Comparison of Sorghum Types for Hay Production.

A sorghum hay trial was initiated in 2007 and repeated in 2008. Only 2007 data is presented in the abstract. Entries included hybrids with the brown midrib (BMR) and photoperiod sensitive (PS) traits. The hybrids were planted in a randomized block design in two 25-ft row plots, on 30-inch raised beds in 3 replications. Plots were furrow irrigated prior to planting and again immediately after the first cutting. A total of two cuttings were made, with the first cutting occurring 60 days after planting and the second cutting when each hybrid was 50% headed. Samples from the first harvest were tested for nutrient and mineral composition. At the first cutting, average yield of the BMR entries was 3.23 ton/Ac. This was 14% lower than the nonBMR entries at 3.66 ton/Ac. NonBMR PS entries yielded the lowest at 3.06 ton/Ac. Yield differences were also reflected in the plant heights. Digestibility based on % IVTD was highest with the BMR entries at 79.4% followed by the NonBMR PS entries at 77.0% and the NonBMR entries at 74.6%. At the second cutting, there were considerable yield differences between individual entries, however, average yield differences between the three types of sorghum were small, ranging from 4.79 ton/Ac with the PS entries to 5.04 ton/Ac with the nonBMRs. Nutrient composition was not determined on the second cutting. When total seasonal yield was examined, three of the top four yielding entries were BMR. Regrowth after the first cutting contributed much more to total yield with some entries than with others. Yield of the first cutting was not necessarily a good indicator of how well the second cutting would yield. Also, there were no PS entries among the top 7 entries in total yield. This is in contrast to what we usually see with a one time cutting for silage.