Another nested case-control study in the US among 993 high-risk pregnant women showed that smoking during pregnancy was associated a higher PlGF and lower soluble endoglin –an anti-angiogenic factor– in the second trimester, but no association with sFlt-1 was observed . The subclinical association of maternal smoking with a higher pro-angiogenic state may be attributable to alterations in trophoblastic invasion and differentiation, and explain the previously reported association with a lower risk of preeclampsia . The current study also showed that cannabis use before and during pregnancy was related to a pro-angiogenic state with lower sFlt-1 and higher PlGF concentrations in both the first and second trimester, whereas cannabis use in early pregnancy showed an anti-angiogenic state in cord blood at delivery. To the best of our knowledge, no previous human studies have examined the associations of maternal cannabis use in pregnancy with angiogenic factors during pregnancy. However, previous animal studies have shown that exposure to Delta-9- tetrahidrocannabinol  during pregnancy alters the placental microvasculature impairing trophoblast cell migration,cannabis grow tray narrowing the vascular network and increasing the labyrinth area .

The impairment in the placental development could be potentially mediated by cannabinoid receptors, since chronic Δ9-THC exposure leads the down-regulation of cannabinoid receptors . Δ9-THC may play a pivotal role in impairing placental angiogenesis . In sum, maternal tobacco and cannabis use in pregnancy may disrupt the normal angiogenesis processes and thereby result in suboptimal placental development. We also observed that maternal tobacco use before pregnancy was associated with higher placental weight, while continued tobacco use during pregnancy was associated with lower placental weight. Maternal continued tobacco and cannabis use were also associated with a higher PW/BW ratio and a higher risk of pregnancy complications. Altered placental growth may be an important predictor of short- and long-term adverse outcomes for the mother and her offspring . In line with our findings, previous studies have shown that pregnant women who stopped smoking had larger placentas, whereas pregnant women who continued smoking had lighter placentas, a higher PW/BW ratio and an increased risk of pregnancy complications . A higher PW/BW ratio also suggests less efficient placental function and reduced nutrient supply to the fetus .

Consistent with our findings, previous observational studies at mid- and late-pregnancy have reported a higher umbilical and/or uterine artery resistance indices in maternal tobacco or cannabis users than non-users, which is a proxy measure for an abnormal placental villous vascular tree . The subclinical association of maternal tobacco and cannabis use with higher umbilical and/or uterine artery resistance indices and the imbalance in angiogenic factors could be attributable to alterations in trophoblastic placental tissue . Therefore, vertical grow system maternal tobacco and cannabis use during pregnancy may have the capacity to alter the placental morphometry and function. Alterations in placental development may lead to subsequent pregnancy complications. The association of maternal tobacco or cannabis use with higher risk of pregnancy complications has long been studied and well documented by observational studies . In our study, no association was observed between maternal tobacco or cannabis use and preeclampsia, gestational hypertension or preterm birth. However, the direction of the odds of these associations seem to be in line with previous studies . Consistent with previous findings, our study showed that continued tobacco or cannabis use during pregnancy was strongly associated with a higher risk of being small for gestational age . Several studies have reported that the risk of preeclampsia was lower among women smokers than non-smokers .

Thus, tobacco and cannabis might have differential effects on placental development and pregnancy complications. Further studies are needed to disentangle the underlying mechanism of these associations. The strengths of our study are the population-based prospective design, the large sample size, and the availability of different angiogenic biomarkers of placental development at different time points, as well as extensive information on potential confounders. Some limitations need to be discussed. First, the Generation R Study consists of a healthy population of pregnant women with relatively few pregnancy complications. Second, while blood samples were available for 94.5% of the mothers, cord blood samples were only available for 48.4% of the newborns. Third, the self-reported assessment of tobacco and cannabis is a valid method, but misclassification may be possible. Participants may have underreported their tobacco and/or cannabis use, which could potentially have led to an underestimation of the observed associations.

The aim of this study was to inform the debate leading up to the New Zealand cannabis referendum by conducting an MCDA with a range of key national stakeholders to identify their preferences for cannabis reform outcomes and in doing so rank cannabis policy reform options. A central aim of our study was to involve a broader range of stake- holders in the MCDA assessment as suggested in recent critiques of MCDA. While these stakeholders possessed practical experience of different aspects of cannabis outcomes, they did not necessarily have de- tailed knowledge of the evidence related to the outcomes of cannabis policy reforms implemented overseas, or the wider research literature on the health and social risks of cannabis use. They also had limited time to digest this research literature and attend a multi-day decision-making workshop . Consequently, to ensure as many stakeholders as possible were able to attend the workshop, much of the development of the MCDA model was completed in advance via a collaborative process with domestic and international cannabis policy experts.

This preliminary work allowed the MCDA workshop to be completed in a single day as stakeholder participants were able to go straight to normative trade-offs assessing projected out- comes from different reform options. From the perspective of the stake- holders,ebb and flow table the MCDA was therefore largely a group discrete choice experiment where they were asked to make comparisons between two alternative projected outcomes that differed in a specified way on a key criterion and reach consensus on the preferred outcome. Developing an MCDA model for evaluating cannabis policy reform options entails four broad stages:  defining the policy reform options,specifying the decision-making criteria and their outcome levels,  determining the relative weights for the different decision-making criteria and related levels, and  ranking the policy reform options based on the relative weighting of the criteria and levels .The two cannabis policy researchers based in New Zealand  initially identified the five key cannabis policy reform decision making criteria  and related levels, by drawing on New Zealand Government documents dis- cussing the overarching policy objectives of cannabis reform , previous New Zealand reports estimating cannabis harms and assessing law reform options, available New Zealand statistics on cannabis use and harm, and the policy evaluation literature from overseas cannabis reforms , 2020 ; Sense Partners, 2018. Criteria 1 – Health and social harm.

The baseline figure of the “health and social harm ”of cannabis use in New Zealand used in the MCDA model of $1.3 billion per year  was taken from the 2016 New Zealand Drug Harm Index commissioned by the New Zealand Ministry of Health . The NZ-DHI provides a comprehensive evaluation of the costs of cannabis use in New Zealand, including the personal and community harm of use and related costs of interventions . The NZ-DHI was written in collaboration with the New Zealand Ministry of Health and other government agencies who provided national statistics on drug use and harm for the report. This method- ology was adapted to New Zealand in 2008 and updated in 2016. The NZ-DHI authors acknowledge a number of gaps and limitations of official statistics which require simplifying assumptions to complete the estimates, including difficulty assigning harms from poly-drug use to individual drug types , quantifying the harm of drug dependency on families, and establishing the causal role of drug use in crime . A limitation specific to cannabis was New Zealand health statistics did not separate natural cannabis from synthetic cannabinoids,flood table recording them together as a combined “cannabinoid ”category . There is evidence from U.S. national data of increasing adult use, frequency of use and cannabis use disorder in legal recreational cannabis states . It has subsequently been noted that only four US states  had established cannabis retail outlets during the period of this study , and those had only been open for a relatively short period of time, suggesting that the longer-term impact of commercial legalization and higher potency legal products on harm is yet to be fully experienced . Evaluations of the impact of cannabis legalisation on youth in the early U.S. recreational legalization states  who implemented largely commercial regimes have found mixed results with meta-analyses suggesting small increases in use .

In this analysis, participants lost to follow-up were assumed to still be engaging in risky cannabis use. In Step 1 of the logistic regression, any demographic or cannabis use characteristics that were significantly different at baseline were entered into the logistic regression. In step 2, experimental group was entered as a dummy coded variable . This step tested the hypothesis regarding the impact of personalized feedback intervention. Secondary hypothesis 2, reductions in perceptions regarding how much others used cannabis, was measured using a continuous scale. As such, the analytic procedure was the same as was employed for the primary hypothesis. Secondary hypothesis 3 was tested using the using the PROCESS macro  to examine whether reductions in perceptions of how much others use cannabis at three months  was positively associated with reductions in the participant’s risky cannabis use at six-month follow-up.Intervention condition was specified as the independent variable in the model to examine whether reductions in normative perceptions mediated the effect of the intervention on reductions in risky cannabis use at six-month follow-up. Bootstrapping was used  to calculate a bias-corrected confidence interval for the indirect effect.

In the current era of rapidly shifting cannabis policies,vertical grow rack there is a need for accessible and scalable interventions for individuals who are engaging in risky cannabis use. This study examined the efficacy of a brief, online personalized normative feedback intervention in a large, non-college sample of adults in Canada following national legalization of recreational cannabis use. Participants who received the personalized normative feedback intervention did not reduce their cannabis use between baseline and three- and six-month follow-ups to a greater extent than those who received the educational materials only. Further, while receiving the normative feedback information did have an impact of participants’ perceptions of how common cannabis use was among adults of the same age and gender, this change did not mediate the impact of the intervention on their own cannabis risk level. As such, it appears that the trial failed to find a significant impact of the intervention on cannabis use. There are several possible reasons for these findings. One possibility is that the educational materials also motivated reductions in cannabis use and the intervention was unable to promote a larger reduction than the provision of these materials alone.

However, the current trial was not designed to test for this possibility so it would be inappropriate to claim that both interventions worked vertical grow table. Another possibility is that the intervention was not an effective means of motivating reductions in cannabis use, particularly among our sample of somewhat heavier users of cannabis. As brief interventions are meant for those with ASSIST scores over 4, and not necessarily on the end of the scale, this may have contributed to the findings observed. Moreover, a recent meta-analysis uncovered that personalized normative feedback may not be effective at reducing drug use without the provision of additional interventions . While the literature is still quite young on the use of personalized normative feedback for substances other than alcohol, we cannot assume the intervention was completely ineffective. The intervention was developed based on a sound theoretical foundation and employed content that has demonstrated efficacy in motivating change in trials targeting other addictive behaviors. This does raise the interesting possibility that there is something different in the use of cannabis versus the consumption of alcohol that then makes social comparisons, and the correction of normative misperceptions, ineffective as a means to motivate change.

Perhaps, while the recreational use of cannabis is now legal in Canada, there is still a counter-cultural mystique to its use. Also related, some participants provided feedback that cannabis use was healthy and queried why we were trying to say its use was bad. While these comments were not common, they might capture the general tone of a proportion of those people recruited for the trial i.e., being unconcerned about their own cannabis use but instead participating because they were interested in issues relating to using cannabis . Other relevant factors to consider when interpreting the results of this trial have to do with the time when it was conducted. First, cannabis use was legalized just a few years previously and the ready availability of cannabis from commercial sources was still continuing to expand . This relative newness of cannabis as a legal substance might be a situation where normative comparisons are less meaningful to those receiving them. Further, with the prevalence of cannabis use increasing, it might be easier for participants to discount information about how much others smoke . Finally, it is unknown what the impact of the pandemic had on peoples’ need to find activities that were distracting  or on the efficacy of this intervention.

In general, administering THC as treatment for CUD carries an element of clinical and ethical concern due to the emerging evidence suggesting that cannabis products with high levels of THC have detrimental effects on mental health and cognitive function among adult and youth users . These concerns are very relevant considering the high rates of psychiatric co-morbidity and negative neurocognitive impact in youth and adults with CUD . Furthermore, the concerns are particularly pertinent with adolescents and emerging adults, as the developing brain is believed to be more susceptible to the adverse effects of cannabis exposure, and THC may interfere with neurodevelopmental processes influenced by the endocannabinoid system . However, in the studies that included cognitive assessment, findings suggest that THC-containing cannabinoid treatment decrease cognitive performance: one study found that 8 mg/day of nabilone  worsened psychomotor task performance , and another found that dronabinol worsened psychomotor task performance and working memory .

While studies of nabiximols reported no differences in adverse events between treatment and placebo groups ,grow lights for cannabis some studies found adverse events related to dronabinol, such as dry mouth, rapid hear, flushing and hypotension . In studies that reported serious adverse events, these were deemed not study related . A final point that is relevant to consider is that THC may interfere with daily functioning, because of its cognitive impairing effects. For example, dronabinol has been found to impair driving performance in a dose-dependent manner , which has implications for potential risk of road accidents attributable to medicinal use of THC in treatment of CUD. As reviewed in Section 5.2, the effect of FAAH inhibitors and CBD on CUD has been much less studied, but evidence from the first two placebo-controlled RCTs in adults with cannabis dependence suggests that FAAH inhibitors can reduce withdrawal symptoms and cannabis use, and that CBD can reduce cannabis use. Furthermore, there were no differences between control groups and groups receiving FAAH inhibitors or CBD regarding adverse outcomes . A key concern about administering pharmacotherapies to youth is their safety. In the only trial to date, the FAAH inhibitor PF-04457845 was administered to male adults aged 18-55.

The trial did not include females of childbearing potential due to the previous lack of safety and toxicity data on PF-04457845. Now that these data are available, a subsequent phase 2b trial is being conducted in males and females aged 18–60 . Due to a lack of safety or toxicity data in younger people, the potential of PF-04457845 in treating youth CUD is currently unclear. There is also limited data on the safety of THC administration in youth, with only one study to date administering THC to adolescent volunteers , as well as the already mentioned concerns about the impact on the developing brain. While the safety and efficacy of CBD for treating CUD in youth is yet to be established, the potential safety of administering CBD is supported by several trials of CBD as a treatment for severe treatment-resistant epilepsy in children . Furthermore, an emerging literature suggests that CBD contains opposing neural, cognitive, and behavioral effects that interact with, and may counteract, some of the harmful effects of THC on cognitive functions, anxiety, and psychotic symptoms . Some studies also point to a greater addiction potential in products with high levels of THC and low levels of CBD .

These effects are mirrored in functional imaging studies, which have revealed opposing acute effects of THC and CBD in areas pivotal to the examined cognitive processes including amygdala ; striatum, grow cannabis hippocampus, and prefrontal cortex ; and auditory and visual cortex .Taken together, these findings point to a safer profile of CBD compared to THC. A potential benefit of cannabinoid treatment in general is that it may be more acceptable than traditional treatment  among cannabis using youth and adults, especially non-treatment seekers. In the only placebo-controlled RCT conducted with CBD so far, retention rates were very high: out of 82 randomized individuals with CUD, only 5 participants did not complete treatment , and in the only placebo-controlled RCT of FAAH inhibitors, 17 % dropped out of placebo and active treatment groups . Overall, drop-out rates were higher and more mixed in studies on THC-based cannabinoid treatment, see also Table 1. As such, cannabinoid medication – particularly non-THC based – may potentially help address the problem of low treatment uptake in youth.

For each lobbyist employed by a cannabis affiliate we examined their other funders and identified additional cannabis affiliates using the same inclusion criteria. Because the CDOS dataset does not include lobbying payments made without a connection to a specific bill, administrative rule, or is- sue, we expanded the dataset by manually appending payments from cannabis affiliates in months where no lobbying was conducted for a specific bill/rule. Including these “retainer ”payments allowed more accurate assessment of lobbying expenditures, because some funders make monthly payments to lobbyists rather than hiring them on an ad hoc basis. Funders also make payments to lobbyists before and after legislative sessions for work during the session. The completed search yielded a list of 1703 monthly payments from 89 cannabis affiliates with linked information on lobbyists they employed, positions on bills, and addresses. Each lobbying report available on the CDOS website included an “industry type ”field where lobbyists provide a description of the funder’s business. We coded these disclosures as “transparent ”if the name or description contained a reference to cannabis, marijuana, cannabis grow tray or hemp and “ambiguous ”if it did not. Cannabis industry affiliates could be represented by lobbying agencies, lobbyists, and subcontractors.

Cannabis affiliates may pay individual lobbyists or pay lobbying agencies  that funnel those payments to salaried lobbyists or subcontractors. Lobbying agencies sometimes list themselves as funders even though this practice was made illegal by the Lobbyist Transparency Act, 2019 . We excluded reported self-funding because it was impossible to identify the under- lying funder. To prevent double counting, we only included direct payments from cannabis affiliates and excluded payments to subcontractors and employees salaried by lobbying agencies. Our primary measure was lobbying expenditures, which we adjusted for inflation using consumer price index data from the U.S. Bureau of Labor and Statistics . We coded for cannabis affiliation, date of payments, address of funders, names and addresses of lobbyists, self-reported industry type, industry type identified through business records, and positions on proposed legislation. We reviewed cannabis lobbying expenditures in Colorado over time using Stata 16 and then qualitatively reviewed lobbying positions on proposed legislation. Our analyses assessed total cannabis lobbying expenditures and the share drawn from national sources,the extent to which expenditures were clearly identified as associated with cannabis,vertical grow system and  alliances with other industries. We conclude with a case study of cannabis industry efforts to create cannabis consumption establishments.

We selected this issue because legislation on the topic was introduced multiple times over the course of three years and under two gubernatorial administrations, allowing insight into changes in lobbying practices over time. We collected data from audio recordings of legislative testimony and floor debate, legislative histories, fiscal notes, and lobbying reports for all legislation dealing with cannabis consumption establishments available through the Colorado General Assembly and Secretary of State websites. We present a narrative description of each bill’s legislative history, including information from lobbying re- ports and demonstrative quotations made in public testimony that indicate cannabis industry influence in the policy making process.

These findings warrant further exploration, and may indicate a need for the development of additional,novel protections for privacy and legal and clinical care consequences and improved means of relaying such protections to patient populations. It also supports the value of triangulation of data from multiple sources. Aerobiological monitoring of pollen grain concentrations in the atmosphere is useful for detecting anomalies in the biodiversity of anemophilous species and the climate . Sufficiently extensive records of airborne pollen data can therefore be considered suitable bio-indicators to assess the behaviour, conservation and pollination disturbances of vegetation .Long-termpollen databases provide excellent means for studying the effects of climate change on pollen-producing plants . In addition, they offer the possibility of establishing forecasting tools such as regression models, time series or the use of artificial intelligence . These tools are essential for many specific applications , such as helping people avoid allergenic elements.It is an herbaceous, usually dioecious plant, although it can also be monoecious. It has been widely used to produce fibre , bird food ,vertical grow rack essential oils and narcotics. Some controversy about its taxonomy exits, but it is classified as a single Cannabis species, C. sativa .

Some of its varieties are cultivated to produce marijuana or hash from the resin found in the stalks, young leaves and flowers, and it is oneof the oldest known psychoactive substances . Industrially grown hemp must contain less than 0.2% tetrahydro cannabinol, and its cultivation from EU-certified seeds does not require a licence.In the 1961 Single Convention on Narcotic Drugs, Cannabis is described as the flowering or fruited tops of the Cannabis plant from which the resin has not been extracted . Its cultivation requires authorisation from the Spanish Agency for Medicines and Medical Devices. In 2020, the WHO removed Cannabis from Schedule IV of the Convention, thereby recognising its potential medicinal properties. However, its recreational use is prohibited in Spain.Cannabis also produces large amounts of pollen .A single flower can release more than 350,000 pollen grains into the environment. This pollen is dispersed by wind,meaning it can be transported over long distances .The presence of Cannabis pollen in southern Spain has been reported as a result of transport from northern Africa . For instance, Cannabis pollen levels increased in the city of Málaga between 1992 and 2015 . This pollen type does not appear in the work by Fernández Rodríguez in Extremadura, a region located in the central-western part of Spain, but it does appear in a study by Maya Manzano of the same region.

This increase in Cannabis pollen in recent years may be a consequence of illegal Cannabis cultivation in cities,cannabis grow racks resulting in local or regional transport of Cannabis air masses.An interesting question to consider is whether the presence of this pollen type corresponds to transport from distant areas, like northern Africa,or whether it is a consequence of increased cultivation in areas close to the sampling points. One of the most commonly used atmospheric transport and dispersion models in the scientific community is HYSPLIT , provided by the Air Resources Laboratory of the National Oceanic and Atmospheric Administration. This model displays weather forecasts and reproduces the trajectories of an air parcel and the results of its dispersion model through a series of interactive web pages . It is a hybrid between the Lagrangian approach,which tracks air parcels moving from their initial locations, and the Eulerian method, which uses a fixed three-dimensional grid to observe the movement of air masses .HYSPLIT back trajectories allow users to trace air mass origins and their paths at different times, helping to identify particle transport at varying altitudes.This model has been used for many applications, such as the description of atmospheric transport, dispersion and deposition of airborne dust, allergens or atmospheric pollutants, smokes, volcanic ash or radionuclides,among others .Air masses from African deserts transport large amounts of biological particles, such as pollen grains, fungal spores, bacteria and viruses, as well as different protein or lipid components .

The incidence of these air masses over the southeastern Iberian Peninsula is relatively high compared to other peninsular enclaves. For example, about 30%of the days in 2004 coincided with North African air masses .The aim of this work is to analyse the behaviour of Cannabis taxon concentration time series in Cartagena , Murcia  and Lorca , the three most populated cities in the Region of Murcia. We study the relationship these concentrations have to the meteorology to establish the origin of Cannabis pollen in the Region of Murciaby analysing back trajectories generated with the HYSPLIT model. We determine whether the transport has been local or long-distance from airmass origins. Aerobiological samples were collected using a Hirst-type trap, model VPPS 2000, from Lanzoni S.R.L .

The final sample was derived by using multiple inclusion and exclusion criteria to ensure higher levels of within-sample homogeneity. Data from male and female adult participants  were considered in the analyses if they consumed cannabis and showed at least one sign of harmful cannabis use in the past 12 months and had valid responses on all questionnaires which were included in the analyses. The six-item Cannabis Abuse Screening Test  was used to assess the presence of signs of harmful cannabis use . Only those individuals were included in the final sample who had at least 1 point on the total scale score of the CAST based on its dichotomized items . Consequently, the final sample size was 750. Table 1 presents the main sample characteristics. High proportions of the sample were males, had secondary educational attainment, worked in full-time, and did not study currently. The Hungarian translation of some of the applied questionnaires  was created in the present study in a step-by-step procedure based on the guidelines of Beaton et al.:  forward translation to Hungarian language, indoor cannabis grow system back translation of the Hungarian version to English,  comparing the original and the back translated English versions and revising the Hungarian version based on the mismatches between the two English versions,  pre-testing the clarity of the instructions and items and asking for written feedback,  finalizing the Hungarian version.

Bivariate correlations between the variables are presented in Table 2. Table 3 and Fig. 2 show the results of the mediation model. Female gender was significantly associated with elevated rates of brooding and reflection, and with lower levels of harmful cannabis use. Anxious-depressive symptoms had significant positive predictive effects on NU, reflection, brooding in addition to the significant and positive direct effect of anxious-depressive symptoms on harmful cannabis use. Anxious-depressive symptoms were also significantly and negatively linked to CRSE and CPBS. A significant and negative relationship was presented between brooding and cannabis use frequency. Reflection had positive predictive effects on CPBS and CRSE. NU was significantly and negatively related to CRSE and cannabis use frequency. Higher levels of CRSE and CPBS were significantly associated with less frequent and less harmful cannabis use. Total, direct and indirect effects are summarized in Table 4. In the case of cannabis use frequency, indirect effects were not estimated as the total effect of anxious-depressive symptoms on cannabis use frequency was non-significant.

Overall, five significant indirect effects were identified on harmful cannabis use. First, anxious-depressive symptoms had a negative effect on CPBS which in turn was negatively linked to harmful cannabis use. Second, higher levels of anxious-depressive symptoms were associated with lower levels of CRSE which subsequently had a negative effect on harmful cannabis use. Third,cannabis grow set up a double-mediation pathway indicated that anxious-depressive symptoms had a positive effect on reflection which in turn was positively associated with CPBS which subsequently contributed to lower levels of harmful cannabis use. Fourth, in a double-mediation pathway, higher levels of anxious-depressive symptoms were associated with increased rates of reflection which subsequently had a positive effect on CRSE which in turn was negatively associated with harmful cannabis use. Fifth, in a double-mediation pathway anxious-depressive symptoms were positively associated with NU which had a negative link with CRSE and higher levels of CRSE were associated with lower rates of harmful cannabis use. The present study aimed to examine the mediating functions of rumination, negative urgency , and constructs of cannabis use regulation  on the associations of anxious-depressive symptoms with cannabis use frequency and harmful cannabis use.

To the Authors’ best knowledge, this is the first time that a comprehensive mediation model was tested which simultaneously covers anxious-depressive symptoms, constructs of ER and cannabis use regulation and outcomes of cannabis use. It is important to highlight that the present sample was consisted of cannabis users showing signs of harmful cannabis use. Moreover, due to the recruitment procedure of the study, it might be possible that the self-selection of those individuals was presented who show high interest and motivation in cannabis- and illicit drug use. These characteristics can indicate that regular and problematic cannabis users might be over represented in the sample which might influenced the levels of other constructs as well. For example, it might be possible that the associations with CPBS and CRSE would have been different by having more recreational users in the sample with less frequent and less harmful consumption patterns .

When comparing the results obtained by both methods of study , no profound limitations to the substitutive method were found to the point of not allowing its use or to put in check its results, as reported in some studies . We agree, however, that in finalistic studies under field conditions or in situations where it needs more directly applicable inferences, the additive method should primarily be adopted. If from one side there are disadvantages, from the other side the substitute method has the advantage of obtaining information as to the community as a whole, providing evidence about the nature of competition between species involved—if it occurs for the same resources, or if one of the species is able to avoid the competition. In addition, discrete varietal differences in competitive ability against weeds are probably best captured by substitutive experiments. Soybean is one of the leading economical crops grown in Brazil, with about 27.7 million hectares planted in the 2013/2014 cropping season. Soybean yields in Brazil had significantly increased in the last decades, and current Brazilian average yield is 3035 kg∙ha−1 .

Among the factors which limit crop yield, the occurrence of weed species can be highlighted as one of the most relevant facts . Recent GMO technologies have aimed to employ herbicide resistance to soybean varieties and the weed infestation have drastically reduced in most fields with such technologies. Lack of Government regulation and Farmer’s mismanagement of such technologies cannabis grow tray, however, led to the selection of weed species tolerant or resistant to the herbicides applied with these technologies . The glyphosate-resistant Roundup Ready® soybean was widely used in Brazil for at least ten years, and currently Conyza bonariensis, C. canadensis, C. sumatrensis, Digitaria insularis, Lolium multiflorum  and Eleusine indica  are resistant to this herbicide, due to its extensive and almost uncontrolled use in Roundup Ready soybean. This abuse, moreover, resulted in the selection of weed species naturally more tolerant to glyphosate, namely Ipomoea spp., Richardia brasiliensis and Commelina benghalensis , among others. These facts have made researchers and companies retreat from the excessive reliability in GMO crops and has provided new possibilities to researches that regard integrated weeds management and integrated cropping systems Researchers also started to notice that it is important to know the key traits of weed plants intended to be eliminated from the system, in order to develop management techniques that are efficient to the controlling of such species .

One of the main management practices which contribute to the reduction in weeds infestation is the continuous maintenance of straw on the soil surface , which limits weeds access to light. In addition, some plant species produce chemicals which usually exudate to soil through the root system, inhibiting germination and/or growth of other plant species. This phenomenon is called Allelopathy . The intercrop of corn second crop  with Brachiaria ruziziensis was developed to allow the maintenance of a bold layer of mulching from the forage on soil after corn is harvested , thus soil would not be exposed to direct rainfall and sunlight when crop is not present. The crop succession soybean-corn + B. ruziziensis year after year, however, also started to select pests and weed species, urging for diversification at the second cropping season in Brazilian Savannah. In addition,vertical grow systems for sale the demand for partial or total substitution of petroleum-based fuel oil for biofuels has become a topic of strategic security for many countries , aiming to meet both the increasing demand for energy and the new required limits for emission of gases responsible for the greenhouse effect . Radish , crambe  and rapeseed  are promising for producing biofuels , being these winter oilseed crops good choices for a profitable second crop while keeping soil protected during fall/ winter; they can be planted later than corn, developing well even when planted after march 10th, which is a deadline for corn planting in the Brazilian Savannah .

Even being a profitable option to replace corn after soybean, the potential of these oilseed crops suppress the occurrence of weed species in areas where these are rotated with soybeans that need to be assessed. Oilseed crops could either demand additional herbicide application in the cropping system throughout the year for not suppressing weeds, or reduce herbicide demand supposing the most important weed species that are properly suppressed—the latter would be a highly desired side-effect. This study aimed to evaluate the potential of oilseed crops planted following soybean, in terms of their ability to inhibit the occurrence of weed species under Brazilian Savannah cropping systems. Sampling precision proved most areas were precisely sampled, according to the demanded by Bordeau  and Goldsmith & Harrison , who stated the variance of sample means increases as the number of sampled quadrats per area decreases.

Creeping wood sorrel numbers decreased linearly and quadratically for those seeded above the rice hull mulch, and decreased linearly for those seeded below. Creeping wood sorrel numbers were greater when seeded below 0.6 cm rice hulls compared to above, while those seeded in 1.3 or 2.5 cm rice hulls were similar with respect to seed placement. Similar to results with flexuous bitter cress at 4 WAP, weed numbers were higher in containers seeded below the rice hulls compared to those seeded above when averaged across rice hull depth . Creeping wood sorrel shoot fresh weights at 4 WAP had a similar response to numbers with respect to rice hull depth and seed placement. Repeated measures analyses showed that rice hull depth and time interacted to affect creeping wood sorrel number seeded above  and below the mulch . Among containers seeded above the mulch, numbers increased from 4 to 16 WAP in non-mulched controls. Among these same treatments, all rice hull depths reduced creeping wood sorrel numbers compared to non-mulched controls, and there were no significant differences between those mulched with 0.6 to 2.5 cm. Among containers in which seed was placed beneath the rice hulls, outdoor cannabis grow creeping wood sorrel responded similar to flexuous bitter cress over time.

At 4 WAP, creeping wood sorrel numbers were higher in containers with 0 or 0.6 cm rice hulls compared to those with 1.3 or 2.6 cm rice hulls. From 8 to 16 WAP, there were no differences in creeping wood sorrel number from seed placed below the mulch layer. Shoot fresh weight had a similar response to rice hull depth and time as weed number. Rice hull depth and seed placement affected percent creeping wood sorrel establishment.Establishment was greater when seed were placed beneath the mulch layer at depths of 0 to 1.3 cm, while establishment was similar above or below 2.5 cm rice hulls. . Flexuous bitter cress germinated in Petri dishes at 1 WAS beneath all shade treatments . Only seeds in complete darkness had lower germination than other treatments. By 3 WAS, percent germination increased quadratically from 0% to 88% shade, then decreased as shade increased from 88% to 100%. Flexuous bitter cress that germinated in 0% to 88% shade appeared to have true leaves of similar greenness and short internodes, with leaves emerging near or directly along the agar surface. At 99% shade, there were no true leaves; only cotyledons were present which were up to 0.5 cm inlength and etiolated. At 100% shade, seedlings were etiolated, had elongated hypocotyls up to 1 cm in length, and yellow cotyledons. At 1 WAS, creeping wood sorrel germination increased linearly from 0% shade up to 99% shade . Germination was lower in 100% shade compared to 99% shade. By 3 WAS, creeping wood sorrel germination was similar across all light treatments and averaged 92%. This is in contrast to work by Holt  who reported decreased germination with decreased irradiance , and no germination in complete darkness.

Creeping wood sorrel were visually larger in 0% to 61% shade treatments, with most seedlings having true leaves. Creeping wood sorrel in 88% to 99% shade had smaller and fewer true leaves, and those present were pale yellow in color. Those in 99% shade lacked true leaves,cannabis grow equipment and had etiolated hypocotyls with green cotyledons. Seedlings in 100% shade were extremely etiolated  with yellow cotyledons. In Expt. 1, a greater percentage of water passed through rice hulls than peat moss at the initiation  of the experiment . By week 2, a greater percentage passed through rice hulls than both pine bark and peat moss. By 4 weeks, there were no differences in the percent of applied irrigation water that passed through the mulches. By this point, the pine bark and peat moss appeared to be visually saturated and unable to hold additional water applied at irrigation, thus a high percent of the applied water passed through these mulch layers later in the experiment. A similar trend occurred in Expt. 2 with respect to percent of water passing through the mulches. Throughout both experiments, rice hulls allowed for 88% to 96% of the applied irrigation to pass through the mulch layer. In both experiments, rice hulls retained less water than pine bark and peat moss at each time point following irrigation in which water content was determined, and at every week data was collected . In both experiments, pine bark retained more water than peat moss at week 0 . This was unexpected considering one of the most important characteristics of peat moss is its capacity to absorb and internally retain large quantities of water.

Extensively established species are those found in 8 or more of the 13 drainage basins of Louisiana. Locally Established Species are those found in 3 to 7 drainage basins, and Potential Arrivals are plants found in 2 or fewer drainages. Some examples of Extensively Established Species are as follows: Water Hyacinth , introduced in 1885 at world’s industrial and cotton centennial exposition in New Orleans, Louisiana as an ornamental plant . A native of South American known for its beautiful flowers can be found in almost all the drainage basin of the state. Parrot feather , a submerged aquatic plant from Amazon River basin of South America, was first discovered in the United States in 1890 at a Washington, D.C pond. It is a popular aquatic gardens plant that probably escaped cultivation through aquarium deliveries into open water bodies. Hydrilla , a rooted, aquatic weed from Asia that inhabits both deep and shallow waters. First observation in Louisiana was in 1973. It sometimes made several water bodies to be unusable for aquatic recreation cannabis vertical farming, for example, Spring Bayou Wildlife Management Area and Henderson Lake in the Atchafalaya Basin has experienced excessive growth of hydrilla plant.

Brazilian Waterweed , introduced to Louisiana in 1960, Brazilian waterweed is a popular aquarium plant because of its oxygenating properties. Some researchers believe this oxygenator plant can be used in control of mosquito larvae. Eurasian Watermilfoil , first observation in Louisiana was in 1973, it is unique because of its ability to tolerate both fresh and brackish waters. Its rapid spread throughout the state could be due to its use as packing material for bait worms sold to fishermen. Water Lettuce , a perennial floating plant from Africa was first observed in the state in 1958. The plant is listed on Federal Noxious Weed List, but it can still be purchased through aquarium suppliers and on the Internet. Common Salvinia , is a floating fern from central and southern America. It was first recorded in Louisiana in 1980 in the Bayou Teche area of St. Mary Parish, and has since been constituting a major nuisance throughout the state especially for farmers. Common salvinia forms thick mats on the water surface and can be up to 25 centimeters deep in some cases . Locally Established Species example is Giant Salvinia , first appeared in Louisiana in 1998 in the Toledo Bend Reservoir. Since then, it expanded into at least 43 locations throughout Southern Louisiana. It is a free-floating fern that reproduces quickly under ideal conditions such as nutrient availability and warmer temperatures.

In Cameron Parish, Louisiana, giant salvinia posed a public health threat because it blocked the operation of floodgates . An example of Potential Arrival Species is Purple Loosestrife , is an invasive plant introduced from Europe in the 1800s as an ornamental plant. A single mature loosestrife plant can produce an estimated 3 million seeds annually. These seeds are prone to wind, animal, and water dispersal. It is an easy-to-grow plant with attractive purplish-magenta flowers that can be purchased in many plant nurseries, and garden stores. United States Department of Agriculture Early Detection and Distribution Mapping system  was used to collate number of positive observations for all the aquatic invasive species in Louisiana. United States Geological Survey Non-indigenous aquatic species  database was used to collate each species years of first and last observations and number of affected HUC in Louisiana State . The collated data were recorded and formatted using Excel spreadsheet. The analyses of the data were done using Excel software to generate different charts. Also, reports from 2005 Louisiana Statewide management plan,cannabis drying racks 2015 reports of Michigan Lake and Stream Association and 2018 Army Corp of Engineers on Aquatic Plant Control Research Program of coastal Louisiana were used to support data from USDA and USGS databases.

The collated data from USGS and USDA EMM Maps shows earliest date of observation of invasive aquatic plant in Louisiana from 1884 as shown in Table 1 and Figure 6 combo chart. Common Water hyacinth has the highest number of observations till date as shown by Figure 4. About 41 hydrological unit areas have been affected by infestation of Alligator weed as depicted by Figure 5. Over 30 invasive aquatic plants species have been documented in the state of Louisiana . Some of them have been eradicated after their first observation.There is progressive increase in the number of observed locations, HUC and specie establishment from the 2005 report of Louisiana Invasive Aquatic species task force and 2018 report of US Army Corp of Engineers . According to combo chart of Figure 6, only feathered mosquito fern and crested floating heart species have achieved a form of eradication with no new observed locations.