No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

Reservoirs are an important resource for both humans and wildlife. They provide drinking water, recreational opportunities, wildlife habitat and more. A major issue land managers face on reservoirs is shoreline erosion leading to water quality impairments, sedimentation, and habitat loss. Traditionally, riprap has been used to mitigate this issue, but is costly and has limited ability to provide habitat. A promising measure to mitigate shoreline erosion and provide habitat is the establishment of giant cane [Arundinaria gigantea (Walt.) Muhl], on shorelines. Giant cane, a bamboo species native to southern Illinois and the southeastern United States, forms monodominant stands called canebrakes. Where canebrakes exist soil stabilization occurs, water quality increases, and habitat is utilized by multiple faunal species. Canebrakes are considered critically endangered habitat for several animal species and regrettably have been reduced to only 2% of their historical extent due to land conversion and loss of traditional burning practices by Native Americans. Giant cane rehabilitation and restoration has been a goal of the US Fish and Wildlife Service and Illinois Department of Natural Resources and is identified as a Critical Species in the Illinois Wildlife Action Plan. Many locations could benefit from cane restoration, especially riparian areas and reservoir shorelines. Research has been conducted on the successful propagation of giant cane, but little is known of the establishment and restoration on shorelines. And thus, this study examined factors that affect the survival and growth of giant cane propagules on shorelines of two southern Illinois i reservoirs (Cedar Lake and Kinkaid Lake) in Jackson County, Illinois to successfully establish canebrake habitat and mitigate shoreline erosion. This study consisted of three replications at three different locations (sites) on each of the two reservoirs. Giant cane transplants were planted along two elevations (30 per elevation) at each site, the beach ~20 cm above the normal reservoir pool and upslope (US) about 1 meter above beach transplants. Initial growth (height of the tallest culm and number of culms) was collected prior to transplanting to be used as factors. Survival, height of the tallest culm (cm), number of culms, and amount of spread (cm) were collected following each of the three growing seasons after planting. Canopy cover (%) was collected after the second growing season on Kinkaid Lake and soil properties (bulk density, texture, and nutrients) were measured on both reservoirs after the third growing season. Key takeaways were 1) significantly greater survival occurred among transplants in the US position (43.8% for the US vs 3.3% for the beach for Cedar Lake and 82.2% for the US vs 67 for the beach for Kinkaid Lake), 2) elevations with lower bulk density and greater organic matter trended toward greater rates of height and culm density and 3) initial height and number of culms had a positive influence on culm density and height after 3 growing seasons. The major takeaway was that much of the mortality was due to shoreline erosion of beach transplants that were missing and washed away. For greater survival, transplants of giant cane should be planted up slope from the beach and the normal pool elevation. It is important to plant outside of the zone which may experience regular flooding and/or wave action from boat traffic or winds. For long term growth, looking at soil parameters may be advantageous. Though giant cane has been shown to grow in various soil conditions, this study did see increased spread and number of culms where organic matter was ii greater and bulk density lower. Larger transplants should be favored to aid in greater future growth and establishment. The findings of this study can help guide the efforts of land managers in the successful establishment of giant cane on reservoir shorelines.

There is growing demand for food grown and sold locally, but climate often limits supply. High tunnels can often overcome these limitations. In order to encourage local availability and production of specialty crops the Natural Resource Conservation Service (NRCS) has launched the Seasonal High Tunnel initiative. This cost-share program provides farmers with a high tunnel intended to encourage the availability of locally grown fresh produce. Using mixed-methods research this thesis examines the social, economic, and conservation impacts of the NRCS high tunnel program. We have run a county by county negative binomial regression of the NRCS high tunnel distribution biophysical, socio-demographic, and market driven factors. Additionally, 7 vegetable farms throughout Virginia were visited during the 2014 growing season to compare high tunnel and field grown cucumbers (Cucumis sativus) and tomatoes (Solanum lycopersicum). Additional detail about high tunnel production and food distribution was obtained with a survey of Virginia high tunnel growers. Survey respondents indicate that the majority of their high tunnel produce is sold within 100 miles of their farm. Regression results indicate that the NRCS high tunnel program is benefiting areas where the availability of local food is high, but may be neglecting areas with historically underserved communities. Our field results show that yield and the yield per pesticide application dividend were higher in high tunnel production of both cucumber and tomato. Therefore, we conclude that, high tunnels meet conservation goals different than the ones outlined by the NRCS. The NRCS high tunnel program is promoting the expansion of local food availability. However, work remains to clarify conservational benefits and to ensure that all communities have equal access to the fresh produce they provide. / Master of Science

Thesis (PhD(Agric) (Horticulture))--University of Stellenbosch, 2005. / Bitter pit fruit in commercial consignments of apples still poses an economic threat to exporters from South Africa. Bitter pit develops pre-harvest, but gets progressively worse during storage and is only traceable once the lesions appear after storage. Accurate, early indications of bitter pit incidence will allow for remedial pre-harvest measures in the field, e.g. Ca foliar applications, to reduce the potential losses. Similarly, the automatic detection of a bitter pit fruit during packing will reduce financial losses by identifying unacceptable fruit before shipping. Fluorescence imaging is a fast, non-destructive technique, able to evaluate numerous fruits individually. Results of pre-harvest imaging on apples to identify fruit susceptible to bitter pit showed that pitted fruit were correctly classified, but misclassification of non-pitted fruit with fluorescence imaging was still too high. NIR-spectroscopy point meter readings could distinguish visible bitter pit lesions from healthy tissue. Important wavelengths associated with visible bitter pit were identified. This technique could also identify immature apples, more prone to bitter pit development. It could however not distinguish between bitter pit and non-pitted fruit when applied randomly on the calyx end of apples at harvest. Pre-harvest foliar applications to increase fruit Ca content and reduce bitter pit incidence, is a standard practice world wide. External Ca uptake by fruit was monitored to determine the efficacy of applications during different stages of fruit development. Two periods of efficient uptake of external Ca were identified, viz., cell division and the last few weeks before harvest. Foliar Ca applications from 40 days after full bloom were more effective in increasing fruit Ca content and reducing bitter pit incidence than at 80 days after full bloom, which was recommended previously. Mineral analysis of fruit has been used with variable success to predict bitter pit prior to harvest. The possibility of increasing the accuracy of existing predictive models by using analysis of individual fruit rather than pooled samples, was investigated. By improving the normality of different mineral distributions and decreasing the overlap between pitted and non-pitted fruit classes, it was attempted to improve the reliability of predictions based on variable threshold values. The Ca distribution showed a variation between pitted and nonpitted classes, but still a significant overlap between classes reduced the accuracy of the predictive capacity of this distribution. Even though our results produced a correct classification of 85% for non-pitted fruit, which can be useful, this was still below the required tolerance, of less that 2%, expected on the market. The effect of pruning and fruit bearing position on two-year-old wood on dry mass and Ca allocation of fruit was determined. ‘Golden Delicious’ fruit set was the lowest at the basal bearing position compared to the other positions evaluated and was contrary to expectations. Fruit in a terminal bearing position was superior to the basal position regarding total dry weight and fruit size. Distal wood possibly inhibited growth and set on the basal position via auxin distribution. Ca allocation differed between seasons and cultivars and could either be influenced by bearing position or presence or absence of re-growth.

Thesis (PhD(Agric) (Horticulture))--Stellenbosch University, 2008. / It is a common practise in the Western Cape to use micro sprinklers as the standard irrigation system for apple trees. Over the past forty years much effort has been put into the optimisation of the tree canopy. Less attention has been given to root proliferation, and the question as to whether root stimulation and proliferation, through intensive water and nutrient management, can contribute towards improved tree efficiency and more efficient water use. This is addressed in this study. ‘Brookfield Gala’ apple trees were studied in the Genadendal area near Greyton, in the Western Cape Province, South Africa. The trees were planted in Dundee soil (well aerated sandy loam soil) during winter 2003. Both horticultural aspects (tree growth, shoot growth, fruit yield and quality, trunk circumference and root growth) and gas exchange were studied from 2004/5 until 2007/8 under three different water application strategies, namely micro sprinkler irrigation, daily drip and pulsing drip irrigation and using two different rootstocks: M793 and M7. Irrigation under micro sprinkler irrigation was applied once to three times weekly, daily drip irrigation once daily/twice daily, and pulsing drip irrigation one to six times daily. Water use for bearing apple trees was calculated using long-term evaporation data (for Villiersdorp and Caledon) and existing crop factors for apples. Annual nutrient requirements were adapted from literature and divided percentage-wise into the requirements for five different phenological stages. Soil sensors were used to keep plant available soil water between 100% and 50%. A computer software program was used to incorporate all the above mentioned information and calculate the exact amounts of water and nutrients, and the application times. In general, drip irrigation systems used ±26% less water than micro sprinkler irrigation system. Significantly higher fruit yields were obtained with trees under daily or pulsing drip irrigation than those under micro irrigation during 2005/6 and 2007/8. During 2006/7 the crop load was low due to unfavourable weather conditions during flowering, resulting in poor fruit set and no differences in yield. There was a significantly higher number of thin plus medium roots (3mm and less in diameter) in the 0─400mm rooting zone and total root mass at 0─800mm rooting zone under drip irrigation systems than under micro sprinkler irrigation. Brookfield Gala’ apple trees grown under daily drip irrigation and pulsing drip irrigation performed better compared to those grown under micro sprinkler irrigation with respect to CO2 assimilation rate (A), stomatal conductance (gs), water use efficiency (WUE) and leaf water potential. None of the three irrigation systems affected the biochemical efficiency of the leaf significantly, except on a few occasions during the pre-harvest period. This implied that the changes in leaf biochemical efficiency were as a result of both stomatal and non-stomatal effects (temperature and vapour pressure deficit). The removal of fruit at harvest had a great influence on leaf photosynthetic capacity under micro irrigation but less so under drip irrigation systems. Higher chlorophyll a and chlorophyll b concentrations were observed under drip irrigation systems than under micro sprinkler irrigation, implying efficient biochemical efficiency under these systems compared to micro sprinkler irrigation during the post-harvest period. Use of daily drip irrigation and pulsing drip irrigation delayed the process of leaf ageing. This study demonstrated the benefits of more intensive water and nutrient application for apple trees. Improved root proliferation, increased fruit yield and photosynthetic efficiency have been found under drip irrigation system than under micro sprinkler irrigation.