset ratings range from 8% to 52% in the germplasm tested at the RRC. The seed size of intermediate wheatgrass varies from 3.6 to 7.2 grams per 1000 seeds. The initial information from the RRC shows that this variation is sufficient. The results are promising, but further studies will be needed to determine whether or not these values are representative of the underlying genetics of the plant.
Adaptation to soil erosion
Adaptation of intermediate wheatgrass to soil degradation is one of its main goals. Its low-water requirements make it an excellent choice for stabilizing disturbed soil. It can also be used in urban areas where irrigation water is scarce. Its heavy root production can produce up to 7000 pounds per acre of soil. Its resilience to soil erosion makes it a viable option for seeding in waterways.
Kernza, also known as intermediate wheatgrass, is a perennial grass that was introduced to the United States in the 1930s from Western Asia and Europe. It is commonly used for forage, hay, and pasture lands. It is a highly versatile plant that is an excellent choice for conservation on a variety of soil types. In addition to soil erosion control, it also provides a high-quality habitat for wildlife, including game and migratory waterfowl.
In addition to reducing soil erosion, another major benefit of intermediate wheatgrass is its ability to compete with aggressive annuals. It also provides feed for livestock and helps stabilize critical areas. During planting, it should be drilled at a depth of 1/2 inch to one inch. The deeper the hole, the more plants you need. Once planted, they will continue to provide both forage and cover. If you are growing it for other purposes, don’t forget to add a protective cover to your soil.
Currently, RRC is working to adapt information on perennial grass seed production to the production of intermediate wheatgrass grain. The research began with establishing plots of ‘Oahe’ intermediate wheatgrass at the RRC in 1984. Various seeding rates have been tested, with the best results obtained when interplanting it with white clover and legumes in late August. The RRC is currently implementing an adapted plan to increase the yield of intermediate wheatgrass.
Grain quality
Although the yield and grain quality of intermediate wheatgrass is not yet established, several recent studies have shown significant improvements in forage and biomass production. These studies have led to the registration of several IWG cultivars with improved forage quality, yield potential, and stand persistence under grazing. In North Dakota, biomass yields ranged from 6.7 to 10 Mg ha-1. Whole-plant in vitro dry matter digestibility was estimated at 649 g kg-1 at anthesis.
A recent two-year research project by the University of Minnesota and Michigan State University aimed to improve Kernza(r) yield and quality, has already begun. Funded by a Ceres Trust grant, the project is testing the potential for growing a dual-use crop that improves soil and water quality. To gather data on how to manage the crop, three farmers from the Midwest were interviewed. Each farmer’s experience with growing wheatgrass is unique, but common concerns remain.
Despite the high-quality of its grain, many farmers are concerned about its productivity. However, the benefits outweigh its negative qualities. This plant is well adapted to urban environments and needs very little irrigation. It can also be used for building soil and stabilizing dikes. It has a dense root system and produces about seven tons per acre. For its low-maintenance needs, this species can be used in areas where irrigation is difficult.
In the first experiment, 18 putative perennial amphiploid lines and two annual wheat varieties were evaluated. Yield, PSCR, and key agronomic traits were evaluated. The yield of the annual wheat varieties and intermediate wheatgrass varied significantly between locations. Despite the low yields, the four highest-yielding amphiploids produced 50 to sixty percent less in different locations. Thus, further work is needed to determine how to improve their yield and grain quality.
Environmental benefits
Growing a perennial forage crop like intermediate wheatgrass has numerous environmental benefits. It is not only an excellent source of fiber and energy, but also a high-value biomass crop. The plant’s roots extend 10 feet deep, making it twice as deep as conventional annual wheat. Because of its perennial growth habit, farmers can plant it just once and reap its benefits for many years to come. This means less effort on the part of farmers, and they can focus more on other tasks such as harvesting.
Another advantage of growing intermediate wheatgrass is that its production is sustainable and tolerant to many agricultural practices. It reduces soil erosion, decreases nitrate leaching, and enhances carbon sequestration. Until recently, the only food-grade perennial grain cultivar was the oats. Now, however, a research team from the University of Minnesota has created a cultivar that provides both food-grade quality and environmental benefits.
The study objectives include determining the forage nutrient and fiber digestibility of Kernza intermediate wheatgrass. The study involves three harvests during the first production year: spring for vegetative growth, summer for grain residue, and fall for regrowth. The study will also compare forage nutrient values of Kernza intermediate wheatgrass grown in monoculture compared to a mixture with red clover. The study will be complete once the test is completed.
The study showed that intercropping Kernza intermediate wheatgrass and red clover increased fall forage yields by 118% and annual forage yields by 39%. This combination increased the nutrient value of fall forage. The greater concentration of CP in Kernza intermediate wheatgrass in the mixture indicates significant N transfer from legume to grass. Zemenchik et al. (2001) showed that grass-legume mixtures significantly outyielded grass monocultures with less than 182 kg N ha-1.