Effect of exotic invasive old world climbing fern (lygodium microphyllum) on soil properties

Old World climbing fern (Lygodium microphyllum) has become one of the most serious ecological threats to the integrity of the greater Everglades ecosystem of south Florida. In this study, we analyzed the effects of Old World climbing fern on surfacesoil characteristics at invaded sites in Florida. We compared soil characteristics of six invaded and adjacent uninvaded plots at three different locations. Our results show that the fern can grow and thrive in a wide range of soil types and the impact on the soil was site specific with effects being more prominent in sites with low nutrient status. Additionally, there were significant differences in the soil nutrient status and microbial population in the invaded and uninvaded sites. Sites with Old World climbing fern had significantly higher nutrient concentrations that correlated with higher soil organic matter. Overall our results indicate that this exotic pest plant can potentially alter its below ground environment to its own benefit by enhancing the soil nutrient status by adding soil organic matter

Soil biotic and abiotic conditions negate invasive species performance in native habitat

Background: Most studies on plant invasion consider the enemy release hypothesis when analyzing native habitats. However, the lower performance of invasive species in the native habitats can be the result of unfavorable soil conditions in the native habitats. While soil biotic and abiotic factors have a potential to restrict the growth of invasive species in their native habitats, our understanding of belowground environment of invasive species in their native habitats is very limited. In this study, we analyzed soil characteristics associated with an exotic invasive plant, Old World Climbing Fern (Lygodium microphyllum), in its native habitat in Australia and the recipient habitat in South Florida. Rhizosphere soil samples from both habitats were analyzed for soil physical, chemical and biological characteristics. Results: Soil characteristics in the recipient habitats were significantly different compared to those in the native habitats. Soil samples from the native habitat had low soil pH, and high concentrations of elements such as aluminum and zinc which are phytotoxic in acidic soil environments. Additionally, mycorrhizal fungi spores were more diverse in the recipient habitat in Florida compared to the native habitat in Australia. Conclusion: Overall, our results indicate that growth of an invasive plant in its native habitats could be restricted by the toxic effects associated with strong soil acidity. Results from this study indicate that invasive plants not only escape from their natural herbivores but also from toxic soil environment in their native habitats

Data on foliar nutrient concentration of invasive plants in the recipient habitat and their native habitat

Higher foliar nitrogen concentration in plants is often attributed to higher biomass assimilation and subsequently higher plant growth rate. To understand the underlying mechanism of extensive growth rate of an invasive plant, Old World climbing fern (Lygodium microphyllum), we analyzed the leaf tissue samples from the native and invaded habitats. In each habitat we selected 3 different locations with varying habitat characteristics (soil type, land use history and coexisting vegetation). Plant aboveground tissue collected from each site were analyzed for macro and micro nutrients. Total C and N were measured with a Truspec CN Analyzer. Total Ca, Fe, Mg, K, Mn, and P in plant tissue samples were measured using inductively coupled plasma mass spectrometry (ICP eMS). Here we present the difference in foliar nutrient concentration of invasive plant species in their native habitats and invaded habitats

Effect of Salinity Stress and Microbial Inoculations on Glomalin Production and Plant Growth Parameters of Snap Bean (Phaseolus vulgaris)

Salinity is a major abiotic stress that can adversely affect plant growth, yield, other physiological parameters, and soil health. Salinity stress on biomass production of salt-sensitive crops, like snap bean (Phaseolus vulgaris), is a serious problem, and specifically in South Florida, USA, where saline soils can be found in major agricultural lands. Research studies focused on the ‘snap bean–Rhizobium–arbuscular mycorrhizal fungi (AMF)’ relationship under salinity stress are limited, and fewer studies have evaluated how this tripartite symbiosis affects glomalin production (GRSP), a glycoprotein released by AMF. A shade house experiment was conducted to elucidate the effects of three microbial inoculations (IC = inoculation control; IT1 = AMF and IT2 = AMF + Rhizobium) on three salinity treatments (SC = salinity control 0.6 dS m−1, S1 = 1.0 dS m−1, and S2 = 2.0 dS m−1) on snap bean growth and yield. Our results indicate that S2 reduced 20% bean biomass production, 11% plant height, 13% root weight, and 23% AMF root colonization. However, microbial inoculations increased 26% bean yield over different salinity treatments. Maximum salinity stress (S2) increased 6% and 18% GRSP production than S1 and SC, respectively, indicating the relative advantage of abiotic stress on AMF’s role in soil. Dual inoculation (IT2) demonstrated a beneficial role on all physiological parameters, biomass production, and GRSP synthesis compared to single inoculation (IT1) treatment with all three salinity levels

Influence of Land Use Intensity and Management on Arbuscular Mycorrhizal Fungi-Avocado Symbiosis

This study was done to assess the effect of soil disturbance on arbuscular mycorrhizal fungi spore abundance and root colonization in avocado (Persea americana Mill.). Rhizosphere soil and root samples of avocado were collected from different farms in south Florida and analyzed for degree of mycorrhizal colonization in roots, spore density and diversity in soil along with soil characteristics. There was significant difference in the soil characteristics among the different farms. Similarly, there was a significant difference in the degree of mycorrhizal colonization in the roots and the arbuscular mycorrhizal fungi spore morphotypes among different land use and management practices. However, there was no significant difference in the total number of arbuscular mycorrhizal fungi spores among these sites. There was no correlation between the number of arbuscular mycorrhizal fungi spores and soil characteristics. However, arbuscular mycorrhizal fungi colonization in roots were strongly influenced by soil characteristics such as soil moisture, carbon, nitrogen, and organic matter. Further research is necessary to identify these AMF species and determine the role of in avocado growth tolerance to anthropogenic disturbance in highly disturbed urban soils

In vitro efficacy of fungal endophytes and silver pyrazolate against Raffaelea lauricola, causal agent of laurel wilt of avocado

The South Florida avocado industry is being severely impacted by laurel wilt disease. Laurel wilt disease of avocado is caused by the fungal pathogen, Raffaelea lauricola (RL) and is vectored by ambrosia beetle, Xyleborus glabratus. Treatments options are limited, economically not sustainable, and require reapplication fungicides every couple of years. There is a crucial need for developing multiple modes of control using novel biological and chemical agents. The ambrosia beetle associated pathogenic fungi are known to outcompete other microorganisms by taking advantage of ethanol produced by the pathogen and the stressed tree. Endophytes, which reside inside the host plant tissue are part of the plant microbiome represent source of new potential biological control agents. In this study, three ethanol tolerant endophytic fungal species, isolated from avocado bark, were evaluated using in vitro dual culture assay and colonization tube (packed with bark/sapwood shaving) against RL. The endophytic isolates Tricoderma crissum, Tricoderma simmonsii, Lasiodiplodia theobromae were found to be highly capable of suppressing the mycelial colony growth of RL. The results suggest that combined abilities of ethanol tolerance and competitive colonization can provide useful criteria for identifying potential biocontrol agents. In vitro anti-RL activity of silver pyrazolate compound was assessed in both agar and liquid medium. Silver pyrazolate at levels of 30 and 45 ppm were found to be highly effective against RL. Further in planta research is needed to study the effects of endophytic fungal isolates and silver pyrazolate to assess their potential as additional tools for management of laurel wilt

Exploring Wireless Sensor Network Technology In Sustainable Okra Garden: A Comparative Analysis Of Okra Grown In Different Fertilizer Treatments

The goal of this project was to explore commercial agricultural and irrigation sensor kits and to discern if the commercial wireless sensor network (WSN) is a viable tool for providing accurate real-time farm data at the nexus of food energy and water. The smart garden consists of two different varieties of Abelmoschus esculentus (okra) planted in raised beds, each grown under two different fertilizer treatments. Soil watermark sensors were programed to evaluate soil moisture and dictate irrigation events up to four times a day, while soil temperature and photosynthetic solar radiation sensors also recorded data every six hours. Solar panels harvested energy to power water pump and sensors. The objectives of the experiments were to evaluate and compare plant and soil parameters of the two okra varieties grown under two different fertilizer treatments. The plant parameters evaluated and compared were basal diameter, plant height, fruit production, and fruit size. Soil parameters measured were soil moisture, soil temperature, and soil nitrate concentration. The commercial sensors were evaluated on efficiency, accuracy, ease of use and overall practicality. Clemson spineless produced larger okra plants with the highest plant parameter values, followed by Emerald okra. However, they both averaged nearly the same yield and length of okra fruit. Nature’s Care fertilizer leached more in beds containing Clemson spineless, while Garden-tone leached more in beds containing Emerald okra. When the WSN is installed properly, the system’s great performance undoubtedly aides the farmer by providing real time field data. However, a properly installed apparatus does not promise a stable system. There are numerous challenges and limitations of which can diminish the performance quality of the WSN, those being battery power, data transmission, and data storage. Data storage is also an issue depending on the amount of data collected, rate of data collection, and size of storage unit. These issues can hinder the decision making for precision farmers

The Effect of Saltwater Stress on the Performance of Cherry Tomatoes

Rising sea levels and saltwater intrusion in aquifers pose significant challenges for South Florida agriculture, leading to increased groundwater salinity and potential crop losses. Utilizing salttolerant crop species presents a potential solution for saline soils and regions with active saltwater intrusion. However, the effects of soil salinization through groundwater alone remains less studied. This research investigates the impact of short-term, below-ground saltwater stress on the growth, survival, and overall health of commonly grown cherry tomatoes (Solanum lycopersicum). The objectives of the study are to: 1) determine the impact of saline groundwater on tomato plant health and 2) compare the nutrient content of soil and tomato plant tissue exposed to varying concentrations of saline water. Established cherry tomato plants were exposed to varying concentrations of NaCl solution, simulating saltwater intrusion into groundwater. Over 28 days, plant height, leaf chlorophyll levels, and disease occurrences were monitored. It was found that the NaCl treatments did not significantly affect cherry tomato performance under the parameters of height, chlorophyll levels, or leaf nutrition when compared to the control group. This study suggests that cherry tomatoes can tolerate short-term exposure to NaCl in groundwater. Further exploration of more intense salt stress conditions from groundwater could be beneficial for utilizing this crop in areas with saline soils or polluted groundwater. Identification of salt-tolerant cherry tomato varieties can provide alternative crop options for non-arable land affected by high soil salinity

Effects of Control Release Fertilizers on Nutrient Leaching, Palm Growth and Production Cost

Objective of this study was to evaluate the effect of different controlled release fertilizer technologies on nutrient leaching and plant growth parameters of two palm species, Chinese Fan (Livistona chinensis) and Queen (Syagrus romanzoffiana). We compared Nutri-Pak (12-4-12 controlled release packet) and Harrell’s (12-4-12 controlled release polymer coated urea) against Atlantic (8-4-12 controlled release polymer coated urea, coated sulfate of potash), the most commonly used palm fertilizer in South Florida. Plants were grown in 25 cm (11 L) pots under 70% shade, watered weekly, with pest and weed control done as required. Plant growth parameters: number of leaves, leaf length and width, and basal diameter, were measured every two months. Leachate was collected weekly after irrigation and a two-month composite sample was analyzed for nutrient concentrations. There was no difference in the growth parameters among the three fertilizers for Chinese Fan plants. However for Queen, Atlantic and Harrell’s had significantly thicker basal diameter than Nutri-Pak. Significant difference in the concentration of nutrients in the leachate was observed among the fertilizer types. Throughout the study period, Nutri-Pak had a lower concentration of nutrients in the leachate than Atlantic and Harrell’s. Our research indicates that Nutri-Pak control release fertilizer is comparable to other commercial fertilizers in Chinese Fan growth, but the larger Queen palms likely require an additional packet. Nutri-Pak fertilizer resulted in less nutrient leaching and could be a better environmental choice

Mycorrhizal fungi status in organic farms of south Florida

TOPRAK, BULENT/0000-0001-6500-7885WOS: 000417937200002In the recent years, low input agriculture has gained high popularity and there is an emerging body of literature on the role of arbuscular mycorrhizal fungi in organic farming and its potential use in low input agriculture systems. This study was conducted to analyse mycorrhizal status of several 31 different plants in organically managed farms in south Florida: organic farm at the Florida International University and the organic fruit, farm Possum Trot. Rhizosphere soil was analysed for mycorrhizal spores and soil nutrients, and plant roots were analysed for mycorrhizal colonization status. Possum Trot, which is a less disturbed site, had higher mycorrhizal spore density in the soil as compared to the organic farm at the Florida International University, which gets highly disturbed with student activities. However, plants at the Florida International University organic farm had higher degree of mycorrhizal colonization in the roots. Of the 31-plant species analysed, Cymbopogen nardus had highest root colonization (75%), while Spinacia oleracea had no signs of mycorhrizal colonization in the roots. Surprisingly, although very low, arbuscular mycorrhizal colonization was observed in roots of Eruca sativa and Chrysophyllum cainito which are normally reported as non-host plants of mycorrhizal fungi. Arbuscular mycorrhizal spore density showed a negative correlation with soil N, while it had a positive correlation with soil P. Though spores of Glomus, Gigaspora, Acaulospora and Scutellospora were found in our study. Glomus were the dominant genera in the rhizosphere of plants grown in the organic farms. Our results indicate that disturbance did not have much impact on the mycorrhizal colonization in the roots, but did have an impact on the rhizosphere spore density. The high occurrence of mycorrhizal fungi in the organic farms of south Florida and potential for the use in organic farm management is discussed