A forage sorghum irrigation study was conducted at Maricopa, AZ to determine water use and if sub-optimal irrigation increases water use efficiency and profitability. Sorghum was planted on July 10 with a row spacing of 40 inches and irrigated three times with a total of 8.7 inches of water to establish the crop. Variable amounts of irrigation water were applied commencing on Aug 12 based on 25, 50, 75, and 100% of estimated crop water use (evapotranspiration, ET). The plots were 53.3 ft wide (16 rows) and 40 ft long. ET was estimated from soil water measurements using a neutron probe. The total amount of water applied was 15.5, 19.8, 23.7, and 27.8 inches for the 25, 50, 75, and 100% ET treatments, respectively. The forage was harvested on Oct 28 near the soft dough stage. Forage yields adjusted to 70% moisture were 11.3, 16.4, 21.5, and 23.1 tons/acre for the 25, 50, 75, and 100% ET treatments, respectively. Yield produced per inch of water used by the crop (WUEET, water use efficiency of water used in ET) increased with water application. Yield produced per inch of water applied to the crop (WUEirr, water use efficiency of irrigation water applied plus rainfall) also increased with water application, but then decreased from the 75 to 100% ET treatments. Nevertheless, sub-optimal irrigation strategies are not economical using the results from this study assuming a water cost of $45 per acre-foot and a sorghum silage value of $20 per ton. For sub-optimal irrigation strategies to be economical, water costs would have to increase, sorghum silage value would have to decrease, or the differences in the irrigation efficiencies of the strategies being compared would have to be greater than measured in the present study.

A nitrogen fertilizer study was conducted in order to develop tissue testing guidelines for fertilizer application to forage sorghum. The study was conducted at the University of Arizona Maricopa Agricultural center on a sandy clay loam soil irrigated using surface flood methods. Forage sorghum was planted on 8 July 09 and fertilized with eight N rates varying from 0 to 350 lbs N/acre in 50 lb N/acre increments. The plants were sampled six times during the growing season and the lower stem, most recently developed leaf, and whole plant were analyzed for nitrogen content. Maximum yield at final harvest was obtained at 150 lbs N/acre and plant growth was highly affected by N rate. Before the initiation of rapid growth, the relationship between plant growth and N content in the various tissues was weak (R2 < 0.20), but was very strong (R2>0.50) from the initiation of rapid growth through the pre-boot stage at the time when post-plant nitrogen fertilizer application may be considered. Stem nitrate was most strongly related to yield for the tissues tested, but the relationships between plant growth and total N in the newest leaf and whole plant were also very strong. Preliminary tissue testing guidelines are suggested for nitrate in the stem tissue. The lower stem, newest leaf, and whole plant are all potential candidates for development of tissue testing guidelines for forage sorghum.

No description available.

A study was conducted in the field to test whether stomatal sensitivity to water stress can be used as a selection criterion for drought tolerance in two pearl millet genotypes. In both cultivars, stomatal aperture was significantly reduced by the water stress. However, the proportion of reduction per 20 mm decrease in applied water was much higher for the hybrid than for the female parent. This is clearly an indication of a higher stomatal sensitivity in the hybrid, which probably explains the superior performance under water stress that was previously observed in this genotype.

No description available.

Eleven full season hybrid grain sorghums, representing seven commercial sources, were grown on a silty clay soil south of Duncan. The test plots were managed the same as the rest of the field planted to DeKalb 69. Grain yields ranging from 6911 to 4546 pounds per acre were obtained, with DeKalb 69 the top yielder.

Nine medium to medium -late maturing grain sorghum hybrids were compared for yield, percent moisture at harvest, bushel weight, plant height, percent bird damage and standability. The highest yielding entry in the trial was a new hybrid from Northrup King (NK 2656). Its yield of 6185 pounds per acre was 11% higher than the most, commonly grown hybrid in the area.

The capability to measure the magnitude of water stress in plants is useful for precision irrigation scheduling and other purposes. This paper reports an evaluation of leaf (TL) and canopy (Tc) temperatures, leaf minus air (TL -Ta) and canopy minus air (Tc -Ta) temperatures, and leaf water stress index (LWSI) and crop water stress index (CWSI) in detecting stress in pearl millet (Pennisetum americanum (L.) Leeke) over two growing seasons. Baselines which were used to compute LWSI and CWSI were obtained. The upper and lower baselines for the Tc data, respectively, were Tc -Ta = 4.10 C and Tc -Ta = 3.87- .2001VPD where VPD is vapor pressure deficit in mbars. For the TL data, the upper and lower baselines, respectively, were TL -Ta = 1.97oC and TL -Ta = 1.308- .03006VPD. Tests against photosynthesis, transpiration, and grain yield showed that LWSI and CWSI are better indices of stress than TL -Ta, Tc -Ta, TL, Tc, or Ta. Average seasonal LWSI and CWSI ranged from approximately 0.03 for non- stressed to 0.80 for stressed plants. The reliability of LWSI and CWSI to detect stress and their relation with grain yield suggested the possibility of using these indices for irrigation scheduling decisions.

Thesis (M.Sc. (Pasture Science)) -- University of Limpopo, 2014 / Forage sorghum is widely grown in South Africa as annual summer forage to supplement pasture production for sheep, beef and dairy cattle. A number of sorghum cultivars are available commercially, and periodically some cultivars are added while others are withdrawn from the market. The potential yield figures and the nutritive value of these forage sorghum cultivars are generally not known. The management practices that improve forage sorghum production and quality include the time of planting and time of harvesting. The genetic makeup of different forage sorghum cultivars also accounted for a portion of the production and quality. A field experiment was conducted at Dewageningsdrift Experimental Farm (DWD), Moloto, Gauteng and Nooitgedacht Agricultural Development Center (NGD), Ermelo, Mpumalanga to study the influence of planting date on the growth potential of different forage sorghum cultivars. Three planting dates were used: mid-December 2006, mid-January 2007 and mid-February 2007. Thirteen different cultivars were incorporated in the trial to evaluate influence of the breeding history. The cultivars were defoliated at three different stages: cut repeatedly at six weekly intervals (Dt 1), cut repeatedly when it reached a grazing stage (± 800 mm high) (Dt 2) and once at the silage stage (soft dough) (Dt 3). At DWD the average total dry matter (TDM) productions, for the six week cutting treatment (Dt 1), were 10760 kg/ha, 5195 kg/ha and 1944 kg/ha for December, January and February planting date respectively. For the same treatment, at NGT, the average TDM productions were 6396 kg/ha and 1737 kg/ha for December and January respectively. The February planting resulted in the poor germination and seedling emergency. The seedlings did not survive due to low temperatures. The minimum of 13 ºC and 11.8 ºC as well as the maximum of 24.1 ºC and 23.0 ºC in February and March were below the required germination temperature (15 ºC). The highest producers that is available in the market were Jumbo, Sentop, Piper, Kow Kandy, and Sugargraze. Defoliated repeatedly at grazing stage (Dt 2), at DWD, resulted in average TDM productions of 8541 kg/ha, 4950 kg/ha and 2683 kg/ha for December, January and February, respectively. At NGT the average TDM productions were 7769 kg/ha and 3010 kg/ha for December and January respectively. The highest producers were Jumbo, Kow Kandy, Piper, Sentop and Sugargraze. The average TDM productions at the silage stage (Dt 3), at DWD, were 17923 kg/ha, 15015 kg/ha and 2529 kg/ha for December, January and February respectively. At NGT the average TDM production iii was 11856 kg/ha and 5350 kg/ha for December and January, The highest producers were Jumbo, Sugargraze, Kow Kandy, Sentop and Kow Kandy.December planting proved to be the best planting date for optimum DM production, compared to later plantings in January and February. Keywords Forage sorghum, cultivars, planting dates, defoliation stages, grazing stage, silage

Von 2005 bis 2011 wurden auf unterschiedlichen Versuchsstandorten in Deutschland die Trockenmasseerträge von Sorghumhirsesorten und Maissorten verglichen. Es stellte sich heraus, dass der Anbau von Sorghumhirsen auf allen geprüften Standorten mit Erfolg möglich ist und eine Alternative zum Mais im Energiefruchtfolgesystem darstellt. Die Sorghum bicolor-Sorten erreichen ein höheres Ertragspotenzial als die Hybridsorten (Sorghum bicolor x sudanense). Die Hybridsorten zeichnen sich durch eine schnellere Abreife aus und erreichen silierfähige Trockensubstanzgehalte. Verglichen mit Mais erzielen die Sorten der Sorghumart Sorghum bicolor insbesondere auf den D-Süd-Standorten gleiche oder bessere Erträge.