Home Lawns Research Articles

Pesticide fate in sodded kentucky bluegrass lawns in response to irrigation

Fertilizers and pesticides applied to home lawns can contaminate surface and groundwater making them unfit for aquatic organisms and human consumption. Application of fertilizers and pesticides can improve the aesthetics of a home lawn, improve turfgrass shoot and root density, water use, organic matter accumulation, and other factors known to be influential in urban hydrology. A field study determined the impact of applying home landscape pesticides with or without supplemental irrigation of leaching into groundwater or runoff to surface water. Free-draining lysimeters having a sandy loam soil (coarse-loamy, mixed, active, mesic Lamellic Hapludalf) were used to monitor total volume and nutrients and pesticides losses. Samples from natural precipitation events were analysed for pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2, 6-dinitrobenzenamine] applied in spring, mecoprop [2-(4-Chloro-2-methylphenoxy) propionic acid]+2, 4-D (2,4-dichlorophenoxyacetic acid) applied both in late spring and early fall, and bifenthrin [(2-methyl-1,1-biphenyl-3-y1)-methyl-3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopropanecarboxylate] applied in late summer. Pesticide concentrations fluctuated over time, but no differences in concentrations were observed from irrigated or non-irrigated turfgrass for any pesticide. Mecoprop and 2,4-D were the most mobile and values found in runoff during establishment were above maximum contaminant levels (MCL) for U.S. standards. Surface runoff of lawn pesticides were observed at concentrations several magnitudes higher than leachate. The total extent of pesticide runoff was 0.71%, 1.3%, 6.0%, and 0.003% of the amount applied for 2,4-D, mecoprop, pendimethalin and bifenthrin, respectively. With the exception of one sampling period, pendimethalin concentrations in runoff and leachate were low; however, when applied during a period of minimal turf growth and high precipitation, pendimethalin could contribute significantly to surface water pollution.

Registration of ‘Mallard’ Kentucky Bluegrass

Kentucky bluegrass is a pseudogomous facultative apomict, requiring viable pollen to stimulate seed set. Since Kentucky bluegrass is a facultative apomict, low levels of sexuality occur that allow for hybridization and genetic recombination. ‘Mallard’ (Reg. No. CV‐100, PI 632598) Kentucky bluegrass (Poa pratensis L.) is a turf‐type cultivar released by the Pennington Seed (Athens, GA) in 2002. Mallard was selected as an open‐pollinated progeny of ‘Unique’ Kentucky bluegrass. Mallard is comparable with ‘Midnight’ (standard) in many turf characteristics, including turf quality and disease resistance. Mallard is significantly better in drought resistance compared with Unique (parent). The combination of these traits makes Mallard a unique, widely adapted, functional cultivar that should perform well in home lawns, golf courses, and municipalities in the Northeast, transition, North Central, and Upper West, and Mountain regions.

Assessment of Genetic Diversity of Bermudagrass (Cynodon dactylon) Using ISSR Markers

Bermudagrass (Cynodon spp.) is a major turfgrass for home lawns, public parks, golf courses and sport fields and is known to have originated in the Middle East. Morphological and physiological characteristics are not sufficient to differentiate some bermudagrass genotypes because the differences between them are often subtle and subjected to environmental influences. In this study, twenty seven bermudagrass accessions and introductions, mostly from different parts of Iran, were assayed by inter-simple sequence repeat (ISSR) markers to differentiate and explore their genetic relationships. Fourteen ISSR primers amplified 389 fragments of which 313 (80.5%) were polymorphic. The average polymorphism information content (PIC) was 0.328, which shows that the majority of primers are informative. Cluster analysis using the un-weighted paired group method with arithmetic average (UPGMA) method and Jaccard’s similarity coefficient (r = 0.828) grouped the accessions into six main clusters according to some degree to geographical origin, their chromosome number and some morphological characteristics. It can be concluded that there exists a wide genetic base of bermudograss in Iran and that ISSR markers are effective in determining genetic diversity and relationships among them.

Stolon Growth and Tillering of Experimental Zoysiagrasses in Shade

Zoysiagrass (Zoysia spp.) grown under shade on golf courses and in home lawns is slow to recover from damage and declines in quality over time. We evaluated stolon growth and tillering of ‘Meyer’ and Chinese Common (both Z. japonica Steud.); ‘Zorro’, ‘Diamond’, and ‘Cavalier’ [all Z. matrella L. (Merr.)]; ‘Emerald’ (Z. matrella × Z. pacifica Goudsw.); and six experimental progeny from ‘Emerald’ × Z. japonica and reciprocal crosses of Z. japonica × Z. matrella under silver maple (Acer saccharinum L.) shade and in full sun in 2008 and 2009 in Manhattan, KS. A single 6-cm diameter plug was planted in the center of 1.2 m × 1.2-m plots, and data were collected weekly on the number of stolons, stolon elongation, and number of stolon branches. Tiller number was collected at the start and end of each study period, and biomass (excluding roots) was determined at the end of each season. Zoysiagrasses under an average of 76% tree shade exhibited reductions of 38% to 95% in stolon number; 9% to 70% in stolon length; 10% to 93% in stolon branching; and 56% to 98% in biomass. Seven of the 10 grasses exhibited a decline in tiller number in each experiment; none of the grasses differed from ‘Meyer’ in percentage change in tiller number under shade. ‘Emerald’, ‘Cavalier’, ‘Zorro’, and several progeny from crosses between ‘Emerald’ × Z. japonica or reciprocal crosses of Z. matrella × Z. japonica produced more, longer, or more highly branched stolons than ‘Meyer’, suggesting they may have improved recovery potential in shade.

Nitrate production and availability in residential soils

The rapid increase in residential land area in the United States has raised concern about water pollution associated with nitrogen fertilizers. Nitrate (NO3-) is the form of reactive N that is most susceptible to leaching and runoff; thus, a more thorough understanding of nitrification and NO3(-) availability is needed if we are to accurately predict the consequences of residential expansion for water quality. In particular, there have been few assessments of how the land use history, housing density, and age of residential soils influence NO3(-) pools and fluxes, especially at depth. In this study, we used 1 m deep soil cores to evaluate potential net nitrification and mineralization, microbial respiration and biomass, and soil NO3(-) and NH4+ pools in 32 residential home lawns that differed by previous land use and age, but had similar soil types. These were compared to eight forested reference sites with similar soils. Our results suggest that a change to residential land use has increased pools and production of reactive N, which has clear implications for water quality in the region. However, the results contradict the common assumption that NO3(-) production and availability is dramatically higher in residential soils than in forests in general. While net nitrification (128.6 +/- 15.5 mg m(-2) d(-1) vs. 4.7 +/- 2.3 mg m(-2) d(-1); mean +/- SE) and exchangeable NO3(-) (3.8 +/- 0.5 g/m2 vs. 0.7 +/- 0.3 g/m2) were significantly higher in residential soils than in forest soils in this study, these measures of NO3(-) production and availability were still notably low, comparable to deciduous forest stands in other studies. A second unexpected result was that current homeowner management practices were not predictive of NO3(-) availability or production. This may reflect the transient availability of inorganic N after fertilizer application. Higher housing density and a history of agricultural land use were predictors of greater NO3(-) availability in residential soils. If these factors are good predictors across a wider range of sites, they may be useful indicators of NO3(-) availability and leaching and runoff potential at the landscape scale.

Selective Postemergence Herbicide Control of Torpedograss in Centipedegrass

Torpedograss infestation in centipedegrass has reduced centipedegrass quality in home lawns along the Gulf Coast. This study was conducted to evaluate three selective postemergence herbicides. Field trials were conducted at two sites in Louisiana to evaluate quinclorac, sethoxydim, and clethodim applied once or sequentially every 4 wk for selective torpedograss control in centipedegrass turf. Herbicides were applied to mixed stands of torpedograss/centipedegrass at two locations in Louisiana and evaluated for changes in torpedograss coverage and centipedegrass injury every 2 wk for 16 wk. All herbicides controlled torpedograss more with each sequential application. Sethoxydim and clethodim applied three times reduced torpedograss cover 84 and 87%, respectively, and more than quinclorac 12 wk after initial treatment (WAIT). Increasing clethodim or sethoxydim rates did not improve torpedograss control. Torpedograss regrowth occurred within weeks after final herbicide applications regardless of herbicide. Only multiple clethodim applied at twice manufacturer's labeled rate or quinclorac applications resulted in commercially unacceptable (> 25%) injury to centipedegrass. Multiple sethoxydim or clethodim applications at 0.32 kg ha−1or 0.30 kg ha−1every 4 wk reduced torpedograss competitiveness in centipedegrass; however, multiple applications for more than 1 yr might be necessary to achieve torpedograss control.

Bentgrass Distribution Surveys and Habitat Suitability Maps Support Ecological Risk Assessment in Cultural Landscapes

The bentgrasses comprise an adaptable group of grasses that include introduced species, cultivated turfgrasses, and native plants in North America. Their distribution in cultural landscapes has not been documented, and this gap in knowledge has limited the development of predictive ecological risk assessments for creeping bentgrass engineered for herbicide resistance. In this study, bentgrass distribution and abundance were surveyed in 289 plots in an 8.5 km2 site surrounding a golf course in the northeastern United States. Four introduced species and two native bentgrasses were identified in seminatural and managed plant communities. Across the study site, 77% of the plots containing creeping bentgrass also had invasive plants. Bentgrasses co-occurred with critical habitat for threatened or endangered animals. Multivariate logistic regression analysis showed that bentgrasses were positively correlated with herbaceous plant cover and mowing, but negatively correlated with tree canopy cover, shrub cover, poorly drained soils, and leaf litter. The most influential ecological factors were tree canopy cover and soil moisture. Geospatial information about these two ecological factors was combined with mathematical models to generate two habitat suitability maps. The favorable environments map (FEM) showed that highly suitable bentgrass habitat covered 36% of the study site and included common features such as home lawns and railroad right-of-ways. Our results suggest that release of herbicide-resistant creeping bentgrass in this cultural landscape could potentially result in pollen-mediated gene flow, interspecific hybridization, environmental hazards, and herbicide selection pressure in some areas. Habitat suitability maps could be critical tools for predictive ecological risk assessments, monitoring projects, and management of herbicide-resistant bentgrasses.

Modeling Carbon Sequestration in Home Lawns

Soil organic carbon (SOC) sequestration and the impact of carbon (C) cycling in urban soils are themes of increasing interest. A model was developed to investigate the potential of C sequestration in home lawns. The model contrasted gross C sequestered versus the hidden C costs (HCC) associated with typical lawn maintenance practices. The potential of SOC sequestration for U.S. home lawns was determined from SOC sequestration rates of turfgrass and grasslands. Net SOC sequestration in lawn soils was estimated using a simple mass balance model derived from typical homeowner lawn maintenance practices. The average SOC sequestration rate for U.S. lawns was 46.0 to 127.1 g C/m2/year. Additional C sequestration can result from biomass gains attributable to fertilizer and irrigation management. Hidden C costs are the amount of energy expended by typical lawn management practices in grams of carbon equivalents (CE)/m2/year and include practices including mowing, irrigating, fertilizing, and using pesticides. The net SOC sequestration rate was assessed by subtracting the HCC from gross SOC sequestration rate. Lawn maintenance practices ranged from low to high management. Low management with minimal input (MI) included mowing only, a net SOC sequestration rate of 25.4 to 114.2 g C/m2/year. The rate of SOC sequestration for do-it-yourself (DIY) management by homeowners was 80.6 to 183.0 g C/m2/year. High management, based on university and industry-standard best management recommendation practices (BMPs), had a net SOC sequestration rate of 51.7 to 204.3 g C/m2/year. Lawns can be a net sink for atmospheric CO2 under all three evaluated levels of management practices with a national technical potential ranging from 25.4 to 204.3 g C/m2/year.

Centipedegrass for Florida Lawns

Centipedegrass is a slow-growing grass with low fertility requirements when compared to other Florida lawn grasses. It grows close to the ground, is medium textured, and is naturally lighter in color than other lawn grasses. Well-adapted to the climate and soils of Central and Northern Florida, it is the most common home lawn grass in the Florida Panhandle. There is now one cultivar adapted to South Florida conditions. This revised 7-page fact sheet discusses the advantages and disadvantages of this turfgrass variety, cultivars available for lawn use in Florida, establishment, maintenance, pest management, and other problems. Written by J. B. Unruh, L. E. Trenholm, and J. L. Cisar and published by the UF Department of Environmental Horticulture, April 2011. ENH8/LH009: Centipedegrass for Florida Lawns (ufl.edu)

Accumulation of Carbon and Nitrogen in Residential Soils with Different Land-Use Histories

Urban areas are growing in size and importance; however, we are only beginning to understand how the process of urbanization influences ecosystem dynamics. In particular, there have been few assessments of how the land-use history and age of residential soils influence carbon (C) and nitrogen (N) pools and fluxes, especially at depth. In this study, we used 1-m soil cores to evaluate soil profile characteristics and C and N pools in 32 residential home lawns that differed by previous land use and age, but had similar soil types. These were compared to soils from eight forested reference sites. Residential soils had significantly higher C and N densities than nearby forested soils of similar types (6.95 vs. 5.44 kg C/m2 and 552 vs. 403 g N/m2, P < 0.05). Results from our chronosequence suggest that soils at residential sites that were previously in agriculture have the potential to accumulate C (0.082 kg C/m2/y) and N (8.3 g N/m2/y) rapidly after residential development. Rates of N accumulation at these sites were similar in magnitude to estimated fertilizer N inputs, confirming a high capacity for N retention. Residential sites that were forested prior to development had higher C and N densities than present-day forests, but our chronosequence did not reveal a significant pattern of increasing C and N density over time in previously forested sites. These data suggest that soils in residential areas on former agricultural land have a significant capacity to sequester C and N. Given the large area of these soils, they are undoubtedly significant in regional C and N balances.

Water Use of St. Augustinegrass and Bahiagrass under Varying Nitrogen Rates

In Florida, state agencies are concerned about St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] for being a possible high water user and excess (N) applications in home lawns. This has resulted in a desire by some municipalities to substitute St. Augustinegrass with bahiagrass (Paspalum notatum Flügge). Consequently, the aim of this study was to determine the effect of different N fertilizer rates on water use and turf quality of bahiagrass and St. Augustinegrass commonly used in residential yards. The experiment was a split‐plot randomized complete block design repeated over two trials. Whole plots arranged in blocks consisted of either bahiagrass cultivar ‘Pensacola’ or St. Augustinegrass cultivar ‘Floratam’. Subplots consisted of two N rates (98 and 294 N kg ha−1 yr−1). Water use rates, was influenced by grass type and by N rates with bahiagrass having higher water use rates (WURs) than St. Augustinegrass in one of the two trails. The high N rate increased turfgrass WURs but only in Trial 1. In both trials clipping yields (CY) were greater for bahiagrass than St. Augustinegrass. Furthermore, the higher N rate produced greater CY than the lower N rate. All treatments produced acceptable turfgrass quality when averaged for each trial though, not for ever cycle. Bahiagrass generally produced superior quality ratings than St. Augustinegrass. In addition, the higher N rate always produced higher quality scores than the lower N rate.

형질전환 들잔디 개발의 최근 동향

Zoysiagrass (Zoysia japonica Steud.), also called Korean or Japanese lawngrass, is the most popular warm-season turfgrass in Korea and is widely used for home lawns, parks, roadsides, golf courses and athletic fields. Its use is rapidly expanding in Korea and the other countries, due to its excellent characteristics which include tolerance to heat, drought and salinity. As the utilization area of this turfgrass increases, there is an increase in the demand for improved cultivars with disease and insect tolerance or with herbicide-tolerance or with extended greening periods. Conventional breeding methods have been used to improve the traits described above with limited success. However, with the advances in biotechnology, genetic transformation can be utilized for turfgrass improvement. In this paper, we review recent progress in biotechnological improvement of zoysiagrass and discuss future molecular breeding of this species.

Osmotic Potential, Sucrose Level, and Activity of Sucrose Metabolic Enzymes in Tall Fescue in Response to Deficit Irrigation

Effects of deficit irrigation applied to home lawns, used as means of water conservation, are an important issue. However, the impact of deficit irrigation on sucrose metabolism in tall fescue (Festuca arundinacea) is unknown and important because sucrose is the dominant form of carbohydrate transported to developing plant organs. The objectives of this study were to investigate the effects of deficit irrigation on leaf water content, osmotic potential (ψS), sucrose level, and the activity of sucrose phosphate synthase (SPS; EC 2.4.1.14), sucrose synthase (SS; EC 2.4.1.13), and acid invertase (AI; EC 3.2.1.26) in tall fescue leaves. Sods of ‘Falcon II’ tall fescue were established in polyvinylchloride (PVC) tubes (10 cm diameter × 40 cm long) filled with a mixture of sand and fritted clay [9:1 (v:v)] and then placed in growth chambers. Reference evapotranspiration rate [ETo (millimeters of water per day)] was determined by weighing the PVC tubes containing well-watered turfgrass every 3 days to determine water loss on a daily basis as ETo. Deficit irrigation treatments were applied as follows: well-watered control, mild drought stress (60% ETo), and severe drought stress (20% ETo). Leaf water content was lower at 6, 12, and 20 days of treatment for the 20% ETo treatment and 20 days after treatment began for the 60% ETo treatment. Compared with the well-watered control, ψS was lower in the 60% ETo treatment on all three measurement dates. Sucrose was higher at 8 and 14 days after treatment began in the 60% ETo treatment and on all three measurement dates in the 20% ETo treatment relative to the well-watered control. No difference in sucrose level was observed between the 20% ETo and 60% ETo irrigation regimes at 8 and 14 days of treatment. Beginning 14 days after treatment, tall fescue had a higher level of SPS in the 60% ETo and 20% ETo treatments compared with the well-watered treatment. Tall fescue receiving 60% or 20% ETo had a lower level of AI activity on all measurement dates. Results suggest that the decrease in ψS was accompanied by higher sucrose levels, which were the result of the increased level of SPS and SS activity and a decline in AI activity.

Morphological mutants of St. Augustinegrass induced by gamma ray irradiation

With 3 figures and 3 tables Abstract St. Augustinegrass is a widely used turf and pasture grass in the southern US. ‘Raleigh’ is a cultivar known for superior cold tolerance than other St. Augustinegrass cultivars. However, its coarse-leaf texture and long internodes are undesirable when planted in home lawns. Mutagenesis by gamma ray irradiation was employed to treat node cuttings and calli for inducing semi-dwarf growth phenotype. Dosages of 48.5 and 72.6 Gy were determined as LD50 and LD20 for the cuttings, respectively. Regeneration ability of callus was greatly reduced when irradiated with higher dosages (over 100 Gy). Thirteen morphological mutants were identified among over 3000 node cuttings and 80 pieces of calli treated. Most mutants were semi-dwarf type with reduced internode length and leaf blade length. One mutant had much less and shorter stolons and displayed an upright and tufty growth pattern. The altered morphological traits were stable as shown by their growth performance in various locations and conditions.

Cultivar Response of Seeded Bermudagrass to Leaf Spot and the Influence of Nitrogen on Disease Severity

Seeded bermudagrass [Cynodon dactylon (L.) Pers.] cultivars are currently replacing hybrid-bermudagrass and cool-season turfgrasses in some golf course renovations, home lawns, and athletic fields. Leaf spot, a destructive disease of bermudagrass, is caused by a fungal complex consisting of Bipolaris and Exserohilum spp. that infect leaves, stems, and stolons resulting in leaf blight and melting-out. A three-year field study was conducted to determine the response of seven seeded bermudagrass cultivars to leaf spot and the influence of nitrogen on leaf spot severity. Princess-77, Riviera, and Yukon were determined to have improved field tolerance to leaf spot. Transcontinental and Savannah cultivars displayed moderate disease response while Nu-Mex Sahara and Arizona Common had poor field tolerance to leaf spot. Seeded bermudagrass cultivars with poor field tolerance to leaf spot displayed increased leaf spot severity in response to high nitrogen (2.0 lb N per 1000 ft2 per month). Leaf spot severity of Arizona Common increased at the highest nitrogen level. Nitrogen levels did not influence leaf spot severity in seeded bermudagrass cultivars that had improved field tolerance. Princess-77, Riviera, and Yukon had the lowest leaf spot severity throughout the growing season each year of the three-year study.

Comparison of Soil P Test Procedures for St. Augustinegrass

St. Augustinegrass [Stenotaphrum secondatum (Walt.) Kuntze] is a home lawn grass widely used in the southern United States. At present, phosphorus (P) fertilization of St. Augustinegrass is based primarily on Mehlich 1 P test. One criticism of Mehlich 1 extractant is that it extracts some fraction of soil P pool that is not available to plants, whereas, iron (Fe) oxide P and water‐extractable P methods are reported to be better related to plant growth in some cases. Literature relative to the soil test procedure comparison for St. Augustinegrass was not found. The objective of this study was to evaluate Mehlich 1 P, Fe oxide P, and water‐extractable P to identify the most suitable soil test method for St. Augustinegrass growth. Established pots of ‘Floratam’ were subjected to P application of 0, 0.14, 0.27, 0.54, and 1.07 g m−2 every 4 wk for 12 wk. Measurements included tissue growth rates, tissue P concentration, soil Mehlich 1 P, Fe oxide P, and water‐extractable P concentrations. Phosphorus application increased soil test P concentrations. Soil Mehlich 1 P, Fe oxide P, and water‐extractable P concentrations were closely correlated to each other. Three soil test P levels and tissue P concentrations were highly correlated with Mehlich 1 P, which best predicted tissue P levels. Three soil test P levels were also closely correlated to the St. Augustinegrass top growth rate. Critical minimum Fe oxide P and water‐extractable P concentration was 3 mg kg−1. Overall, Mehlich 1 P was the best soil P test for St. Augustinegrass among the three extractants tested.

Registration of ‘Bedazzled’ Kentucky Bluegrass

Apomictic reproduction makes breeding Kentucky bluegrass (Poa pratensis L.) challenging. It is often difficult to identify a cultivar with the right combination of traits that will be successful in the marketplace. ‘Bedazzled’ Kentucky bluegrass (Poa pratensis L.) (Reg. No. CV‐94, PI 631168) is a turf‐type cultivar released by Turf Merchants Inc., Tangent, OR, in 2002. It was selected as an open‐pollinated progeny of ‘Unique’ Kentucky bluegrass. Bedazzled is comparable to ‘Midnight’ Kentucky bluegrass (the top industry standard) in many characteristics, including turf quality and disease resistance; however, Bedazzled has significantly better spring green‐up compared to Midnight. This combination of traits makes Bedazzled a unique, widely adapted, functional cultivar that should perform well on home lawns, athletic fields, parks, and golf courses in the Northeast, North Central and Intermountain West regions of the United States.

Heterogeneous Distribution of Weedy Paspalum Species and Edaphic Variables in Turfgrass

Dallisgrass (Paspalum dilatatum Poir.) and bahiagrass (Paspalum notatum Fluegge) are two of the most troublesome weed species in managed turfgrass. These rhizomatous, perennial grass species affect appearance, texture, and playability of turf in home lawns, golf courses, and athletic fields. The severity and prevalence of these problem species as well as the difficulty of achieving control with herbicide management alone invite the examination of their realized niches for clues to improved management tactics. The distribution of these species was evaluated in both fairways and roughs of three holes on each of two golf courses in North Carolina. Golf courses were selected based on the presence of both weed species. Individual plants were mapped using a high-precision global positioning system unit. This unit was also used to delineate between the rough and fairway height of cut as well as obtain elevation characteristics of each hole. Soil moisture and soil compaction estimates were obtained by sampling on a 9-m grid. Environmental characteristics used for χ2 analysis consisted of mowing height, soil compaction, soil moisture, and elevation. Data were subjected to χ2 analysis to determine if the existing distribution of Paspalum spp. differed from an expected random distribution across all environmental factors. Bahiagrass growth and distribution was more affected by mowing height than dallisgrass. Bahiagrass was predominantly distributed in the rough, whereas dallisgrass occurred at both mowing heights. Similar responses were observed for both species with regard to soil compaction. Higher plant density for both species was observed in moderately compacted soil (40 to 60 N·m−2). Bahiagrass distribution was unaffected by soil moisture. Dallisgrass density was lower in areas with low volumetric soil water content (less than 27%). Although different from an expected uniform distribution on all six holes, the elevation with the highest Paspalum spp. density varied across holes. Results suggest that it may be possible to disadvantage Paspalum spp. in competitive interactions with desirable species through the alteration of landscape attributes. Substrate selection during construction, aeration, and mowing height may help create a landscape that discourages Paspalum spp. infestation.

Comparative impacts of white grub (Coleoptera: Scarabaeidae) control products on the abundance of non-target soil-active arthropods in turfgrass

A study was conducted over 3 years on an experimental home lawn to detect, measure and contrast the effects of white grub (Coleoptera: Scarabaeidae) control products on the abundance of soil-active arthropods. Both short-term effects (those caused by a single application) and cumulative effects (those attributed to repeated yearly applications) were evaluated for five different control regimes: trichlorfon, imidacloprid, halofenozide, entomopathogenic nematodes and elemental sulfur. Treatments were applied to replicated plots (10 m×10 m) from 2000 to 2002. Invertebrates were sampled monthly from July to October in 2001 and 2002 by extracting soil cores in modified Tullgren funnels. All 293,868 captures were identified to class (arthropods) and order (hexapods). Overall extraction rate was 37,772 individuals/m2 of turf and associated topsoil. The ten most abundant taxa were analyzed in more detail to compare impacts across treatments. A consistent short-term effect due to individual applications was not detected. But when data were examined across both seasons, a significant cumulative effect of treatment was detected for total hexapods, Collembola, Thysanoptera and Coleoptera adults, but not oribatid mites, non-oribatid mites, Hymenoptera, Hemiptera, Coleoptera larvae or Diptera. Contrary to predictions, only imidacloprid – a systemic neonicotinoid applied early in the life cycle to target neonate white grubs – had a discernible impact on non-target abundance. Relative to the untreated check, it suppressed the abundance of those broad taxonomic groups by 54–62%. The implications of these results are discussed with respect to their functional relevance and to the role of neonicotinoids for white grub management in turfgrass.

Weed Management in Home Lawns

Revised! ENH-884, a 9-page fact sheet by J. Bryan Unruh, Barry Brecke, and Laurie E. Trenholm, provides homeowners with information to carry out a carefully planned and coordinated weed control program for their lawns. Describes types of weeds, proper lawn management, weed biology and control, weed control prior to turf establishment and in established turf, and pesticide application procedures. Published by the UF Department of Environmental Horticulture, April 2008. ENH884/EP141: Weed Management Guide for Florida Lawns (ufl.edu)