Nematodes in Texas Golf Courses

4 pp., 2 photos, 2 illustrationsPlant parasitic nematodes are microscopic roundworms that feed on plant roots. In turfgrasses they cause damage similar to that of water stress, nutrient deficiency or root diseases. Golf course managers can use this publication to learn about testing for nematodes, identifying the species that damage turf, and managing nematodes

Ball Moss

2 pp., 1 photoBall moss is a bromeliad that grows on trees. It is not a parasite and does not take nutrients from trees. It can be controlled, if desired, by mechanical removal or by applying fungicides that contain copper

Management of Root-knot Nematode (Meloidogyne incognita) onPittosporum tobira Under Greenhouse, Field, and On-farm Conditions in Florida

Root-knot nematodes are important pests of cut foliage crops in Florida. Currently, effective nematicides for control of these nematodes on cut foliage crops are lacking. Hence, research was conducted at the University of Florida to identify pesticides or biopesticides that could be used to manage these nematodes. The research comprised on-farm, field, and greenhouse trials. Nematicide treatments evaluated include commercial formulations of spirotetramat, furfural, and Purpureocillium lilacinum (=Paecilomyces lilacinus) strain 251. Treatment applications were made during the spring and fall seasons according to manufacturer's specifications. Efficacy was evaluated based on J2/100 cm3 of soil, J2/g of root, and crop yield (kg/plot). Unlike spirotetramat, which did not demonstrate any measurable effects on Meloidogyne incognita J2 in the soil, furfural and P. lilacinum were marginally effective in reducing the population density of M. incognita on Pittosporum tobira. However, nematode reduction did not affect yield significantly. Although furfural and P. lilacinum have some potential for management of M. incognita on cut foliage crops, their use as a lone management option would likely not provide the needed level of control. Early treatment application following infestation provided greater J2 suppression compared to late application,suggesting the need for growers to avoid infested fields

Microwave Implementation of the Two-Source Energy Balance Approach for Estimating Evapotranspiration

A newly developed microwave (MW) land surface temperature (LST) product is used to substitute thermal infrared (TIR) based LST in the two-source energy balance approach (TSEB) for estimating ET from space. This TSEB land surface scheme, the Atmosphere Land Exchange Inverse (ALEXI) model framework, is an approach that minimizes sensitivity to absolute biases in input records of LST through the analysis of the rate of temperature change in the morning. This experiment is therefore an important test of the ability to retrieve diurnal temperature information from a constellation of satellites with microwave radiometers that together provide 6-8 observations of Ka-band brightness temperature per location per day. This represents the first ever attempt at a global implementation of ALEXI with MW-based LST and is intended as the first step towards providing all-weather capability to the ALEXI framework. The leveraging of all sky capability of MW sensors is the main motivation of this work, as TIR-based ALEXI is limited to clear sky conditions.The analysis is based on a 9-year long record of ALEXI ET generated with MW-LST as an input, which is compared to an existing implementation of the same framework with thermal infrared based LST. In this study, the MW-LST sampling is restricted to the same clear sky days as in the IR-based implementation to be able to analyse the impact of changing the LST dataset separately from the impact of sampling all-sky conditions. The results show that long-term bulk ET estimates agree with a spatial correlation of 92 for total ET in the EuropeAfrica domain and agreement in seasonal (3-month) totals of 83-97 depending on the time of year. Most importantly, the ALEXI-MW also matches ALEXI-IR very closely in terms of 3-month inter-annual anomalies, demonstrating its ability to capture the development and extent of drought conditions. The weekly ET output from the two parallel ALEXI implementations is further compared to a common ground measured reference provided by the FLUXNET consortium. Overall, they indicate a surprisingly close match in both performance metrics (correlation and RMSE) for all but the most challenging sites in terms of spatial heterogeneity and level of aridity. Moreover, merging MW- and IR-based ALEXI may provide estimates of ET with a reduced uncertainty, even during nominally clear sky days. It is concluded that a constellation of MW satellites can effectively be used to provide LST for estimating ET through TSEB, which is an important step towards all-sky satellite-based ET estimates

Vertical Distribution of Pasteuria penetrans Parasitizing Meloidogyne incognita on Pittosporum tobira in Florida

Pasteuria penetrans is considered as the primary agent responsible for soil suppressiveness to root-knot nematodes widely distributed in many agricultural fields. A preliminary survey on a Pittosporum tobira field where the grower had experienced a continuous decline in productivity caused by Meloidogyne incognita showed that the nematode was infected with Pasteuria penetrans. For effective control of the nematode, the bacterium and the host must coexist in the same root zone. The vertical distribution of Pasteuria penetrans and its relationship with the nematode host in the soil was investigated to identify (i) the vertical distribution of P. penetrans endospores in an irrigated P. tobira field and (ii) the relationship among P. penetrans endospore density, M. incognita J2 population density, and host plant root distribution over time. Soil bioassays revealed that endospore density was greater in the upper 18 cm of the top soil compared with the underlying depths. A correlation analysis showed that the endospore density was positively related to the J2 population density and host plant root distribution. Thus, the vertical distribution of P. penetrans was largely dependent on its nematode host which in turn was determined by the distribution of the host plant roots. The Pasteuria was predominant mostly in the upper layers of the soil where their nematode host and the plant host roots are abundant, a factor which may be a critical consideration when using P. penetrans as a nematode biological control agent

Synthesis and Characterization of Copolyimides Containing Fluorine and Silicon Surface Modifying Agents

Understanding the effects that monomer chemistries have on material properties allows for fine tuning of polymer synthesis for current and future applications. In order to develop polymeric based coatings that have minimal surface adhesion characteristics when exposed to a variety of contaminants, a more thorough understanding of fundamental structure-property relationships is needed. In the aeronautics field, one concept to improve fuel efficiency of future aircraft is to modify the wing design to enable laminar flow. There is a concern that contaminants such as insect residue and other debris will adhere to airflow surfaces and have sufficient height to disrupt laminar flow thereby increasing drag with concomitant loss of fuel efficiency. One potential solution would be a polymer surface or coating that prevents or minimizes adhesion of such contaminants. As part of a structure-property relationship study involving modification of surface properties, a series of copolyimides containing both fluorine and silicon surface modifying agents (SMAs) were prepared and characterized. Based on knowledge of structure-property relationships with polyimides containing either type of SMA, it was hypothesized that the combination of two different surface-modifying agents may lead to unique surface properties as the two SMAs competed for surface area at the polymer-air interface. Copolyimides for this study were prepared through a multi-step synthesis using an aromatic dianhydride with equimolar amounts of diamino functionalities comprised of an aromatic diamine along with two SMAs. Films were cast from copoly(amide acid) solutions that were subsequently thermally imidized under a nitrogen atmosphere. Polyimide films and coatings were characterized using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), ultravioletvisible spectroscopy (UV-Vis), contact angle goniometry (CAG), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) to determine chemical, thermal, and surface properties. Select samples were subject to high velocity insect impacts in a small scale wind tunnel and the resulting residues were characterized for height and surface area and compared to those of a control surface