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The growth of various halophytes in coastal saline soils was compared and the effect of halophytes on changes in chemical properties of saline soils and rehabilitation of coastal saline soils was investigated at the Sirlndhorn Int...
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The growth of various halophytes in coastal saline soils was compared and the effect of halophytes on changes in chemical properties of saline soils and rehabilitation of coastal saline soils was investigated at the Sirlndhorn International Environmental Park, Cha-am district, Petchaburi province between April 2010 and September 2011. The experimental design was a randomized complete block design with 4 replications. The halophyte species were: i) Dixie grass {Sporotxilus virginicus coarse type), ii)Smyrna grass {Sporotmlus wginicus smooth type), Hi) Seabrook grass {DIstichlis spicata), iv) Georgia grass (Spartina patens), and 5) natural grasses. It was found that Dixie grass showed the highest survival rate, followed by Smyrna grass, Georgia grassand Seabrook grass. Seabrook grass had the highest fresh and dry weights of 19,796.25 and 12,178.75 kg ha~(-1), respectively, followed by Georgia grass, Dixie grass and Smyrna grass. Seabrook grass accumulated larger amounts of sodium (Na) than Georgiagrass. Dixie grass and Smyrna grass. The study of the effect of halophytes on soil chemical changes found that in general, soil organic matter, as well as phosphorus and potassium levels, increased, while soil electrical conductivity decreased.
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The first goal of this study was to measure geographic variation in the abundance of Microphallus turgidus in the grass shrimp Palaemonetes pugio and to determine whether salinity at collection localities and parasite abundance ar...
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The first goal of this study was to measure geographic variation in the abundance of Microphallus turgidus in the grass shrimp Palaemonetes pugio and to determine whether salinity at collection localities and parasite abundance are related. To do so, grass shrimp were collected at multiple localities along the Altamaha and Ogeechee rivers that varied in salinity from oligo- to polyhaline We found a positive linear relationship between salinity and mean parasite abundance. The second goal of the study was to measure temporal variation in populations of M turgidus in the grass shrimp P pugio and Palaemonetes vulgaris to determine whether a relationship between temporal changes in parasite population size and variation in salinity or water temperature exists To do so, grass shrimp were collected twice each season over the course of approximately 2 5 yr at 1 locality each on 3 tidal rivers in southeast Georgia: the Ogeechee, Broro, and Altamaha rivers Variation between seasons in the abundance of M turgidus in P. vulgaris was not significant In P pugio collected at the Altamaha and Ogeechee river localities, parasite abundance and, to some extent, parasite prevalence varied over the course of the sampling period Correlation between water temperature and parasite abundance in P. pugio shrimp from both the Altamaha and Ogeechee river collection localities and between salinity and parasite abundance at the Altamaha River locality was slight but significantly positive. Neither relationship was observed in P. vulgaris shrimp The results provide evidence that geographic differences in salinity might explain some of the variation in parasite abundance from one locality to another and that temporal variation in water temperature and, to some extent, salinity might also affect M turgidus populations in P. pugio
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A persistent, perennial cool-season grass could reduce winter feed costs for beef production in the lower South. Festuca arundinacea cv. Georgia 5 is an endophyte-infested (Neotyphodium coenophialum) tall fescue cultivar developed...
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A persistent, perennial cool-season grass could reduce winter feed costs for beef production in the lower South. Festuca arundinacea cv. Georgia 5 is an endophyte-infested (Neotyphodium coenophialum) tall fescue cultivar developed for improved persistence in the Coastal Plain. Two experiments were conducted to define the response of oversown Georgia 5 to autumn grazing deferment varying in starting date and duration, and to evaluate its potential contribution to winter feed for beef production. Plots of this tall fescue, oversown on a warm-season grass pasture on upland Coastal Plain soils (near Tifton, Georgia) in 2 years, were grazed continuously after establishment except for 60-, 90-, or 120-d autumn grazing deferments beginning at 15-d intervals after 31 August. Deferments beginning mid-October or later provided benefit to Georgia 5 survival. Deferments longer than 60 days allowed greater herbage accumulation, but did not further enhance persistence. Georgia 5 tall fescue was oversown on bermudagrass (Cynodon dactylon) cv. Coastal or bahiagrass (Paspalum notatum) cv. Pensacola flatwoods pastures in October of 2 years. Continuous stocking (1.9 heifers/acre in the first and 1.2 in the second year) of pastures began in the following April. Performance of heifers grazing oversown pastures from December to April was compared with heifers fed bermudagrass hay ad libitum and 6.8 lb/head of a ground maize-cottonseed mixture three times weekly. Tall fescue herbage mass ranged from about 200 to 600lb dry matter/acre from December through April. Growth of hay-fed heifers was faster (P<0.05) than non-supplemented grazing heifers (1.51 vs 0.50 lb/d) in the first year, but similar for both treatments in the second year (0.99 lb/d). Foliar cover of tall fescue was stable in bermudagrass pastures and averaged 51%. Tall fescue declined in bahiagrass pastures from 61% in spring of 1990 to 35% in spring of 1992. Minor, but transient, fescue toxicosis symptoms were observed. It is concluded that Georgia 5oversown on warm-season grass pastures can be used for winter grazing and contribute to reduced beef production costs in the lower South.
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Rotational stocking (RS) may be useful in alleviating nutrient runoff problems from high rates of broiler litter application while improving animal performance of steers grazing mixed grass pastures of endophyte-infected (E+) tall...
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Rotational stocking (RS) may be useful in alleviating nutrient runoff problems from high rates of broiler litter application while improving animal performance of steers grazing mixed grass pastures of endophyte-infected (E+) tall fescue (Festuca arundinacea) and common bermudagrass (Cynodon dactylon). Six 2.0-acre bermudagrass pastures no-till seeded with E+ tall fescue cv. Georgia 5 were fertilized annually with approximately 6 tons (dry weight)/acre of broiler litter, allowing three replicationseach of continuous stocking (CS) and RS methods. Broiler litter was applied on 16 March and 30 October 1995, and 4 March and 25 September 1996, to follow generally recommended guidelines for fertilization of tall fescue-bermudagrass pastures in the Southern Piedmont. Rotationally stocked pastures with eight paddocks each allowed 3 days of grazing and 21 days of rest per paddock. With both CS and RS there was a decrease of 21 and 26% in bermudagrass basal cover and frequency, respectively, accompanied by a 21% increase in frequency of tall fescue. Grazing method had no significant effect on tall fescue or other species basal cover, or frequency of other species. Grazing method had no effect on monthly harvested forage samples measured for crude protein(CP), neutral detergent fibre (NDF), or acid detergent fibre (ADF) content. Rotational stocking resulted in increased forage available of tall fescue in January and November. Rotational stocking had no effect on stocking rate in the first year, but increased it by 24% during the second year. Steer average daily gain and gain per acre of 1.04 and 551 lb, respectively, were unaffected by grazing method and were in the expected range for steers grazing E+ tall fescue pastures. Rotational stocking maintained bermudagrass better than CS in the aggressive heavily fertilized E+ tall fescue of the mixed pastures. Rotational stocking did not improve steer performance and was similar to CS in utilizing nutrients from broiler litter.
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Endophyte-free tall fescue (Festuca arundinacea) furnishes better animal performance than endophyte-infected grass but is less persistent under grazing, especially in mixture with common bermudagrass (Cynodon dactylon). Rotational...
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Endophyte-free tall fescue (Festuca arundinacea) furnishes better animal performance than endophyte-infected grass but is less persistent under grazing, especially in mixture with common bermudagrass (Cynodon dactylon). Rotational (RS), compared with continuous (CS), stocking of endophyte-free tall fescue may improve persistence when grown with an aggressive warm season perennial grass. In a field experiment at Eatonton, Georgia, F. arundinacea cv. AU Triumph (endophyte-free) was sown on 4 mowed (3-inches height) 40-acre bermudagrass swards. Rotationally grazed plots were divided into 12 paddocks to allow 2 days of grazing and 22 days of rest. Twenty Hereford (Bos taurus) X Brangus (B. indicus X B. taurus) beef cows/40-acre pasture were maintainedyear around for 3 years with additional cows added in spring and summer to maintain similar forage availability. Grazing method had no effect on live weight change, pregnancy rate or calf weaning weight. Stocking rate and calf weaning weight/acre were 38 and 37% higher, respectively, and winter hay consumption was 31% lower from rotationally stocked pastures because of better tall fescue persistence and forage availability. Crude protein (CP) and in vitro dry matter digestibility of available forage generally exceeded 8 and 50%, respectively, throughout the year. It is concluded that rotational grazing is useful in maintaining stands of endophyte-free tall fescue in bermudagrass pastures.
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In strip-tillage peanut production, situations occur when dinitroaniline herbicides are not applied in a timely manner. In these cases, dinitroaniline herbicides would be applied days or weeks after seeding. However, there is no i...
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In strip-tillage peanut production, situations occur when dinitroaniline herbicides are not applied in a timely manner. In these cases, dinitroaniline herbicides would be applied days or weeks after seeding. However, there is no information that documents the effects of delayed applications on weed control. Trials were conducted in 2004, 2005, and 2007 in Georgia to determine the weed control efficacy of delayed applications of pendimethalin in strip-tillage peanut production. Treatments included seven timings of pendimethalin application and three pendimethalin-containing herbicide combinations. Timings of application were immediately after seeding (PRE), vegetative emergence of peanut (VE), 1 wk after VE (VE+1 wk), VE+2 wk, VE+3 wk, VE+4 wk, and a nontreated control. Pendimethalin containing herbicide programs included pendimethalin plus paraquat, pendimethalin plus imazapic, and pendimethalin alone. Among the possible treatment combinations was a current producer standard timing for nonpendimethalin weed control programs in peanut, which was either imazapic or paraquat alone applied VE+3 wk. Pendimethalin alone did not effectively control Texas millet regardless of time of application (69 to 77%), whereas southern crabgrass was controlled by pendimethalin alone PRE (87%). Delayed applications of pendimethalin controlled Texas millet and southern crabgrass when combined with either paraquat or imazapic, with imazapic being the preferred combination due to better efficacy on southern crabgrass than paraquat at most delayed applications. Peanut yield was improved when any of the herbicide combinations were applied PRE compared to later applications. Across all times of application, pendimethalin plus imazapic effectively maximized peanut yield with interference from annual grasses.
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Nymphs of all instars and adults of a lygaeoid bug, the myodochine rhyparochromid Cnemodus mavortius (Say), were collected from fallen pine cones, mainly those of longleaf pine (Pinus palustris Mill.; Pinaceae), at 22 sites in the...
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Nymphs of all instars and adults of a lygaeoid bug, the myodochine rhyparochromid Cnemodus mavortius (Say), were collected from fallen pine cones, mainly those of longleaf pine (Pinus palustris Mill.; Pinaceae), at 22 sites in the southeastern United States (Alabama, Georgia, North Carolina, South Carolina). Nymphs and adults of C. hirtipes Blatchley were found in fallen pine cones at eight sites in Florida. Nymphs (occasionally >20/cone; n = 5) of all instars, exuviae, and teneral nymphs and adults were observed in cones, suggesting more than incidental and ephemeral occupancy by species of Cnemodus. The bugs might use the labium to transport seeds of pine and other plants to the shelter of cones before they begin to feed, obtain nutrition from pine seeds that remain in fallen cones, or feed on seeds of grasses or other plants that lodge in cones. Fallen cones could be used for overwintering and oviposition but might be most important for allowing the bugs to minimize desiccation in xeric habitats characterized by high soil-surface temperatures, especially if nymphs cluster in cones. Other heteropteran species were infrequent inhabitants of fallen pine cones: the rhyparochromids Eremocoris setosus Blatchley (Florida, Georgia, South Carolina), Neopamera bilobata (Say) (Florida), and Ozophora trinotata Barber (Florida); and the largid A rhaphe carolina Herrich-Schaeffer (South Carolina). We also record C. mavortius from crowns of bunchgrasses in southern states (Georgia, North Carolina, Oklahoma, South Carolina, Texas) and C. hirtipes from bunchgrasses in Florida.
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Endophyte (Neotyphodium coenophialum) toxicosis of cattle on tall fescue (Festuca arundinacea) pasture was investigated during 1992-95 at the Central Georgia Station, Eatonton, by determining beef steer (Bos taurus X B. indicus) p...
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Endophyte (Neotyphodium coenophialum) toxicosis of cattle on tall fescue (Festuca arundinacea) pasture was investigated during 1992-95 at the Central Georgia Station, Eatonton, by determining beef steer (Bos taurus X B. indicus) performance and plant persistence as affected by endophyte infected (E+) and endophyte-free (E-) F. arundinacea cultivars, the addition of a grazing-tolerant legume (Medicago sativa cv. Alfagraze) and increased grazing pressure (GP) during spring and autumn, on continuouslystocked pastures. Average daily gains (ADG) from March to June averaged for 3 years on E+ or E- (cv. Jesup) F. arundinacea, E+ plus Alfagraze, and Alfagraze alone were 0.95, 2.50, 1.24 and 2.14 lb at low GP and 0.66, 2.04, 1.22 and 1.45 lb at high GP, respectively. High GP resulted in a detrimental effect on ADG, and this effect was greater from October to December than in the spring. Higher stocking rates were needed on E+ than on Jesup to achieve similar GP. Both E+ F. arundinacea and Jesup survivedwell after a severe drought in the first grazing season, indicating good drought tolerance of Jesup. Alfagraze plus E+ F. arundinacea resulted in improved ADG by 30% at low GP and 84% at high GP, even though the legume represented only 6% of the available forage. It is suggested that the high ADG obtained on Jesup and its excellent stand persistence may indicate its potential for grazing.
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