Weed Science Commons^™

Yield And Quality Of Tropical Legumes During The Dry Season: Galactia Striata (Jacq.) Urb., R R. Vera, E A. Pizarro, M Martins, J.A. C. Viana

IGC Proceedings (1977-2023)

A small-plot experiment was conducted during 2 consecutive years in the cerrados of Brazil to evaluate the effect of four dates of deferment (21 February, 7 and 21 March, and 4 April, respectively) on rate of growth, chemical composition, and in-vitro dry-matter digestibility (IVDMD) of a pure stand of Galactia striata, a naturalized legume. The chosen dates of deferment em­braced the last 2 months of the rainy season. Yields were estimated at intervals of 28 days, over an experimental period of 237 days, ending with the beginning of the following rainy season. Asymptotic growth was observed throughout the experimental period. …

Potential Of Aeschynomene Sp. For Pastures In The Tropics, A E. Kretschmer Jr, G H. Snyder

IGC Proceedings (1977-2023)

The objectives of this study were to assess the forage potential of readily available world germ plasm of the genus Aeschynomene, which comprises 160 species; to compare some attributes of the commercial American jointvetch (Aeschynomene americana L.) with those of other accessions of the same and of other species; and to compare the seasonal growth pattern and response to phosphorus (P) of commercial jointvetch with two perennial tropical legumes. Evaluations were made of 342 accessions, including 25 identified species. Data collected from observational plots in 1978 and 1980 included initial flowering dates, plant vigor, and growth habit; from replicated plots, …

Residual Effects Of Two Years Of Very High Nitrogen Applications On Clay Soil Under Grass In A Humid Temperate Climate, W H. Prins

IGC Proceedings (1977-2023)

In recent field trials on all-grass swards on clay soils, fertilizer rates of 480 kg/ha and higher showed distinct residual effects in the following year. This paper analyzes the considerable residual effects of one treatment on heavy clay soil over 2 experimental years, after very high rates of N had been applied during 3 pretreatment years (totaling 800 kg N or more/ha/yr). The residual effect was measured through the increase in yield over a reference treatment, at one rate of N application ( 40 kg N/ha/cut, total­ing 200 and 240 kg N/ha in the first and second experimental years, respectively). …

Waste- Water Application, Dry-Matter Production, And Nitrogen Balanced Rhodesgrass Grown On Fine-Textured Soil Or On Sand Dunes, T Kipnis, A Feigin, I Vaisman, J Shalhevet

IGC Proceedings (1977-2023)

The shortage of irrigation water in the semiarid zone of Israel necessitates the use of partially treated municipal effiuents for irrigation of forage grasses. Irrigation with sewage effiuents is being considered very carefully with the aim of maximizing pro­duction and minimizing the pollution ha.zarc;l. A high nitrogen (N) input originating from intensive application of effiuent water may well increase dry-matter production, but it also increases t,he pollution hazard. Frequent application of relatively small quantities of effiuent water was suggested as an efficient method of improving N uptake by rhodesgrass ( Chloris gayana Kunth.) swards. It was expected that nitrate pollution …

Comparison Of Italian Ryegrass And Meadow Fescue With F2, F3, F4 Hybrids Of Both Grass Species, H Kaltofen, E Wojahn

IGC Proceedings (1977-2023)

In forage-grass breeding there is an increasing interest in hybrids of Italian ryegrass (Lolium multiflorum Lam.) and meadow fescue (Festuca pratensis Huds.). The objective of this study was to investigate some agronomic properties of such Festulolium hybrids with special reference to the question of whether these hybrids change from one generation to the next. In a pot experiment with four levels of nitrogen fertilization, Italian ryegrass and meadow fescue as well as F2, F3, and F4 hybrids of the two grass species were examined for 2 years. In each year four cuts were taken. All the F2, F3, …

Genetic Variability For Morphological And Agronomic Characters In Desmodium Uncinatum (Jacq.) D.C. And D. Intortum (Mill.) Urb., E.M P. Oliveira, P S. Martins, A B. Cruz

IGC Proceedings (1977-2023)

Objectives of this research were to study the performance of eight populations of D. unicinatum and ten populations of D. intortum, with relation to morphological and agronomic characters to estimate the genetic variation between populations and between plants within populations, and to estimate genetic and phenotypic parameters for these characters.

The Grass Hillsides Of Jiangxi Province, Fan Xie, Suehen Wang

IGC Proceedings (1977-2023)

For researching into vegetation on grass slopes, their types, characteristics, yield and prospect of application in livestock husbandry, a sampling investigation on the semi-location spot has been carried out. Jiangxi province is situated in Southeast China, belonging to the monsoon region in Southeast Asia. According to the principles of ecological condition and dominant species, the grass hillsides can be classified into 7 herbosa groups: Ischaemum ciliare grass-land on hilly land, Arundinella setosa grass-land on hilly land, Dicranopteris dichotoma grass-land on hilly land of low hills, Miscanthus sinensis grass-land on hilly land of mid-low hills, M. floridulus grass-land on hilly land …

Intensive Use Of Young Japanese Cedar Forest For Grazing, K Sugawara, T Isawa, M Goto, I Ito

IGC Proceedings (1977-2023)

Experiments were conducted to investigate the intensive forest grazing in young Japanese cedar forest by introducing improved pasture species to forest floor. Study area (1-year old Japanese cedar forest) was divided into three treatment plots; unseeded and unfertilized ( unseeded plot), seeded with nitrogen (N)- phosphorus (P)-potassium (K) fertilizer ( seeded-NPK plot) and seeded with twice amount of fertilizer ( seeded-2NPK plot). Herbage production, grazing capacity, injury to the tree by grazing cattle and growth of the tree were compared among the treatments. The mean of annual fresh matter yield was 11.6 t/ha at unseeded plot, 12.7 t/ha at seeded-NPK …

Evaluation Of Grain Sorghum As A Silage Crop, R L. Smith, K K. Bolsen

IGC Proceedings (1977-2023)

Three experiments were conducted to determine the nutritive value and yield potential of grain sorghum cultivars harvested as whole-plant silage. A commercial yellow endosperm grain sorghum was harvested at late-dough and hard-grain stages of maturity. Each silage was fed unprocessed and processed through a roller mill to steers in growth and digestion trials. A yield study compared five cultivars of grain sorghum and one forage sorghum, each harvested at three stages of matuirity (milk to early dough, late-dough, and hard-grain). Processing the silages significantly improved steer gains and feed efficiencies. There was a nonsignificant increase in silage DM digestibility due …

Influence Of Reduced Intensity Of Grassland Management On Herbage Yield, Forage Quality, Sod Density And Botanical Composition, P Dahmen, W Kuhbauch, U Thome

IGC Proceedings (1977-2023)

In the Federal State of Northrhine Westfalia, a number of programs have been initiated to reduce intensity of land use with respect to unwanted environmental effects presumably coming from conventional agricultural systems. On grassland most of the programs require delayed first cuttings for hay and silage, reduced fertilization and/or less grazing pressure on pastures. Field experiments were established in order to evalu­ate consequences of these programs for practical farming and grassland ecology. Treatments include conventional grassland management systems with intensive fertilization and utilization as well as intermediate and low intensity systems.

Diversity In Macroptilium Atropurpureum (Dc.) Urb., A E. Kretschmer Jr, R M. Sonoda, R C. Bullock, G H. Snyder, T C. Wilson, R Reid, J B. Brolman

IGC Proceedings (1977-2023)

A replicated experiment was used to determine the diversity of 77 accessions of Mexican Macroptilium atropurpurem compared with cv. 'Siratro'. Siratro yielded less than the mean of the 5 highest yielding entries in 3 of 6 harvests; it flowered earlier and more consistently between harvests than many other entries. Siratro rust incidence was relatively very high while mildew and Rhizoctonia incidence was relatively very low when compared to Siratro. Mite damage was also relatively low for Siratro. There was great diversity among the populations studied with regards to the attributes studied. Several accessions had more desireable attributes than Siratro. More …

Intensive Maize Production - The Basis For Intensification Of Cattle Production In Venezuela, J Cizec

IGC Proceedings (1977-2023)

The two main branches of cattle production in Venezuela are beef production and dairy production. Both branches are still rather extensive, mainly due to very extensive forage pro­duction. This is particularly evident in beef cattle production where almost 50 % of the weight gain achieved in the rainy season is lost during the dry period. Thus, it takes three to four years for the cattle to achieve slaughtering weight (Moore, 1970). On the other hand, relatively satisfactory milk production of dairy cows is enabled only by consumption of large quantities of expensive concentrates. Within an agricultural and industrial development project …

The Dry Matter Yield Of Grass Cultivars In The Uplands Of Serbia, Z Tomic, M Stosic, D Colic

IGC Proceedings (1977-2023)

The arable lands in hilly and mountainous regions of Serbia are used mostly for production of cereals and potatoes. Since the soil are loose and situated on slopes they are seriously damaged by erosion. An earlier investigation (Radojevic and Stosic, 1980) of different grass-legume mixtures helped these mixtures to be accepted in practice and thus provided a double benefit : protecting the soil from erosion and providing larger quantities of livestock food. However, there are few results which refer to the possibilities of organizing continuous pro­duction during the vegetation period by introducing different species and their cultivars. The aim of …

The Economic Groups Of Grassland Plants In Xinjiang, Xu Peng

IGC Proceedings (1977-2023)

The research in classifying the economic group of grassland plants according to their economic value is quite significant to the grassland management. Yield, feed quality and geographic distribution - the three factors reflecting the economic value of grassland plants - are controlled by ecobiological and form anatomical characteri­stics. We consider that to classify the economic groups of grass­land plants based on plant life-form by combining with taxo­nomic family group is the most appropriate conclusion of influential factors, and adopt a two degree classifying system -

group and subgroup. Group : On the basis of Keller's lifeforms - tree, bush, semibush, …

Forage Production And Nutritive Value Of Leucanea Leucoephala In Southern Puerto Rico, L E. Tergas, R Milton Martinez, A V. Mendez Cruz

IGC Proceedings (1977-2023)

Leucaena leucocephala (L.) is a perennial schrub native to Mexico, Central America and the Caribbean, considered by investigators as a valuable forage legume because of its capacity for high production of digestible forage with a high protein content and tolerance to drought in semiarid regions with annual rainfall less than 1,000 mm (Skerman, 1977). The soil fertility of the semiarid region in southern Puerto Rico is adequate, but rainfall distribution is limiting for forage production and nutritive value. There is a demand for a suit­able and inexpensive source of high quality forage to improve the diet of the grazing cattle …

Smooth Brome Response To Rate And Date Of Mefluidide Application, B Anderson, R S. Moomaw, C A. Shapiro

IGC Proceedings (1977-2023)

Smooth brome (Bromus inermis Leyss.) often produces over 70 % of its annual growth during spring. Summer growth and forage quality are poor. Mefluidide suppresses seedstalk pro­duction and improves forage quality of many cool-season grasses (Sheaffer and Marten, 1986). This study evaluated the response of smooth brome to date and rate of mefluidide appli­cation.

Forage Production And Nutritive Value Of Cynodon Spp. Under Grazing In Puerto Rico, L E. Tergas, Y Q. Cabrera, A Sotomayor Rios

IGC Proceedings (1977-2023)

Livestock production in the tropics is highly dependent on forages to meet the nutritional requirements of grazing cattle. However, seasonal fluctuations on dry matter production and nutritive value are limiting factors affecting animal perform­ance and production. Stargrass Cynodon nlemfuensis var. nlemfuensis is a highly productive grass recommended for intensive management in the humid tropics of Puerto Rico (Vicente-Chandler et al., 1974). Bermuda Cynodon dactylon and Stargrass produced high yields of quality forage and persisted under intensive grazing in the humid northern coastal plains of Puerto Rico; however, the average production of both grasses was related to rainfall distribution, decreasing during …

Influence Du Mode Des Semis Et Des Associations Annuelles Graminees-Legumineuses Sur Le Rendement Et La Qualite Du Fourrage, S Ostojic

IGC Proceedings (1977-2023)

Chaque anncc en Y ougoslavie, 1,5 million d'hectares sont ensemences avec des cereales de printemps. Apres la moisson, ccs terres restent generalement non semees jusqu'au printemps de l'annee suivante ou !'on scme des cultures sarclees. Eberhardt (1975) estime qu'en Yougoslavie, I% seulement de ces surfaces sont labourccs, ce qui est tres faible si !'on prend en consideration le fait que la periode de vegetation apres la moisson du ble se prolonge pendant environ 90 jours et que la somme de temperature bioclimatique est d'environ 1800 °C. De pareilles conditions rendent possible, a vcc !'irrigation, la reus­site d'une production de fourragc …

The Potential Of Lolium Multiflorum X Festuca Gigantea Hybrids, M O. Humphreys, H Thomas, B F. Tyler

IGC Proceedings (1977-2023)

The potential for combining traits from broadly adapted Festuca with more highly specialised Lolium has been investi­gated for many years especially with regard to cytological behaviour (Breese et al., 1981). In the USA, efforts to increase the nutritive value of tall fescue through hybrids with ryegrasses succeeded in producing the variety Kenhy (Buckner et al., 1977). So far, Lolium/Fescue hybrids have not been able to compete commercially with more productive ryegrasses in intensive UK farming systems (Breese and Lewis, 1984). How­ever, with recent economic changes in European agriculture there is a need for more efficient, lower input grassland …

Sesbania Sesban: A Promising Forage Legume In Semi-Arid Central Tanzania, D N. Msariri, M L. Kusekwa

IGC Proceedings (1977-2023)

Seventy-four accessions of Sesbania sesban were evaluated alongside 7 of S. goetzel for forage production at Mpwapwa, In Tanzania. The former was promising while the latter was generally unsuccessful. For S. sesban, germination of scarified inoculated seed in nursery was 34%. Survival of the seedlings was 96% at transplanting at 8 weeks. Growth in the field, measured in terms of mean incremental height, was 2.9 m at l year of establishment. On average, 50% of the plants flowered and formed pods at 158 and 190 days, respectively. Seed yield averaged 348 g per plant, while forage yield averaged 4.5 t …

Intensive Lucerne Production In Washington, William P. Ford, Dayid W. Evans

IGC Proceedings (1977-2023)

Hay is the sixth valuable agricultural commoditing in the state of Washington in the USA. Lucerne (Medicago sativa L.) was grown on 190350 ha and represents 74% of all hay, 36% of the state's lucerne acreage and 48% of its production was found in two counties. Three to 5 harvests per year can be made in Central Washington. Lucerne farms under intensive management can yield as much as 22.4 Mg of 12% moisture hay/ha. A balance between stand maintenance, high yields and good quality hay can be obtained by cutting lucerne at the bud stage of growth. In 1991, over …

Change In Botanical Composition, Dry Matter Yield And Forage Quality Of Grassland After Five Seasons Of Extensification, W Kuhbauch, J Schellberg

IGC Proceedings (1977-2023)

Extensification of grassland management in Germany has 2 major objectives (I) to reduce the surplus of crop and animal products, and (2) to diminish unwanted side effects against the environment from intensive production systems. Some of the programmes on offer require a reduced number of cuttings and grazings per season, including a very late first cut of the sward and a reduction of nitrogen fertiliser. In a 5-yenr experiment at the grassland research station Rengen, Eifel-mountain-range, Germany, extensification of this type on productive grassland sites created an unbalanced botanical composition and, with nitrogen applied, a major portion of quackgrass in …

Effect Of Method And Intensity Of Selection For Yield In White Clover, J R. Caradus, W M. Williams

IGC Proceedings (1977-2023)

The effectiveness of various strategies of selection for yield was tested using high performing white clover (Trifolium repens L.) lines derived from crosses between elite Grasslands Huia genotypes and elite genotypes from introduced germpiasm. There appeared to be no clear advantage of selecting genotypes, at the same intensity of selection, in the top 12.5% of families compared with the top 50% of families, There was a weak trend towards higher yielding progeny with increasing selection intensity. It was more effective to use individual selection within families based on performance rather than family selection, However, this effect was specific to …

Environmental Physiology Of Medical Cannabis, F. Mitchell Westmoreland

All Graduate Theses and Dissertations, Fall 2023 to Present

Cannabis (Cannabis sativa L.) is increasingly being cultivated for industrial and medical uses. Medical cannabis is grown for cannabinoids and terpenes, compounds that continue to show promising therapeutic potential. Cannabidiol (CBD) and delta-9- tetrahydrocannabinol (Δ9-THC) are the two most common cannabinoids, but more than 150 have been identified in cannabis. The 2018 Farm Bill federally legalized cannabis containing less than 0.3% THC and high-THC medical cannabis is legal in 38 states. There is a need to understand environmental effects on yield and quality to ensure safety and quality for medical use.

The cultivation of medical cannabis is centered around …

Measuring Spatial Variation Within Pastures, C K. Mcdonald, R M. Jones

IGC Proceedings (1977-2023)

Paddock means of pasture yield and composition can be inadequate or even misleading due to the spatial variability within pastures. The use of visual estimation procedures, particularly the BOTANAL technique, provides data suitable for analysing variability as many quadrats are sampled within the one paddock. Examples show how data from routine BOTANAL samplings can reveal small and paddock scale spatial variation, and how BOTANAL data can be used to examine relationships between the yield of legume and grass in a mixed pasture grazed at different stocking rates.

Effect Of White Clover Defoliation On Seed Production And Maturity, Slepetys, R Dapkus

IGC Proceedings (1977-2023)

Experiments were carried out in Lithuania over the period 1990- 1995. They involved white clover (Trifolium repens L.) cultivars Atoliai (large - leaved) and Bitunai (intermediate - leaved). Different defoliation treatments were carried out at a height of 5, 10 and 15 cm every week over the period from 7 May to 18 June. On 21-28 May, two more treatments consisting of an application with 0.5 and 1.0 l ha-1 reglone were added. When defoliation was carried out on 11-18 June, the seed of cv. Bitunai and cv. Atoliai matured 7 d and 13 d later, respectively than the …

Cutting Date Effects Of Yield And Quality Of Unimproved Kudzu (Pueraria Lobata (Willd.) Ohwi.), T H. Terrill, S Gelaye, S Mahotiere, E A. Amoah, S Miller, W R. Windham

IGC Proceedings (1977-2023)

Kudzu (Pueraria lobata (Willd.) Ohwi.), a vigorous, perennial warmseason legume, is considered a weed in the southern United States. It is tolerant of drought and low soil fertility and has potential as a low-input forage for livestock production. A field experiment tested effects of cutting date on yield and nutritive value of an unimproved stand of kudzu (10-15 yr old) in central Georgia. Yield measurements were made in June, July, September, and November, 1994, with forage samples taken to determine quality parameters. Soil fertility was unaffected by cutting treatment. Whole plant and leaf dry matter (DM) production and crude …

Establishment Vigor Of Endophyte Free And Endophyte Infected Tall Fescue Cultivars In Southern Ohio, C D. Penrose, H M. Bartholomew, R M. Sulc, E M. Volborn

IGC Proceedings (1977-2023)

Eleven cultivars of tall fescue (Festuca arundinacea, Schreb.) and two cultivars of orchardgrass (Dactylis glomerata L.) are part of a study to evaluate yield, establishment vigor, persistence and palatability under autumn stockpiling conditions. Included in the study are two endophyte infected-cultivars of tall fescue to compare interactions with endophyte free and infected cultivars. The results demonstrate that the newer endophyte-free and low-endophyte tall fescue cultivars evaluated are similar to other orchardgrass and endophyte-infected tall fescue cultivars in establishment vigor and early growth the year following establishment.

Effect Of The Cutting Frequency On Yield, Crude Protein And Mineral Contents Of A Panicum Maximum/Centrosema Macrocarpum Mixture, J Faria-Marmol, D E. Morillo, R Gonzalez, Z Chirinos

IGC Proceedings (1977-2023)

Dry matter (DM) yield, crude protein (CP) and mineral composition of Panicum maximum-Centrosema macrocarpum association as affected by three cutting frequencies (28, 42 and 56 days) were compared in a tropical dry forest of Venezuela. No differences (P<0.05) among defoliation frequencies for any of the variables were detected. All mineral concentrations evaluated in Guineagrass (P. maximum) were considered adequate for grazing ruminants. In C. macrocarpum only P (0.24%) and N (0.08%) were close to critical level for deficiencies in ruminants. P. maximum-Centrosema macrocarpum mixture offered adequate levels for grazing ruminants for all nutrients evaluated.

Effects Of Three Cutting Frequencies On Yield, Crude Protein And Mineral Contents Of Centrosema Macrocarpum, J Faria-Marmol, D E. Morillo, R Gonzalez, Z Chirinos

IGC Proceedings (1977-2023)

Dry matter (DM) yield, crude protein (CP) and mineral composition of Centrosema macrocarpum as affected by three cutting frequencies (28, 42 and 56 days) were compared in a tropical dry forest of Venezuela. DM yield and plant height were increased (P<0.05) by increasing the cutting intervals, whereas CP, ash and most minerals were not affected (P<0.05). Only P concentration declined (P<0.05) with increasing plant maturity. The lowest P concentration (0.18%) resulted from the longest cutting interval. Average CP concentration and mineral contents of C. macrocarpum were adequate with grazing ruminant requirements with exception of P (0.21%) and Na (0.073%).