Soybean seed is one of the most costly inputs for soybean producers. Research was conducted in 2016 and 2017 in Mississippi to evaluate the impact of row spacing, planting date and seeding rate on soybean yield. Additional research was conducted to determine the optimal replant seeding rate, following a sub-optimal stand of soybean, to maximize soybean yield. These data suggest an early planting date, mid-April, at a seeding rate of 296,400 seeds ha-1, no matter the row spacing, resulted in the greatest soybean yield. No yield differences were observed for a replant seeding rate of 160,500 seeds ha-1 added to a 50% reduced stand when compared to the optimum stand treatment. Soybean yield was greater for the optimum stand treatment when compared to complete removal followed by full replant treatment, or 321,000 seeds ha-1.

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Maximizing productivity and profitability are the primary reasons for double-cropping soybean with small grain in the Mid-Atlantic, USA. Reduced double-crop yield can be attributed to: delayed planting that results in a shortened growing season and less vegetative growth; later-maturing cultivars that terminate main stem growth after flowering and have less growth and nodes; less soil moisture and plant-available nutrients due to small grain uptake; greater air and soil temperatures during vegetative stages that reduce early-season growth; and more favorable conditions for disease development during pod and seed formation. Field experiments were conducted in 2012 and 2013 in eastern Virginia to 1) evaluate cultivar stem growth habit, seeding rate, seed-applied inoculant, starter nitrogen (N) applied at planting, and foliar fungicide on soybean vegetative growth, total N uptake (TNU), seed yield and quality, and yield components; 2) determine the effect of starter N rate, applied with and without inoculant, on soybean vegetative growth, TNU, seed yield and quality, and yield components; and 3) evaluate the response of maturity group (MG) IV and V soybean cultivars to foliar fungicide. Greater seeding rates, inoculant, N, and fungicide typically were not required together to increase yield. Although cultivar interacted with other factors, early-maturing indeterminate 95Y01 yielded more than late-maturing determinate 95Y20 at 4 of 6 locations. Seeding rate interacted with other factors, but the greater seeding rate increased MG IV yield at 1 of 6 locations and decreased MG V yield at 2 of 6 locations. Starter N increased seed yield by 6 kg ha-1 per kg N applied until yield plateaued at 16 kg N ha-1, which continued to 31 kg N ha-1. When N rate was increased greater than 31 kg N ha-1, yield decreased. Fungicide increased yield for MG IV and V cultivars at 4 of 6 and 3 of 6 locations, respectively and prevented yield loss via mid- to late-season disease control, delayed leaf drop, and greater seed size. Optimum fungicide timing depended on environment and disease development. These data assisted in understanding agronomic inputs' combined or individual effects on double-crop soybean growth, canopy, N uptake, seed yield, and yield components. / Ph. D.

Biopsy is a standard practice in the diagnosis and treatment of many cancers. Despite its integral role in cancer diagnosis, in some instances, the biopsy tool facilitates metastasis by transferring cancerous cells attached to its exterior into the healthy tissue or the blood circulation during its retraction from the tumor. These few cancer cells can then serve as seeds for the malignant tumor to grow in the healthy tissue. Cauterization using extreme heat or cold can destroy cells in the region and minimize the chance of seeding but this can be an inexact process that increases damage to otherwise healthy tissue and prolongs healing time following a biopsy procedure. In our laboratory, we have developed the concept of a new smart biopsy tool that can reduce the chance of cancer cell dissemination during a biopsy. This tool improves on the conventional biopsy needle by introducing an impedance sensor on the biopsy tool which is housed in a sliding sheath. Due to the significant difference in the electrical conductivity of the tumor and the healthy tissue, the sensor is able to distinguish between the two and locate the exact tumor interface. The protective sheath placed around the instrumented biopsy tool and above the interface isolates the healthy tissue and prevents or at least minimizes the transfer of tumor cells. Delivering an RF dose through the sheath can kill any malignant cells that might be lurking around the interface. This thesis, in particular, will concentrate on the development of the design, fabrication and calibration of the impedance sensor and its integration with the biopsy tool. The impedance sensor essentially consists of conductive electrodes sandwiched between insulating layers. They are built on thin-film polymer, Polyimide, using conventional microfabrication techniques. These sensors are further calibrated to estimate the cell constant. Once calibrated, these probes are used to measure the conductivity of porcine tissues, and in-house prepared agar phantoms. / Master of Science

Cloud geoengineering approaches aim to mitigate global warming by seeding aerosols into clouds to change their radiative properties and ocurrence frequency. Ice-nucleating particles (INPs) can enhance droplet freezing in clouds, reducing their water content. Until now, the potential of these particles has been mainly studied for weather modification and cirrus cloud thinning. Here, using a cloud-resolving model and a climate model we show that INPs could decrease the heat-trapping effect of mixed-phase regime clouds over the polar oceans during winter, slowing down sea-ice melting and partially offsetting the ice-albedo feedback. We refer to this concept as mixed-phase regime cloud thinning (MCT). We estimate that MCT could offset about 25% of the expected increase in polar sea-surface temperature due to the doubling of CO2. This is accompanied by an annual increase in sea-ice surface area of 8% around the Arctic, and 14% around Antarctica.

Microphysical properties of precipitating hydrometeors, such as size, concentration, or shape, can be retrieved by vertically-resolved remote-sensing measurements. For a thorough quality assessment, a direct evaluation of those retrievals is required. Surface in-situ observations of precipitation particles are one possible approach. In the framework of the Master’s thesis presented in here, the two-dimensional video disdrometer (2DVD), a ground-based precipitation sensor was applied for this purpose. The 2DVD provides horizontal line scans of two orthogonally aligned cameras so that hydrometeors in a well-defined measurement area are detected. This allows the derivation of single-particle properties as well as precipitation rates, particle number concentrations, or particle size distributions. In this thesis defense, the 2DVD including its measurement and calibration principle, the data processing chain, as well as former 2DVD-related research is presented. Further, the successful instrument evaluation of the 2DVD against other precipitation in-situ sensors and its capabilities to distinguish different ice crystal shapes will be elaborated on. Additionally, case studies about combined 2DVD and remote-sensing observations of cloud seeding experiments will be shown to demonstrate that the 2DVD can contribute to the investigation of clouds and precipitation processes. Data used in this thesis were collected during the PolarCAP / CLOUDLAB campaign near Eriswil, Switzerland between 12/2022 and 02/2023.:1 Introduction 2 Measurement campaign and operating instruments 2.1 Cloudlab and PolarCAP 2.2 Instrument overview 2.3 Two-dimensional video disdrometer (2DVD) 2.3.1 Measurement principle and data processing 2.3.2 Calibration procedure 2.3.3 Former 2DVD research 2.4 HOLIMO 3 2DVD – deducible hydrometeor and precipitation properties 3.1 Properties of single particles 3.2 Precipitation properties 3.2.1 Precipitation rate 3.2.2 Particle size distribution 3.2.3 Relations of particle properties 3.2.4 Particle number concentration 4 Measurement results 4.1 2DVD calibration and evaluation 4.1.1 Calibration procedure on 12 December 2022 4.1.2 Comparison of precipitation rates of different instruments 4.2 Detection of different ice crystal shapes 4.2.1 17 January 2023, 11:30 – 11:35 UTC: irregular crystals and aggregates 4.2.2 17 January 2023, 13:50 – 13:54 UTC: dendrites, strongly rimed particles, irregular crystals 4.2.3 17 January 2023, 14:07 – 14:11 UTC: dendrites 4.2.4 18 January 2023, 09:44 – 09:48 UTC: needles / columns 4.3 Case studies: Precipitation monitoring during cloud seeding experiments 5 Discussion 6 Summary, Conclusions, and Outlook Appendix A 2DVD data processing chain Appendix B Calibration offset between Mira-35 and RPG94 LACROS Appendix C Unrealistic particles not filtered by the 2DVD sno-algorithm Bibliography

No / A novel method for manufacturing granules with a large particle at their core, referred to as seeded granules, is presented. As an example, calcium carbonate powders (Durcal) of different grades are used as primary particles and polyethylene glycol (PEG) as liquid binder in high shear granulators of different scales (Cyclomix, manufactured by Hosokawa Micron B.V., The Netherlands). The conditions giving rise to seeded granulations are specified in the form of an operational regime map. It is found that the seeded structure is strongly dependent on the impeller speed and the primary particles size distribution. It is shown that a Stokes number of around 0.1 represents the optimal dynamic conditions in the given example for producing seeded granules, regardless of the scale of the granulator.

The research explored strategies to improve cover crop (CC) establishment and nitrogen (N) uptake in response to the time constraints commonly faced by Mid-Atlantic farmers. The first study examined whether broadcasting CCs at corn harvest—using various incorporation techniques—can reduce nitrate leaching and enhance biomass production, compared to broadcasting or drilling CCs 4-weeks post-harvest. Four seeding methods were tested across a range of CC species, including cereal rye (Secale cereale L.), hairy vetch (Vicia villosa Roth), rapeseed (Brassica napus L.), and their mixture. Over two years, data revealed that CCs planted at corn harvest achieved significantly higher fall biomass (721 to 846 kg ha-1) than those seeded four weeks later (134 to 200 kg ha-1). Year 2 data showed a reduction in fall soil nitrate levels with at-harvest planting (5.2 mg kg-1), compared to post-harvest CC planting (11.4 to 11.8 mg kg-1). Additionally, certain at-harvest treatments, particularly those with hairy vetch and the mix, increased aboveground N accumulation (181 to 208 kg ha-1) and, in Year 1, improved corn yield (10,113 to 11,586 kg ha-1). The second study focused on a combine-mounted seeder's capacity to address similar N management goals in corn-soybean systems, allowing for seeding CCs directly at harvest and bypassing the need for additional field passes. Results from one year demonstrated that the combine-mounted seeder produced equal or greater biomass and N accumulation compared to delayed drilling. Following corn, the combine seeded treatments increased fall biomass tenfold (205 kg ha-1 vs. 1116 to 1314 kg ha-1) and nearly doubled spring biomass (2345 kg ha-1 vs. 5867 to 6323 kg ha-1). The effectiveness of at-harvest broadcasting was also evident even in late-season drought conditions following soybean, showing comparable results to drilling two weeks post-harvest (4528 kg ha-1 vs. 4434 kg ha-1). Both studies highlight that earlier CC establishment, whether by broadcast seeding with or without incorporation or utilizing combine-mounted seeders, offers a promising approach for enhancing biomass production and reducing fall nitrate leaching in Mid-Atlantic farming systems. / Master of Science / This research examined ways to aid Mid-Atlantic farmers in establishing earlier cover crops (CCs) and improving CC nitrogen (N) uptake. The first part of the study compared broadcasting CCs at corn harvest with waiting four weeks to either broadcast or drill them after harvest. Four species of CCs were tested, including cereal rye, hairy vetch, rapeseed, and a mixture of these. Results over two years showed that broadcasting CCs at corn harvest resulted in significantly more biomass growth in the fall, with levels ranging from 721 to 846 kg per hectare (643 to 755 lb per acre), compared to just 134 to 200 kg per hectare (120 to 178 lb per acre) with later planting. Additionally, soil nitrate levels were lower when CCs were planted at harvest—5.2 mg/kg, compared to 11.4 to 11.8 mg/kg when planted later. Certain combinations, especially those including hairy vetch, led to higher N accumulation and improved corn yields. The second part of the study evaluated a new combine-mounted seeder that allows farmers to plant CCs during cash crop harvest, reducing the number of times they need to work the fields. Results after one year showed that the combine-seeded method produced similar or greater biomass and N accumulation than conventional post-harvest drilling. Following corn, fall biomass increased tenfold and spring biomass nearly doubled compared to delayed drilling. Even with drought conditions in soybeans, the combine-seeded method yielded results comparable to drilling CCs two weeks later. The second year of the study is still in progress. Overall, both studies suggest that starting cover crops earlier, whether by broadcasting or using the combine seeder, can significantly boost biomass growth while reducing nitrate leaching in farming systems throughout the Mid-Atlantic region. Future research is needed to test the effectiveness of the combine-mounted cover crop seeder in different soil types and climates.

Aciphylla species (wild spaniard/speargrass) are an iconic component of the Australasian high country flora, but their reproductive system is enigmatic. They are insect-pollinated dioecious mast seeders (synchronous highly variable seed production), which seems maladaptive. The resource supply to pollinators is highly variable, yet dioecious plants are dependent on pollinators, and dioecious masting requires male and female plants to flower synchronously. Floral display in Aciphylla is relatively large, with tall inflorescences bearing thousands of flowers, suggesting that plants would not have the resources to produce such large stalks every year. But why do they have such huge inflorescences in the first place? I tested whether pollinator attraction is providing an economy of scale which favours intermittent production of very large inflorescences, by manipulating floral display size during a high-flowering year and measuring insect visitation rates and seed set (female reproductive success). Using space-for-time substitution and selective removal of male inflorescences, I also tested whether female seed set was affected by distance to flowering male plants (i.e. changes in local pollen availability) to see if flowering asynchrony would reduce pollination success. Bags were used to exclude pollination by insects and test for wind pollination, and hand pollination was done to test for pollen limitation. Insect surveys suggest that Aciphylla has a generalist pollination system (to avoid satiating a specialist pollinator during 'mast' years'). Male inflorescences received significantly more visits than females, and some seeds were set inside bags (although only 20-30%), suggesting wind pollination may occur at low levels. Seed set rate was higher for taller inflorescences with greater flowering length in A. aurea but tall inflorescences with excess flowers led to a decrease in seed set rates in A. scott-thomsonii. Hand pollination significantly increased seed set rates although these effects were not as large as expected (e.g. 10% increases from natural to hand-pollinated inflorescences were typical). There was no evidence for resource limitation in any species. Female plants in dense flowering populations had higher seed set rates, and individual floral display size in females was particularly important when females were 'isolated' from males. Insect visitation rates were generally higher on inflorescences with a larger floral display, suggesting that display size is important for pollinator attraction. Overall, these results suggest that the pollinator-attraction benefits of such a large floral display (at both the plant and population level) are possibly providing an economy of scale, although the relative effects are small.

Siekiant įvertinti supaprastinto žemės dirbimo ir tiesioginės sėjos įtaką žieminių kviečių agrofitocenozei ir dirvos fizikinėms savybėms atlikti tyrimai 2009-2010 m. ilgalaikiame eksperimente, kuris įrengtas 1988 m. Lietuvos žemės ūkio universiteto Bandymų stotyje giliau karbonatingame giliau glėjiškame išplautžemyje – IDg4-k2 (Endocalc(ar)ic Endohipogleyic Luvicol – LWg-n-ww-cc) FAO, vidutinio sunkumo priemolyje ant smėlingo lengvo priemolio. Lauko eksperimento variantai: 1. Įprastinis arimas 23-25 cm gyliu (IA); 2. Seklusis arimas 12-15 cm gyliu (SA); 3. Gilusis purenimas (kultivavimas strėliniais noragėliais 23-25 cm gyliu) (GP); 4. Seklusis purenimas 12-15 cm gyliu (SP); 5. Tiesioginė sėja į neįdirbtą dirvą (glifosatu purškiama pagal reikalą) (ND). Nustatyta, kad žemės dirbimo supaprastinimas bei tiesioginė sėja ženkliai padidino trumpaamžių ir daugiamečių piktžolių daigų tankumą žieminių kviečių krūmijimosi tarpsnyje, lyginant su įprastiniu arimu. Taikant ilgalaikę tiesioginę sėją žieminių kviečių agrofitocenozėje krūmijimosi tarpsnyje daugiau išplito bekvapis šunramunis, mažoji strugena, dirvinis garstukas ir trikertė žvaginė, lyginant su kitais žemės dirbimo būdais. Bekvapių šunramunių gausumas žieminių kviečių pieninės brandos tarpsnyje buvo taip pat ženkliai didesnis tiesiogiai javus sėjant į ražienas, negu taikant įprastinį ir supaprastintą žemės dirbimą. Didesnis trumpaamžių piktžolių skaičius rastas kviečių pieninės brandos tarpsnyje giliai ir sekliai... [toliau žr. visą tekstą] / In order to evaluate the effect of reduced tillage and direct seeding on agrophytocenosis of winter wheat and physical properties of soil, tests were carried out. In a long-term experiment conducted in the period between 2009 and 2010, which was installed in 1988 in Experimental Station at Lithuanian University of Agriculture in calcarous and endohypogleyic luvisol – IDg4-k2 (Endocalc(ar)ic Endohipogleyic Luvicol – LWg-n-ww-cc) FAO, in medium loam on sandy light loam. Field experiment options: 1. Routine Plowing depth of 23-25 cm (RP) 2. Shallow Plowing depth of 12-15 cm (SP); 3. Deep Hoeing (cultivation with arrow-type ploughshare, depth of 23-25 cm) (DH); 4. Shallow Hoeing depth of 12-15 cm (SH); 5. Direct Seeding in uncultivated soil (sprayed with glyphosate if necessary) (US). The results show that when compared with conventional tillage, the reduced tillage and direct seeding have significantly increased the density of seedlings of short-lived perennial weeds at the stage of tillering of winter wheat. When compared with other methods of tillage, during long-term direct seeding, at the stage of agrophytocenosis and tillering of winter wheat, the scentless false mayweed, mouse-tail, wild mustard and shepherd's purse were more widespread. Abundance of scentless false mayweed at the stage of lactic ripeness of winter wheat was significantly greater when grains were directly sown in the stubble than using conventional and reduced tillage. A larger number of short-lived... [to full text]