Digital Commons Network^™

Sensitivity Of Soybean And Rice To Dicamba, Owen Wesley France

Graduate Theses and Dissertations

Although the integration of dicamba as a postemergence (POST) herbicide has proven useful in controlling many herbicide-resistant weeds, its damage to soybean at low rates, such as supplied by drift and volatility, has been well-documented. Injury to other crops, such as rice, from off-target movement of dicamba and other commonly used herbicides, such as glyphosate, may also occur. Practical options for mitigating injury and yield loss to soybean and other crops from dicamba off-target movement could prove beneficial if dicamba continues to be used during summer months. Experiments were conducted to determine the effects of multiple agricultural practices, including cultivar …

How Do Cover Crops Change Soil Health In A No-Till System?, Aysha Kirsten Tapp Ross

Electronic Theses and Dissertations

Nutrient levels and aggregation measurements are currently the most accurate means to measure soil health. It has been suggested that bacterial and fungal communities may prove to be a more accurate measure of soil health. In this study soil microbe communities and nutrient levels were compared in rye cover cropped soils to measure for differences between treatments. Effects between the microbial communities and environmental measurements were also measured within those treatments to test for correlations between soil health measures and microbial communities. The plots were put in a biennial corn (Zea mays L.) and soybean (Glycine max …

Recapture And Reuse Of Nitrogen And Phosphorus From Rendered Animal Materials To Enhance Nutrient Use Efficiency And Produce Quality In Agricultural Crop, Bhupinder Jatana

All Dissertations

The current fertilizer regime heavily relies on inorganic fertilizers to meet the crop nitrogen (N) and phosphorus (P) demand. However, the United States has a limited N production capacity, with 50% N demand met through imports. On the other hand, the nonrenewable natural reserves of P are being depleted at an unprecedented rate and are expected to be exhausted with in next 100 years. Additionally, high solubility/liability of the field applied inorganic fertilizers often results in lower nutrient use efficiency (NUE;

The MBM led to rapid N mineralization, with 35% of the applied N mineralized within the first five days …

Effects Of Nitrogen Management And Cultivar On Strawberry Production Under Disease Pressure, Kamille A. Garcia-Brucher

Master's Theses

Effects of nitrogen management and cultivar on strawberry production under disease pressure

Kamille Garcia-Brucher

California strawberry growers face increasing regulatory pressures to manage nitrogen (N) applications in their production system. Standard practice in the California strawberry industry is to apply a synthetic pre-plant controlled release fertilizer (CRF) to ensure the crop has sufficient N during winter establishment. Some research from the UC Cooperative Extension suggests this practice is not efficient at delivering N to the crop since most of the N is released from CRF before strawberry crop N uptake is significant. Another concern for California strawberry growers is loss …

Nutrient Uptake And Management Strategies In Recirculating Hydroponic Systems, Lauren Leigh Houston

Graduate Theses and Dissertations

Nutrient management in recirculating hydroponic systems requires the periodic replenishment of water and nutrients to the nutrient solution reservoir. Common nutrient management strategies, such as replenishing the reservoir with fresh solution and maintaining a constant solution electrical conductivity (EC), can lead to ion accumulation and nutrient imbalances since nutrients are taken up by roots and depleted from solution at different rates. To avoid nutritional disorders, commercial growers typically dump and replace the hydroponic solution periodically, which is wasteful and has an economic cost. A potential alternative is to specially formulate the nutrient replenishment solution to balance the supply of nutrients …

Field Evaluation Of A New Third Generation Push-Pull Technology For Control Of Striga Weed, Stemborers, And Fall Armyworm In Western Kenya, Duncan Cheruiyot, Frank Chidawanyika, Charles A.O. Midega, Jimmy O. Pittchar, John A. Pickett, Zeyaur R. Khan

All Peer-Reviewed Publications

Production of cereal crops in sub-Saharan Africa is threatened by parasitic striga weeds and attack by stemborers and the invasive fall armyworm (FAW), compounded by increasing hot and dry conditions. A climate-smart push-pull technology (PPT) significantly reduces effects of these biotic challenges. To improve further resilience of the system to climate change, more adapted and suitable companion plants were identified and integrated in a new version of PPT, termed 'third generation PPT'. Our study evaluates field performance and farmer opinions of this new version in comparison with the earlier version, climate-smart PPT, and farmers' own practices of growing maize in …

Economic Potash Fertilizer Rate Recommendations, Kimberly B. Oliver

Graduate Theses and Dissertations

This thesis is comprised of two studies that estimate profit-maximizing potassium (K) fertilizer application rates for various crops across different time periods. Estimation of profit-maximizing fertilizer-K rate (K*) for both studies considered the initial soil test level of K (STK) and yield response information, as traditional recommendations do, and added crop price and the cost of fertilizer. Profit maximum occurs where the marginal revenue from additional yield is equal to the marginal cost of applying an additional unit of fertilizer-K. The first study calculated K* for corn (Zea mays) and cotton (Gossypium hirsutum) and compared results to previous studies on …

Assessing Freezing Effect On Kiwifruit Cultivars And Mapping Suitable Areas For Growing The Crop In Eastern Texas, Lais De Oliveira Machado

Electronic Theses and Dissertations

Kiwifruit is a perennial vine originating from China where it has been grown for centuries. In the United States, green kiwifruit (Actinidia deliciosa) is primarily produced commercially in California. They are fuzzy, green fleshed and well known in the marketplace. Kiwifruit plants require low to moderate soil pH, adequate winter chilling and adequate precipitation to guarantee plant development and good fructification. Actinidia chinesis or golden kiwifruit are smooth skinned, feature golden flesh and are a more recent introduction into the global market. Kiwifruit crops have attributes that favor production in east Texas, including low pest problems, current long …

Forage Production From Perennial Vs. Annual Crop R~ On In Sandy Soils In Egypt, Z. Abdelhalim, O. Niemeläinen, I. A. Hanna, A. M. Rammah

IGC Proceedings (1977-2023)

Forage production was studied on newly reclaimed sandy soil in Egypt trom perennial lucerne (Medicago sativa L.) and two annual crop rotations. The cropping systems were: A) lucerne, B) berseem clover (Trifolium alexandrinum L.) in the winter followed by pearl millet (Pennisetum glaucum R. Br. Emend. Stantz.) in the summer and C) triticale (XX Triticosecale Wittm.) (forage cut + grain harvest) in the winter followed by maize (Zea mays L.) (grain + stover) in the summer. Mean annual dry matter yields (t ha^-1 ) were 20.65, 26.59 and 27.48 from A, B and C, respectively. However, …

Forage Quality Evaluation Of Chopped Elephantgrass Hay Through Intake And Digestibility Trial, E. M. De Aguiar, G. F. Da C. Lima, L. G. Da Paz

IGC Proceedings (1977-2023)

The research was carried out to evaluate forage quality of chopped elephantgrass (Pennisetum purpureum Schum.) hay and to define a proper stage for cutting and haymaking of this grass. Chemical composition, voluntary intake, and apparent digestibility of the hays were studied at five different growth stages (30, 48, 63, 76, and 91 days). Twenty-five common wethers were utilized in a completely randomized experimental design. Dry matter (DM) voluntary intake was not different (P> 0.05) from 30 to 63 days of regrowth and from 63 to 91 days and comprised 3.9; 3.5; 3.2; 2.1; and 2.4% of animal liveweight, respectively …

Seeding Rate Effects On Forage Mass And Vegetation Dynamics Of Cool-Season Grass Sod Interseeded With Sorghum-Sudangrass, John A. Guretzky, D. D. Redfearn

Department of Agronomy and Horticulture: Faculty Publications

Interseeding annual warm-season grasses into perennial cool-season grasses has the potential to increase summer forage mass and nutritive value. Knowledge of how seeding rate affects annual warm-season grass establishment, forage mass, and vegetation dynamics remains limited. From 2016–2017, we conducted a field experiment evaluating the effects of seeding rates on sorghum-sudangrass (Sorghum bicolor x S. bicolor var. sudanense) density and forage mass and on the frequency of occurrence of plant species in cool-season grass sod in Lincoln, NE. The experiment had a completely randomized design consisting of six replicates of four seeding rates [0, 14, 28, and 35 …

Berseem Clover In Binary Mixtures With Oats, Triticale Or Barley For Silage And Late Season Grazing, S. M. Ross, J. R. King

IGC Proceedings (1977-2023)

An experiment was conducted at northerly latitudes with berseem clover (Trifolium alexandrinum L) in binary mixtures with oats (Avena sativa L.), barley (Hordeum vulgare L.) and triticale (X Triticosecale Wittmack). The effects of cereal species, variety and density were assessed for a two cut harvest. Total dry matter yields were 11.7 to 14.5 t ha^-1, with 7.8 to 10.2 t ha^-1 as silage, and 2.0 to 6.0 t ha^-1 as berseem regrowth. Berseem regrowth added an average of 4.0 t ha^-1 in forage yield. Total yields did not differ with cereal …

Transgenic Maize Hybrid Crop Residues: Nutritive Value And Their Effects On Performance Of Grazing Beef Cows, S. K. Barnhart, J. R. Russell, M. J. Hersom, D. E. Farnham

IGC Proceedings (1977-2023)

Several maize (Zea mays) hybrids, including three transgenic hybrids containing Bacillus thuringiensis (Bt) enzymes (Bt-maize hybrids), were planted in a field study. Mature, midgestation, beef cows (Bos tarus) strip-grazed post-harvest residues as paddocks over 126 days. Body condition-scores and weights were monitored. Forage yield, weathering losses and forage composition were monitored on grazed and ungrazed areas. Forage selection and intake were estimated. Grain yields, dropped grain, initial crop residue concentrations of dry matter (DM), organic matter (OM) and in vitro digestible organic matter (IVDOM) yields were similar among hybrids. Hybrids varied in infestation of maize borers, …

Supplementation Of Temperate Pastures, D. H. Rearte, G. A. Pieroni

IGC Proceedings (1977-2023)

Generally in temperate regions, beef and milk were produced on extensive systems with forage from perennial pasture and natural grassland being the main component of animal diet. Supplementation on pasture was usually applied strategically to supply nutrients to grazing cattle only when forage availability was not enough to satisfy animal’s requirements. At present beef and dairy production systems have become more intensive and even when forage from pasture continue being the main component of the diet higher level of different type of supplement are fed to the animals. Intensive systems are characterized by a higher stocking rate capable of consuming …

Feeding Of Conserved Forage - Implications To Grassland Management And Production, C. W. Holmes, P. N. P. Matthews

IGC Proceedings (1977-2023)

This review will focus on the use of conserved forages in pastoral dairy farm systems; especially on their conservation as an aid to good grazing management during periods of rapid pasture growth, and on their consumption as an aid to good feeding management and grazing management during periods of slow pasture growth. Conservation of pasture, in order to move it from one time to another later time, always involves “costs”, either financial expenditure or physical losses (of dry matter/quality) or both, which must be evaluated in the whole system.

Most of the data is drawn from New Zealand and Australia, …

High Moisture Sorghum Grain Silage: Effects Of Tannin Content And Urea Treatment On The Performance Of Dairy Cows, L. A. Romero, E. A. Comerón, O. A. Bruno, A. R. Castillo, M. C. Gaggiotti

IGC Proceedings (1977-2023)

Grain sorghum silage tannin content effect was evaluated on milk production and chemical composition of Argentinean Holstein bred cows, and it are described dry matter (DM) and crude protein (CP) in situ digestion parameters and effective degradability. The base diet was constituted by alfalfa pasture, maize silage, and a protein – mineral supplement, differing in three treatments based on high moisture grain silage characteristic: LTS= Low tannin grain sorghum, HTS= High tannin grain sorghum, and HTSu= High tannin sorghum plus the addition of urea. Grain sorghum silage tannin content affects milk production, without significant alteration of chemical composition. Beside the …

Comparative Growth Performance Of West African Dwarf Goat Supplemented With Calliandra Calothyrsus, Leucaena Leucocephala, Or Cotton Seed Cake In West Cameroon, E. Tedonkeng Pamo, G. D. Assontia, C. Njehoya

IGC Proceedings (1977-2023)

A comparative growth performance study of African Dwarf Goats supplemented with Calliandra calothyrsus, Leucaena leucocephala or cotton seed cake was carried out on farm around Dschang and in the University Experimental Farm. Goats between 12 and 16 months of age were divided into 4 groups of 11 goats each with one group kept as a control. The supplemented animals received respectively 390 g of L. leucocephala, 380 g of C. calothyrsus (fresh matter) and 88.8 g of cotton seed cake each, corresponding to 6 g of nitrogen per animal per day. The animals were weighed every 21 days …

The Effect Of Browse Species When Fed As A Supplement To Low Quality Native Grass Hay On Animal Performance, A. Elgersma, J. F. Oerlemans, D. B. Coates

IGC Proceedings (1977-2023)

A pen trial was conducted to measure the impact of some browse species when fed as a supplement on the nitrogen (N) and dry matter intake of cattle receiving low quality native grass hay. There were 8 treatments consisting of a nil-supplement control treatment, a urea supplement control, a green oaten hay control and 5 treatment groups based on browse supplements (Albizia lebbeck, Carissa spp. and Bursaria spp.). Treatment effect on increased native pasture intake was related to the amount of supplementary nitrogen (N), such that there was a significant linear relationship between dry matter intake of native …

Effects Of Different Levels Of Energy Supplementation On Growth Of Grazing Holstein Heifers, L. P. Novaes, C. E. Polan

IGC Proceedings (1977-2023)

Growth of Holstein heifers was studied for 1987 grazing season to evaluate pasture-drylot systems for raising dairy replacements. Orchardgrass (Dactylis glomerata L), tall fescue (Festuca arundinacea Schreb), bluegrass (Poa pratensis L) and white (Trifolium repens L) and red clover (Trifolium pratense, L) were the principal components of the grass-legume mixture in six paddocks of 1.5 ha each. Carrying capacity was estimated at six animals/ha (3.1 animal units) and excess forage was harvested as hay to control forage growth and quality. Grazing days were 140 days. None or 2.0 kg/d …

Fatty Acid Composition And Eating Quality Of Muscle From Steers Offered Grazed Grass, Grass Silage Or Concentrate-Based Diets, A. P. Moloney, P. French

IGC Proceedings (1977-2023)

The effects of grazed grass, grass silage or concentrates on the eating quality and fatty acid composition of intra-muscular fat of steers fed to achieve similar carcass growth rates were investigated. Fifty steers were assigned to one of five dietary treatments. The experimental rations offered daily for 85 days pre-slaughter were (a) grass silage plus 4 kg concentrate, (b) 8 kg concentrate plus 1 kg hay, (c) 6 kg grazed grass dry matter (DM) plus 5 kg concentrate, (d) 12 kg grazed grass DM plus 2.5 kg concentrate or (e) 22 kg grazed grass DM. Decreasing the proportion of concentrate …

Supplementation Of Lactating Cows Grazing Stargrass (Cynodon Nlenfuensis Var. Nlenfuensis) With Conjugated Linoleic Acid: Effects On Persistency And Estimated Net Energy Balance, S. R. Medeiros, D. E. Oliveira, L. J. M. Aroeira, M. Mcguire, D. P. D. Lanna

IGC Proceedings (1977-2023)

Thirty crossbread cows grazed stargrass (Cynodon nlenfuensis var. nlenfuensis) receiving 4kg/d of a supplement formulated to provide 115% of metabolizable protein requirements from the 4^th to the 11^th week of lactation. The cows received either 150g/head/day of Megalac (Control) or 150g/head/day of a Ca-protected conjugated linoleic acid (CLA, Church & Dwight). Residual effects of treatment were evaluated in weeks 12^th and 13^th. Milk production increased in CLA treated cows (P< 0.05). CLA decreased milk fat content (P< 0.0001) and yield (P< 0.01). Protected CLA increased protein content (P< 0.01) and yield (P< 0.01). The CLA residual effect on milk fat ends within one week after withdrawal but the benefits on milk yield and total solids production continued, due to the increased persistency. The estimated energy balance and intake were not greatly affected by treatment, as treated cows had higher milk volume and had higher protein productions.

Use Of Supplements For Maintenance Of Nelore Bullocks In Brachiaria Decumbens, During The Dry Season In Acre, Brazilian Amazon, J. C. Carneiro, Judson F. Valentim, L. A. R. Valle

IGC Proceedings (1977-2023)

This study had the objective of evaluating animal performance and net economic returns of Nelore bullocks receiving: 1) mineral mixture (MM), 2) mineral mixture + urea (MMU), and 3) multiple supplement (MS), during the dry season of 1999 in Acre, Brazilian Amazon. The animals were maintained in pastures of Brachiaria decumbens, and liveweight gains, forage availability and chemical composition were assessed during the experimental period. Liveweight gains of 0.58, 0.65 and 0.60 kg/day, respectively, for MM, MMU and MS, were not different (P> 0.05). The use of MMU provided additional net economic return of 10.8% in comparison with the …

Roots And Potatoes As Supplements To An Alfalfa – Grass Diet To Dairy Cows, T. Eriksson, P. Ciszuk, E. Burstedt

IGC Proceedings (1977-2023)

Fourteen multiparous dairy cows were used in 3 x 3 change-over experiment designed to study effects of replacing barley by roots and potatoes in diets based on leguminous forage on feed intake, milk production and utilisation of feed nitrogen. The cows received a mixture of alfalfa (Medicago L.) and grass silage ad libitum and an isoenergetic quantity of a supplement based on either barley and potatoes (Ba/P), fodder beets (Beta vulgaris L.) and potatoes (Be/P) or barley (Ba). The grass in grass silage was dominated by timothy (Phleum pratense L.). Total DM intake as well as yield …

Agronomic Evaluation Of Forage Grasses Under Mature Rubber Plantation, N. L. Costa, Valdinei T. Paulino, A. C. M. Igreja, C. R. Townsend, J. A. Magalhães, R. G. De A Pereira, T. S. Paulino

IGC Proceedings (1977-2023)

The agronomic performance of seven forage grasses, under a mature rubber plantation, was assessed in a cutting trial carried out at Porto Velho, Rondônia. During the rainy season, the higher dry matter yields were obtained with B. brizantha, P. atratum BRA-9610 and B. humidicola. During the dry season, the grasses more productive were B. brizantha and P. atratum BRA-9610. In both seasons, magnesium and potassium contents did not vary among grasses. During the rainy season, the higher nitrogen and phosphorus contents were obtained with P. regnelli BRA-0159 and, P. guenoarum BRA-3824 and B. humidicola, respectively, while P. atratum …

Constraints And Opportunities For Development Of Grasslands In Urban Areas Of The Niayes Zone In Senegal, S. T. Fall, I. Cissé

IGC Proceedings (1977-2023)

A survey was carried out in urban areas of the Niayes zone in Senegal to explore grasslands development in agropastoral systems around towns. Rapid rural appraisal and farms multiple visits were done to describe the forage cropping system, identify constraints and opportunities of developing grasslands in urban areas. In Niayes urban areas, forage production system is being developed based on the cropping of several grass and tree species. Only a minority of farmers is involved in that activity. Level of grass production is rather low. Weak development of grasslands is observed. Main reasons are: farmer poor willingness to crop for …

Nutritive Quality Of Tropical Grasses Sown Under A Pine Plantation, D. Gutmanis, Antonio João Lourenço, V. B. G. Alcantara, Maria T. Colozza

IGC Proceedings (1977-2023)

A trial was conducted in Brazil to evaluate the nutritive quality of 6 tropical grasses: tanzania (Panicum maximum cv. Tanzania), green-panic (P. maximum var. Trichoglume), aruana (P. maximum cv. Aruana), brizanta (Brachiaria brizantha), humidicola (B. humidicola) and tifton-85 (Cynodon dactylon cv. Tifton 85), planted under two different densities of pines (Pinus elliottis): 200 and 400 stems/ha, as well as in full sunlight. The results showed a significant increase in protein content and a significant decrease in NDF and cellulose contents as tree density increased. Comparing the values obtained under shading conditions …

Production And Mineral Composition Of Tropical Grasses Sown Under A Pine Plantation, D. Gutmanis, V. B. G. Alcantara, Maria T. Colozza, Antonio João Lourenço

IGC Proceedings (1977-2023)

A trial was conducted in Brazil to evaluate the performance of 6 tropical grasses: tanzania (Panicum maximum cv. Tanzania), green-panic (P. maximum var. Trichoglume), aruana (P. maximum cv. Aruana), brizanta (Brachiaria brizantha), humidicola (B. humidicola) and tifton-85 (Cynodon dactylon cv. Tifton 85), planted under two different densities of pines (Pinus elliottis): 200 and 400 stems/ha, as well as in the full sunlight. The results showed that the dry matter yield decreased as shading increased. The grasses tanzania and brizanta were the most tolerant to shading. Although N concentration increased with …

Dry Matter Production And Nutritive Value Of Alfalfa (Medicago Sativa L.) And Orchardgrass (Dactylis Glomerata L.) Under Different Light Regimes, A. C. Varella, P. L. Peri, R. J. Lucas, D. J. Moot, D. L. Mcneil

IGC Proceedings (1977-2023)

Spring and summer alfalfa dry matter and nitrogen production rates were greater than orchardgrass in open pasture and under three shade levels. Ten years old Pinus radiata allowed 60% light transmissivity. The addition of artificial shade resulted in 45% and 25% transmissivity. Orchardgrass pastures were nitrogen deficient and water stressed. In contrast, alfalfa was not stressed and it was more light responsive than orchardgrass. Differences in nutritive value were relatively small between species and between light regimes. Sheep liveweight gain on alfalfa was greater than on orchardgrass. Orchardgrass demonstrated shade tolerance, but alfalfa was more productive even at 25% transmissivity. …

Optimizing Yield And Quality Of Orchardgrass Pasture In Temperate Silvipastoral Systems, P. L. Peri, R. J. Lucas, D. J. Moot, A. C. Varella, D. L. Mcneil

IGC Proceedings (1977-2023)

The objective of this study was to provide grazing management recommendations for a silvipastoral system by determining the effects of shade and nitrogen (N) on the pattern of dry matter accumulation and nutritive value of orchardgrass (Dactylis glomerata) in a subhumid temperate environment. Orchardgrass in open pasture (100% transmittance) and under 10 year old Pinus radiata tree shade (60% transmittance) at 200 stems/ha was used as the main plot and nitrogen (0 and 300 kg N/ha as synthetic urine) was the subplot factor. Dry matter (DM) production of orchardgrass in the first 60-day spring rotation was similar in …

Herbage Characteristics As Affected By The Canopies Of Dominant Trees In A Savanna Of Southern Mozambique, James P. Muir, A. Alage, Inacio C. Maposse

IGC Proceedings (1977-2023)

This study surveyed the species composition, forage yield and forage nitrogen concentration of the herbaceous layer 50, 100 and 200% of the canopy radius from the trunks of many-stemmed false thorn, knob thorn, scented thorn and marula trees in a southern Mozambican savanna. Tree species did not affect herbaceous DM yield or species diversity. Neither direction nor distance from the tree trunk affected DM or specific diversity. Crude protein percentages were 15% higher for legumes and 9% higher for grasses at 50% canopy than at 200% canopy. Grasses under the marulas, the only non-legume tree in the study, had 18% …