Wednesday 30 December 2020

Lupine Publishers | Help! Our Tinnitus Patients Want A Drug?

 Lupine Publishers | Journal of Otolaryngology


Abstract

Tinnitus is common and can severely affect life quality in many. There are no FDA approved drugs for tinnitus treatment and no surgery for sensorineural tinnitus. Up till now, there are no medications or supplements approved for tinnitus; our impression is that they are widely used. Therefore, we believe it is helpful to review the literature and provide some suggestions for clinicians and sufferers. We review studies which describe current and emerging pharmacotherapies. In addition, we describe recent advances in the tinnitus field which may help overcome obstacles faced in the pharmacological treatment of tinnitus.

Introduction

Tinnitus is a common complaint and can be very debilitating [1]. The prevalence of tinnitus in adult populations ranges from 7 % to 19 %. It increases with age [2]. In up to 5% of the adult population, tinnitus interferes negatively with the ability to lead a normal daily life; affecting many activities of daily life; including (a) thought and emotions, (b) hearing, (c) sleep, and (d) concentration. Each person is affected differently [3]. Several counseling and sound therapies are used and are helpful to many patients Tyler [4]. The Psychological Model of tinnitus considered as an important distinction between the tinnitus from reactions to the tinnitus [5]. The counseling and sound therapy help with the reactions, but tinnitus suffers often prefer pill [6]. Medications can be used to treat patients with depression and anxiety and to help with sleep problems, but do not directly change the tinnitus. Despite the significant clinical need for effective treatment of tinnitus, there is currently no single U.S Food and Drug (FDA)-approved medication for treatment of   tinnitus. Various drug regimens have been tried and a few of them had shown some favorable results, but most did not result in significant benefits [7]. As with any bothersome, common disorder which lacks understanding and effective treatments, tinnitus considered as an easy target for scams [8]. Thousands of purported cures can be found on the internet and in stores providing ‘over the counter’ pills.  People waste billions of dollars on tinnitus treatment yearly. Some scams are blatant.  Others are subtle.

Drugs for Tinnitus Treatment

It seems unlikely that there will be one single drug which will cure all forms of tinnitus. It is likely that many subtypes of tinnitus exist and that each will require a different form of treatment. Thus, one of the pressing needs in tinnitus research is a scheme to classify patients into subtypes that might respond positively to a specific drug treatment. Indeed, some drugs have been reported to provide some kind of symptoms relief in a subset of patients but in others not [9]. We will review some of these drugs which might help in tinnitus symptoms relief.

Anti-Arrhythmic

a) Lidocaine

In 1935, lidocaine was suggested and used to suppress tinnitus through nasal administration and since then many clinical studies confirmed transient suppression of tinnitus through lidocaine administration [10].  Its effect seems to be dose dependent with suppression of tinnitus occurring at free arterial plasma concentrations from 1.75 to 3.5 μmol/L.  However, it was found that concentrations more than 3.5 μmol/L might induce tinnitus [11]. The mechanism of action by which intravenous lidocaine might suppresses tinnitus is incompletely understood, but there is evidence that it affects both the cochlea and the central nervous system [7]. It is used as local anesthetic and anti-arrhythmic, it acts mainly through binding to fast voltage-gated sodium channels, reducing the magnitude of the sodium current during depolarization [12]. It also affects calcium, potassium, and glycine-evoked chloride currents [13]. Since the effects of lidocaine are short lived and due to its potentially life-threatening side effects, like cardiac arrhythmia, drowsiness, dizziness, confusion, and restlessness; lidocaine is not an option for long-term treatment. Oral analogues of lidocaine such as tocainide have been evaluated as a potential long-term therapy for tinnitus. However, several randomized, controlled studies found that tocainide had little benefit for tinnitus [14]. A nonsterile patch (Lido PAIN TV, EPI Cept) has been developed for delivery of lidocaine applied over preauricular skin. Its clinical efficacy is under clinical trial. It is produced under the pharmaceutical company EPI Cept which has less systemic concentrations than intravenous lidocaine which is needed to suppress tinnitus [5

Anti-Depressants

The tricyclic antidepressants nortriptyline, amitriptyline and trimipramine have been investigated for the treatment of tinnitus. Beside their antidepressant properties, tricyclics have been shown to be highly efficient for the treatment of chronic pain, which is of interest in view of the proposed etiological similarities between tinnitus and neuropathic pain [16]. Examples of tricyclic antidepressant which can be used for tinnitus include (amitriptyline, trimipramine, and nortriptyline), the latter found to inhibits mainly the reuptake of norepinephrine and to a lesser extent serotonin, whereas amitriptyline inhibits the reuptake of serotonin and noradrenaline almost equally, on the other hand trimipramine differs in its mode of action from other tricyclic antidepressants in that it blocks postsynaptic dopamine and serotonin receptors [17]. From all tricyclic antidepressants, nortriptyline is worth noting. Sullivan et al. [18] reported small-scale, single blind placebo-washout study involving patients with severe tinnitus and major depression, nortriptyline significantly reduced depression and tinnitus loudness (10 dB reduction) in some. In a follow-up double blind placebo- controlled study involving subjects with severe tinnitus and severe depression or depressive symptoms, nortriptyline significantly reduced depression scores, tinnitus disability scores, and tinnitus loudness (6.4 dB reduction) relative to a placebo [19].  They concluded that there was a significant correlation between the reduction in tinnitus disability scores and depression scores, suggesting that nortriptyline is effective in reducing tinnitus loudness and severity in severely depressed tinnitus patients.  There was less benefit in non-depressed individuals [20].

a) Amitriptyline

Bayar et al. [21] reported a study (n= 37) to compare amitriptyline with placebo and found after 6 weeks of 100 mg amitriptyline, a significant reduction of tinnitus complaints and tinnitus loudness compared to the placebo group. Podoshin et al. [22] reported another study (n=225), where amitriptyline was compared with biofeedback, and 27.5% of patients reported improvement with amitriptyline while 43.5% reported improvement with biofeedback revealing the superiority of biofeedback.

b) Trimipramine

Mihail et al. [23] evaluated Trimipramine small double-blind placebo cross-over study (n=19) and did not demonstrate any difference between trimipramine and placebo treatment.

c) Selective serotonin reuptake inhibitors (SSRI)

SSRI such as sertraline have been tested. In a randomized double-blind placebo-controlled study (n=76), patients without severe hearing loss, but with depression, anxiety, and a high risk for developing severe tinnitus, sertraline was significantly more effective than placebo in reducing tinnitus loudness and tinnitus severity [24].

On the other hand, paroxetine was evaluated in a double-blind, placebo-controlled study involving chronic tinnitus patients without comorbid depression, the paroxetine group showed little difference from placebo on tinnitus loudness, Tinnitus Handicap Questionnaire (THQ) scores, and other measures [25]. Collectively, the results suggest that tinnitus patients with depression and anxiety may benefit from antidepressants [25]. However, this effect may not to be a direct effect of antidepressants on tinnitus severity, but rather due to the beneficial effect of antidepressants on comorbid depression and anxiety. Dose of antidepressants for the treatment of tinnitus is in a similar range as that used in the treatment of depression. In general, a low starting dose and slow increase of the dosage reduce side effects. Since beneficial effects do not occur immediately, minimum treatment duration of 6–12 weeks at the effective dose is recommended. If treatment effects are unsatisfactory and the decision is made to discontinue or change treatment, dosage should be reduced slowly. If a patient experiences beneficial effects, treatment should be continued at a stable effective dose for about 6 months, then the dose can be reduced over the course of weeks to months. Should the tinnitus get worse during a reduction of the dose, it is recommended to keep the dosage at the minimum providing relief.

Anxiolytics

Since tinnitus is thought to be the result of an imbalance between excitatory and inhibitory neurotransmission toward the GABA receptor [26], and benzodiazepines are allosteric potentiators of the GABAA receptor so, they have a positive effect on tinnitus by increasing inhibitory neurotransmission. Furthermore, due to their anxiolytic and sleep-inducing properties, benzodiazepines should have beneficial effects on comorbid anxiety and insomnia, and thus may help patients cope with their tinnitus.

a) Alprazolam

Johnson et al. [27] reported double-blind placebo-controlled study(n=36), 12 weeks of alprazolam administration at an individually adjusted dosage reduced tinnitus loudness in 76% of subjects  measured with a tinnitus synthesizer and a visual analog scale – whereas only 5% showed a reduction in tinnitus loudness in the control group. Although the strong positive effects of alprazolam are encouraging, the study has been criticized because of the small sample size, drug dosing method, and failure to assess emotional effect.

b) Clonazepam

Bahmad et al.  [28] Stated in their retrospective study of medical records from over 30patients taking clonazepam (0.5–1 mg/day, 60–180 days) for vestibular or cochleovestibular disorders, that 32% of patients reported an improvement in their tinnitus. Due to their immediate effects, short-acting benzodiazepines such as lorazepam or alprazolam are widely used for acute treatment of anxiety, agitation, and insomnia, symptoms that frequently occur with tinnitus. The longer acting clonazepam provides some relief in a considerable subgroup of patients. The use of benzodiazepines should be restricted to short periods of time due to the risk of drug dependency. Moreover, caution is warranted since protracted tinnitus has been reported after discontinuation of benzodiazepines [29].

Anticonvulsants

 Anticonvulsants are increasingly used in the treatment of several non-epileptic conditions, including various psychiatric disorders and pain syndromes [30].  Some of them have also been investigated for the treatment of tinnitus. As this anticonvulsant act on voltage gated Sodium and calcium channels, and on synaptic transmission mainly mediated by gamma amino butyric acid type A (GABAA) receptors [31] with resultant reduction in neuronal excitability, thus they should be beneficial for the treatment of tinnitus.

a) Carbamazepine

Carbamazepine binds to voltage-gated sodium channels and stabilizes the sodium inactivation state, thereby reducing neural firing [32], it had been investigated for tinnitus and results were mixed. Based on the assumption that carbamazepine resembles lidocaine in its mechanism of action, studies investigated the effect of carbamazepine in tinnitus patients who previously had responded to intravenous lidocaine [33]. About half of these patients had a positive response to carbamazepine (600–1,000 mg daily). A significant benefit from carbamazepine has been reported for a rare group of patients who have intermittent tinnitus that sounds like a typewriter, popcorn, or ear clicking, and which is caused by a neurovascular conflict [34].

b) Gabapentin

The anticonvulsant gabapentin acts on voltage gated calcium channels and is also used for the treatment of seizures, neuropathic pain, and migraine [35]. Results with gabapentin for the treatment of tinnitus are contradictory; one controlled trial (n=39) has shown a significant improvement in tinnitus annoyance and loudness for a subgroup of participants with tinnitus related to acoustic trauma [36], other study (n=76) did not detect any improvement in tinnitus handicap, but did report a significant improvement in tinnitus annoyance when compared to placebo [37].

Anti-Glutamatergic Agents

Glutamate receptor antagonists have been tried in tinnitus sufferers. The rationale behind it is that imbalance between inhibitory versus excitatory neurotransmission which was observed in several regions of the auditory pathway in tinnitus development thus blocking glutamatergic neurotransmission could also exert neuro protectant effects [38].

a) Caroverine

Caroverine, a spasmolytic drug, which is an antagonist of non- N-methyl-D-aspartate (NMDA) and NMDA glutamate receptors [39], has been investigated in patients with putative cochlear tinnitus. Patients were randomized to receive either caroverine (I.V., maximum dose 160 mg) or placebo. Within the caroverine group, 63% showed a reduction in loudness immediately after treatment and 43 % still showed improvement one week later, whereas there was no improvement in the placebo group [40].

b) Acamprosate

Acamprosate is non-selective NMDA receptor which had been tried in a double-blind study (n=50), Patients received placebo or acamprosate (333 mg, three times per day) and rated the loudness and annoyance of their tinnitus before and at monthly intervals of treatment. Acamprosate had no beneficial effects after 30 days of treatment, a modest benefit at 60 days, and a significant effect at 90 days. Approximately 87% of the subjects in the acamprosate group showed some improvement, including three subjects in which tinnitus disappeared, compared to 44% in the placebo group [41]. This study has not been published but the main author said it had no effect on tinnitus. A larger clinical trial is currently underway to analyze the encouraging results from this preliminary study (http://clinicaltrials.gov/ct2/show/NCT00596531).

Dopaminergic–Antidopaminergic Drugs

Dopaminergic pathways in limbic and prefrontal areas found to be involved in mediating emotional aspects of tinnitus so both dopaminergic and antidopaminergic drugs have been proposed for treating tinnitus.

a) Sulpiride

An antipsychotic drug that selectively blocks dopamineD2 receptors [42], significantly reduced subjective ratings of tinnitus and tinnitus visual analogue scores in one double-blind, placebo-controlled study. Further studies investigated combinations of sulpiride with melatonin, A prospective, randomized, double-blinded, placebo-controlled study was done (n=120) patients consulted for subjective tinnitus. They were included randomly in four groups of 30. One group took sulpiride (50 mg/8 h) alone, the second group took melatonin (3 mg/24 h), the third group took the same doses of sulpiride (50 mg/8 h) plus melatonin (3 mg/24 h), and the fourth group took placebo (lactose 50 mg/8 h), all for 1 month, Subjective grading of tinnitus perception and a visual analogue scale (0-10) were done for evaluation of results. Based on the subjective grading, tinnitus perception diminished by 56% in patients treated with sulpiride, by 40% in patients treated with melatonin, by 81% in patients treated with sulpiride plus melatonin, and by 22% in patients treated with placebo, concluding that Sulpiride and melatonin reduce tinnitus perception, decreasing dopamine activity. The tinnitus auditor-limbic dopaminergic pathway has broad therapeutic implications [43].

b) Piribedil

Piribedil was investigated recently in a double-blind placebo-controlled cross-over study (n=56). Results showed that piribedil was not superior to placebo; however, a post-hoc analysis suggested that a subgroup of patients with specific findings in electrocochleography may benefit from piribedil [44].

Other drugs

a) Misoprostol: is a synthetic prostaglandin E1 analogue which is primarily used to prevent gastric ulcers induced by non-steroidal anti-inflammatory drugs [45]. In a small, placebo-controlled cross-over study, tinnitus severity improved in 33% of subjects during misoprostol treatment (escalating to 800 mg/day), while none improved with placebo [46]. A subsequent double-blind placebo-controlled study (n=40) has shown a significant reduction of tinnitus loudness with misoprostol treatment, but no differences in subjective measures of tinnitus severity [47]. A further study has shown efficacy of misoprostol in the treatment for chronic tinnitus in hypertensive and/or diabetic patients [48].

b

b) Cyclandelate, a vasodilator used in the treatment of cerebrovascular and peripheral vascular disorders, that is believed to act by blocking calcium influx [49], has been investigated for the treatment of tinnitus based on the assumption that some forms of tinnitus may arise from cerebrovascular insufficiency. In an open multicentric clinical trial of patients with tinnitus, vertigo, and visual disturbances, 90-day treatment with cyclandelate reduced the severity and frequency of these symptoms with minimal side effects [50]. However, in a subsequent placebo-controlled double-blind study, cyclandelate did not significantly change audiometric measures of tinnitus loudness and pitch and caused side effects in many patients [51].

c) Furosemide is a loop inhibiting diuretic used to treat congestive heart failure and edema; it inhibits the Na-K-2Cl cotransporter [52], which is expressed in the inner ear as well as in the brain [53]. Furosemide has been proposed as a treatment for tinnitus of cochlear origin because it strongly suppresses the endolymphatic potential and other cochlear responses [54]. In one study, approximately 50% of patients reported a reduction of tinnitus symptoms following intravenous furosemide treatment. Furosemide has also been found to suppress tinnitus in approximately 40% of patients with Meniere’s disease [55]. In contrast to these positive findings, high doses of furosemide have also been found to induce temporary hearing loss and tinnitus [56].

d) Nimodipine, a calcium antagonist, which crosses the blood - brain barrier and blocks L-type calcium channels [57], is primarily used in the treatment of subarachnoid hemorrhage. Pilot studies also suggest beneficial effects in mood disorders [58]. In animal studies nimodipine significantly reduced tinnitus related behavior caused by high doses of quinine or sodium salicylate [59]. The first open clinical trial suggested positive effects of nimodipine on tinnitus in some patients [60]. However, these results could not be confirmed in a second open clinical trial [61].

e) Cyclobenzaprine a centrally acting muscle relaxant with pharmacological properties similar to amitriptyline, used in the management of fibromyalgia, low back pain, neck pain and temporomandibular disorders. Two open preliminary studies evaluated the action of cyclobenzaprine in the treatment of tinnitus have shown evidences that this drug presents a clear action in reducing tinnitus magnitude as well as in tinnitus discomfort [62,63]. Another study conducted in animal model found that cyclobenzaprine was effective in the transient suppression of noise-induced tinnitus in rats. Cyclobenzaprine is a promising drug to treat tinnitus and preliminary results need to be validated in controlled clinical trials [64].

f) Other drugs that have been tested with either limited efficacy or are in need of further controlled trials include the HMG-CoA reductase atorvastatin [65], betahistine [66], Deanxit [67], oxytocin [68], naltrexone [69], ondansetron [70], the phosphodiesterase inhibitors cilostazol [71]and cannabinoids [72].

Drugs in the pipeline for patients with tinnitus

a) Neramexane: acts as a non-competitive, voltage dependent NMDA antagonist and also blocks α9α10 nicotinic cholinergic receptors which are expressed on hair cells in the inner ear [73]. After obtaining positive results from a Phase II trial. (http://clinicaltrials.gov/ct2/show/NCT00405886), Merz Pharmaceuticals is currently conducting Phase III multi-center clinical trials to determine the efficacy, safety and tolerability of Neramexane for treating tinnitus.

b) LidoPAIN TV: is a non-sterile patch delivering lidocaine, which is applied to the periauricular skin region. According to the company’s web page, it demonstrated efficacy in a clinical proof of- concept study and has been in phase II trials for tinnitus [15].

c) SPI-1005: contains ebselen which acts as an antioxidant by stimulating glutathione peroxidase. It has completed a phase I trial and phase II trials are planned for the treatment of noise-induced hearing loss and tinnitus [9].

d) AM 101: is an NMDA antagonist, which is applied topically to the cochlea by round window Injection for the treatment of acute tinnitus. In a randomized, double-blind placebo-controlled German Phase I/II trial in 24 patients with acute tinnitus following noise trauma or sudden deafness, single-dose AM-101 intratympanic injection was well tolerated. It also had a positive effect on tinnitus loudness. Currently a double-blind, randomized, placebo-controlled Phase II trial with cochlear application of AM-101 is being carried out. The study involves patients with acute (<3 months) noise-induced tinnitus that have not responded to glucocorticoid treatment. he same company has also a second compound under development (AM-102). This compound is of unidentified pharmacologic activity and is also delivered by intratympanic application. It is currently in preclinical test [9].

e) Vestipitant: is a novel antagonist of the neurokinin-1 (NK-1) receptor which binds substance P. Neurokinin receptors are present in the inner ear and therefore represent a potential therapeutic target for tinnitus [74]. Vestipitant and the combination of vestipitant and paroxetine are currently undergoing a phase II clinical trial for the treatment of tinnitus [75].

f) EGb-761: is a concentrated extract of Ginkgo biloba, enriched in flavonoids and terpenes, which has a broad spectrum of pharmacologic actions, including a free-radical scavenger effect and which has shown efficacy for tinnitus in a phase I trial (Table 1).

Table 1: Drugs under development for tinnitus.

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Conclusion

The use of drugs to treat tinnitus is widespread. Some subjects report benefits from drugs, while others do not. There is likely a placebo effect influencing those results. It is also noteworthy that many patients develop side effects. Patients using drugs might not be aware of the side effects, even though warnings might be present on labels. Tyler et al. [76] stated that there are many subgroups of tinnitus and it might be that different drugs help some subtypes tinnitus sufferers, but not all tinnitus sufferers. Despite the huge potential market, we still lack approved pharmacological treatments for tinnitus. Despite the significant unmet clinical need for a safe and effective drug targeting tinnitus relief, there is currently no single FDA approved drug on the market. The empirical approach, in combination with new developments in information technology such as the advent of big data approaches in medicine, might facilitate the identification of promising drugs. We have also stressed the importance of examining individual results.

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Lupine Publishers | Effect of GA3 on Germination Parameters of Different Varieties of Kiwi

 Lupine Publishers | Current Investigations in Agriculture and Current Research



Abstract

Premises of the Research: Kiwi, Actidinia deliciosa is a temperate fruit with high nutritional and medicinal value which is commonly propagated through rootstock grafting. Low seed germination because of seed dormancy and chilling requirement limits seedling production which can be improved by chemical treatment and varietal selection.

Methodology: Germination response of three varieties viz. Abbot, Allison, Bruno pre-treated with 2000, 4000, 6000ppm of GA3 including control was studied in two factor Factorial Complete Randomize Design with six replications in laboratory of Lamjung Campus.

Pivotal Results: Significantly higher germination percentage (68.67%) was found in Bruno without pre-treatment of seed followed by Allison pre-treated with 6000ppm of GA3 (47.33%). GA3 alone significantly influenced mean germination rate and time. However, Allison with 6000ppm GA3 had fastest mean germination rate (0.059 day-1) and time (17 days). Statistically different germination index, coefficient of variation of germination time and uncertainty of germination was found.

Conclusion: Seed germination can be enhanced by treating 4000-6000ppm GA3 for Abbot, Allison while Bruno requires no pretreatments of seeds.

Keywords: Dormancy; Germination Percentage; Mean Germination Time; Pre-treatment; Vigor

Introduction

Kiwi fruit (Actnidia deliciosa (A Chev)) called as ‘Chinese Gooseberry’ is native to Yangtze valley where it evolved with the southeastern subtropical flora [1]. It is planted in T-bars or pergola and woody vines can go up to 9m height. The Kiwi fruits can withstand up to -15oC and flower appearance takes in the spring [2]. The fleshy fruits with seeds embedded inside are called berries which are of different size, shape, color and hairiness [3].

The global Kiwi production reached 4.27 billion metric ton in 2016 [4]. The export trade of kiwi is increasing year over year, increased 8.1% in 2016 to 2017. In 2017, the major exporter are European countries (mainly Italy and Belgium) 43.9% and Oceanian countries (mainly New Zealand) 43.7%. New Zealand is the largest exporter while China is the largest producer of Kiwi fruit. Nepal ranked 83rd in Kiwi exporter with 0.0001% world total export. The export was about $3000 only. There is a good opportunity to country like Nepal with negative net export to increase the production of Kiwi for export which would decrease the overall trade deficit (Workman, 2018). Kiwi fruit is gaining popularity and cultivated commercially by farmers of Kabrepalanchowk, Lalitpur, Kathmandu, Dolakha and Illam districts where sapling is supplied by a nursery in Kabrepalanchowk and by ICIMOD. It can be a source of cash income to farmers to improve livelihood. Also, in sloping land it helps in erosion control and sustainable land management practice. In the areas, economic yield is 40 to 60Kg per vine of 5 to 8 years old vines or 20 to 25tons per hectare [5].

Kiwifruit is propagated either sexually or asexually by grafting, micro-propagation or cutting and grafting on seedling rootstock is common commercial practices [6]. But the seed have low germination capacity [7] which makes Kiwi propagation difficult in general ways. During favorable condition and germination permissive environment too, seed germination is poor and erratic due to seed dormancy [8-12]. Stratification under cool and moist condition or gibberellic acid treatment improves germination rates [13,14]. Treatment with 2500ppm of gibberellic acid gives 31. 67% germination [15]. The higher concentration of gibberellic acid of about 2000ppm to 6000ppm for 24 hours shortens the germination period [16]. The use of GA3 primed seed is believed to increase the seed germination and seedling vigor. Since, the germination of Kiwi seed is low and there were unsatisfactory researches based on single factor it was necessary to combine several factors to increase Kiwi seed germination [17]. Thus, we used two factor CRD in this experiment to enhance seed germination of different varieties of Kiwi and specifically, to determine germination parameters of Kiwi seed.

Methodology

Preparation of Materials (seed and solution)

The fruits of Kiwi after a week of harvest were used for seed extraction: peeled, cut and crush to separate seed from pulp. These seed were cleaned (rinsed with water), dried and were packed in polythene seed packet before priming. The GA3 powder was dissolved in water using ethanol (99%) and slight heat to get required concentration viz. 2000ppm, 4000ppm and 6000ppm.

Experimental Design

Laboratory test was performed in Horticulture Laboratory, Lamjung Campus. A two-factor factorial Complete Randomize Design with six replications were used with following treatments:

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Each of treatment had 150 seeds with 25 seeds in each of 6 replications. 12 beakers each containing 150 seed of 3 variety in equal proportion were taken. Distilled water, 2000ppm GA3, 4000ppm GA3 and 6000ppm GA3 was poured twice their volume and primed for 24 hours and dried for next 24 hours. Petri-dish covered with moistened filter paper (12mm) was used. Petridish was put for germination at 22oC in darkness in germinator. Rehydration for moisture maintenance was done as required.

Data Collection and Statistical Analysis

Each day scoring of each petri-dish was recorded, counting germinated when sprout is 2mm long. The scoring was done until no germination for 3 consecutive days. Removal of molded and dead seeds were continuous in the test period. The data from the test datasheet were used for calculating following parameters using excel.

Germination Date: According to Labouriau [12], First Day of Germination: to = Time for the first germination known as First Germination of Day (FDG). Last Day of Germination: tg = Time for the last germination known as Last Germination of Day (LDG). Time Spread of Germination (TSG): It is time in days between FDG and LDG in a germination test period.

Germination Percentage (GP): According to Labouriau [12], it is percentage of seed in which germination process ends to the sample taken in the experiment conducted.

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Mean Germination Time (MGT): According to Labouriau (1983a),

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Coefficient of Velocity of Germination (CVG): It is reciprocal of Mean Germination Time. According to Nichols & Heydecker [18],

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Coefficient of Variation of Germination Time (CVt)

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Germination Index (GI): As per Throneberry and Smith’s method, adopted by Maguire [19]

Lupinepublishers-openaccess-Agriculture and Timson Lupinepublishers-openaccess-Agriculture Ajmal Khan & Ungar (1998)

Uncertainty of Germination Process (U): According to Labouriau & Valadares [20]

Lupinepublishers-openaccess-Agriculture where fi = relative frequency of germination Lupinepublishers-openaccess-Agriculture

Synchrony of Germination (Z): According to Primack [21],

Lupinepublishers-openaccess-Agriculture where Lupinepublishers-openaccess-Agriculture combination of seeds germinated in i time

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Seedling Vigor Index (SVI): According to Abdul-Baki and Anderson [22]

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Where Sl = Average shoot length (cm)

Rl = Average root length (cm)

In above formulae,

ni = number of seeds germinated in the sample ith day or time observation

N = number of seeds taken in sample

ti = day or time of experiment from start to ith observation

k = last day or time of observation

G = Germination percentage and T = Germination Period

The parameters taken were statistically analyzed by Fischer test in two-factorial ANNOVA Complete Randomize Design in R - Stat 3.1.3 software package. The mean separation was performed by Duncan’s Multiple Range Test at 0.05 probability level.

Result

Number of Seed Germinated Per Day During Germination Period

Figure 1: Number of seeds germinated of different Kiwi varieties with 0ppm GA3.

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Figure 2: Number of seeds germinated of different Kiwi varieties with 2000ppm GA3.

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The first day of germination was 9th day and last day of germination was 38th day after sowing. Accordingly, time spread of germination (Germination Period) was of 30 days (Figures 1-4). The experiment revealed among Kiwi varieties without pretreatment of GA3, the variety Bruno had higher number of germinated seeds per day. This was significantly higher in the period of 19th to 33rd days after sowing (Figure 1). On the other hand, among seed pretreated with 2000ppm of GA3 Allison variety showed higher germinated seed per day during period 9th to 28th day after sowing which was significant (Figure 2).

Likewise, among the seed pretreated with 4000ppm of GA3, Allison had significantly greater number of germinated seeds during period of 9th to 23rd day (Figure 3). While, both Allison and Bruno had similar and statistically higher number of germinated seeds per day than. Abbot, among the seeds pretreated with 6000ppm of GA3 (Figure 4).

Figure 3: Number of seeds germinated of different Kiwi varieties with 4000ppm GA3.

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Figure 4: Number of seeds germinated of different Kiwi varieties with 6000ppm GA3.

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Effect of variety and GA3 on germination parameters viz. GP, MGT, CVT, MGR, U, Z, CVG and GI of Kiwi seed.

Significant difference was found between influence of variety and GA3 on the parameters of germination viz. Final Germination Percentage, Coefficient of Variation of Germination Time, Uncertainty of Germination and Germination index whereas for Mean Germination Time, Mean Germination Rate, Synchrony of Germination and Coefficient of Velocity of Germination wasn’t significant (images 1).

Table 1: Interaction effect of variety and GA3 on GP, MGT, CVt, MGR, U, Z, CVG and GI of Kiwi seed.

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Note: GP → Germination Percentage (%), MGT → Mean Germination Time (day), CVt →Coefficient of Variation in Germination Time (%), MGR → Mean Germination Rate (day-1), U → Uncertainty of Germination Process (bit), Z → Synchrony of Germination (unit less), CVG → Coefficient of Velocity of Germination (%), GI → Germination Index (seed day-1)

*p – value < 0.05

**p – value < 0.01

Germination Percentage

Bruno with 0ppm of GA3 had significantly higher germination percentage (68.67%) than other treatments. It was followed by Allison with 6000ppm statistically at par with 4000ppm, 2000ppm and 0ppm. Minimum germination was found in Bruno with 2000ppm (12.00%) which was statistically at par with Abbot with 2000ppm, 4000ppm and 6000ppm; Bruno with 4000ppm and 6000ppm. This showed germination capacity of Kiwi seed is influenced by gibberellic acid concentration. Allison with 6000ppm with higher followed by continuously decreasing germination with 4000ppm, 2000ppm and 0ppm which clearly showed stimulating effect of the gibberellic acid on germination of Allison seed whereas opposite effect in Bruno variety indicated gibberellic acid at higher concentration can have inhibitory effect on germination as well.

Mean Germination Time

The overall Mean Germination Time was found to be 21 days and shortest time of germination was for Allison with 6000ppm (17 days) and longest time of 24 days was taken by Abbot with 0 ppm which was at par with 24 days taken by Bruno with 6000ppm which again showed negative effect of gibberellic acid on Bruno.

Mean Germination Rate

Mean Germination Rate is reciprocal to Mean Germination Time mathematically which was showed by analysis too which is Allison at 6000ppm (0.059 day-1) had maximum rate and Abbot with 0ppm along with Bruno with 6000ppm had the slowest rate.

Coefficient of Variation of Germination Time

Bruno with 0ppm (222.53%) had highest coefficient of germination time which was statistically at par with coefficient of Allison with 6000ppm and 4000ppm. Furthermore, both Abbot and Bruno with 6000ppm, 4000ppm and 2000ppm; and Allison with 0ppm had statistically inferior coefficient of variation of germination time.

Uncertainty of Germination

The germination was most spread for Bruno with 2000ppm with uncertainty of germination 1.06 bit which is statistically at par with Bruno with 4000ppm and 6000ppm along with Abbot with 6000ppm. The degree of spreading time of germination was least for Bruno with 0ppm followed by Allison with 6000ppm, 4000ppm, 2000ppm and 0ppm. As a whole 2.1-bit uncertainty of germination indicated Kiwi seed has a higher degree of germination in germination period.

Synchrony of Germination

The grand mean of Synchrony of Germination 0.07 indicated negligible degree of overlapping was seen in germination. Being non-significant greater synchrony was for Allison with 4000 (0.10) and Bruno with 6000ppm (0.11) and lowest for Abbot with 2000ppm (0.01).

Coefficient of Velocity of Germination

The number of seeds germinated per unit time was greater for Bruno with 4000ppm with CVG of 3.41% followed by Allison with 6000ppm, 4000ppm and 2000ppm. It is similar to the rate of germination.

Germination Index

The germination index was found to be maximum for Bruno with 0ppm statistically superior to others. All GA3 treatments of Abbot and Bruno (excluding with 0ppm) has lower germination index than Allison with GA3 treatments.

Effect of variety and GA3 on Seedling Vigor Index and Root Shoot Ratio

Seedling Vigor Index (295.18) was greatest for Allison with 6000ppm and lowest for Bruno with 6000ppm and lowest for abbot with 0ppm GA3 which had no difference statistically (Figure 5). The Root Shoot Ratio of the Kiwi germinated seed after 38th day of sowing (Figure 6). The average Root Shoot Ratio was 0.2235 for the Kiwi and variety Allison, Abbot and Bruno had 0.2310, 0.2253 and 0.2145 as Root Shoot Ratio respectively.

Figure 5: Seedling Vigor Index of Kiwi germinated seed pretreated with different concentration of GA3.

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Figure 6: Root Shoot of Kiwi germinated seed pretreated with different concentration of GA3.

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Discussion

Number of Seed Germinated Per Day During Germination Period

The first day of germination was 9th day after sowing which is earlier than first germination after 1 month of harvest [23]. Furthermore, last day of germination was 38th day after sowing, while findings show in control condition it takes 52 days to complete germination [24]. Accordingly, spread of germination (Germination Period) of 30 days is also shorter than that at normal condition. This result is supported by reasons that period of germination is shorten by 2000 -6000ppm of GA3 priming for 24 hours [25,16]. These shortening of first and last day of germination is due to GA3 effect on rate of germination. This effect is due to increased imbibition of water for initiation of germination and increased cell division [26]

Germination Percentage

The result for germination percentage of Bruno variety is in accordance to Mattiuz et al. [27] that low germination of 35.47% seeds treated with 6000ppm GA3 than germination of 36.85% with 2000ppm. The findings of Ozcan and Erisgin [15] that 6000ppm of GA3 has low germination (35%) than 2000ppm of GA3 with germination (44%) also similar to our result.

On the other hand, researchers have performed experiments which resulted higher germination at higher concentration of GA3 such as 79% germination at 6000ppm GA3 and 28% germination of untreated seeds [17]. This findings are in accordance to the result of variety Allison and Abbot in this experiment. The germination stimulating role of GA3 in Allison and Abbot variety is mainly due to breaking of dormancy that substituted necessity of stratification [28]. Its acts on germination promotion as it removes impermeability of seed coat [29] and it helps exposing macrosclereids cells in imbibition of water for initation of germination [26]. Its affect in cell division and dry weight gain which shows marked effect on seedling growth [28]. However, the germination retarding or negative effect in Bruno variety is due to low chilling requirement of the variety which is ill affected by higher concentration of GA3. This inhibition can be compared to findings that germination inhibition is nearly associated with stimulation which appers in different concerntration, sometimes one after another [30]. The performance of untreated seeds can further be explained from previous facts that germination is improved by activity of antioxidants like superoxide dimutase, catalase and ascornbate peroxidae which is achieved by hydro priming only [31].

Mean Germination Time

The overall Mean Germination Time was found much lower than that previously reported Kiwi seed takes 52 days for germination [24] at 15oC under controlled condition which indicates GA3 hastens the process of germination and increase rate. This finding of shorten mean germination time on seed priming is supported by result of Lawes and Sim [25] that GA3 2000 - 6000ppm shortens germination period. This is because GA3 helps in early seed emergence and growth [32,33]. Overall period and time of germination shortened because of dormancy breaking action of GA3. It stimulates hypocotyl growth by initiation of cell division and elongation by primarily acting on cell division, then on cell enlargement [34,35].

Mean Germination Rate

Findings of Ynoue et al. [14] that chemical treatments using GA3 for 24 hours or stratification increases germination rate supports this result of overall increase in germination rate which also resulted shortened mean germination time.

Germination Index

The result indicates that variety had greater influence in germination index while it is less effected by GA3 concentration. The average germination index of 1.05 (higher than 100%) showed similar germination per day of Kiwi seed in germination period. The similarity and correspondence in GP and GI show to the report that use of germination percent eliminates the effect of sample size to calculate germination index than number of seeds germinated [36].

Seedling Vigor Index

Ashraf and Foolad [37] reported seed primining enhance the seedling vigour which contrasts our findings. Also, higher superior seed vigor index and seedling dry weight than non-primed cowpea seed [38-40] contrast our finding.

Conclusion

It can be inferred from the experiment that GA3 primed seed have faster germination rate and lower mean germination time than hydro-primed seed. Seed germination can be enhanced by treating 4000-6000ppm GA3 for Abbot, Allison while Bruno requires no pretreatments of seeds.

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Tuesday 29 December 2020

Lupine Publishers | About Economic Justification of Determining the Optimal Depth of Flowing Well

    Lupine Publishers | Current Investigations in Agriculture and Current Research


Abstract

The article concerns the problem of determining the optimal depth of flowing well. It suggests that the increase of the well yield subject to the elongation of water intake part occurs rather irregularly, and its pattern is more likely to be hyperbolic. Based on the detail analysis of the case it is not recommended to situate the water intake of the well along the all thickness of the aquifer since there comes a time point when the capital inputs made for further elongation of the water intake are not compensated by the corresponding yield increase. As first approach we suggest that the length of the water intake filter should be accepted of (0,5 … 0,6) size of the aquifer part. For precise determination of optimal length of the water intake, thus for the entire well, it is suggested to build the curve of capital unit costs by formula (11), determine the coordinates of points of its minimum and, following this, as a final result – appropriate for it length of water intake.

Keywords: Flowing well; Yields; Hydraulic resistance; Water intake filter; Optimal depth; Capital costs

Introduction

The highly confined aquifer of the Ararat valley, which in general is a source of drinking water supplied to the Republic settlements, is situated at a great depth. Huge capital inputs are required for building here each water intake flowing well. The costs that depend on the drilling depth, in case the rest conditions are equal, increase in direct ratio. At that, in case of great depths (dipper than 50 m) the cost of drilling 1 linear meter rises 1,63 times. Considering this, it is important to develop a method of determining the optimal depth for embedding the well.

Materials and Methods

To minimize the construction costs of flowing well it is necessary to reduce the drilling depth as much as possible. It is clear that reduction of depth will be done only within the limits of the aquifer, by minimizing the length of the water intake part. But the reduction of the latter causes the increase of imperfection coefficient of the well and this in its turn leads to a significant yield drop. In case of pump-operating vertical well the size of depth reduction can be minimized if the piezometric head drop is increased, whereas in case of flowing well it is impossible since the water intake here is mainly performed at the expense of inner elastic compression energy some part of which actually will be spent on overcoming the generated additional hydraulic resistances. From the theory of groundwater movement, we know that the functional relation of water intake filter length and well imperfection coefficient is hyperbolic, and when the length of the water intake reaches to the half of aquifer thickness its inclination abruptly changes, and it asymptotically gets close to the horizontal axis [1-3]. That is why during the constant elongation of water intake part the yield at first increases more abruptly, but further its growth decreases. There comes a moment when the further elongation of the water intake does not cause such considerable yield increase which can compensate additional capital expenses done for this elongation.

The essence of the problem is to determine such depth of flowing well in case of which the capital expenses done for producing one-unit yield will be the least. Let us consider the solution of the problem at first approach by assuming that the well construction costs, dependent on its depth, increase in a way of direct linear relation. It should be mentioned that in case of flowing well we certainly must consider also the energy longitudinal losses in the water intake filter. Let us calculate these losses considering the water intake as a pipe with equally distributed affluent with q intensity [4-6]. For the pressure losses on length dz in cross section z, by the Darcy-Weisbach equation we can write:

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where QB- affluent of subterranean waters through the well bottom, λ-Darcy’s coefficient, ro- radius of the well.

Herein, with some approximation, we accept that λ along the entire length of the water intake filter does not change and has the same value as it is in the blind part of the well (Figure 1).

Figure 1: Design scheme of determining the pressure losses in the water intake.

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By integrating equation [1] along the entire length of water intake, we get:

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based on which

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Usually there is a settler built at the end of the water intake of the well at the availability of which we get QB=0. In this case equation (3) will get the following look:

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Formula (4) indicates that pressure losses at variable yield make up 0,33 part of losses on the same length with constant Q yield. In case there is no settler, partially, in the fractured rocks, ignoring QB does not lead to significant errors. It is justified by considering that if the water intake has such length at which we should also take into account the pressure losses, thus, as a rule, the total affluent along the length certainly exceeds that of the bottom. For determining the yield of a single operating flowing well N. Melikyan suggested the following formula [7-10]:

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where k is aquifer filtration coefficient, m is bed thickness, Hp is positive pressure of the wellhead,

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 is transmissivity coefficient of this bed, μ*-ն elastic yield coefficient, t is the time for which the well yield is determined, ξ=ξ12 is the general imperfection coefficient of the well, ξ1 and ξ2 are imperfection coefficients according to the aquifer passing pattern and size, respectively; η is total inner hydraulic resistance:

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where ℐ and ℐF are respectively the lengths of blind part of the well and of the water intake, λ – longitudinal resistance coefficient of hydraulic friction which for simplicity is accepted the same in both parts.

To solve the problem let us consider variation of Q, when in equations [5] and [6] the only variables are ℐF and ξ2. In this case from equation [5] we get:

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At that ξ2 relation from ℐF can be accepted according to VM Shestakov [11-14] in the following way:

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where ε coefficient is determined in accordance with the following table: Approximating (8) the data in Table 1, we get

Table 1:

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To determine the capital construction costs of the whole well we use the following equation:

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where Kօ is the cost of one linear meter of the well which is chosen according to the corresponding standards in accordance with the soil types. The capital unit cost of the yield produced by the flowing well will be as follows:

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Results and Discussion

We can determine economically efficient depth of the flowing well on the basis of extremum condition of F(ℐF) function:

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As we see in formula (11) (Table 2), the analytical solution of equation (12) depends on considerable mathematical complexities, though they can be circumvented if the problem is solved graphically. Let us elucidate it by the example of a flowing well of the Ararat valley, the aquifer hydrogeological characteristic of which is as follows: k = 40 m/day, m = 50 n, HB = 20 m, а = 2·104 m2/ day, well radius ro = 0,1 m, the aquifer roof is situated at 50 m depth (ℐ= 50 m) from the earth surface. For clarity let us assume that the coefficient of longitudinal friction resistance at the entire length of the well, including also the water intake part, remains constant, and in this case λ = 0,012, let us also accept that the well in accordance with the aquifer passing pattern is perfect (ζ1= 0).

Table 2: Calculation of Capital Unit Costs.

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By the values of the aquifer and well parameters, the formula (7) constants will be as follows:

A=19,92; B=1749,9 1/m; C=1,734 · 10–3 1/m; D1 =0,8 m, D2=3,96·10-3.

Inserting these values in formula (7), we have:

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Figure 2: Graphs of ζ= ƒ1(ℓF)‚ Q=ƒ2(ℓF) and K=ƒ3(ℓF) functions.

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By giving to ℓF different values in the interval from 0 to 50 m, let us calculate ζ2 by corresponding to them formula (9), Q - by formula (5), K - by formula (10) and Lupinepublishers-openaccess-Agriculture - by formula (11). Based on the data presented in columns 1, 3, 4 and 6 of Table the graphs of ζ21(ℓF), Q= ƒ2(ℓF) and

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dependences are built and suggested in Figure 2. As we see in the graph, function ƒ3(ℓF) has one extremum point and it is the minimal. The value of ℓF corresponding to this point will be the economically optimal length of the well water intake. In the studied example it makes up ℓF = 26 m, thus the total length of the well will be 76 m.

Conclusion

  1. The functional relation of the flowing well yield and its water intake length has approximately hyperbolic view and after some values of the water intake length the capital inputs done for its elongation are not compensated by the corresponding yield increase.
  2. Drilling of flowing well along the entire thickness of the aquifer is not economically efficient.
  3. The length of the well water intake at first approach is suggested to be assumed 55 - 65 % of the aquifer size.
  4. In case of any proximate existing initial data the water intake optimal length can be defined if the curve of capital unit costs will be built up by formula (11) and its minimum point will be defined.

Monday 28 December 2020

Lupine Publishers | Rodent Control Strategies in Houses

   Lupine Publishers | Current Investigations in Agriculture and Current Research


Abstract

Rats and mice are not only a nuisance but can also cause property damage and transmit diseases. You’ll know they’ve arrived if you see rodent droppings near a food source or shredded fabric or paper. If you identify rodents, there are several steps to take to ensure permanent removal of these pests. Removing rodents with traps or poisons will not keep rodents out of your home in the future. To permanently keep rats and mice out of your home or business, you will need to prevent access by sealing all possible entry points. It is equally important to eliminate rodent attractions such as food and water by keeping food in tightly sealed containers and repairing leaky pipes.

Introduction

All rodents require food, shelter, and water. The shelter provides protection from predators, inclement weather, and a favorable place to bear and rear their young. Although rodents require water, those water requirements vary greatly by species. Because rodent food and cover (i.e., vegetation) can be influenced by human activities, there has been considerable development of strategies to reduce populations and damage by manipulating vegetation [1,2]. Use exclusion and sanitation tactics to get rid of rodents in a safe and cost-effective way. The most effective long-term solution is to keep rodents out in the first place. Measures such as sealing entry points prevent rodents from entering buildings and help you avoid a fullscale invasion. Follow the tips in the sections below and you will be one step closer to keeping your home permanently free of rats and mice (SRC).

Common sources of food and water are attractive to rodents

  1. Food in unsealed containers such as bags of chips, rice, cereal, crackers, flour, and other non-perishables.
  2. Pet food and water left out overnight or in a bag rather than in a secure container.
  3. Fruits or vegetables in open bowls left outside of refrigerator.
  4. Leaky pipes or faucets throughout the house.
  5. Close trash (SRC).

Common rodent access points

  1. Holes near cabinets, closets or doors leading to outside or crawl spaces.
  2. Holes around sink or appliance pipes.
  3. Cracked foundations in the basement or unscreened ventilation holes in the attic, especially in older structures.
  4. Holes around windows or doors.
  5. Missing screens in vents or crawl spaces under buildings.
  6. Once you have blocked the access points and removed sources of food and water, you’ll need to eliminate the remaining rodents. The following sections offer an overview of different treatment options and serve as useful guidance for keeping your home or business permanently free of rats and mice (SRC).

Guidelines to Maintaining a Rodent-Free Home

Three Guiding Principles:

Prevent

Seal entry points to prevent rodents from entering your home or business. Be sure to use 1/4” x 1/4” metal mesh to seal off existing entry points.

Remove rodent attractions such as food or shelter by ensuring that food is securely stored and that surroundings are clean.

Identify

Look for signs of rats and mice such as rodent droppings round food, kitchen corners, inside cabinets or under sinks.

Also, look for nesting material such as shredded paper or fabric.

Treat

Remove rodents by using snap or electronic traps. Be cautious with live traps as rodents might urinate which increases the risk of spreading disease (SRC).

Outdoor recommendations

  1. Don’t plant ivy — it provides shelter and a food source for rodents: snails and slugs. Ivy on walls can form “rat ladders” to windows, attics and other interior spaces.
  2. Keep compost piles as far away from structures as possible and grass cut to no more than two inches tall.
  3. Maintain at least a 2-foot space between bushes, shrubs, fences, and buildings. Also, remove tree limbs within 3 feet of a structure or roof.
  4. Avoid having a bird feeder since it provides a source of food for rodents.
  5. Keep outdoor grills and cooking areas clean.
  6. Keep firewood off the ground and as far away from structures as possible to mitigate shelter opportunities.
  7. Use city-issue plastic trash bins. If cracked or missing a lid, contact the Department of Sanitation for a replacement (SRC).

Indoor recommendation

  1. Encase all food items such as breakfast cereals, chips, and crackers in containers.
  2. Opt for garbage bins and compost containers with a top that seals tightly.
  3. Rinse food and beverage containers before discarding or recycling.
  4. Clean your garbage and recycling bins frequently.
  5. Do not leave pet food or water out overnight.
  6. Maintain stove tops clean and free of food scraps.
  7. De-clutter your home of papers, fabric, and any similar materials that attract rodents for nesting.
  8. Repair leaky pipes.
  9. Seal entry points around cabinets, interior walls, attic, and crawl spaces with steel wool, caulk, or 1/4″ x 1/4″ metal mesh.
  10. Maintain attic, crawl spaces, and cabinets near sinks clean and free of moisture (SRC).

Promote natural predators

Natural predators such as cats, snakes, hawks, and owls can help to control rodent populations by feeding on rats and mice (SRC).

Treating rodent infestation

If you confirm that rats or mice are present in your home, you will need to use a combination of preventative measures and treatment options to get rid of them. The preventative measures include, removing food, water, shelter, and access to your home. This section will focus on the treatment options available and provide an overview of traps (SRC).

Types of traps

Benefits of using traps: Using traps instead of rodent poisons gives you clear confirmation of a captured rodent and allows you to better gauge the effectiveness of treatment. You are also able to dispose of rodents immediately rather than dealing with the foul odor of rotting carcasses from poisoned rodents inside your walls or otherwise out of reach. Most important, using traps allows you to avoid rodenticides, which pose a greater threat of exposure to children, pets, and non-target wildlife, including natural predators (SRC).

Traps description

Live-animal trap: This is a catch and release system that avoids killing a rat or mouse. Some states prohibit releasing rodents into the wild. The Center for Disease Control (CDC) warns that captured rats or mice might urinate and increase risk of spreading disease.

Snap trap: This is the oldest type of trap and uses a springloaded bar to kill a rodent on contact. Some modern snap traps prevent risk to children and pets by enclosing the device in a plastic box.

Multiple-Catch Live Mouse Trap

This is a catch and release system that allows for capture of multiple mice.

Glue trap

Glue traps are not recommended because the adhesive plate that is used to capture rodents can also trap birds, baby animals, lizards, and even pets. These traps also cause undue suffering to rodents. The CDC warns that captured rats or mice might urinate and increase the risk of spreading disease. Enclosure boxes are plastic boxes that can fit a single snap trap, sometimes more, in order to provide an additional layer of protection for kids and pets. These boxes also hide the dead rodent, making for easier disposal of rodent, and can be re-used (SRC).

Electronic trap

This battery-powered trap delivers an electric shock that kills rodents quickly. This is a newer type of trap, and models are available for both rats and mice.

When using traps, take the following safety steps

Be sure to place traps in locations where children and pets cannot access them or place traps in safety enclosure boxes.

Cleaning up after trapping rodents: The Center for Disease Control (CDC) recommends the following safety tips:

  1. Use gloves when disposing of dead rodents, nests, or any nesting material.
  2. Spray the dead rodent or nesting material with a disinfectant solution and allow them to soak for 5 minutes before disposing rodent or materials in a secure plastic bag.
  3. Spray and wipe up the area surrounding dead rodent or nesting material with a disinfectant.
  4. Place the plastic bag with rodent or nesting material into another plastic bag along with any wipes or rags that were used to sanitize the surrounding area.
  5. Be sure to wash your hands thoroughly with soap and water (SRC).

Rodenticides

  1. Rodenticides consist of different types of poisons used to kill rodents. Rodenticide baits can be lethal for any mammal or bird that ingests them and are not only poisonous for rodents. As a result, all baits pose a high risk of poisoning for non-target animals that might eat the bait or consume a poisoned rat or mouse.
  2. If you choose to use rodenticides, you should be ready to deal with these potential consequences:
  3. Rodents are likely to die in locations where they cannot be retrieved. The smell of a dead animal will persist for several weeks to several months.
  4. If you or your neighbors have cats or dogs, they may die or become acutely ill from eating poisoned rodents.
  5. Predatory birds like hawks, eagles and owls, and mammalian predators such as foxes and coyotes may die from eating poisoned rodents or a rodenticide bait.
  6. Children are at risk of accidental poisoning since they might mistake the rodenticide bait for candy or food.
  7. If after assessing the risks to children, pets, and wildlife of using rodenticides, you still determine that rodenticides are necessary, take these precautionary steps to reduce risk:
  8. Always read and follow the label instructions on the pesticide product. The label is the law and you could be liable for any damage resulting from not following the label instructions.
  9. Use only US EPA approved products that are sold and used with tamper resistant bait stations to protect children, pets, and wildlife. See US EPA’s list of rodenticide bait station products here (EPA) [3].
  10. Indoors, only place rodenticide bait stations in locations that are completely inaccessible to children and pets—inside walls, under heavy appliances, or in enclosed crawlspaces.
  11. It is best to use anticoagulants because they are environmentally safe [4].
  12. Once all signs of rodents are gone, remove bait stations promptly by placing in a secure plastic bag [5,6].

Achieving Success

Preventing and treating rodent infestations requires a combination of eliminating access points rats and mice might use to enter your home, removing food sources and shelter that attract rodents, and using traps to get rid of existing rats and mice in or around your home. Using a multi-tactic approach to manage rodents decreases the risk of dealing with future infestations since a significant piece of the puzzle is adopting preventative measures such as blocking access and eliminating food and water sources that attract rats and mice (SRC) [7].


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