Hemp Growing

At this time point, the green biotype appeared slightly more damaged by the fungus than the red biotype. This effect was supported by fresh weight analysis from plants at the 48-h time point . Severe loss of fresh weight occurred in both biotypes compared to that of untreated their respective control plant shoots. The green biotype was slightly more damaged with respect to fresh weight biomass. Three-week-old green biotypes were generally more susceptible to infection by MV than were red biotype plants at this age . Severe infection of 3-week-old biotypes  occurred after 48 h, and increased to 4.5 after 96 – 120 h. In comparison, a disease rating of only 2.6 occurred on 3-week-old red biotype plants after 96 h, but this increased to a disease rating of 3.5 after 120 h . In the biotypes, MV disease progression and severity were generally greater on 3-week-old plants as compared to 6-week-old plants . The green biotype might be compromised under natural environmental conditions and stress since betalains have been shown to be involved in plant photoprotection mechanisms. For example, photosynthetic capacity damage was reduced in red-pigmented versus green leaves after exposure to excess light Betalain synthesis in a related plant, cannabis grow system Amaranthus tricolor, has been shown to be under photo control .

Other reports show that betalain production in plants is upregulated after exposure to light or UV radiation There was a definite trend that the green biotype was somewhat more susceptible to MV when treated under greenhouse conditions. This may suggest that lack of the red betacyanin pigment renders the green biotype less resistant to pathogen attack. As outlined and presented earlier, betacyanin has been implicated in disease resistance. Further testing of the effects of MV on these two biotypes under field conditions and expanded characterization of the pigment contents and traits of these two biotypes  will help to clarify the interaction of the bioherbicide, Myrothecium verrucaria on these two glyphosate-resistant Palmer amaranth biotypes. In 1990, the Federal government enacted a non-indigenous aquatic nuisance prevention and control act to compact the effect of invasive species in the United States of America. Many organizations and agencies were created to specifically tackle problems that result from the nuisance invaders. In 2005, Governor Mike Foster of Louisiana formed a 29-member non-indigenous aquatic species advisory task force from public and government entities. This task force designed a management master plan for the state and several agencies were later empowered to carry out control, management and eradication of aquatic invasive species when possible.

Tulane and Xavier University Center for Bioenvironmental Research, Louisiana State University AgCenter, Louisiana Sea Grant, United States Army Corp of Engineers, and Louisiana Department of Wildlife and Fisheries are among the organizations that have been assessing and controlling the impacts of aquatic invasive plants in the state. There is a need to review what has been done by these agencies and assess the current trend of aquatic invasive plants in Louisiana State. The southeastern part of the country has the highest diversity of habitat, marijuana grow system with 47 percent of the nation’s wetlands, 78 percent of its coastal marshes, and over 70 major river basins. The warm climate and ample rainfall help support many of the world’s plants and animals. The abundant waterways open the region to non-native species more than any other regions of the country. Invasive species are non-native aquatic plants and other organisms whose introduction can cause adverse impacts on environment, economy and human health.

These invaders have been introduced into the Louisiana coastal waterway through shipping vessels, animal and human immigrations. Ecologically, they make the waterways to have unsightly aesthetics, serve as vector habitat, alter food web relationships, and disrupt recreation, flood control, and hydroelectricity. Toxicity of the surface waters can result in fishkills, and health hazards for humans.This includes plants that are rooted in the sediment with part or all of the plant underwater, as well as plants that float freely without contacting the sediment Aquatic plants may invade both marine and freshwater environments, including habitats such as wetlands, lakes, rivers, estuaries, coastal zones, irrigation systems, hydroelectric systems, and aquaculture facilities . These aquatic invasive plants have several traits such as short reproductive cycle, high genetic variability, ability to thrive in a wide range of environments and ability to aggressively compete to displace other plants from the coastal waterway .

The distribution of dry matter between the above- and below-ground parts of a plant does not account for these differences at the seedling stage, however, which is also the case for annual and perennial plants . Based on initial seedling growth, all fescues , with the exception of Kentucky bluegrass, showed a greater accumulation of dry matter, biological productivity and growth rate within the first 5 weeks when compared to the nimblewill, showing that nimblewill has a slower developmental stage and can be suppressed by pastures in field conditions. In general, the first plant to take root has a better chance in competing for environmental resources. However, bluegrass showed an accumulation of dry matter that was less than that of the weed, indicating that the bluegrass and pasture may suffer from competition with the nimblewill. In another experiment,  found that bluegrass grows much slower than other species. Those species that grow faster would be able to preempt the uptake of growth resources and, thus, would be expected to be more competitive . Control of spreading nimblewill is usually attempted with a nonselective systemic herbicide, when the weedy plants are young.

The mother plants are easily killed but, oftentimes, the weed will return, growing from the stolons; thus, an additional application of the herbicide is recommended.One must weigh the advantages and disadvantages before deciding whether to attempt control measures. Knowledge of the best stage during weed development to apply a control measure may increase the effectiveness of management strategies. Information on nimble will growth rates can be used to estimate the optimum period for post-emergence weed control with herbicides and the optimum timing of herbicide application or cultural control in conventional planting. Although riparian areas comprise less than 2% of the land area in the arid and semiarid western United States, they contribute disproportionately to physical and biological processes. They serve as pathways for the flow of energy, matter,cannabis grow equipment and organisms through the landscape, acting as ecotones between the terrestrial and aquatic zones and corridors across regions . Riparian vegetation plays important roles in trapping soil eroded from uplands and removing nutrients from surface and soil water , stream morphological dynamics , and aquatic, avian, and large game habitat requirements . Since the late 1800s, dry land small grain production has been practiced on nearly all the arable land of the inland Pacific Norwest .

Before widespread motorized mechanization of farming practices in the 1940s, the bottomland of second and higher order streams in this region were used extensively for grazing livestock, particularly draft horses, mules, and oxen. Beginning in the 1940s, much of this bottomland was converted to small grain production, resulting in the elimination of natural stream channels and riparian areas and the disruption of flood plains. Infrastructure  maintenance requirements, the need for farm operation efficiency, and government incentives led to the channelization of many of the streams in this region. Channelization creates steep banks unprotected by vegetation cover or consolidating root structure. Deep, channelized storm flow saturates unprotected stream banks, creating positive pore pressures that cause bank failure when the storm flow recedes , and concentrates energy to transport soils eroded from uplands, stream banks and bottoms to deposition areas.

Whereas the goal of stream channelization is to drain soil water more efficiently, the effect is to disconnect the hydrologic flux between stream channel and adjoining land. In forest or rangeland situations, this change in hydrology facilitates the establishment of opportunistic weed species. In croplands, the rapid draining of soil water short-circuits chemical and biochemical processes that would occur if the water were resident longer. For example; if water is stored in a floodplain from 2 to 10 days, nitrate concentrations would be reduced through denitrification . Functioning riparian areas are necessary to create multifunctional production systems as described by Jordan et al. . Until the late 1990s, efforts to restore or rehabilitate riparian areas occurred primarily in forests and rangelands on public lands through the efforts of USDA Forest Service, USDI-Bureau of Land Management, and USDI-National Park Service, with smaller scale private land projects sponsored by nongovernmental organizations such as The Nature Conservancy.

Under HDPE film mulching cropping system, the objective of this study is to select the optimal thickness of HDPE film for rice production. Herein, we investigated the effect of various thickness of HDPE film on physiological index of rice, soil parameter and weed control, etc. It is hoped that our study could improve current management strategies in rice production. Ontario is one of the leading provinces in Canada in production of dry bean , producing 118,000 MT of dry bean on 49,000 hectares with a farm-gate value of approximately $108 million in 2012 . Major market classes of dry bean grown in Ontario include black, cranberry, kidney, and white  bean. Dry beans are very sensitive to weed interference resulting in substantial yield losses. In research conducted in Ontario the average yield loss due to weed interference in winter wheat was 2%, in spring cereals 12%, in soybean 40%, in corn 52% and in dry beans 58% . More research is needed to identify new weed management herbicide options that have an adequate margin of crop safety, provide consistent broad spectrum weed control, have low environmental impact and maximize dry bean yield and net returns.

Halosulfuron is a sulfonylurea herbicide that controls nutsedge species , redroot pigweed , common lambsquarters , wild mustard , ladysthumb , velvetleaf  and cocklebur , including triazine resistant biotypes . Halosufuron is readily absorbed by roots and foliage and is translocated throughout the plant causing rapid growth inhibition in susceptible plants. Halosulfuron can be applied preplant incorporated , preemergence  or postemergence . Injury symptoms in susceptible plants include chlorosis, death of the growing point and complete death within 14 – 21 days Halosulfuron has low environmental impact as it is active at low doses, has low mammalian toxicity,cannabis grow trays and is relatively immobile in soils . Halosulfuron will be available for the first time in the Ontario market during the 2014 field season. Halosulfuron will provide Ontario dry bean growers with a new, low-use-rate herbicide that provides full-season control of a number of annual broadleaf weeds. There is little information on the crop safety and efficacy of halosulfuron applied PPI, PRE and POST to control broadleaf weeds in dry bean under environmental conditions in Ontario. Mangroves are habitat specific and inhabit swampy and saline environment  Mangrove weed are plants that are found in disturbed mangrove forest such as reclaimed land, sand filled and dredged sites .

Weeds are unwanted plants that grow in any place that is favorable for their growth and survival such as water, soil, tree trunk, wall of building and coastal soil.For instance these weeds can change the ecology of the area by supplying or utilizing soil nutrients, which may be detrimental to the native species Weed can affect fish spawning capability by obstructing breeding grounds ; they can also increase the heavy metal concentration through the actions of their root, which break up the parent soil to expose more metals. Humans also introduce seeds of weed into the mangrove forests, which embed in the soil and grow. Growth of weed in disturbed mangrove forests converts indigenous mangrove soil to sandy soil. The weed species are able to grow at the fringes and perimeters of the mangrove forest that had been cut down for the purpose of creating access way for pipelines .

This is because the pipeline route is usually covered with sandy soils brought elsewhere, which further introduce and accelerate weed growth . Furthermore, the sand filling of mangrove forest also changes the soil chemistry when muddy soils are converted to sandy soil. Change in soil chemistry can lead to increased heavy metal load, which has ripple effect on the aquatic environment . For instance, fishes and other aquatic organisms bioaccumulate the excess heavy metals, which they pass on to humans who feed on them Over the years several questions had been asked as to the role played by the mangrove weeds, which are often found in degraded mangrove forests. Do these foreign plants growing in mangrove forest play positive and/or negative roles? These questions are yet to be addressed. However, it is revealed by previous studies that in agricultural farms weeds can act as habitat for insect pollinators e.g. butterfly, grasshoppers, praying mantis beetles etc., which is a positive role for nearby plants. Nevertheless, weeds can play negative role by acting as nesting sites for pathogenic organisms such as mosquitoes, black fly etc. .

The vote of each tree is tallied; then the unknown sample is assigned the class in which it received the most votes. For each tree, a subset of the variables is used to develop the split. Also, a variable importance ranking is derived with the algorithm. Analysts can evaluate the ranking and identify variables that are relevant to the model for prediction or classification problems, leading to reduction in the number of variables used for the analysis. Random forest ranks very well among other classifiers . Recently, it was ranked in the top ten of 100 classifiers tested for classification purposes . It is capable of processing large datasets, can analyze numerous variables without deletion, is robust for analysis of datasets with missing variables, and has the ability to process unbalanced datasets. Models derived for classification can be used on other datasets. Light reflectance data recorded from sensors on-board satellite, airborne, and ground-based platforms have shown promise as input data for random forest to use for classification   and regression   problems. Currently, no information is available on using vegetation indices derived from multispectral data as input into random forest for soybean weed discrimination. The objective of this study was to evaluate normalized difference vegetation indices as input into random forest to differentiate soybeans and three broad leaf weeds: Palmer amaranth, redroot pigweed, and velvetleaf.

The study focused on leaf multispectral reflectance data of simulated World View 3 satellite sensor bands. Two experiments were completed in 2014 in which 30 replicates of soybean variety 4928LL , Palmer amaranth, redroot pigweed, and velvetleaf were grown in a greenhouse located at USDA-ARS, Stoneville, MS. Planting dates were June 13, 2014, and August 28, 2014, for experiments one and two, respectively. Seeds of the different plants  were sown into plugs. After emergence, the plant species were transferred to two liter pots. All plant species were exposed to a fourteen-hour photoperiod, and light was supplemented at the beginning and ending of the day with sodium vapor lamps. Day/night temperatures of the greenhouse was maintained at 28˚C/24˚C ± 3˚C, cannabis grow tray respectively. The soybean variety used in the study had an indeterminate growth habit and gray pubescence and was assigned to maturity group 4.9. The weed seeds were obtained from a seed bank maintained at the laboratory. Leaf reflectance measurements were obtained with a plant contact probe attached to a spectroradiometer  sensitive to a spectral range of 350 to 2500 nm. The contact probe has its own light source allowing the user to collect data anytime during the day or night. Reflectance measurements were collected from the most recently matured leaf of each plant; each reading was an average of fifteen readings. The spectroadiometer was calibrated in fifteen minute intervals with a white spectralon panel. Leaf reflectance measurements were collected prior to the plants reaching 1 foot tall. The goal of weed management strategies is to detect and kill the weeds in the vegetative growth stages and prior to the seeds reaching full maturity levels. Broadband and narrowband data have been used to develop vegetation indices.

Therefore, the simulated band center wavelength closest to center wavelengths used in other studies were employed in developing each vegetation index. Periodically, two vegetation indices were developed for a designated index because the band centers were equidistance from the band centers used by other investigators. These include the advanced normalized difference vegetation index , shortwave infrared water stress index , and structure insensitive pigment index . The hsdar package of R  and base R packages  were used to develop the sixteen spectral bands and the twelve vegetation indices, respectively. The conditional inference version of random forest was used for the classifications.Cforest is more stable in deriving variable importance values in the presence of highly correlated variables, thus providing better accuracy in calculating variable importance . Differences of cforest compared with the original version of random forest are as follows. Cforest employs conditional inference trees as base learners; random forest uses classification and regression trees as base learners Cforest develops unbiased decision trees based on subsampling without replacement instead of using bootstrap samples. The algorithm uses the conditional permutation scheme described by Strobl et al.   to determine variable importance ranking.

According to their report, the distribution of P. hysterophorus was limited to roadsides, rural villages, and urban areas with less abundance while all other IAPS had already interred to agricultural fields. However, the current investigation confirmed that the coverage of P. hysterophorus was more abundant in the cities. It is alert that the weed has already established itself and ready to move to agricultural fields such as the arable and grazing lands. Furthermore, the weed has started spreading from the area surrounding the Zeghibridge to the adjacent cropland and pasture on both sides of the river. In this particular study, there was no way to know when and how the plant was first introduced to the place; however, we speculated that the weed might have introduced with sand and stones used for the construction/maintenance of the bridge. Moreover, the presence of P. hysterophorus at the nursery site most likely speeds up its spread across the area. It should be noted that raising seedlings at the place infested with P. hysterophorus is like providing transportation to agricultural fields. This way, the weed will not only infest crop fields but also be able to travel long distances and cover large areas relatively within a short period. In general, P. hysterophorus is on the fast move to agricultural fields in the MZ.

The crop and livestock production in the area has been already constrained by many factors like lack of agricultural technologies, disease and pests’ pressure, and low production awareness of farmers. Thus, the invasion of Parthenium in agricultural fields, coupled with the existing problems, can be devastating and causes food insecurity. Therefore, the public administrators and policymakers of the regional government, in collaboration with all stakeholders, should take a decisive and timely decision to mitigate the weed when it is still sparse and small. The critical weed-free period has provided Ontario growers with the knowledge of when to control the weeds that cause detrimental yield loss in maize  and soybean  for quite some time. Researchers have also recognized that the critical weed-free period can vary from year to year and location to location undermining the potential utility and implementation of this integrated weed management strategy . Yet, research continues to be conducted as a better understanding of some of the underlying physiological mechanisms that underpin the critical weed-free period have recently been published In general,indoor cannabis grow system crops need to be maintained under weed-free conditions from the start of the critical weed-free period until at least the 10-leaf stage in maize   and the R1  stage in soybean Ontario maize and soybean growers have numerous herbicide options  for managing weeds during the critical weed-free period. Unfortunately, growers can sometimes miss registered herbicide application windows due to adverse weather conditions or mechanical breakdowns which leave large, highly competitive weeds present in the crop at a point beyond the critical weed-free period when rapid yield loss occurs.

At this time, growers would like to apply a high dose of postemergence  herbicide to ensure effective control of these large weeds, but growers also are concerned that crop injury could negatively impact yield. Regrettably, the tolerance of maize and soybean to a high herbicide dose at a late POST application timing is largely unknown. The exception to this is maize, which can tolerate over two-fold of the maximum labeled dose of glyphosate applied at the 10-leaf stage with minimal injury and little to no yield loss . Furthermore, to the best of our knowledge, few studies have been conducted in the absence of confounding weed competition effects that examine both a range of herbicides comparing relative crop tolerance  and the tolerance of crops to a late POST herbicide application . Therefore, the objective of this research was to determine the tolerance of maize and soybean to a late application of select POST herbicides in the absence of weed interference. Maize exhibited excellent tolerance to the POST herbicides applied at the 9- to 10-leaf growth stage. At 3 DAT, only the sequential application of 2,4-D/atrazine caused significant visible injury of 9%.At 7 DAT, the sequential application treatments of dicamba/diflufenzopyr, foramsulfuron, and 2,4-D/atrazine caused 6, 8, and 9% injury, respectively.For example, 3% injury was observed for a single foramsulfuron application whereas the sequential application treatment caused 7% injury 14 DAT.Furthermore, a single application of dicamba/diflufenzopyr caused no injury, but the sequential application caused 6% injury 14 DAT.

Weeds control by chemical method, aiming balance shifting of the agro-ecosystem in favor of cultivated crop, which proved to be relatively more efficient and economical. The efficacy of herbicides, however, depends more upon their formulation in addition to time, methods and rates of application . It was concluded from an experiment that hand weeding and mixture of herbicides Puma super 75 EW and Buctril-M 40 EC showed better results for controlling winter weeds .  while evaluating 5 post-emergence herbicides alone at recommended doses and in combination with DMA-6 for weed control in wheat concluded that herbicide application suppressed weed population effectively. Dosanex + DMA-6 and Arelon provided the best weed control. However, Dicuran M.A. 60 WP + DMA-6 produced the maximum grain yield. DMA-6 alone and in combination with Dicuran M.A. 60 WP was more economical than all other herbicidal treatments.  investigated the effect of different graminicides used at varying levels and concluded that lesser dose of Topik15WP is required for the control of wild oat as compared to Puma Super 75 EW. The maximum weed efficiency was noted for Isoproturon 50 WP while minimum value  was observed for Aim 40 DF . These results are in line with who reported that herbicides application effectively controlled weeds.

These findings are also in conformity with those of , who reported that herbicides significantly reduced weed density. Similarly,stated that Puma Super 75 EW @ 1.25 L·ha–1 gave maximum control of narrow-leaved weeds in wheat out of varying herbicides applied at different doses. The best performance of Isoproturon 50 WP and other herbicidal applications could be attributed to the best control of weeds due to minimal weed competition which caused an increased flow of nutrients towards the grain and ultimately yield was increased. These results are supported by . They reported that herbicidal treatments significantly increased the grain yield in wheat. The maximum number of tillers m–2 was noted for Isoproturon 50 WP whereas minimum number  was reported in weedy check. These results showed that maximum weed control enhanced the production of fertile tillers m–2 which subsequently contributed towards the increase in wheat yield. These results are in agreement with the work of  who obtained an increase in tillering with the application of different herbicides. The low yield  in weedy check plots indicated that weeds utilize maximum resources of the main crop which ultimately reduced the crop yield. These results are in conformation with those of , who applied Puma Super 75 EW and Topik 15 WP at different doses to control Avena fatua in wheat crop and reported that lesser dose of Topik 15 WP and higher dose of Puma Super 75 EW was required to control this weed. Wheat is the most important cereal crop in the USA, where it was planted on 23 million ha in 2012 .

Most of the wheat grown in the USA is winter wheat . Kansas state ranks first in winter wheat cultivation  in the USA . Winter wheat is not a good competitor with some broadleaf weeds even when wheat emerges before weeds . Common weeds found in winter wheat in the US are blue mustard , cannabis grow tray henbit , flixweed , bushy wallflower , field pennycress , wild buckwheat , shepherd’s purse , and pinnate tansymustard.Their interference can cause significant yield reduction in winter wheat. Season-long competition of 11, 33, and 98 blue mustard plants·m−2 reduced wheat grain yields by 28%, 42%, and 51%, respectively . Conley and Bradley reported yield reductions of 13 and 38% because of henbit interference at 82 and 155 plants·m−2 , respectively. Northam et al. also reported wheat grain yield loss of 48% with 221 henbit plants·m−2 . Bushy wallflower at 272 plants·m−2 reduced wheat yields by 25% . Hence, winter annual broadleaf weed control is very important for successful wheat production. For more than two decades acetolactate synthase -inhibiting herbicides have been primary herbicides used in winter wheat, however continuous usage of those herbicides led to selection of ALS-inhibitor resistant weeds. Currently 126 ALS-inhibitor resistant weed species have been reported worldwide; 45 in the USA . Bushy wallflower and flixweed, two common broadleaf weeds in winter wheat, were reported ALS-inhibitor resistant in 2005 and 2006, respectively in Kansas . Rotating herbicides with different modes of action can avoid selection for weeds biotypes that are resistant to certain herbicides. Hence, there is a need for herbicides with alternative modes of action to ALS-inhibitor herbicides in wheat.Pyrasulfotole inhibits 4-hydoxyphenylpyruvate dioxygenase  and blocks the pathway of prenylquinone biosynthesis in plants .

Bat optimization algorithm is inspired by biology and is a heuristic method for solving difficult optimization problems. It represents an attempt to simulate the behavior of bats to hunt prey and the algorithm was presented by the research Yang in Bat Algorithm is based on the bat community, which is flying through the search solutions space in a specific or special order to find the best areas. Each bat element represents one solution in  dimensions of the search space. The solutions are evaluated based on the appropriate value and using the given fitness function . For example, the dimensions  are a real value for the optimization solution space. Each solution represents a bat, and evaluation is done using the given fitness function. There are also two real values of the dimension  of vectors associated with every bat in society . The first vector is the value of the real value and represents the location of the bat in the solution to the search space. The second vector is the real value vector and represents the velocity in all directions of dimensions . The location and velocity of the vectors randomly configured at the beginning of the algorithm.

On each occurrence the appropriate value of each element in the bat group is calculated by the given fitness function. The new velocity vector is calculated on the basis of the relative distance from the best and current solution in society. Later, the position of all the bats is updated according to the speed vector. At the end of each iteration, the best solution is created and used as a new reference point, and the search space continues to be explored until the stopping condition is met. Usually, this condition is the maximum number of iterations or improvements in the best solution . One of the creations of animal life studied by many zoologists is the echo-locating  of bats . There are a few other animal groups that also have echo-positioning capabilities such as birds , whales, outdoor cannabis grow dolphins, and small insects, but this is very rare. This behavior of bats began by Lazzaro Spallanzani in . Then the term “echolocation” was introduced by Donald Griffin in 1944 with the ability of bats to produce sound with echoes beyond the frequency of human hearing and using it for general guidance in the dark and finding prey at night with echo location, bats emit ultrasound pulses with either a modified frequency  or fixed frequency  and sometimes a mixture of the two Tonal signals produced in the larynx  are emitted in short bursts through the mouth or gills .

Suga in  described that the reflected sounds were in a state of Doppler pressure or transformation which made the received resonance at a higher frequency than previously produced sound. Bats can determine the object and distance by measuring the modified echo reflection time When bats begin to search for prey in the research phase, they emit pulses at a low rate around the 10 Hz frequency . During the approach phase, where bats discover and approach prey, the pulses must be shorter to prevent interference . The shorter pulses cause a decrease in time between the pulse and echo. Also at this moment, the pulse emission rate gradually increases to 200 beats per second as bats continue to update the prey site . Suga  states that the pulse emission rate increases because bats need to produce more signals to accurately follow prey as the angular position of prey changes more quickly due to the closer distance between the bat and the object. In the last stage , the frequency of the emitted pulses increases by more than 200 Hz and the pulse emission rate becomes faster in only a small fraction of a millisecond long before the prey is caught .

A colony of bats has two exclusive approaches to avoid colliding with one another while echo locating . This behavior mostly applies to vampire bat types such as regurgitation from blood meals from successful bats to feed them to their useless member in the colony as a response to the meticulously balanced energy budget of each member of the colony . Wilkiuson discovered  that surviving altruistic behavior grows in survivors so that his fitness is relatively high to non-recipient, and mutual altruism also occurs during community nursing . Several researchers built algorithms by hybridizing common and difficult problems with the NP-Hard. Researchers have therefore worked in recent years to hybridize algorithms with normal and difficult problems and have achieved the best results by applying hybrid problems. The real purpose of the hybridization process is to obtain general and varied solutions that can deal with problems in the real world.

At harvest , Common Lambsquarter plants of up to 1.8 m height were observed in the control treatment, linked to a very low CCL and associated, also, with a very low WSI. When weeds emerge together with the crop and are not controlled, crop competition ability is very low, as already found by Nelson and Thoreson , who determined reductions in yields of 54% when weeds emerged together with the crop and reductions of 16% when they emerged 3 weeks later; allowing the crop to better compete with them. When Clomazone 1.6 was applied, there was not an adequate control of Common Lambsquarter and Spiny Cocklebur, then CCL and WSI were low, when compared with the Clomazone 2.0 or the Clomazone + Metribuzin combinations . Lake Kyoga is a large shallow lake in Uganda of about 1720 km2  in area with mean depth of 3.6 m and maximum depth of 6 m About 9.3 million people inhabit Lake Kyoga Basin and their major economic activity is agricultural productivity  practiced by 85% of the population Fishing is also carried out on the lake by an estimated 200,000 people and the lake is used for inland water transport as well as source of water for drinking and other domestic uses for most of the inhabitants in the lake basin Unfortunately, Lake Kyoga has been invaded by the free-floating aquatic weed, giant Salvinia molesta D.S. Mitchell with a high potential to infest the numerous satellite lakes in Kyoga Basin .

Therefore, there is an urgent need to collect baseline data and information on the extent of S. molesta infestation in the Kyoga Basin lakes . Salvinia molesta belongs to Order Hydropteridales, Family Salvinanceae and genus Salvinia with about 12 species which are all native to South America Salvinia molesta formally existed only in South America, but since the 1940s the weed has been dispersed by humans to different tropical and subtropical countries in Africa, Asia, and Australia   as well as USA in the recent years . The plant is known by a number of common names such as giant Salvinia, Kariba weed, aquarium water moss, water fern, and giant azalea etc. These names often reflect the environment the weed inhabits or its invasiveness The weed is called “Nankabirwa” by locals in Uganda,vertical grow system due to lack of a native name . The free-floating S. molesta weed comprises of an underneath horizontal rhizome which lies close to the water surface . It has two types of leaves attached to each node of the rhizome. The submerged leaves of S. molesta are modified to perform the function of roots as the weed does not have true roots . S. molesta exhibits several morphological variations ranging from slender floating plant with less than 15-mm wide leaves to a robust plant having leaves up to 60-mm wide brought about by crowding and nutrient availability in the habitat The weed is capable of spreading easily over water bodies using its floating structures and even survives in unfavourable environments using the most suitable growth form .

It seemingly produces only sterile spores, hence reproduces entirely by vegetative means which can be extremely rapid under suitable conditions . For instance, S. molesta can double in biomass in 2 to 3 days under favourable conditions . This enables S. molesta to out-compete other plant species and completely cover the water surface with mats as thick as 1 m . Salvinia molesta has been recently added onto the list of the world’s 100 most invasive species and ranks second to water hyacinth  Solms-Laub.The thick mat also severely reduces dissolved oxygen content  in aquatic ecosystems sometimes resulting into fish kills For the case of Lake Kyoga, the thick mats of S. molesta on the lake  have hampered activities such as abstraction of water by surrounding communities, watering of domestic animals, docking and boat take-off, bathing and swimming . Fortunately S. molesta weed has been successfully managed in other countries e.g. lake Moondara, Australia where the weed had threatened the biodiversity and the life of the lake . Studies in Australia showed that successful management of Salvinia molesta is achieved through integrated control strategies combining herbicide spraying, biological control agents and mechanical removal including the containment of the weed to keep some areas free of S. molesta . However, the best management practices for Salvinia in Africa can be found from those countries  where the weed is non-native but has apparently not led to major disruptions to use of water resources  as well as Senegal, Mauritania  and South Africa  among other countries where successful control by biological agent  was achieved. The use of Cyrtobagous salviniae biological agent to control S. molesta in these countries was based on the outstanding success of Cyrtobagous salviniae in Australia and Papua New Guinea  Nevertheless, planning a management strategy for S. molesta involves identification of the source of the infestation, mapping the infestation, identification and minimising sources of nutrients entering the water body .

H1: Individual marijuana use will increase with the number of friends who use marijuana H2: Individual marijuana use will increase with peer- group acceptance of marijuana use Mauss situates marijuana experimentation within the context of college preparation, arguing that many university-bound high school students begin use before matriculating to assist in the cultural assimilation process . Conversely, Brown finds that college students cease marijuana use following graduation, citing social pressures of work, family, and social integration as key causal factors . Yamaguchi and Kandel use cross-sectional event history analysis to demonstrate that marijuana use is negatively related to marriage and becoming a parent, yet positively related with separation/divorce. Since this study’s sample will consist entirely of marijuana users, I expect that the average level of education will be higher than the general population, and that more individuals will be single and childless than the general population.Do licensed medical marijuana users differ from their illegal counterparts in their rationalizations for using the drug? The universe of possible reactions to marijuana are multifaceted and, often, mutually contradictory; Goode’s qualitative study of users illustrates this phenomenon well . Reinarman et al. provide the lone scholarly attempt at identifying characteristics of medical marijuana users .

Using a sample of 1746 patients from nine separate medical marijuana clinics in California, the authors find that Blacks and Native Americans use at higher rates than other ethnic groups, while Latinos and Asians have lower rates of use . Use is heaviest in the 25 44 year age range, and males made up 73% of the sample. Chronic pain suppression and improved sleep were the most commonly cited uses/benefits of marijuana reported by subjects . Other conditions/uses of medical marijuana included relaxation, muscle spasms , headaches , anxiety , nausea , and depression . Studies of non-medical use suggest two dominant views by users: 1) the drug is perceived to stimulate creative thinking,cannabis grow equipment particularly among artists, musicians, and writers, and 2) users consume it to relax and experience euphoria. Weil et al., in the first controlled study of marijuana use, found that self-reported feelings of well-being were improved with consumption of the drug, and that the intensity of these feelings was dose-dependent.Rather than being distracted from personal problems of unusual sights, sounds, or tastes, such persons may experience marijuana as a confrontational drug, which focuses attention on the very aspects of self that are currently most troublesome .While there is pointed evidence indicating that the drug affects individuals in varying manners, the subjective experiences described by users also points to a methodological problem unaddressed by previous research: different varieties of marijuana tend to elicit different results.

Hillig and Mahlberg’s review and analysis of 157 different cannabis accessions lends credibility to the anecdotal evidence reported by users; genomically, drug cultivars of cannabis are limited to two subspecies of cannabis indica , with narrow leaf plants generally producing soaring mental euphoria in users and broad-leaf plants inducing a more lethargic, body-numbing effect . The wide variation in effect is attributed to different ratios of two key cannabinoids in these plants—THC and CBD—with low amounts of CBD in narrow leaf varieties and high amounts in broad-leaf plants. Plant-induced variations in experience aside, current evidence suggests that medical users of the drug will focus on symptom alleviation in an attempt to rationalize their use; non-medical users should report using for either creative stimulation/personal insight or simply to numb themselves from reality . Accessing hidden populations—a status marijuana users, producers, and sellers are relegated to in the United States—poses two unique challenges to investigators; as Heckathorn notes: First, no sampling frame exists, so the size and boundaries of the population are unknown; and second, there exist strong privacy concerns, because membership involves stigmatized or illegal behavior, leading individuals to refuse to cooperate, or give unreliable answers to protect their privacy . To address these concerns, researchers have tradition-ally relied upon snowball sampling, key informant sampling, and targeted sampling to investigate hidden populations. The shortcomings of each approach are detailed elsewhere, but the primary concern is derived from the lack of independence between observations, which is an unassailable artifact of snowball and targeted sampling . Heckathorn’s Respondent-Driven Sampling offers an elegant addendum to chain referral procedures by limiting the number of potential recruits that each respondent can bring into a research program and incorporating both primary and secondary incentive structures into the recruitment process .

Given the aforementioned literature, the present study aimed to examine correlates of marijuana use in a sample of Southeast U.S. college students. Specifically, we examined sociodemographics, other health risk behaviors , and psychosocial correlates in relation to marijuana use. The US Asian American population grew by 43% between 2000 and 2010, compared to a 9.7% growth in the general population, making Asian Americans the fastest growing racial group . Asian Americans are projected to constitute6.5% of the US population by 2025, and 9.3% by 2050 . The Asian American population is a heterogeneous group that includes at least 43 ethnic subgroups with different languages and dialects, immigration histories, religious beliefs, socioeconomic statuses, and traditional patterns for seeking health care. These social and cultural differences among Asian Americans may affect their psychiatric clinical manifestations, severity of mental health problems, access to health care,and treatment compliance and outcomes .Overall, the reported prevalence of mental illness is lower in the Asian American adult population compared to other ethnic groups .

Despite the lower risk of mental illness among Asian Americans, it is still important to investigate because recent studies have shown that Asian American patients were admitted to the San Francisco Psychiatric Emergency Services twice as frequently as European and Latino/a Americans. They showed significantly higher functional impairment based on their Global Assessment Functioning scores . In addition, a prevalence study showed that schizophrenia and psychotic disorders,cannabis grow lights which are severe and chronic types of psychiatric disorders, are more common among Asian American veterans than among African American and Latino/aveterans .Substance use studies have shown that Asian Americans are less likely to use substances and have a lower severity of drug use than European Americans . Of Asian Americans, Filipino/a Americans were reported to have the highest prevalence of substance use and cigarette smoking. Japanese Americans were found to have the highest number of alcohol related problems and binge-drinking episodes, followed by Filipino and Multi-Asian Americans including Korean and Chinese . Substance use within the Asian American population has largely been ignored, mainly due to the popularity of the model minority theory which paints Asian Americans as the exemplary racial/ethnic group, thus minimizing the perceived severity of the problems . Often, it is considered shameful within Asian cultures to have a family member with a mental illness or substance use problem, resulting in familial pressures to avoid seeking proper treatment.

Substance dependent Asian Americans have already been shown to underutilize available programs and treatment when compared to European Americans. Park, Shibusawa, Yoon, & Son found that the majority of Chinese Americans and Korean Americans referred to such treatment by the legal system denied having alcohol problems. Only five percent of the sample admitted to having alcohol problems. Very few of them had ever heard about the Alcoholics Anonymous program and none of them had ever attended the program. Similar results were found in another study that showed that Asian Americans utilized legal services more frequently than medical and psychiatric services related to their alcohol and drug use problems .Co-occurring substance use in persons with mental disorders is a common issue. About 18.5% of the adults with mental disorders met the criteria for substance use disorders, whereas only 5% of the adults without mental disorders met the criteria for substance use disorders . According to a recent epidemiology study, the prevalence of lifetime co-occurring substance use and mental disorder was about 7%.Depressive disorder was significantly related to higher rates of alcohol, stimulant, and opiate use, whereas schizophrenia and schizo affective disorder were significantly related to lower rates of alcohol, opiate, and poly substance use. In another national 10-year longitudinal survey,persons with major depression, anxiety disorder, and disruptive behavior disorder were at a significantly greater risk to start using illicit drugs during the follow-up period . Although there were subgroup psychiatric diagnostic differences regarding the prevalence of substance use, persons with mental disorders generally showed a higher prevalence of substance use.However, little has been done to study the coexistence of mental illness and substance use in the rapidly growing Asian American population.