Cannabis Grow

An early concern with the planting of trees and shrubs in channels was they would be too effective and cause the channel to migrate, especially in areas where the original channel was some distance, and lower, than the constructed channel. Although more sinuosity in a channelized stream might ultimately be a desirable objective, in the early phases of the project channel movement could have jeopardized establishment of newly planted vegetation. Anecdotally, there seemed to be substantially more raptors and upland game birds at the site than in surrounding fields or adjacent to Gerking Creek above and below the project. This was expected, as avian communities increase with increasing plant community complexity, including variety in plant size and life form, and accumulation of detritus . Before the project was begun, the site was a mono-cropped agricultural field, and in 2000 and 2001 the site supported a monoculture of the targeted-nonnative tall wheatgrass.

By 2008, we observed patchiness in the distribution of vegetation, with distinct areas of tall wheatgrass, non target-nonnative species , and accumulations of detritus in various states of decomposition throughout the site. In the Philippines, rice  is the most important source of food, where it is mainly grown after intensive tillage in wet conditions. There are two seasons  and farmers grow rice in both seasons. In dry seasons, however, rice requires a huge amount of water for puddling  and planting . Farmers in Asia, including the Philippines, are expected to have limited irrigation water in the future to flood their rice fields.The risk of water scarcity may lead to changes in production systems to bring about less water demanding systems . They may include dry seeded rice and crop diversification. Soybean  is one of such crops,mobile vertical rack which can be grown in dry seasons. Compared to rice monoculture systems, the rice-soybean cropping system may prove more water-efficient in the Philippines. At present, soybean is not grown on a large area in the Philippines; however, there is a trend of increasing its area in the response to water scarcity and need for crop diversification. In different countries, soybean is grown at different row spacing . The row spacing in soybean can vary from 19 to 76 cm . Narrow row spacing is known to suppress weed growth by closing crop canopy earlier than wider row spacing .

Narrow row spacing may also increase available moisture to the crop, for example, corn In soybean and corn, narrow row spacing was found to increase light interception . Soybean yield can also be influenced by the plant to plant spacing within a crop row. A computer search of published literature revealed that there is limited information available on the effect of row spacing and plant to plant spacing on the growth and grain yield of soybean in the Philippines. Plant geometry can also influence weed growth in the crop. A study was therefore conducted to evaluate the effect of plant geometry on the growth and yield of soybean at Los Baños, Philippines. Palmer amaranth  is an important weed that has spread from its origin in southwestern North American, to eastern North America, Europe, Asia and Australia It has been reported to be resistant to several classes of herbicides including the triazines, acetolactate-synthase inhibitors, dinitroaniline, protoporphyrinogen oxidase inhibitors and glyphosate -. The molecular mode of action of glyphosate is inhibition of 5-enolpyruvylshikimate-3-phosphate synthase , a key enzyme in the shikimate pathway , responsible for the synthesis of aromatic amino acids  and phenolic compounds, some of which are related to plant defense .

Currently, 44 weed species have been found resistant to glyphosate . Glyphosate resistance in Palmer amaranth plants has been attributed to high copy numbers of the EPSPS gene, compared to glyphosate-susceptible plants  and high EPSPS copy numbers enable adequate EPSPS production and the concomitant synthesis of required aromatic amino acids even when high levels of glyphosate exist in the resistant plant tissues. The high EPSPS gene copy number trait is heritable when plants are cross-bred . The transfer of resistance through cross-breeding, its aggressive nature and the prolific seed-producing capacity of Palmer amaranth  have intensified its spread. Previously we found two biotypes of Palmer amaranth in a population of this economically important weed that were resistant to glyphosate but differed with respect to pigmentation . One biotype was typically red-pigmented while the other was green, with no visual appearance of red hue on any plant part at any growth stage. The compounds responsible for these pigmentations are betalains, a small group of in dole-derived glycoside pigments.

Most of the weeds found in this study are dominant because they are all aquatic and lowland weeds that benefit from the closeness of the area to a river. The change in the habitat from swampy to sandy soil contributed to the transition from exclusively a mangrove community to a weed community. Loss of mangrove forest as a result of anthropogenic action lead to a loss of the ecosystem services they provide e.g. carbon sequestration, fire wood and basket production and fisheries. The weed are not known to provide any significant ecosystem services to the environment apart from being host to some disease parasites, causing bush fires and acting as a nuisance in the environment. The species Mariscus longibracteatus are more dominant because they are aquatic weed that grow in wet grounds in forest zones. They are of the family Cyperaceae . They are large tufted sedge that can grow to about 1 m, and are produced from seeds. Their seeds are tiny and are propagated by wind. They have very prominent spikes on an inflorescence, which sticks to clothing and facilitates dispersal and propagation.

This has made them to be found in any environment. Although they are mangrove forest plants, but are introduced through human activities such as logging, sand filling, construction and reclamation. High concentration of Zn can be ascribed to increased land runoffs and influx of metal-rich water in the weed root soil giving rise to elevated metal levels. Similarly, elevated levels of metals in weed root soil were observed in Pondicherry Harbor . However, it was found that the total concentrations of all selected heavy metals in the weed root soil were below the critical soil concentration values , which reflect the topography and bed rock of the area as the origin of these metals. Several studies of plant phenology and insects have focused on the relationship between plants and the life cycle or population dynamics of phytophagous insects.Published studies on the influence of plant phenology on carabid beetles  have examined the consumption of weed seeds by carabid species,grow lights for cannabis as well as the role of weeds as a refuge and dispersal aid for carabids in agroecosystems There are also reports of weedy plants causing changes in the carabid community structure Feeding habits of carabid beetles range from carnivory to phytophagy, but there are also carabid species with more-specialized feeding behaviors .

For example, in terms of phytophagy, carabids can be classified into two groups: 1) those that are carnivorous but supplement their diets with vegetation; and 2) those that are seed consumers Thus, in addition to being recognized as important biological control agents of crop pests, carabids are also an important group of seed feeders and, thus, can act efficiently to reduce the size of weed populations in agroecosystems Carabids and crickets dominate the granivorous taxa of temperate regions  whereas ants are dominant in the tropics . Among the carabid beetles, the Harpalini and Zabrini tribes contain the most granivores Despite the rich carabid fauna in Brazilian agroecosystems there are no specific studies from this region on carabid beetles as weed seed consumers or on their relationship with the phenological stages of weedy plants. The only studies published on the feeding habits of Brazilian carabids were by Barbosa et al. , who evaluated the effect of different diet types on biological aspects of two carabid species, and Matta et al. , who determined the types of food within the digestive tract of carabids associated with herbaceous plants and colored cotton.

It is also worth noting that the life cycle of Brazilian carabids inhabiting agroecosystems is almost unknown; however there is information available about seasonal activity of several dominant carabid species in the state of São Paulo . Therefore, in the current study, a survey of adult carabids was carried out in the edge habitat covered by weedy plants and located between a forest fragment and a soybean/corn crop or an orange orchard in five sites in northeastern São Paulo state, Brazil. The objective was to determine the changes in the density of carabid species in relation to different phenological stages of weeds. We considered the increased number of individuals of a carabid species during the reproductive stages of weedy plants, an indication of preference to feed on seeds of agricultural weeds.

Those indices are sensitive to moisture content in plant leaves suggesting leaf succulence was important in crop weed separation and weed to weed separation. The SWIR band serves as a measure of water content, leaf internal structure, and dry matter; whereas, the NIR band serves as measurement of only leaf internal structure and dry matter . When combined into an index, SIWSI provides a measurement of leaf water content expressed as equivalent water thickness. Also, GRNDVI was ranked within the top three indices for each date supporting the role that plant pigment played in separating the plant species. Other pigment indices having relevant variable importance values on both dates were GNDVI and NPCI. NDVI, the most wildly used vegetation index throughout the literature  was ranked eighth and eleventh according to the variable importance tabulated for the June 30, 2014 and September 17, 2014 datasets respectively, indicating its weak relevance for discriminating between the plant species.

Thus, the variable importance rankings of the former were easily understood by evaluating the variable importance rankings of the latter. Therefore, vegetation indices derived with one those bands would be ranked higher on the variable importance scale than a vegetation index excluding SWIR bands . The findings of this study are similar to those of , which indicated shortwave-infrared data were important for soybean weed discrimination. Their study focused on the following weeds discrimination from soybean: hemp sesbania , palm leaf morning glory , pitted morning glory , prickly sida , sicklepod , and small flower morning glory . Overall,vertical grow systems for sale this study demonstrated that vegetation indices derived from leaf reflectance data can be used as input into cforest for differentiating soybean, velvetleaf, and two pigweeds. It is important to note that the data were collected using pure leaf spectra and not canopy spectra. For canopy spectra, some differences will occur due to in-canopy shadowing, leaf orientation, and differences in leaf area. One of the strengths of vegetation indices is that they are influenced less by shadowing and sensor viewing angle than multispectral bands, indicating the benefit of using them at the canopy level.

Conyza bonariensis  Cronq. Walker is a weed annual broad-leaved species in the Asteraceae family native to South America , present in fallow in autumn and spring in Argentina. Previous to the widespread adoption of no-till systems, this species was confined to pastures and undisturbed areas . No-till favours germination and emergence of small-seeded weed species including Conyza spp which typically emerges during the whole fallow period. In the last years, applications of glyphosate in no-till fallow have increased significantly achieving initially very good control of Conyza spp. in the region of the study . At present, control of some populations is difficult in many sites of the Argentine soybean region, although no glyphosate resistant Conyza spp. biotypes have been reported. The selection of these tolerant biotypes may be due to suboptimal growth stage at application,overreliance on glyphosate and long-term use of sublethal doses . Resistance to glyphosate of C. bonariensis was observed for the first time in 2003 in South Africa . At present, resistance to five modes of action with Conyza canadensis  Cronq. and four modes of action C. bonariensis have been reported . Resistance biotypes were identified in Europe -, Brazil  and USA . In Argentina, a better understanding of the differences in control between biotypes is essential for developing effective long-term management strategies.

The small size of weed plants at herbicide application is relevant for achieving an acceptable control as at this stage, weeds are more susceptible.Glyphosate efficacy is particularly influenced by weed size In some biotypes of Conyza spp., glyphosate control fails due to an inappropriate dose when there is a delay in application that allows plants to reach sizes that are difficult to kill consistently . In no-tillage fallow, control of annual weeds increases by applying residual herbicides combined with glyphosate Many of the residual herbicides for Conyza spp. control are acetolactate synthase – inhibiting herbicides, particularly chlorimuron-ethyl, metsulfuron-methyl and diclosulam Mixtures of such herbicides with glyphosate may control biotypes resistant to glyphosate . Other herbicides included in this group consist of mixtures containing sulfometuron or chlorsulfuron and are less studied, so the dose for adequate control is not clear.

Spot applications of glyphosate at the same rate previously mentioned were also utilized to control perennial weed species, Canada thistle  and field horsetail , within all plots. Weed control treatments were initially applied in the spring of 2008. Data were collected for the growing seasons of 2008 and 2009. Dormant season data were collected in the springs of 2009 and 2010. Annual weed control was evaluated twice per season at 10 and 20 weeks after application . Weed control was quantified as percent control by visual inspection compared to weed presence in an untreated plot margin near the treated row where 0 equated to no control and 100 indicated complete plant death or no plants present outdoor cannabis grow.Plant growth was evaluated as vine shoot length and biomass production through dormant pruning weight. Each measure was averaged for the two vines within each sub-plot for analysis. Plant shoot lengths were measured during the dormant season as the length of the combined trunk and cordon from ground level.

Dormant pruning weight was determined as the total fresh weight of one-year-old wood removed. In both years, each vine was pruned under the same goals of removal of dead material, trunk and cordon establishment, reduction in the number of trunks, and removal of undesirable lateral branches. Effects on vegetative bud-break timing were monitored as the number of Julian days prior to the first unfurled leaf. Values were averaged over the two vines within each cultivar subplot for analysis. Bud hardiness was evaluated each spring as the number of viable primary buds in a 50 bud sample taken from 10 random stems during dormant pruning. Randomly selected buds were sampled from stems with different diameters and from different positions in order to be representative of the entire vine. Viable buds were determined as buds that retained green tissue in the primary bud Primary buds that were brown were considered not viable. Soil temperature was monitored using thermistors  and soil water content was monitored using soil probes  with periodic recording after calibration for the soil type. Thermistors and soil water content probes were placed in the center of each main-plot at a depth of 15 cm. Temperature and moisture content were recorded hourly from July 8 to November 13 during the summers of 2008 and 2009.

Values were averaged monthly for analysis. Data were subjected to analysis of variance using proc mixed with SAS statistical analysis software . Treatment effects on plant growth and development were evaluated as randomized complete block designs with a split-plot arrangement with four weed control methods as wholeplots and four cultivars as subplots with three replications. For weed control and soil conditions, data were evaluated as a randomized complete block design with four weed control treatments and three replications cannabis grow equipment. Years were treated as repeated measures. Months were treated as repeated measures when soil temperature and moisture content were evaluated and were independently evaluated for weed control data. Cultivars differed in their combined trunk and cordon establishment. MN 1131 had longer shoots  compared to either DM 8521 or St. Croix  indicating greater progress toward establishment. The applied weed control treatments did not affect the rate of trunk and cordon establishment in the current study . Dormant pruning weights also did not differ among weed control treatments or among cultivars in the two studied years . Overall, impacts on growth rate and progress toward vine establishment were caused by cultivar differences and were not attributable to weed control methods.

There were no significant deficiencies caused by the alternative weed control measures, thus mulches may be considered acceptable weed control methods in North Dakota vineyards during establishment. St. Croix broke-bud significantly later than DM 8521 and MN 1131 , while MN 1200 did not differ from any other cultivar. The interaction between weed control method and year also showed significant variation . When tests of simple effects were used to evaluate the variation within each year, treatments significantly varied in 2009, but not in 2010. In 2009, vines in plots where herbicide was used broke-bud as much as five days earlier than vines in plots treated with mulch. The early bud-break of these vines may lend them more susceptible to late spring frosts in certain years. It was anticipated that the mulches would delay bud-break due to their moisture conserving and soil cooling effects .

By tank mixing additional modes of action with dicamba, growers will be able to effectively manage glyphosate and ALS-resistant Palmer amaranth and other troublesome broadleaf weeds while helping to minimize the selection of dicamba resistant weed biotypes. The ability to use either dicamba, glyphosate, or a tank-mix of both herbicides before planting or at selected periods during soybean development will allow growers greater flexibility in managing troublesome weeds in their crop management practices . A proactive approach to weed control is critical; this will slow down or prevent the selection of resistant weed biotypes. Therefore, the objective of this research was to evaluate the efficacy of selected dicamba herbicide programs for the control of Palmer amaranth and pitted morningglory in dicamba tolerant soybean. Pitted morningglory control varied significantly within treatments in 2012 and 2013 when evaluated at 2 WAP1 and 2 WAP2 compared to Palmer amaranth in study 1. This led to a treatment by year interaction being observed for 2 WAP1 and 2 WAP2 rating periods. Some experimental or environmental factors could have contributed to the treatment by year interaction observed, mainly the difference in rainfall observed between the two trial years .

Unlike in Palmer amaranth, a dicamba PRE only, controlled pitted morningglory better than a flumioxazin PRE only when rated 3 WAP . In 2012, 2 WAP1, dicamba PRE only provided marginal pitted morning glory control  and in 2013, at the same rating period, control increased to 36%.Niekamp also observed that flumioxazin, while being a good broad spectrum PRE herbicide for broadleaf weed control, provided inconsistent morning glory spp. control. Treatments containing two or three herbicide applications offered good to excellent pitted morning glory control; however, the PRE followed by POST1 were slightly less effective in 2012 than 2013. In 2013,cannabis drying racks all dicamba based treatments provided excellent  pitted morning glory control at 2 WAP2.Dicamba PRE alone was not as effective on broad leaf weed control in soybean compared to flumioxazin PRE only. This can be attributed to the high water solubility of dicamba and its rapid loss in the soil profile, especially in coarse textured soils . Overall, a PRE  followed by a dicamba + glyphosate POST tank mix provided excellent control of Palmer amaranth and pitted morningglory in these studies. In the treatments evaluated, those containing 2 applications  were similar in effectiveness as those containing 3 applications .

In terms of cost, fewer herbicide applications are more efficient and will be able to benefit growers who use these programs by reducing overall input costs. Dicamba PRE alone with no additional POST treatments provided the lowest level of weed control in these studies. Non-dicamba containing POST treatments did provide good to excellent control of Palmer amaranth and pitted morning glory. Although the treatments in these research studies showed good to excellent control of broadleaf weeds in diamba tolerant soybean, more research is needed on additional broadleaf weeds across different environments not present in the selected study locations to validate their effectiveness across a larger geographic area. Wheat  is an important cereal grain crop all over the world. It is the staple food crop of Pakistan. It contributes 13.1 percent to the value added in agriculture and 2.8 percent to GDP. During 2008-2009, it was grown on an area of 9.062 million ha–1 with an annual production of 19.5 million tons of grains giving average yield of 23.421 tons ha–1  which is far below the yield level obtained in other wheat growing countries of the world. Every effort is being made to meet the wheat requirements of the country. There are many reasons for low yield of wheat crop but weed infestation is the basic and major component of low yield in crop production system. With the advent of new short stature varieties, weeds competition has become even more severe. The estimated annual losses caused by weeds may be more than 10 billions rupees in Pakistan . Because of high competitive ability and high reproductive potential of weeds, it is imperative to check their infestation. Only due to high weed infestation, average yield losses in wheat crop are about 25% – 30% in Pakistan . Weeds compete with crops mainly for light, nutrients, water and CO2 for canopy development and other growth requirements . Weeds utilize three to four times more nitrogen, potassium and magnesium than a weed free crop .  reported that yield losses due to weed are in proximity of 17 – 25 percent which in terms of wheat grain comes to about 2.43 to 3.57 million tons annually.

Limitations with X-Ray CT include the complicated equipment required for the survey and the extensive job of distinguishing roots against soils. Consequently, the images obtained were not exceptionally clear but did give a broad depiction of the area covered. For example, small roots were not distinguishable from the soil matrix . Similarly, shovelomics will generate a general structure of the root area, but the results lack detailed information on individual root parts . Mathematical models employing fractural geometry create a reasonable estimate of root architecture measurements and aid in viewing root systems . Measurements from 2-dimensional, planar models or images obtained from soil cores may serve as a base for 3D model construction. Although mathematical models can provide insight into root formation patterns, a failure results in accounting for natural recourses that significantly affect a plant’s root structure .

Field observations of root systems are time-consuming and tedious but do garner useful general information . There is a vital need for an accurate visual root architecture method. Three-dimensional imaging software combined with MRI scanning techniques advances the prospect of using rice as an experimental subject for studying root structure . The complete unique development of RSA can be obtained through 3D imaging techniques; additionally,vertical grow system this digital phenotypic data can be analyzed repeatedly for various traits The limitations with these methods include the equipment needed, finding compatible soil media for these methods, and image processing time and software ability to distinguish soil from the root Efforts to create bioassays for herbicide dose responses or observe root growth patterns gave way to germination pouches. This method is rapid, cost-efficient, reproducible, accurate, non-invasive, and easily controlled . Germination pouches allow visualization of seedling growth patterns and have been utilized for various crops and purposes . These transparent bags make it possible to promptly and practically observe and image roots at any growth stage. Screening in a lab setting allows for a uniform and controlled environment as well as sterile conditions.

Images obtained can be analyzed and screened through publicly available user-friendly software programs. Adeleke et al. made germination pouches at an even lower cost than those purchased for this study and were able to successfully germinate seedlings and obtain photographs at the end of the study in less than five minutes per plant, producing fast and effective results . This phenotyping strategy can increase non-invasive screenings by saving time and space in the seedling stage of development, leading to exploring traits in the accessions screened . This study aimed to characterize root morphological traits of allelopathic and non-allelopathic weedy rice and identify root traits related to allelopathyFrom Shrestha et al. , seeds of the five most barnyard grass-suppressive  and four least barnyard grass-suppressive  weedy rice accession were selected. Cultivated rice lines Rex, Rondo, PI312777, CL163, and PI388046 were also included in this study for comparison. All seeds were surface-sterilized by soaking in 70% ethanol for 30 seconds and 5% bleach for 20 minutes and rinsed six times with distilled water. Sterilized seeds were germinated in plastic 9-cm Petri dishes lined with What man No. 1 filter paper and soaked with 5 ml distilled water.After germination, four seedlings of equal height were selected for each accession and placed using forceps into germination pouches .

Pouches holding the seedlings were placed in the growth chamber in the Weed Physiology Laboratory at Mississippi State University, set at 30˚C/21˚C day/night for 28 days after germination . Plants were watered with 20 ml half-strength Hoagland’s No. 2 basal salts  every two days to keep the roots damp until 28 DAG. At 28 DAG, the bags were cut open, and the roots were removed and placed directly onto an Epson Perfection V370 Photo scanner . Black paper was placed over the root to contrast the image. Four images were obtained for each accession serving as individual replications. Root images were measured using Image J® software . Each image was cropped to encompass the area each root covered and converted into an 8-bit grayscale format. The length of each root was recorded in cm, and to obtain the total area covered by each root, the images were first converted to a binary format to remove the background and create a contrast. Weedy rice was characterized as allelopathic or non-allelopathic based on data from a screening performed in a prior study .

Hecky and Bugenyi  obtained higher concentrations of phosphorus  near the mud surface  than the upper photosynthetic zone. Hence the high coverage of S. molesta near the shoreline areas may be linked to the rich organic material usually found at the lake bottoms along the shorelines. This is reflected by the high phosphate  levels in Acholi inn landing site  though Masindi port, Waitumba and Kayei landing sites had phosphate values contrary to the average S. molesta coverage at those sites . There was accumulation of phosphates  at Kayei landing site  resulting from less uptake by S. molesta at low coverage. On the other hand, the high coverage of the weed at Waitumba and Masindi port landing sites might have led to the depletion of phosphates  in the water at those sites due to increased uptake by the weed. According to Divakaran et al. , the rapid proliferation of S. molesta causes depletion of nutrients. However, S. molesta carriage through attachment on boats increased the weed coverage at Acholi inn landing site  which also recorded high phosphates  at the same time. The enriched phosphates in Acholi inn could have resulted from the decay of organic matter in the habitat of the weed .

According to Lavelle and Spain , organic matter decomposition is a good source of phosphorus. The high coverage of S. molesta at waste sites and gardens  is associated with increased nutrient  availability  as the pH  and temperature  ranges at all the study sites were relatively constant and suitable for growth of the weed. According to Cary and Weerts , S. molesta grows optimally in nutrient-rich  conditions at pH 6 – 7.5 and water temperatures ranging from 20˚C to 30˚C. However, nutrient availability is more influential to the growth of the weed than pH . The high coverage of S. molesta weed close to the waste sites and gardens is expected as growth of aquatic weeds  increases with increase in agricultural productivity . This is due to the fact that agricultural and wastewater runoffs into freshwater ecosystems enrich the nutrient levels in the water bodies . For the case of Lake Kyoga, about 85% of the population in the lake basin is currently engaged in agriculture  hence increased cultivation and livestock rearing around the lake. On the other hand, cannabis grow supplies more wastes have also been discharged into the lake from increased human activities and livestock in the lake basin thus elevating phosphate levels in the lake The high coverage of S. molesta at boat docks despite the relatively lower nutrient  levels is attributable to the weed getting stuck on boats and then washed off in the boat docks.

Global Invasive Species Database  showed that S. molesta can be spread within and between water-bodies by contaminated boats.According to Parsons and Cuthbertson  and Gewertz , S. molesta spread between aquatic systems as a hitchhiker on boats, or in shipments of fish is common. For example, the spread of S. molesta into inland waterways of Zimbabwe was associated with the boat movements to and from Lake Kariba . As Lake Kyoga is very much used for fishing  and inland water transport , the number of boats on the lake is high hence increased coverage of S. molesta at the boat docks. The coverage of the S. molesta at the different landing sites and anthropogenic activities decreased the concentrations of dissolved oxygen at those sites in line with previous studies which indicated that solid mats of S. molesta reduce the dissolved oxygen concentrations in the water column For instance, dissolved oxygen concentration underneath S. molesta mats in Lake Naivasha only attained 10% saturation as opposed to 64% – 85% in the open water . The relatively high dissolved oxygen  concentrations recorded at the boat docks  despite the high weed coverage  is probably due to the constant breaking of the thick S. molesta mats and mixing of the water at the boat docks as a result of boat movements.

According to Wanda et al. , the brittle stolons of S. molesta are easily broken by the movement of boats. Ongom et al.  also reported that mixing of Lake Kyoga water increases the oxygen circulation in the lake. S. molesta weed coverage was the least in the fishing areas  associated with low nutrient  concentrations  and the low weed coverage also resulted into increased dissolved oxygen concentrations at the fishing areas. Water stress or drought is one of the most important abiotic constraints in rice, reducing yield on 23 million  ha of area in South and Southeast Asia . In Asia alone, the average loss in rice production in years of drought can exceed one billon US dollars. In water-limited regions, drought risk reduces yield because growers avoid investing money in inputs when they fear crop loss . In irrigated areas, too, water shortage is becoming an increasing problem because of the rising demand for water in urban areas. Water shortage has been historically associated with food shortage, especially in Asia and Africa . By 2025, 13 Mha of irrigated wetland rice in Asia may experience physical water scarcity and 22 Mha of irrigated dry-season rice may suffer from economic water scarcity .

Their study demonstrates the importance of proper controls to limit the use of unique IDs to one person; implementing such controls is relatively easy in a web-based survey environment.Though unaddressed by Wejnert and Heckathorn due to the nature of their study, web RDS poses an additional complicating feature with hidden populations, particularly those who are security conscientious—that of pro-viding anonymous financial incentives . Bauermeister et al. confront this by issuing “Visa e-gift” cards via email to respondents upon completion of their initial survey and reloading them after their chain referred recruits complete the survey . This appears to be one of the more secure options available to researchers, but it does not fully protect participants in the case of compelled disclosure , as the original “loading” of the cards is linked to researchers and recipients are required to provide a name and address before using the cards. Such a disclosure may seem like a minor consideration when studying use prevalence of multiple drugs in a large sample, but the issue is much more salient as sensitivity and security concerns become more of an issue—as is the case with drug producers or sellers.

Limiting or completely eliminating monetary incentives to participants is one method of maintaining anonymity; however, no one has attempted a RDS study of this nature. This study, in addition to investigating marijuana users in Oregon, attempts the first non-monetary primary incentive RDS implementation. To answer the research questions posed in this study, I developed a web RDS protocol and web-based survey to examine a sample of marijuana users in Oregon. To investigate the role of different secondary incentive types in the success of RDS studies and to protect respondents’ anonymity, I chose to forego all monetary payments. Instead, mobile vertical rack multiple non-monetary secondary incentives were implemented: 1) prospective respondents were ap-pealed to based on the potential political and economic importance of examining their population; 2) live updates and total network referral counts for each respondent were posted on a web site to encourage competition among participants to recruit others; and 3) respondents were granted access to near-live aggregate data and summary statistics as the project developed. Respondents were eligible to participate if they were Oregon residents, over the age of 18, used marijuana in the last year, and received a unique study ID from a previous participant in the study. The web-based survey instrument included a question that tracked study IDs; any previously used IDs were barred from reuse. After completing the survey, respondents were redirected to another web page with instructions about the referral process, as well as links to five additional recruitment letters that could be downloaded and shared with prospective recruits by email, Facebook, or instant message.I identified a single “super seed” with a very large number of friends who are users, producers, and sellers of marijuana in several counties identified in my parallel research study as “areas of interest” within Oregon .

The super seed was fully briefed on the project, the referral process, and the importance of collecting chain referrals by following up with prospective respondents.However, the lack of monetary incentives and the format of the recruitment letters appear to have quickly affected recruitment rates com-pared to previous RDS studies , as the referral process died out with only 72 respondents . The implications of this finding are discussed later. The survey instrument collected self-reported information on: 1) individual characteristics, such as gender, age, height, weight, frequency of exercise, county of residence, ethnicity, political party membership, education level, employment status, relationship status, occupational category, health insurance coverage, number of close friends, and income; 2) marijuana-related questions, including frequency of use, reasons for use, medical license status and roles, number of close friends who use, reasons for growing, number of plants growing, method of growing, source and reimbursement rate for obtained marijuana, amount consumed, and the perceived acceptance of marijuana use by immediate social circle and local community; and 3) a detailed political orientation index .Variables of interest for hypothesis testing in this analysis include frequency of marijuana use, amount of marijuana used per month, number of close friends who use marijuana, perceived peer-group acceptance of marijuana use, use status , level of education, relationship status, number of children, and reasons for using marijuana.The number of close friends who use marijuana is a ratio measure, with a minimum of zero and maximum of 20.

It is also possible that the higher proportion of patients with schizophrenia and schizoaffective disorder in this study is associated with lower rates of substance use due to a limited access to substances. Although schizophrenia was found to be a protective factor of substance use in this study as well as in other studies , having psychiatric disorders such as depression and anxiety is generally considered to increase vulnerability to substance use. Specifically, anxiety patients may seek drugs such as marijuana to relieve their anxious or depressive symptoms as a coping mechanism.These self-medicating behaviors may be more common among untreated patients with underlying psychiatric disorders,and in turn, co-occurring substance use can aggravate the severity of their psychiatric symptoms . In this study, however, the relationship between anxiety and more alcohol, stimulant, and marijuana use was unable to support this explanation due to the very low rate of anxiety disorder among Asian Americans.

It is obvious that co-occurring substance use leads to difficult psychiatric treatment, higher treatment costs, and longer hospital stays.Studies have shown that substance users receiving care for their substance use showed decreased depressive symptoms and integrated treatment programs improved patients’ psychiatric symptoms.Although co-occurring substance users are considered a highly vulnerable population, treatment services such as psychiatric outpatient visits and substance abuse treatment programs are still inadequately used . Especially for Asian Americans, there may be other potential issues regarding the underutilization of mental health services such as lower English proficiencies,grow lights for cannabis stigma around having or being diagnosed with psychiatric disorders, cultural beliefs about receiving psychiatric care, limited access to health care services, and discrimination within health care systems . Therefore, these barriers should be addressed in health care systems and efforts should be made to increase access to psychiatric mental health services for Asian Americans at individual, community, and policy levels. This study used a cross-sectional design to examine predictors of co-occurring alcohol, stimulant, and marijuana use of Asian Americans with psychiatric disorders receiving residential treatment services; therefore, a causal relationship cannot be assumed.

The sample of this study came from residential treatment programs only in the San Francisco Bay area where Asian Americans and the homeless are over represented, resulting in a limited representation of the US population. In addition, this study did not examine Asian subgroup differences in the prevalence of and risk factors of substance use; therefore, it may overlook important factors such as levels of acculturation, length of residence in the US ,and immigration generation. Variables reflecting socioeconomic status such as income level and current or past job which are possible risk factors of psychiatric disorders and substance use were not included in this study because most participants were homeless due to their lower level of functioning related to their psychiatric disorder prognosis. This study’s sample was mostly diagnosed with severe psychiatric disorders such as schizophrenia and schizoaffective disorder, which may have led to biased findings. Lastly, findings from this study indicated that there may be patterns of poly substance use among Asian Americans with psychiatric disorders; however, this study did not look at the prevalence of and risk factors of poly substance use, indicating the need for future research study.Aside from using marijuana, are there any substantial differences between regular marijuana users and the general population?

What do these friendship networks suggest about relations with non-users? Are there any differences between illegal marijuana users and licensed medical marijuana users? Finally, can individual-level factors explain the varying rates of medical marijuana patient participation between geographic areas? This study addresses these questions using a survey of marijuana users in Oregon—a location ripe for investigation along these lines. Oregon has one of the highest rates of marijuana use in the US, with the most recent estimate indicating that 14.09% of individuals over 12 years old have used marijuana in the last year. Oregon is also home to one of the oldest medical marijuana pro-grams in the US, established in 1998, just two years after the first was created in California, and publishes county- level counts of medical users dating back to 2005.

The use of natural plant fibers as a reinforcement in FRP to replace synthetic fibers such as glass and carbon fibers is presently receiving attention because of advantages such as renewable resources, low density and high specific strength.Furthermore, in recent years, development of biodegradable composites using natural plant fibers such as flax, bamboo, pineapple , silk ,jute , kenaf and ramie as a reinforcement and biodegradable resin as a matrix is conducted actively. And researches on molding condition, mechanical properties and interfacial bonding have been carried out.In former paper , the research about development of high strength unidirectional Manila hemp fiber reinforced biodegradable composites was reported.The unidirectional biodegradable composites were made from Manila hemp fiber bundles and a starch-based emulsion-type biodegradable resin. The tensile and flexural strengths of the composites increased with increasing fiber content up to 70%. The aim of this study is to develop cross ply biodegradable composites to expand the range of applications of the biodegradable composites.

Manila hemp textile was used as the reinforcement for cross ply biodegradable composites and investigated about their mechanical properties. and marijuana use is a public health challenge all over the world and especially in Sub Saharan Africa. The problem of substance abuse in the region has compounded an already existing burden of infectious and non-infectious diseases. The combination of low socioeconomic status and substance use can be described as a social and economic disaster for many poor families of Africa. Whereas some substances such as alcohol and tobacco have always been traditionally accepted especially among adults,cannabis drying racks their use has reached epidemic proportions in young Nigerians. The uses of other substances such as marijuana, cocaine and amphetamines have also grown disproportionately over the years .Tobacco is risk factor for many acute and chronic diseases nevertheless, about1.1 billion people use tobacco worldwide and about 7 million die yearly of tobacco related illnesses. The burden tobacco use and morbidity is rising in developing countries especially in sub-Saharan Africa. A recent systematic review on the index problem has reported a steady increase in the sub-continent .

It is estimated that the in the continent from 12.8% to 18.9%by the year 2025 .The World Health Statistics report of 2017 showed that the highest prevalence of smoking in SSA was 55%and the lowest 0.2%. Similar to many other countries of the world, tobacco smoking in sub-continent is a predominantly a male dominated problem across all socio-economic strata. In a review of 26 papers from 13 countries spanning a total 8 years, Brathwaite et al. , the prevalence of smoking ranged from 1.8% in Zambia to 25.8% in Sierra Leone and was consistently higher in men compared to women in all studies. The problem of smoking is increasing among adolescents in SSA. In a cross sectional school based survey in Khartoum State the prevalence of current cigarette smoking was 13.6% .Studies in Nigeria have also reported high prevalence of smoking among adolescents . Urban rural differences in smoking habits exist and vary between countries and regions in SSA .The prevalence and pattern of tobacco use reported in several studies in Nigeria have shown a consistent trend: significant higher rate of smoking among males, urban-rural differences, high exposure at an early age, easy accessibility and poor understanding of the risk associated with the substance. In Nigeria, the overall prevalence of cigarette smoking was estimated to be 17.4% in males and 1.1% in females . Obvious regional differences exist in the prevalence of smoking and use of other forms of tobacco in Nigeria. In a national survey of substance abuse in Nigeria the lifetime, 1-year and 30-day prevalence of smoking were 12.2%, 6.4% and 5.3% respectively with the highest prevalence in south eastern part of the country.

The prevalence of smoking among undergraduate students in various universities in Nigeria were similar to population-based studies possibly because of the age distribution of smokers which is favor of the young. In university of Ilorin, the prevalence rate of current cigarette smoking was 5.7% and lifetime smoking was 17.1% . It has been estimated that the majority of smokers start smoking as early as in their teens most of whom were influenced into smoking by peer pressure and commercial advertisements. The mean age of first exposure to cigarette among university students suggest that most start people start smoking in secondary schools .WHO statistics suggest that 68.9% of youth in the African Region bought cigarettes in a store and were not refused purchase because of their age.There is some evidence that this may be also be related to religious, social and psychological reasons .