Biodiversity is in rapid decline, but the extent of loss is not well resolved for poorly known groups. We estimate the number of extinctions for Australian non-marine invertebrates since the European colonisation of the continent. Our analyses use a range of approaches, incorporate stated uncertainties and recognise explicit caveats. We use plausible bounds for the number of species, two approaches for estimating extinction rate, and Monte Carlo simulations to select combinations of projected distributions from these variables. We conclude that 9,111 (plausible bounds of 1,465 to 56,828) Australian species have become extinct over this 236-year period. These estimates dwarf the number of formally recognised extinctions of Australian invertebrates (10 species) and of the single invertebrate species listed as extinct under Australian legislation. We predict that 39–148 species will become extinct in 2024. This is inconsistent with a recent pledge by the Australian government to prevent all extinctions. This high rate of loss is largely a consequence of pervasive taxonomic biases in community concern and conservation investment. Those characteristics also make it challenging to reduce that rate of loss, as there is uncertainty about which invertebrate species are at the most risk. We outline conservation responses to reduce the likelihood of further extinctions.

Two introduced carnivores, the European red fox Vulpes vulpes and domestic cat Felis catus, have had extensive impacts on Australian biodiversity. In this study, we collate information on consumption of Australian birds by the fox, paralleling a recent study reporting on birds consumed by cats. We found records of consumption by foxes on 128 native bird species (18% of the non-vagrant bird fauna and 25% of those species within the fox’s range), a smaller tally than for cats (343 species, including 297 within the fox’s Australian range, a subset of that of the cat). Most (81%) bird species eaten by foxes are also eaten by cats, suggesting that predation impacts are compounded. As with consumption by cats, birds that nest or forage on the ground are most likely to be consumed by foxes. However, there is also some partitioning, with records of consumption by foxes but not cats for 25 bird species, indicating that impacts of the two predators may also be complementary. Bird species ≥3.4 kg were more likely to be eaten by foxes, and those <3.4 kg by cats. Our compilation provides an inventory and describes characteristics of Australian bird species known to be consumed by foxes, but we acknowledge that records of predation do not imply population-level impacts. Nonetheless, there is sufficient information from other studies to demonstrate that fox predation has significant impacts on the population viability of some Australian birds, especially larger birds, and those that nest or forage on the ground.

A comparative study of the growth and development of several populations of dinitroaniline-susceptible (DS) and -resistant (DR) goosegrass [Eleusine indica (L.) Gaertn. # ELEIN] biotypes was conducted under noncompetitive field conditions. Plant height and width, number of tillers, aboveground dry weight, relative growth rate (RGR), number of inflorescences/plant, total inflorescence dry weight, individual inflorescence dry weight, number of spicate branches/inflorescence, and flag leaf length and width were recorded periodically during the growing season. There were no significant differences between biotypes in most characteristics with the exception of total inflorescence dry weight. The DS biotype produced more total inflorescence dry weight than the DR biotype at 8 and 13 weeks after transplanting. Significant variation among DS and DR populations occurred in 37 and 33 of 56 evaluations, respectively. When variation existed within a biotype, populations exhibited broad ranges of response for the various growth parameters. With the exception of total inflorescence dry weight, DS and DR biotypes generally exhibited similar ranges of variability.

Seed dormancy and soil longevity characteristics of three weedy cowpea [Vigna unguiculata (L.) Walp.] cultivars were investigated. Seed germination was maximum at 40 C; however, ‘Clay’ had greater germination than ‘Black’ or ‘Red Ripper’ cowpea at temperatures ≥ 20 C. Concentrated sulfuric acid soaks, hot (70 C)-water soaks, and piercing the seed coat promoted germination. Seed with an initial water content of 12.3% were stored at relative humidities ranging from 0 to 60% at 25 C. After 4 weeks of storage at relative humidities of 0 to 50%, seed water content varied from 4.6 to 11.4%. Germination and hard seed content was 11% or more and 89% or less, respectively, for seed with water content ranging from 6.9 to 11.4%. Except for seed with an initial water content of 6.9%, cowpea seed water content increased after 3 weeks of storage in a 70% relative humidity environment. Rehydration increased germination for seed with initial water content of 9.2% or more, but not for seed with initial water content of 8.4% or less. In mid-November 1981 and 1982, Black, Clay, Red Ripper, and sicklepod (Cassia obtusifolia L. # CASOB) seed were buried at soil depths of 2.5, 7.5, and 15 cm for 3, 6, and 9 months. Seed survival of Black and Red Ripper was similar to that of sicklepod; however, longevity of Clay seed was less than sicklepod. Survival was greater for seed buried in 1981 than in 1982 because of low seed water content of the 1981 seedlots.

Plant growth regulators paclobutrazol and flurprimidol were evaluated for suppression of Poa annua spp. reptans, a perennial biotype of annual bluegrass, in a creeping bentgrass green. Paclobutrazol at 0.6 kg ai/ha applied on Mar. 15, followed by 0.3 kg/ha on Apr. 29, 0.6 kg/ha on Oct. 1, and 0.3 kg/ha on Nov. 12 for each of 2 yr suppressed P. annua spp. reptans 28% approximately 4 mo after the final treatment. When paclobutrazol was applied at 0.3 kg/ha in each of four applications during the same period, suppression was similar to that with the higher rate 1 and 2 mo after final treatment but declined to 7% by 4 mo. Suppression of P. annua spp. reptans from flurprimidol applied four times during each of 2 yr was 22 to 27% 1 mo after final treatment but no suppression was noted 2 mo after the final treatment. Maximum creeping bentgrass injury was less than 20% when either paclobutrazol or flurprimidol was applied in the spring. However, creeping bentgrass injury was approximately 30% in the fall when either chemical was applied in the spring and repeated in October at 0.6 kg/ha.

The presence of a dinitroaniline-resistant biotype of goosegrass [Eleusine indica (L.) Gaertner. ♯3 ELEIN] was confirmed in the northeastern area of South Carolina. It was also found in seven adjoining counties. It showed resistance to seven dinitroaniline herbicides but not to herbicides from six other chemical groups. One biotype was not affected by trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) at 3.4 kg ai/ha where a dinitroaniline-susceptible biotype was controlled at 0.3 kg/ha. Under similar conditions, another biotype showed resistance to trifluralin at 0.6 kg/ha but was controlled at 1.1 kg/ha, indicating that at least two unique biotypes may exist.

Sequential applications of MSMA plus metribuzin with selected plant growth regulators interacted synergistically and increased injury of ‘Tifway’ bermudagrass 1 and 2 wk after treatment. However, the higher injury at 3 wk after treatment, from sequential MSMA plus metribuzin with flurprimidol plus mefluidide or paclobutrazol with mefluidide, was additive. The vegetative growth suppression of bermudagrass at 2 wk after treatment with 2,4-D plus mecoprop plus dicamba with flurprimidol was antagonistic. The higher growth suppression 2 wk after treatment for MSMA plus metribuzin and flurprimidol plus mefluidide was additive compared to flurprimidol with mefluidide alone.

HERB, a computer-based expert system for soybean weed management developed at North Carolina State University, was evaluated for managing weeds under Georgia conditions. The project was initiated in two phases: a) training Cooperative Extension county agents followed by evaluation in six Georgia counties and b) revision, licensing, and distribution across the state. Field evaluations indicated that HERB was not highly accurate for predicting final yield loss because of weed species senescence and environmental extremes later in the growing season. HERB generally provided a reasonable prediction for a positive economic return due to treatment approximately 60% of the time. Accuracy was directly dependent upon the accuracy of weed-free yield estimates and extremes in growing conditions. HERB should not be the sole source of weed management information but may be useful to producers and county agents where mixed or low populations of weeds exist. The program was distributed statewide in 1993 after revision, duplication, and training was completed.

Preemergence herbicides were applied on February 28 at the recommended and three times the normal rate to determine the tolerance of tall fescue that was seeded in September, October and November of the preceding year. Fall seeding date of tall fescue significantly affected its tolerance to spring-applied preemergence herbicides. Generally, preemergence herbicides at normal rates were safe to apply to September- or October-seeded tall fescue. No herbicide was completely safe to apply to November-seeded tall fescue. The density of November-seeded tall fescue was generally reduced less with benefin, bensulide, dithiopyr, oxadiazon G and WP than with benefin plus oryzalin, oryzalin, or pendimethalin.

Studies were conducted to measure the foliar activity of sethoxydim (BAS 9052 OH) {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl-3-hydroxy-2-cyclohexen-1-one} and RO-13-8895 {acetone-O-[D-2-[p-[(α,α,α-trifluoro-p-tolyl)-oxy] phenoxy] propionyl] oxime} as affected by adjuvants, soil moisture, and growth stage of grasses, and to compare the responses of three grass species to these herbicides. The activity of both herbicides was increased by adjuvants. The activity of sethoxydim was not significantly affected by soil moisture. Goosegrass [Eleusine indica (L.) Gaertn. ♯3 ELEIN] and broadleaf signalgrass [Brachiaria platyphylla (Griseb. ♯ BRAPP) Nash] control was greater with RO-13-8895 at the high than at the low soil moisture level. Soil moisture did not influence large crabgrass [Digitaria sanguinalis (L.) Scop. ♯ DIGSA] control, since it was relatively tolerant to RO-13-8895. Both herbicides gave greater control at early than at late growth stages. When averaged over all variables, sethoxydim gave greater large crabgrass control than RO-13-8895, but RO-13-8895 gave greater goosegrass and broadleaf signalgrass control than sethoxydim.

Paclobutrazol and flurprimidol were evaluated for suppression of a perennial subspecies of annual bluegrass in a creeping bentgrass green. Three applications of paclobutrazol in the spring (Mar. 17, Apr. 17, and May 17) followed by three applications in the fall (Oct. 2, Nov. 2, and Nov. 30) suppressed the perennial subspecies ≥ 72% at 3 wk after the final treatment. However, suppression was reduced to ≤ 57% by 4 mo after the final fall application. Flurprimidol applied in three spring and three fall applications did not suppress the perennial subspecies as effectively as paclobutrazol. Suppression was ≤ 47% at 3 wk after the final flurprimidol treatment and was only ≤ 20% by mid-March. Neither chemical injured creeping bentgrass greater than 20% in the spring. However, leaf discoloration injury from the initial October application ranged from 26 to 30% for paclobutrazol in 1993 and 21 to 28% for flurprimidol in 1994. When injury occurred in October it was temporary and the creeping bentgrass recovered within 3 to 4 wk. Paclobutrazol and flurprimidol applied in November did not injure creeping bentgrass.

Acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid} applied 7 days after cowpea [Vigna unguiculata (L.) Walp.] emergence (unifoliolate leaf stage) gave better control than later applications. Cowpea control was obtained with one acifluorfen application at 7 days after cowpea emergence in 1981, but in 1980 and 1982, applications at 7 and 14 days were necessary for acceptable control (> 80%). Acifluorfen reduced cowpea plant dry weights relative to the weedy control. A single application 7 days after emergence reduced cowpea plant growth more than one at 21 days after emergence. Of all times of application, the greatest soybean [Glycine max (L.) Merr.] injury occurred when acifluorfen was applied at 7, 14, and 21 days after emergence, but seed yields were not reduced relative to the untreated weed-free control. There was no difference in response among three weedy cowpea cultivars to acifluorfen.

Field experiments were conducted in 1989 and 1990 to evaluate the tolerance of ‘Penncross' creeping bentgrass and ‘Tifway’ bermudagrass fall-overseeded with perennial ryegrass to irrigation water containing simazine. Creeping bentgrass was more sensitive to simazine than the bermudagrass/ryegrass mixture. The predicted critical simazine concentration necessary to reduce creeping bentgrass quality ≤ 60% was 0.22 mg L–1 which corresponded to a cumulative simazine rate of 98 g ha–1. For bermudagrass/ryegrass, the predicted critical simazine concentration and cumulative simazine rate that reduced quality ≤ 60% was 0.68 mg L–1 and 306 g ha–1, respectively.

Bermudagrass [Cynodon dactylon (L.) Pers.] control for at least 1 yr is necessary to establish other forage species in pasture and hay field renovations, or to plant pine (Pinus spp.) in infested fields. Potential herbicides for hybrid Bermudagrass control were evaluated using single, repeat, and multiyear applications. Repeat applications were made 30 d after the first application beginning in mid-August each year. Imazapyr applied once at 0.56 or 1.12 kg/ha controlled hybrid Bermudagrass (cv. ‘Tifton 44’) 88 and 97%, respectively, 52 wk after treatment with no difference between rates observed. Additionally, imazapyr applied for two consecutive years controlled hybrid Bermudagrass 100%. Glyphosate isopropylamine salt and glyphosate trimethylsulfonium salt, applied for 1 yr at rates of 4.2 or 1.7 fb (followed by) 1.7 kg ae/ha and 4.8 or 1.9 fb 1.9 kg ae/ha, respectively, provided between 70 and 78% control at 52 wk after the last treatment (WALT). Hybrid Bermudagrass control from either formulation of glyphosate applied for two consecutive years ranged between 79 and 91% at 52 WALT. Relative to a 1-yr application program, either glyphosate formulation applied for two consecutive years did not significantly improve Bermudagrass control at 52 WALT. The addition of fluazifop-P at 0.42 kg ai/ha or clethodim at 0.2 kg ai/ha to glyphosate formulations did not significantly improve hybrid Bermudagrass control relative to glyphosate applied alone. However, a tank-mix of clethodim plus either formulation of glyphosate applied for two consecutive years generally improved hybrid Bermudagrass control relative to applications in only 1 yr.

Centipedegrass is a warm-season turf grass that has increased in popularity in recent years. However, more information is needed on the use of herbicides during centipedegrass establishment from seed, particularly in seed and sod production systems. The intent of this study was to evaluate turf-grass injury and weed control when atrazine, imazapic, imazethapyr, and simazine are applied immediately after seeding centipedegrass. Atrazine and simazine (applied at 1.1, 2.2, and 4.4 kg ai/ ha) injured centipedegrass less than 15% at 5 wk after treatment (WAT) in 2001. Imazethapyr and imazapic (applied at 0.04, 0.07, and 0.1 kg ai/ha) injured centipedegrass between 7 and 13%, 5 WAT, in 2001 and from 30 to 77% in 2002. Herbicide and application rate also affected centipedegrass cover. At 3 WAT, cover decreased with all herbicides as application rate increased. At 12 WAT in both years, centipedegrass cover increased as atrazine application rate increased and imazethapyr application rate decreased. Imazapic and simazine were less consistent, causing increases in cover one year and decreases, or no change, the next. Imazapic controlled Texas panicum 80 to 89% and was more effective than any other herbicide. Atrazine and simazine controlled crowfootgrass better than any other herbicide. Imazethapyr often injured centipedegrass and failed to control weeds. Atrazine effectively controlled grass and broadleaf weeds with minimal centipedegrass injury. Imazethapyr and imazapic were too injurious to permit usage during centipedegrass establishment from seed.

Seashore paspalum is used on golf courses in warm temperate regions, but prolific growth and seedhead development may reduce turfgrass quality. Field experiments were conducted to investigate efficacy of flazasulfuron and trinexapac-ethyl on seashore paspalum seedhead suppression, clipping reduction, and canopy height. Flazasulfuron applied from 4.5 to 27 g ai ha−1 increased clipping reductions from the untreated by 22 to 75% and seedhead suppression from the untreated by 16 to 86% at 2 to 4 wk after treatment. Trinexapac-ethyl applied alone at 96 g ai ha−1 provided erratic levels of seedhead suppression from the untreated, but reduced clippings by approximately 50 to 75% from nontreated by 2 to 4 wk after treatment. On several dates, trinexapac-ethyl enhanced clipping reductions and seedhead suppression from flazasulfuron compared to flazasulfuron alone. Trinexapac-ethyl exacerbated seashore paspalum injury from high flazasulfuron rates (18 to 27 g ha−1) but injury never exceeded 23%. Trinexapac-ethyl reduced seashore paspalum height by 50% in unmowed areas at 16 wk. Flazasulfuron at 16 or 27 g ha−1 with trinexapac-ethyl provided consistent seedhead suppression and clipping reductions ranging from approximately 70 to 95% of nontreated. These tank-mixtures have promising implications for use in seashore paspalum golf course fairways.

Studies examined the effect of herbicides on the quality and root strength of winter-installed tall fescue and hybrid bermudagrass sod. Sod was installed in February and treated approximately 30 to 45 d after installation with a variety of preemergence (PRE) and postemergence (POST) herbicides. Tall fescue quality was not affected by any herbicide treatment in 2000 or 2001. Root strength reduction occurred only in 2001 by dithiopyr applied PRE at 2.5 kg ai/ha, which is 4.5 times the maximum use rate. No other herbicides decreased tall fescue root strength in either year. Bermudagrass quality was decreased by triclopyr plus clopyralid applied POST, which resulted in 22 and 6% injury 42 d after initial treatment (DAIT) in 2000 and 2001, respectively. However, POST herbicides did not affect bermudagrass root strength in either year. PRE herbicide treatments did not reduce root development in bermudagrass in 2000. However, dithiopyr applied at 0.84 and 2.5 kg/ha reduced bermudagrass rooting by 59 and 70%, 60 DAIT, in 2001. Pendimethalin reduced root development of bermudagrass by 62% when applied at 10.2 kg/ha, three times the maximum use rate, in 2001. However, by 120 DAIT, only dithiopyr applied at 2.5 kg/ha decreased bermudagrass root development.

Field studies evaluated the effect of brown patch control on preemergence herbicide efficacy in tall fescue. Pendimethalin (1.7 followed by [fb] 1.7; 3.4 kg ai/ha), prodiamine (0.7 fb 0.6; 1.3 kg ai/ha), and oxadiazon (2.2 fb 2.2; 4.5 kg/ha), applied sequentially and as a single application, were evaluated for smooth crabgrass control with and without the use of azoxystrobin, a fungicide that controls brown patch. Azoxystrobin suppressed brown patch and increased smooth crabgrass control with pendimethalin in both years. This enhanced efficacy with azoxystrobin was attributed to improved tall fescue turf density and thus increased competition between this turf species and smooth crabgrass. Longer soil-residual herbicides such as oxadiazon and prodiamine provided high levels of smooth crabgrass control (often >90%). With the exception of oxadiazon at 4.5 kg ai/ha in 2000, smooth crabgrass control with oxadiazon and prodiamine was unaffected by the use of azoxystrobin.