Palatability and efficacy to possums and rats of pest control baits containing bird repellents

Repellents used to reduce by-kill of birds during pest control must not compromise acceptance by target species. Two repellents combined, anthraquinone (AQ; 0.4 g kg^?1) and d-pulegone (DP; 1.0) did not reduce the palatability of blue-coloured carrot baits to laboratory rats (Rattus norvegicus); nor did DP (2.0). Green-coloured carrot baits coated with AQ, DP or AQ + DP were taken from bait stations by wild possums (Trichosurus vulpecula) and rats. Toxic (1080) bait coated with AQ (0.4) and peanut oil (0.1) had reduced palatability but was accepted by laboratory rats. However, laboratory rats did not consume enough baits coated with AQ and bacon, peanut butter, cinnamon or DP to be killed. Anthraquinone (0.4 or 0.8) plus cinnamon and DP (0.5) did not affect palatability or lethality to captive ship rats (R. rattus) or possums. Anthraquinone and DP as surface coatings on baits are therefore acceptable to possums and possibly rats, at concentrations that deter some bird species.     

Primary poisoning risk for encapsulated sodium nitrite,a new tool for pest control

ABSTRACT

Acute toxicity of sodium nitrite (NaNO₂) was assessed in chickens (Gallus gallus domesticus) and domestic mallard ducks (Anas platyrhynchos domestica) by oral gavage and in free-feeding trials with chickens, domestic mallard ducks, pigeons (Columba livia f. domestica), budgerigars (Melopsittacus undulates) and wētā (Family: Rhaphidophoridae). Free-feeding trials involved the presentation of toxic paste and pellet baits containing encapsulated NaNO₂ developed for the control of common brushtail possums (Trichosurus vulpecula) and feral pigs (Sus scrofa). The oral gavage LD₅₀ value for NaNO₂ in solution was approximately 68.50?mg/kg (95% CI 55.00–80.00?mg/kg) for both chickens and ducks. In feeding trials, six out of 12 chickens consumed toxic paste bait and four of these birds consumed a lethal dose. When chickens consumed toxic paste bait, the LD₅₀ value was approximately 254.6?mg/kg (95% CI 249.1–260.2?mg/kg). Of the other three species of birds presented with toxic baits only one duck consumed a lethal dose of paste bait. There was no evidence of wētā feeding on toxic baits.     

Developing indices of relative abundance for monitoring cave and ground wētā (Orthoptera) in southern beech forest,New Zealand

We sampled populations of forest-floor dwelling cave and ground wētā using footprint tracking tunnels and spotlight transect counts in southern beech forest, New Zealand. Samples were compared to estimates of wētā density based on mark–recapture estimates from 25?m² enclosures. Both activity indices captured variability in cave wētā in time and space, were strongly correlated with each other, and have the potential for monitoring cave wētā activity levels. Comparisons between indices and cave wētā density estimates were equivocal, as recapture rates were too low to calculate high-resolution density estimates. We also found that cave wētā counts had a curved relationship increasing with temperature, and a negative relationship with increasing shrub and woody debris cover. Based on these preliminary results, tracking tunnels could be a viable method of monitoring cave wētā as they appear more efficient than transect counts and are relatively inexpensive. However, further calibration trials are needed to determine if indices mirror robust population density estimates.     

Diet selectivity in a terrestrial forest invertebrate,the Auckland tree wētā, across three habitat zones

Insects are important but overlooked components of forest ecosystems in New Zealand. For many insect species, information on foraging patterns and trophic relationships is lacking. We examined diet composition and selectivity in a large‐bodied insect, the Auckland tree wētā Hemideina thoracica, in three habitat zones in a lowland New Zealand forest. We asked whether H. thoracica selectively forage from available plant food sources, and whether these choices were lipid‐rich compared to nonpreferred available plants. We also identified the proportion of invertebrates in their frass as a proxy for omnivory. From reconnaissance plot sampling, together with fecal fragment analysis, we report that more than 93% of individual tree wētā had eaten invertebrates before capture. Additionally, wētā in the highest elevation hillslope habitat zone consumed significantly fewer species of plants on average than wētā on the low‐elevation terrace habitat. Upper hillslope wētā also had the highest average number of invertebrate fragments in their frass, significantly more than wētā in the low‐elevation terrace habitat zone. Wētā showed high variability in the consumption of fruit and seeds across all habitat zones. Generally, we did not observe diet differences between the sexes (although it appears that male wētā in the mid‐hillslope habitat ate fruits and seeds more voraciously than females), suggesting that the sexes have similar niche breadths and display similar degrees of omnivorous behavior. Extraction of leaf lipids demonstrated a range of lipid content values in available plants, and Ivlev's Electivity Index indicated that plant species which demonstrated high electivity tended to have higher concentrations of lipids in their leaves. Our findings indicate that H. thoracica forage omnivorously and selectively, and hence play multiple roles in native ecosystems and food webs.     

Ground wētā in vines of the Awatere Valley,Marlborough: biology,density and distribution

The endemic New Zealand ground wētā (Hemiandrus sp. ‘promontorius’) has a Naturally Uncommon conservation status. This is because of the paucity of information on its density and distribution. Here, the biology, density and distribution of a population of this wētā found in and around vineyards in the Awatere Valley, Marlborough was studied. Wētā density was assessed in vineyards, paddocks and shrublands in this valley. Soil moisture, penetration resistance, pH and organic matter were recorded at locations with and without wētā. Wētā density in vineyards was significantly higher than in either paddocks or shrub habitats. In vineyards, the density of this insect was significantly higher under-vines than in the inter-rows. Higher numbers of this wētā were found in moist soils that required lower force to burrow. Females laid an average of 55 eggs between March and April, which hatched in September. These findings highlight the intersection between agriculture and conservation.     

Beetle and wētā community responses to mammal eradication on Maungatautari,Waikato, New Zealand

ABSTRACT

Predation by introduced mammals frequently limits abundance of New Zealand’s native invertebrates. We investigated responses of beetle and wētā communities to mammal eradication at two fenced forest sites at Maungatautari. Ground-dwelling beetle abundance, but not species richness, increased inside the southern exclosure two years after all mammals were eradicated. In the next 5 years, when all mammals except mice were eradicated from all of Maungatautari, beetle abundance and species richness were frequently higher in the mouse-free southern exclosure. Beetle community composition changed after mammal eradication, and over time with increasing mice densities outside the southern exclosure. Large, predatory, and native beetles showed the most differences between inside and outside the southern exclosure over some years. Wētā were more responsive to mammal removal than beetles. Wētā abundances both inside and outside the southern exclosure were similar when most mammals were eradicated and mice were controlled to low numbers. However, wētā declined in the following 2 years outside the southern exclosure when mouse abundance increased. Abiotic and biotic factors affecting the beetle and wētā communities are complex and interactions poorly understood. This study indicates that climate and predation by native fauna are likely to be important factors.     

Evaluating tree wētā (Orthoptera: Anostostomatidae: <Emphasis Type="Italic">Hemideina</Emphasis> species) as bioindicators for New Zealand national biodiversity monitoring

Indicator taxa are increasingly being used to evaluate the natural environment because they provide both quantified and simplified information about complex phenomena and because they result in huge cost savings compared with monitoring entire biotas. In this paper, we examine the suitability of an iconic New Zealand invertebrate, the tree wētā (Orthoptera: Anostostomatidae: Hemideina species), as a bioindicator for invertebrates under a national biodiversity monitoring scheme in New Zealand. Tree wētā are common and widespread in New Zealand, comprising a distinctive component of the native invertebrate fauna, being large-bodied (up to 40 mm in length), relatively long-lived, flightless, and nocturnal. Arboreal tree wētā species are commonly monitored in conservation areas containing scrub or forest, particularly after mammal control, because they can be easily monitored using artificial roosts without harming them and they are readily identified by field workers. We evaluated whether data supported the use of tree wētā as a range of bioindicators for such monitoring and conclude that the arboreal species are good indicators for monitoring the effects of controlling the abundance of insectivorous mammals and that they are likely to be reliable population indicators of taxa sensitive to mammalian predation pressure, especially by rodents. However, it is unlikely that arboreal tree wētā are useful population indicators of habitat change (e.g. degradation and fragmentation) as they commonly survive in exotic vegetation and urban gardens throughout New Zealand. Although poorly studied for indicator value, tree wētā may not be good biodiversity indicators although there are insufficient data to establish this. We recommend further research be undertaken to develop standardised methods for monitoring so that conservation managers and researchers produce results that are consistent and comparable across different locations.     

四种植物精油对黑翅土白蚁触杀和驱避作用

为筛选出高效防治黑翅土白蚁的天然植物精油,减少有机合成农药的使用,该文研究了大蒜精油、肉桂油、丁香油和印楝素油四种植物精油对黑翅土白蚁的触杀效果和驱避作用。结果表明:大蒜精油、肉桂油和丁香油的浓度为5和10 mg·m L~(-1)时,处理2 h后,黑翅土白蚁的校正死亡率达100%,而相同浓度的印楝素油和对照处理的黑翅土白蚁校正死亡率低于5%。随着处理时间延长,浓度为1.25和2.5 mg·m L~(-1)的大蒜精油、肉桂油和丁香油处理6 h时,黑翅土白蚁的校正死亡率仍达100%,而此时对应的印楝素油和对照处理的黑翅土白蚁校正死亡率仅为10%,说明大蒜精油、肉桂油和丁香油对黑翅土白蚁具有较强的触杀效果。大蒜精油、丁香油和肉桂油在处理黑翅土白蚁2 h后LC_(50)值(半致死量)分别为1.572、1.05和1.03mg·m L~(-1),说明肉桂油对黑翅土白蚁的毒性相对最大,触杀效果最好。此外,10 mg·m L~(-1)的大蒜精油、肉桂油、丁香油和印楝素油的驱避试验表明,处理4、6、8和12 h后,大蒜精油、肉桂油和丁香油三精油处理区的黑翅土白蚁数均显著低于对照区的,驱避率总体93%,而对应的印楝素油的驱避率总体28.5%,表明大蒜精油、丁香油和肉桂油三种植物精油对黑翅土白蚁均有显著的驱避活性。综上可知,四种植物精油中大蒜精油、肉桂油和丁香油在防治黑翅土白蚁方面应用潜力很好,是开发绿色环保白蚁防治药剂的可选材料。     

Assessment of EDDS and vermicompost for the phytoextraction of Cd and Pb by sunflower (Helianthus annuus L.)

The effects of Ethylenediamine disuccinic acid (EDDS) (0 and 5?mmol·kg^?1) as a synthetic chemical amendment, vermicompost (0 and 5%w/w) as an organic amendment and their combined application were evaluated for the phytoextraction by sunflower (Helianthus annuus L.) of cadmium (Cd) and lead (Pb) at three artificial contamination levels in soils (0, 50, and 100?mg·kg^?1 for Cd and 0, 100, and 200?mg·kg^?1 for Pb). The results showed that the application of EDDS was the most effective method to increase Pb and Cd concentrations in both parts of the plant. The results also showed that the application of EDDS increased 9.27% shoot Pb content at 200?mg·kg^?1 but decreased 15.95% shoot Cd content at 100?mg·kg^?1 contamination level with respect to the respective controls. The bioavailable concentrations of Cd at 100?mg·kg^?1 and Pb at 200?mg·kg^?1 contamination level in the soil at the end of experiment increased 25% and 26%, respectively after the application of EDDS but vermicompost decreased 43.28% the bioavailable Pb concentration relative to their controls. Vermicompost increased the remediation factor index of Cd, thus making it the best treatment for the phytoextraction of Cd. The combined application of EDDS and vermicompost was the best amendment for Pb phytoextraction.     

Feeding by Captive Rare Birds on Baits Used in Poisoning Operations for Control of Brushtail Possums

Non-toxic plain and cinnamon-flavoured carrots and cereal-based baits used in poisoning operations for control of the brushtail possum (Trichosurus vulpecula) were offered to seven species of captive rare birds at Mt Bruce National Wildlife Centre. Some individuals of all species ate plain baits. Antipodes Island parakeets (Cyanoramphus unicolor) preferred carrot to cereal- based baits, North Island kokako (Callaeas cinerea wilsoni) and North Island saddlebacks (Philesturnus carunculatus rufusater) preferred cereal-based baits to car-rots, but the other species showed no bait preference. Most baits eaten were greater than 2 g. Some individuals of all species also ate cinnamon-flavoured baits. However, cinnamon deterred North Island kaka (Nestor meriodionalis septentrionalis), Antipodes Island parakeets, and kokako from feeding on baits the first day offered, though not subsequently. Insufficient baits were eaten by North Island weka (Gallirallus australis greyi), red-crowned parakeets (Cyanoramphus novaezelandiae novaezelandiae), and Reischek's parakeets (Cyanoramphus n. hochstetteri) to determine whether they were also deterred by cinnamon. Only saddlebacks were definitely not deterred. All species except red-crowned and Reischek's parakeets probably ate sufficient to receive a lethal dose if the baits had been toxic. Baits may be made less acceptable to birds by increasing the strength or slowing the release of cinnamon, or by using a more repellent flavour. Because baits may always be acceptable to some birds, wildlife managers need to know the chances of wild rare birds feeding on baits before approving poisoning operations in areas where they occur.     

Anaerobic detoxification fermentation by Rhodospirillum rubrum for rice straw as feed with moderate pretreatment

A novel and effective process was put forward for converting rice straw into feed by combining diluted acid hydrolysis and ammonization with Rhodospirillum rubrum fermentation. After pretreatment with dilute sulfuric or phosphoric acid (1%, w/w) at 100°C, materials were subjected to fermentation under several gases (N₂, CO₂, and air) and different light intensities in a 2-L fermentor. The key indexes of feed for fermented materials were estimated and several toxic substances were investigated during the fermentation. Following sulfuric acid treatment, the true protein of rice straw increased from 29 to 143?g?kg^?1 and the crude fiber decreased from 359 to 136?g?kg^?1 after fermentation at 0.3?L?min^?1?L^?1 of N₂ flow and a light intensity of 3400 lux; and following phosphoric acid treatment, the true protein increased by 286% and the crude fiber decreased by 52% after fermentation at 0.4?L?min^?1?L^?1 of N₂ flow and a light intensity of 3000 lux. Other key contents were also improved for use as feed, and some toxic substances (i.e., furfural, hydroxymethylfurfural, acetic acid, phenol, cresol) produced by the pretreatments could be removed at low levels during the fermentations.     

Petroleum Degradation,Biosurfactant and Laccase Production by Fusarium neocosmosporiellum RH-10: A Microcosm Study

The aim of this study was to evaluate the potential of crude oil removal by fungal strains isolated from Arak refinery. The results showed that the RH10 strain is a potent strain as a surfactant producer and degrader of petrochemical hydrocarbons. The strain was identified as a Fusarium neocosmosporiellum and could degrade 58% of hydrocarbons in the minimal medium and reduce the surface tension from 45 to 26.5 mN m^?1. Moreover, residual crude oil analysis with Fourier transform infrared spectrophotometry showed that this strain was able to degrade 50% of aliphatic compounds. To investigate the mechanism of degradation, oxidase enzymes were assayed and it was found that F. neocosmosporiellum can produce 1.94 U L^?1 of laccase in 10 g L^?1 crude oil. Carbon, nitrogen, phosphorus and soil pattern optimization in a microcosm study showed that this strain removed 44% and 27% of the crude oil from contaminated soil in 1% and 5% crude oil concentrations, respectively. Under optimum condition, 9.66 g kg^?1 crude oil was removed by F. neocosmosporiellum when the initial oil concentration was 50 g kg^?1, at the end of 150 days microcosm experiment. The results demonstrated the promising potential of fungi strain for cleaning of contaminated soil.     

Use of two formulations and two application techniques to deliver Bacillus thuringiensis var. israelensis for the control of Musca domestica (Diptera: Muscidae) larvae and adults in poultry houses

A field study was carried out for 6 wks to assess, from both an efficiency and economic perspective, the effect of individual and integrated success of feeding and topical applications of two formulations of Bacillus thuringiensis var. israelensis (Bti) in controlling house fly (Musca domestica L.) larvae and adults in poultry houses. There was no significant difference between the 1 g and 2 g L^?1 spray applications of Bti. In the absence of spray applications, no significant differences in larval mortalities were observed between the 250 mg and 500 mg kg^?1 feed applications. The percentage mortality of larvae accomplished as a result of using a combination of 250 mg kg^?1Bti feed and 2 g L^?1 spray applications was equivalent to that obtained as a result of combining 500 mg kg^?1Bti and 1g L^?1 spray applications. Treatment with Bti caused significant reductions in the emergence (up to 74%) of house fly adults compared to the control. The fact that the emergence of adult house flies was affected by Bti treatments implies that Bti has sublethal effects on house fly larvae. The cost–benefit analysis (expressed in terms of mortality of larvae growing) indicated that the most effective combination for house fly larvae and adult house fly emergence control was the 500 mg kg^?1 of feed and 2 g L^?1 spray application combination that resulted in 67% larval mortality and a 74% decrease in adult house fly emergence. This study presents commercial users with various alternatives for possible combinations of the two Bti formulations.     

Progeny of the maize weevil,Sitophilus zeamais,is affected by parental exposure to clove and cinnamon essential oils

The interest in and utilization of botanical insecticides, particularly essential oils, has become increasingly relevant to the control of insect pests. However, the potential ecotoxicological risks or flaws (including sublethal effects on the targeted pest generation and its subsequent progeny) of this pest control tool have been neglected frequently. Here, we evaluated the effects of sublethal exposure to clove, Syzygium aromaticum (L.) Merrill & Perry (Myrtaceae), and cinnamon, Cinnamomum verum J. Presl (Lauraceae), essential oils on adult (F0) maize weevils, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), and the physiology (e.g., body mass, respirometry, and grain consumption) and population dynamics (e.g., daily emergence and sex ratio) of their progeny. Longevities of the parents were negatively affected by the essential oils in a concentration‐dependent manner. Parental sublethal exposure to clove oil (0.17 μl cm^?2) accelerated offspring emergence but delayed the emergence of females compared to males. Parents that were sublethally exposed to clove (0.17 μl cm^?2) or cinnamon (0.35 μl cm^?2) essential oils produced heavier offspring. Parental sublethal exposure to cinnamon essential oil accelerated offspring emergence (at 0.70 μl cm^?2), delayed female emergence (at 0.17 μl cm^?2), and enhanced grain consumption (at 0.35 and 0.70 μl cm^?2) of the progeny. Thus, our findings indicate that sublethal exposure to clove and cinnamon essential oils is capable of promoting transgenerational effects in S. zeamais that can negatively impact the control efficacy of such products.     

Memory retention of conditioned aversion training in New Zealand's alpine parrot,the kea

New Zealand pest control operations commonly deploy toxic sodium fluoroacetate (1080) baits to control introduced mammalian predators and protect vulnerable native fauna, yet the highly intelligent kea (Nestor notabilis) is at risk of mortality following ingestion of toxic baits intended for their protection. We tested the retention of conditioned aversion in 11 captive kea that had learned to avoid baits containing the bird repellent anthraquinone alongside color, olfactory, and taste cues. We revisited kea over increasing time intervals (3 days, 5 weeks, 3 months, 6 months, and 1 yr) offering them otherwise identical non-repellent baits. Kea retained their aversion until the final session, 1 year after previous exposure to reinforcement, and almost 2 years since previous exposure to repellent. Whether the kea forgot their aversion or the repeated exposures to non-repellent baits resulted in extinction of the aversion, our results indicate that kea are capable of remembering an aversion for long enough to be of practical use to conservation managers in reducing kea mortality through 1080 operations.     

EDTA-assisted phytoextraction of lead and cadmium by Pelargonium cultivars grown on spiked soil

The aim of this study was to assess EDTA-assisted Pb and Cd phytoextraction potential of locally grown Pelargonium hortorum and Pelargonium zonale. Plants were exposed to different levels of Pb (0–1500?mg kg^?1) and Cd (0–150?mg kg^?1) in the absence or presence of EDTA (0–5?mmol kg^?1). P. hortorum and P. zonale accumulated 50.9% and 42.2% higher amount of Pb in shoots at 1500?mg kg^?1 Pb upon addition of 5?mmol kg^?1 EDTA. Plant dry biomass decreased 46.8% and 64.3% for P. hortorum and P. zonale, respectively at the combination of 1500?mg kg^?1 Pb and 5?mmol kg^?1 EDTA. In Cd and EDTA-treated groups, P. hortorum and P. zonale accumulated 2.7 and 1.6-folds more Cd in shoots at 4 and 2?mmol kg^?1 EDTA, respectively, in 150?mg Cd kg^?1 treatment. Plant dry biomass of P. hortorum and P. zonale was reduced by 46.3% and 71.3%, respectively, in soil having 150?mg Cd kg^?1 combined with 5?mmol kg^?1 EDTA. Translocation factor and enrichment factor of both plant cultivars at all treatment levels were >1. Overall, the performance of P. hortorum was better than that of P. zonale for EDTA-assisted phytoextraction of Pb and Cd.     

Production of precursors for anti-Alzheimer drugs: Asymmetric bioreduction in a packed-bed bioreactor using immobilized D. carota cells

(S)-1-Phenylethanol derivatives, which are the precursors of many pharmacological products, have also been used as anti-Alzheimer drugs. Bioreduction experiments were performed in a batch and packed-bed bioreactor. Then, the kinetics constants were determined by examining the reaction kinetics in the batch system with free and immobilized carrot cells. Also, the effective diffusion coefficient (D_e) of acetophenone in calcium alginate-immobilized carrot cells was investigated. Kinetics constants for free cells, which are intrinsic values, are reaction rate V_max?=?0.052?mmol?L^?1?min^?1, and constants of the Michaelis–Menten K_M?=?2.31?mmol?L^?1. Kinetics constants for immobilized cells, which are considered apparent values, are V_{max, app}?=?0.0407?mmol?L^?1 min^?1, K_{M, app}?=?3.0472?mmol?L^?1 for 2?mm bead diameter, and V_{max, app}?=?0.0453?mmol?L^?1 min^?1, K_{M, app}?=?4.9383?mmol?L^?1 for 3?mm bead diameter. Average value of effective diffusion coefficient of acetophenone in immobilized beads was determined as 1.97?×?10^?6?cm²?s^?1. Using immobilized carrot cells in an up-flow packed-bed reactor, continuous production of (S)-1-phenylethanol through asymmetric bioreduction of acetophenone was performed. The effects of the residence time and concentrations of substrate were investigated at pH 7.6 and 33°C. Enantiomerically pure (S)-1-phenylethanol (ee?>?99%) was produced with 75% conversion at 4-hr residence time.     

Potential use of endophytic root bacteria and host plants to degrade hydrocarbons

Abstract

Microbe-assisted phytoremediation depends on competent root-associated microorganisms that enhance remediation efficiency of organic compounds. Endophytic bacteria are a key element of the root microbiome and may assist plant degradation of contaminants. The aim of this study was to investigate the application of four hydrocarbon-degrading endophytic strains previously isolated from an oil sands reclamation area. Strains EA1-17 (Stenotrophomonas sp.), EA2-30 (Flavobacterium sp.), EA4-40 (Pantoea sp.), and EA6-5 (Pseudomonas sp.) were inoculated in white sweet clover growing on soils amended with diesel at 5,000, 10,000, and 20,000?mg·kg^?1. Our results indicate that plant growth inhibition caused by diesel fuel toxicity was overcome in inoculated plants, which showed significantly higher plant biomass. Analysis of soil F2 and F3 hydrocarbon fractions also revealed that these soils were remediated by inoculated plants when diesel was applied at 10,000?mg·kg^?1 and 20,000?mg·kg^?1. In addition, quantification of hydrocarbon-degrading genes suggests that all bacterial strains successfully colonized sweet clover plants. Overall, the endophytic strain EA6-5 (Pseudomonas sp.), which harbored hydrocarbon-degrading genes, was the most effective candidate in phytoremediation experiments and could be a strategy to increase plant tolerance and hydrocarbon degradation in contaminated (e.g., diesel fuel) soils.     

Nutrient Removal as a Function of Corn Stover Cutting Height and Cob Harvest

One-pass harvest equipment has been developed to collect corn (Zea mays L.) grain, stover, and cobs that can be used as bioenergy feedstock. Nutrients removed in these feedstocks have soil fertility implication and affect feedstock quality. The study objectives were to quantify nutrient concentrations and potential removal as a function of cutting height, plant organ, and physiological stage. Plant samples were collected in 10-cm increments at seven diverse geographic locations at two maturities and analyzed for multiple elements. At grain harvest, nutrient concentration averaged 5.5 g?N kg^?1, 0.5 g?P kg^?1, and 6.2 g?K kg^?1 in cobs, 7.5 g?N kg^?1, 1.2 g?P kg^?1, and 8.7 g?K kg^?1 in the above-ear stover fraction, and 6.4 g?N kg^?1, 1.0 g?P kg^?1, and 10.7 g?K kg^?1 in the below-ear stover fraction (stover fractions exclude cobs). The average collective cost to replace N, P, and K was $11.66 Mg^?1 for cobs, $17.59 Mg^?1 for above-ear stover, and $18.11 Mg^?1 for below-ear stover. If 3 Mg ha^?1 of above-ear stover fraction plus 1 Mg of cobs are harvested, an average N, P, and K replacement cost was estimated at $64 ha^?1. Collecting cobs or above-ear stover fraction may provide a higher quality feedstock while removing fewer nutrients compared to whole stover removal. This information will enable producers to balance soil fertility by adjusting fertilizer rates and to sustain soil quality by predicting C removal for different harvest scenarios. It also provides elemental information to the bioenergy industry.     

Antifungal and enzymatic evaluation of plant crude extracts derived from cinnamon and rosemary against Sclerotinia carrot rot

The objective of this study was to assess the antifungal potential of plant crude extracts derived from cinnamon and rosemary against three isolates of Sclerotinia sclerotiorum under in vitro and in vivo conditions. The crude extracts were obtained using two different solvents including ethyl acetate (EA) and ethanol. The results showed that crude extracts of cinnamon are able to reduce mycelial growth of isolate 2 at volatile and contact phase by 35.4% and 78.2%, respectively. Furthermore, sclerotial myceliogenic at contact phase and carpogenic germination of isolate 2 were inhibited by 94.3% and 68.1%, respectively. In general, rosemary extracts showed less inhibitory efficacy than cinnamon. As the most effective treatment, EA extract of cinnamon was analysed using Gas Chromatography/Mass Spectrometry. The results showed the presence of 33 components and the major constituents were E‐cinnamaldehyde (66.4%) followed by Alpha‐Muurolene (4.86%), Alpha‐Copaene (4.73%) and 2H‐1‐Benzopyran‐2‐one (3.72%). The enzyme analysis showed that the activity of phenylalanine ammonia lyase, polyphenoloxidase and peroxidase decrease in the inoculated carrots after application of plant crude extracts indicating that they cannot be considered as resistance inducers against Sclerotinia carrot rot. In conclusion, cinnamon extract was found to be more effective against the pathogen. Although crude extracts of cinnamon and rosemary were able to reduce severity of carrot rot during storage, EA extract of cinnamon (2 g L^?1) was found to have practically significant effect against the disease.