Tripsacum dactyloides (L.) L., commonly known as eastern gamagrass, is useful for grazing, stored forage, soil amelioration and conservation, and as a biofuel feedstock. Our goal was to calculate accumulated growing d...Tripsacum dactyloides (L.) L., commonly known as eastern gamagrass, is useful for grazing, stored forage, soil amelioration and conservation, and as a biofuel feedstock. Our goal was to calculate accumulated growing degree days (GDD) from existing datasets collected for eastern gamagrass forage production experiments in northwestern Oklahoma, and discuss the use of GDD, instead of calendar harvest dates, in the production of eastern gamagrass forage. Growing degree days were calculated from 1 January each year using the “optimum day method”. For 10 harvest years, the first eastern gamagrass harvest required 690 ± 26 cumulative GDD. Based on long-term weather data from Woodward, Oklahoma, this would place the first harvest on or near 1 June. The second harvest required 635 ± 27 cumulative GDD which would place the second harvest on or near 15 July and the third harvest required 690 ± 23 cumulative GDD placing it on or near 30 August. Each of the 30 harvest required an average of 670 ± 15 cumulative GDD. Using GDD to predict harvest events is a useful tool that forage producer can use in the production of eastern gamagrass forage in the USA and possibly elsewhere.展开更多
Oklahoma phlox (Phlox oklahomensis Wherry) is endemic to Butler, Chautauqua, Comanche, Cowley, and Elk Counties of Kansas and Woods and Woodward Counties of Oklahoma. The species comprises populations of a few scatter...Oklahoma phlox (Phlox oklahomensis Wherry) is endemic to Butler, Chautauqua, Comanche, Cowley, and Elk Counties of Kansas and Woods and Woodward Counties of Oklahoma. The species comprises populations of a few scattered individuals to several hundred in mixed-grass prairie sites in Oklahoma where cow-calf production is the common agricultural enterprise. It has successfully withstood periods of short-term drought (1 to 4 years) under light to moderate continuous stocking rates (41 to 52 animal unit days per hectare). Under heavy continuous stocking rates and/or prolonged drought, populations of P. oklahomensis tend to decrease in size and number and may disappear in some localities. Prolonged heavy stocking rates and drought will disrupt the reproductive cycle, severely limiting seed production and recruitment of new individuals to populations. During drought periods, livestock managers should use lighter stocking rates or deferred grazing to ensure rapid recovery of all prairie plants, including P. oklahomensis, once the drought ends. This recommendation would likely sustain prairie sites during long-term (longer than 10 years) droughts as well.展开更多
文摘Tripsacum dactyloides (L.) L., commonly known as eastern gamagrass, is useful for grazing, stored forage, soil amelioration and conservation, and as a biofuel feedstock. Our goal was to calculate accumulated growing degree days (GDD) from existing datasets collected for eastern gamagrass forage production experiments in northwestern Oklahoma, and discuss the use of GDD, instead of calendar harvest dates, in the production of eastern gamagrass forage. Growing degree days were calculated from 1 January each year using the “optimum day method”. For 10 harvest years, the first eastern gamagrass harvest required 690 ± 26 cumulative GDD. Based on long-term weather data from Woodward, Oklahoma, this would place the first harvest on or near 1 June. The second harvest required 635 ± 27 cumulative GDD which would place the second harvest on or near 15 July and the third harvest required 690 ± 23 cumulative GDD placing it on or near 30 August. Each of the 30 harvest required an average of 670 ± 15 cumulative GDD. Using GDD to predict harvest events is a useful tool that forage producer can use in the production of eastern gamagrass forage in the USA and possibly elsewhere.
文摘Oklahoma phlox (Phlox oklahomensis Wherry) is endemic to Butler, Chautauqua, Comanche, Cowley, and Elk Counties of Kansas and Woods and Woodward Counties of Oklahoma. The species comprises populations of a few scattered individuals to several hundred in mixed-grass prairie sites in Oklahoma where cow-calf production is the common agricultural enterprise. It has successfully withstood periods of short-term drought (1 to 4 years) under light to moderate continuous stocking rates (41 to 52 animal unit days per hectare). Under heavy continuous stocking rates and/or prolonged drought, populations of P. oklahomensis tend to decrease in size and number and may disappear in some localities. Prolonged heavy stocking rates and drought will disrupt the reproductive cycle, severely limiting seed production and recruitment of new individuals to populations. During drought periods, livestock managers should use lighter stocking rates or deferred grazing to ensure rapid recovery of all prairie plants, including P. oklahomensis, once the drought ends. This recommendation would likely sustain prairie sites during long-term (longer than 10 years) droughts as well.
