PSXI-11 Assessing in situ rumen degradability of late season kudzu (Pueraria montana var. lobata)

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 350-350
Author(s):  
J B Adkins ◽  
J P Gulizia ◽  
Kevin M Downs ◽  
S Cui

Abstract Kudzu (Pueraria montana var. lobata) is an invasive weed species native to eastern Asia affecting much of the southeastern United States. Its broad leaves and viny growth allow it to outcompete native plant species for sunlight and nutrients. Kudzu, however, is a leguminous plant, making it a potential feedstock for ruminant species. Browsing ruminants in areas affected by kudzu could benefit animal productivity while serving to ameliorate rapid plant growth. This study specifically sought to assess the overall rumen degradability, rate of digestion, digestible fraction, and indigestible fraction using an in situ methodology. In situ rumen degradability was analyzed using four ruminally fistulated steers as individual experimental units over two repeated trials. Samples were incubated at 1, 12, 24, 36, 48, 60, and 72 h. Kudzu used in these trials was collected during September, making analysis in this study a reflection of degradability toward the end of the growing season. Data were analyzed as a randomized complete block design with repeated measures showing no significant differences between steers or trials (P > 0.05). Overall degradability across all steers and times was 69.79%. Significant changes in dry matter disappearance across all steers were observed at 1, 12, and 24 h (P < 0.05) with values of 33.86, 64.78, and 74.26%, respectively, and highest observed degradability at 72 h (79.55%). Incubation times between 24 and 72 h were not used in determining rate of digestion as dry matter disappearances throughout these times were not significantly different (P > 0.05). Rate of digestion (kd) was determined, using linear regression, to be 1.68% ∙ h-1 along with a digestible fraction (Do) of 28.29% and indigestible fraction (U) of 22.03%. The results of this study reflect that kudzu maintains a relatively high level of rumen degradability toward seasonal senescence, making it a functional feedstock even into the cooler months.

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 85-85
Author(s):  
Joseph Gulizia ◽  
Kevin Downs ◽  
Song Cui

Abstract Early and late season kudzu (Pueraria montana var. lobata) leaves were collected to analyze dry matter (DM), crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) in situ rumen disappearance to assess kudzu quality. Four studies were conducted during different growing seasons [2 repeated early season (ES); 2 repeated late season (LS) to determine age variability effects. Kudzu collected from 7 middle Tennessee counties were incubated in the rumen for designated lengths of time (0.25, 1, 12, 24, 36, 48, and 72 h) to determine total rumen degradation (%) and rate of disappearance (% / h). Data were analyzed as a randomized complete block design (RCBD) with repeated measures. Regression analysis was used to determine degradation rate. Overall season effects (across incubation times) for dry matter disappearance (DMD) were significantly different (P < 0.0001). Significant season by incubation time interactions were exhibited for total DMD at 12 (P < 0.0001), 24 (P = 0.0004), 36 (P = 0.0055), 48 (P = 0.0209), and 72 h (P = 0.0384) incubation, with an average rumen degradability of ES kudzu being 9.75% higher than LS between 12 and 72 h. Slope regression between 1 and 24 h determined a rumen degradation rate of 2.41% / h across both seasons, with no significant seasonal difference (P = 0.3396). These results are indicative that ES kudzu is more highly rumen degradable than LS, as evidenced by the significant season by incubation time interactions between 12 and 72 h of incubation. Although there are significant seasonal effects on kudzu DMD during certain incubation times, DMD overall for ES and LS is still indicative of high rumen degradability with an average of 81.45% at 72 h across both seasons. Season effects were minimal for NDF, ADF, and CP rumen disappearance.


2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 38-38
Author(s):  
Joseph Gulizia ◽  
Kevin Downs ◽  
Song Cui

Abstract Early and late season kudzu (Pueraria montana var. lobata) leaves were collected to analyze dry matter (DM), crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) in situ rumen disappearance to assess kudzu quality. Four studies were conducted during different growing seasons [2 repeated early season (ES); 2 repeated late season (LS) to determine age variability effects. Kudzu collected from 7 middle Tennessee counties were incubated in the rumen for designated lengths of time (0.25, 1, 12, 24, 36, 48, and 72 h) to determine total rumen degradation (%) and rate of disappearance (% / h). Data were analyzed as a randomized complete block design (RCBD) with repeated measures. Regression analysis was used to determine degradation rate. Overall season effects (across incubation times) for dry matter disappearance (DMD) were significantly different (P < 0.0001). Significant season by incubation time interactions were exhibited for total DMD at 12 (P < 0.0001), 24 (P = 0.0004), 36 (P = 0.0055), 48 (P = 0.0209), and 72 h (P = 0.0384) incubation, with an average rumen degradability of ES kudzu being 9.75% higher than LS between 12 and 72 h. Slope regression between 1 and 24 h determined a rumen degradation rate of 2.41% / h across both seasons, with no significant seasonal difference (P = 0.3396). These results are indicative that ES kudzu is more highly rumen degradable than LS, as evidenced by the significant season by incubation time interactions between 12 and 72 h of incubation. Although there are significant seasonal effects on kudzu DMD during certain incubation times, DMD overall for ES and LS is still indicative of high rumen degradability with an average of 81.45% at 72 h across both seasons. Season effects were minimal for NDF, ADF, and CP rumen disappearance.


2004 ◽  
Vol 22 (4) ◽  
pp. 529-537 ◽  
Author(s):  
P.S.L. Silva ◽  
Z. Barbosa ◽  
O.F. Oliveira ◽  
R.P. Antonio ◽  
P.I.B. Silva

Weeds have a negative influence on several fruit tree characteristics, such as yield, making it difficult to management practices in orchards. Alternative weed management methods, aiming to reduce the use of herbicides, have become attractive since herbicides are costly and cause environmental degradation. The use of cultivars with greater competitive ability against weeds has attracted international attention. The objective of this work was to evaluate the floristic composition and growth of weeds under the canopies of irrigated custard apple tree progenies. Twenty halfsibling progenies around three years of age were evaluated in a random block design with five replicates and four plants per plot. A circle with a 0.5 m² area was established around the trunk of each plant. Floristic composition, fresh matter, and dry matter mass of the above-ground part of the weeds, were evaluated in this area. Root collar and canopy diameters, as well as leaf area of the progenies were also evaluated. Fifty-eight weed species were recorded. The five weed families with the most species were Leguminosae, Convolvulaceae, Euphorbiaceae, Malvaceae and Sterculiaceae, in decreasing order. The number of weed species per plot ranged from 6 to 18, but there was no difference between the mean percentages of different weeds under the canopies of the progenies. The lowest weed fresh and dry matter masses occurred in progenies JG1 and SM8, respectively. There were no differences between progenies with regard to root collar diameter and leaf area; however, one of the lowest weed dry matter yields was observed under the canopy of progeny FE4, which showed the largest canopy diameter.


Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 576
Author(s):  
Wang ◽  
Awaya ◽  
Zhu ◽  
Motooka ◽  
Nelson ◽  
...  

Non-native plant species have become serious pests in Hawaii’s delicate island ecosystems. It is necessary to control invasive plants. The herbicides hexazinone and tebuthiuron were evaluated for defoliation efficacy to control several major invasive plants and for non-target effects on native plants at Site I in a rainforest at 1200 m elevation and Site II in a mesic area at 640 m elevation on the island of Kauai, Hawaii. The invasive weed species in the sites included daisy fleabane (Erigeron karvinskianus DC.), faya tree (Myrica faya Ait.), strawberry guava (Psidium cattleyanum Sabine), banana passion fruit (Passiflora mollissima Bailey), vaseygrass (Paspalum urvillei Steud.), and highbush blackberry (Rubus argutus Link. 1822). Native plants included ohia lehua (Metrosideros polymorpha Gaudich.), naupaka (Scaevola cerasifolia Labill.), pilo (Hedyotis mannii), hona (Urera glabra (Hook. & Arn.)), aalii (Dodonaea viscosa Jacq.), and amau (Sadleria sp.). The results showed that broadcast applications of hexazinone granules and tebuthiuron pellets were effective on some of those invasive species. Herbicidal tolerance varied among the native species. For example, D. viscosa showed high tolerance to hexazinone. S. cerasifolia was susceptible to hexazinone, but not to tebuthiuron. The inconsistent defoliation of Sadleria sp. occurred among different applications rates of the two herbicides. M. polymorpha, particularly when it was small, could tolerate hexazinone and tebuthiuron. U. glabra was severely injured by the two herbicides. H. mannii was moderately tolerant to hexazinone, but fairly sensitive to tebuthiuron. The invasive loblolly pine (Pinus taeda L.) was highly tolerant to hexazinone, but was very sensitive to tebuthiuron. M. faya was very sensitive to hexazinone, but very tolerant to tebuthiuron. P. cattleyanum was sensitive to both herbicides. Six and nine months after hexazinone and tebuthiuron treatment, respectively, native plants were transplanted into the Sites to observe injury from residual herbicides. Approximately less than 10% mortality was observed for the out-planted native species three months after planting (MAP), indicating that the native species showed less injury in the early period of transplant. The mortality of the three endangered species Kauai hau kuahiwi (Hibiscadelphis distans), Kauai delissea (Delissea rhytidosperma H.Mann) and kawawaenohu (Alsinidendron lynchnoides), however, increased as the MAP increased. Overall, broadcast treatments of hexazinone and tebuthiuron at rates higher than 1 kg active ingredient per hectare would be problematic. The dissipation half-life values of hexazinone and tebuthiuron in the 1-15 cm layer of soils at the two sites were approximately 7 days and greater than 180 days, respectively.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 228-229
Author(s):  
María Victoria Burjel ◽  
Alvaro Simeone ◽  
Oscar Bentancur ◽  
Natalia Zabalveytia ◽  
Virginia Beretta

Abstract This study aimed to evaluate the effect of winter-feeding system (grazing, GFS vs. feedlot, FFS) and ration roughage level (RL), on subsequent spring grazing behavior and forage dry matter intake (DMI). Thirty-two Hereford female calves (149 ± 13 kg) were assigned to four winter dietary treatments (110 days) in a randomized block design (n = 2/treatment): three feedlot rations differing RL (Setaria italica) (0%, 35% or 70% DM) or oats grazing (5 kg DM/100 kg LW). In spring (84 days) all treatments grazed a mixed grass-legume pastures (4317 ± 1009 kg DM/ha; 6 kg DM/100 kg LW). During weeks 1, 3 and 5 after changing diets, diurnal behavior activity (effective/search grazing, rumination, idling or water intake) was visually recorded and DMI estimated from the in vivo DM digestibility (DMD) and fecal production. Data were analyzed according to a block design with repeated measures, with general model including block, treatment (T), week (W) and T×W effects. Means were compared through orthogonal contrasts (Table 1). Spring DMI varied with T (P = 0.0084) regardless of W effect (P = 0.1619), with higher values for GFS compared to FFS (1.55 vs. 1.16 kg/100 kg LW, P = 0.0034) and for 70RL compared to 35RL (P = 0.0286). DMD did not differ between treatments (P = 0.2488) but was lower on W1 than W5 (55 vs. 64 %, P = 0.0150). T×W was significant (P &lt; 0.0001) for effective grazing, rumination and idling. On W1, heifers from GFS grazed less (0.40 vs. 0.49, P = 0.0268) but tended to ruminate more (0.26 vs. 0.18, P = 0.0591) than FFS. As pasture DMD improved (W5) GFS grazed more (0.64 vs. 0.51, P = 0.0020) but ruminated less (0.14 vs. 0.21, P = 0.0450) than FFS. Transition from FFS to spring grazing might reduce pasture DMI modifying animal ingestive behavior compare to animals from GFS. Impact could be higher when ration RL is below 70%.


2021 ◽  
Vol 30 (1) ◽  
pp. 29-37
Author(s):  
Jovana Krstić ◽  
Goran Malidža ◽  
Miloš Rajković ◽  
Miloš Krstić

Seed dormancy is an important trait that contributes to the survival rate of weeds, helps to avoid the effects of herbicides and protects them against adverse environmental conditions. In order to determine which methods are effective in breaking seed dormancy of invasive weed species (Ambrosia artemisiifolia, Abutilon theophrasti, Xanthium strumarium), an experiment was set up in 2019 in a randomized block design, with three replications in the experimental field of the Institute of Field and Vegetable Crops (Novi Sad). The collected seeds of one population of A. artemisiifolia and A. theophrasti, were cleaned and stored in cold storage at 4°C until testing, while X. strumarium was stored at room temperature. Seed propagation was done in a weed science laboratory, using nine different methods for breaking seed dormancy. The seeds were exposed to different conditions of temperature, light and humidity over a certain period of time (24h or 48h). The dynamics of weed emergence were monitored daily, for a period of 31 days and expressed cumulatively in percentages. Based on the obtained results, the highest percentage of sprouted plants was determined in treatments where the seeds were propagated under light conditions, in water. An appropriate method of propagation can influence the breaking of seed dormancy and emergence in field conditions, which can have practical significance in the research of competitive relations between crops and tested weed species.


Author(s):  
Joilson Sodré Filho ◽  
Ricardo Carmona ◽  
Robélio Leandro Marchão ◽  
Arminda Moreira de Carvalho

Abstract: The objective of this work was to evaluate the influence of sorghum and cover plant cropping systems before soybean cultivation on the occurrence of weeds during soybean growing in the Brazilian Cerrado. The experiment was carried out in a randomized complete block design, with four replicates. The treatments comprised six cropping systems before soybean: sorghum (Sorghum bicolor), palisade grass (Urochloa brizantha), and Congo grass (Urochloa ruziziensis) as cover plants, alone or intercropped, in addition to fallowing. Weeds were evaluated as to: density, dry matter mass, diversity, importance value, and similarity. The greatest similarity of weeds ocurred in single crops of sorghum, palisade grass, and Congo grass, in comparison with their intercroppings. Congo grass before soybean promoted a greater reduction in weed diversity overtime, when compared with palisade grass. The absence of cover crops before soybean cultivation increased weed infestation during the soybean cycle. The cropping systems with sorghum intercropped with cover crops before the soybean cultivation affect the diversity and the importance value of weed species.


2018 ◽  
Author(s):  
Jayalakshmi Mitnala

An experiment was conducted for two consecutive years (2011-2012 and 2012-2013) on fine texture soils of Agricultural college farm, Bapatla. The experiment was laid out in a randomized block design in wet season with four treatments and five replications. The treatments consisted of M1 (recommended dose of fertilizers (RDF) - Control), M2 (10t farmyard yard manure (FYM) ha-1 + RDF), M3 (1.5t vermicompost ha-1 + RDF), M4 (Green manuring + RDF). Data collected on biometric observations (plant height, number of tillers, dry matter accumulation) and yield. The yield of crop was significantly increased with the application of 100%NPK in combination with FYM @10t ha-1. However, it was at par with green manuring along with the application of 100% RDF (NPK).Thus, green manure in situ with Dhaincha may be used as an alternative organic source of nutrients to the FYM.


2021 ◽  
Vol 34 (2) ◽  
pp. 388-397
Author(s):  
MÁRCIO ALEXANDRE MOREIRA DE FREITAS ◽  
HAMURÁBI ANIZIO LINS ◽  
MATHEUS DE FREITAS SOUZA ◽  
GABRIELLA DAIER OLIVEIRA PESSOA CARNEIRO ◽  
VANDER MENDONÇA ◽  
...  

ABSTRACT Stress caused by soil water deficit has been one of the main factors that inhibit plant growth. The knowledge of the factors related to the behavior of weed species under water stress conditions can contribute to the elaboration of effective control strategies. Two experiments were carried out to evaluate the effects of the degree and duration of water deficit on physiological and growth indicators of two weed species (Bidens pilosa L. and Bidens subalternans DC.). The stress degree was simulated by four soil moisture: 100, 75, 50, 25% of total soil capacity. The water deficit duration was evaluated by five intervals of water supply: 0, 1, 2, 3, 4, 5, and 6 days. The experiments were carried out in a randomized complete block design with six replicates. The evaluated variables were: the photosynthetic rate (A; μmol CO2 m-2), stomatal conductance (gs; μmol H2O m-2 s-1), transpiration (E; mmol H2O m-2 s-1), number of leaves per plant, and dry matter of the roots, stems, leaves, and total. The results showed that the species of B. pilosa and B. subalternans tolerate low water availability conditions. Low stomatal opening and loss of leaves are mechanisms that ensure the survival of Bidens plants to the water deficit. However, water stress close to 25% of field capacity caused the death of species. The B. subalternans had higher sensitivity to the water deficit, showing a lower dry matter of leaf, stem, and root than B. pilosa.


2017 ◽  
Vol 38 (4) ◽  
pp. 2041 ◽  
Author(s):  
Egon Henrique Horst ◽  
Mikael Neumann ◽  
Jony Cley dos Santos ◽  
Julina Mareze ◽  
Ivone Yurika Mizubuti ◽  
...  

This study aimed to evaluate the contents of hemicellulose, cellulose, and lignin, as well as the rates of dry matter degradability in forage and pre-dried silage of different winter cereals harvested at pre-flowering. The experiment was conducted by the Animal Production Center (NUPRAN), Department of Agricultural and Environmental Sciences, State University of Midwest (UNICENTRO). It is located in Guarapuava – PR, Brazil. The study was part of the Master's Degree in Crop Production. As experimental materials, we used black oat (Avena strigosa) cv. EMB 139 and cv. IAPAR 61; white oat (Avena sativa) cv. IPR and 126 hp. URS Taura; barley (Hordeum vulgare) cv. BRS Brau and cv. BRS Cauê; wheat (Triticum aestivum) cv. BRS Umbu and cv. BRS Tarumã; rye (Secale cereale) cv. Temprano and cv. BRS Serrano; and triticale (X Triticosecale) cv. IPR and 111 hp. BRS Saturn. Dry matter degradability was measured by an in situ technique, arranged in a completely randomized block design with three replications (animal), subdivided in subplots. Treatments were the plots and subplots digestion times. The incubation times were 0, 6, 12, 24, and 48 hours. To that end, we used two 24-month rumen fistulated steers with 350 kg average weight. A similarity was observed in the results of both forage and pre-dried silage degradability, displaying the same trends. Barley cv. BRS Brau had the highest hemicellulose content in its composition; however, IPR 111 triticale was showed the highest degradability potential, both for green forage and pre-dried silage.


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