Transgenic Cotton

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1 Transgenic Bt Cotton Background Human beings have participated in agricultural activities since the beginning of time. Agriculture provides raw materials and food to the people. A large number of people are also employed in the agricultural sector. People decide to venture into food crop farming or cash crop farming depending on land availability and other resources. Cotton is one of the crops that people cultivate for commercial purposes. Cotton farming has turned out to be an integral element of the industrial and agricultural economy. Unfortunately, it is faced with numerous challenges emanating from minimal finances, lack of market, pests, and disease-causing microorganisms.

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2 Naranjo (2005) pointed out that Cotton fields are inhabited by a wide range of pests and arthropod predator species. Researchers have acknowledged that pests can negatively affect production and returns in agriculture. Farmers and leaders have devised numerous approaches to deal with the pests and other challenges affecting cotton farming. Whereas these interventions have resolved most of the challenges, they have not completely eradicated the cotton farming problems. Pesticide use, for instance, eradicates pests but affects environmental stability and productivity of crops. Adverse effects associated with insecticide use have triggered the need to employ more effective approaches. The introduction of biotechnology is one of the proposed solutions to most agricultural problems. Biotechnology has contributed to the rapid advancement of the agricultural sector in the last four decades. It has not only improved agricultural yields but has also improved returns in farming. In cotton farming, researchers have proposed using Bacillus thuringiensis (Bt) cotton, which is resistant to a wide range of pests (Luo et al., 2017). However, the use of Bt cotton has faced opposition from many people. Notably, no society has completely accepted the introduction of genetically modified crops. The uncertainty of the safety and effectiveness of such crops lingers in the minds of many. Many people believe that Bt cotton and other genetically modified products can cause harm and increase the risk of chronic conditions. Some people have also raised the argument that such crops are ineffective against pests compared to traditional crops. Problem Statement Although researchers have clarified that genetically modified crops pose a minimal health threat to the people, it will take decades to convince everyone to support the shift towards genetically modified products. Conservatives argue that Bt cotton's introduction will lead to


3 cross-contamination of food crops, thus risking the people's health. These groups also argue that GM crops are not resistant to pests and disease-causing microorganisms and affect various pests' natural predators. Such arguments continue to derail the widespread introduction of GM crops. Farmers have long relied on pesticides to eradicate pests and improve yields. Unfortunately, these chemicals predispose people to health risks besides affecting the stability of the environment. Besides being harmful to the environment, insecticides do not eradicate all pests. Farmers are, thus, forced to use different types of toxic agents to prevent infestation by a wide range of pests. The risk of developing resistance towards certain pesticides is also high. These chemicals also affect crop productivity. Naranjo (2005), for instance, pointed out that crop production is depressed by the continuous use of insecticides. Therefore, it is imperative to identify a more potent approach to prevent pests and improve yields. Purpose Statement Transgenic researchers argue that using Bt cotton and other genetically modified crops can reduce the need to use pesticides by increasing the crop's ability to resist pests. Researchers have also proposed that transgenic crops can enhance productivity and improve the economic value of crops. This paper explores the literature on the biotechnology aspects that improve Bt cotton's productivity and effectiveness against pests. The paper will also investigate the factors that influence the Bt protein content. This information will help determine if Bt cotton can effectively resist pests, thus reducing the largescale use of pesticides. Results and Discussion Summary of the Articles Transgenic studies have generated reliable information concerning various aspects of Bt cotton and other GM products. The study by Naranjo (2005), for instance, explored the long-


4 term effects of Bt cotton on pests. The researchers noted that field studies investigating transgenic crops' impact on non-target organisms focus primarily on non-target abundance and diversity. Only a few studies have looked into the effects of these crops on non-target communities. The study by Naranjo (2005) was carried out for over five years. This study's primary purpose was to determine if transgenic cotton producing the Cry1Ac toxin of Bacillus thuringiensis (Bt) affected the natural enemy community of three major posts: Bemisia tabaci, Lygus hesperus, and Pectinophora gossypiella. Naranjo (2005) acknowledged that cotton fields have a rich biodiversity of arthropod and parasitoid predator species. These species play an invaluable role in regulating the populations of herbivore pests. As pointed out by Naranjo (2005), extensive use of pesticides has devastating effects on both pests and natural predators. The toxic nature of these agents leads to the death of many parasitoid predators. Pesticide use makes it almost impossible for farmers to achieve the biological control of pests. The impact of pesticides on natural predators needs to be minimized to improve compatibility between chemical and biological control (Naranjo, 2005). Farmers and researchers can attain this compatibility by using transgenic crops capable of producing insecticidal proteins. Naranjo (2005) noted that Bt cotton contributes to pests' biological control by reducing the need to use broad-spectrum insecticides. These crops also have a highly selective activity as compared to the insecticides they replace. Fleming et al. (2018) conducted a meta-analysis to investigate transgenic Bt cotton's effects on insecticide use, cotton yield, and plant damage. The researchers analyzed primary sources between 1996 and 2015 containing information on Bt cotton. In line with the articles' information, Fleming et al. (2018) noted that none of the pest prevention strategies employed by farmers achieve the anticipated pest reduction, soil improvement, and increase yields. Fleming et


5 al. (2018) identified Bt cotton as an effective strategy to achieve these goals. Transgenic Bt cotton produces proteins with insecticidal activities. The article by Zeilinger, Olson, and Andow (2016) highlights a meta-analysis of previous studies investigating the competitive release and outbreaks of non-target pests associated with transgenic Bt cotton use. In this study, Zeilinger et al. (2016) wanted to determine if release from competition with Bt susceptible pests contributes to stink bug pest outbreaks in transgenic Bt cotton. The researchers also performed experiments to determine if herbivory by Bt susceptible pests increased the leaving rates of stink bugs. These experiments were also intended to determine if the presence of herbivore pests deterred oviposition on non-Bt cotton. The researchers noted that increased use of Bt cotton contributes to environmental and economic benefits by alleviating the need to use commercial insecticides. These benefits have, however, been uneven. Some regions in the southern parts of the United States, for instance, experience frequent outbreaks of secondary and non-target pests. These outbreaks force farmers to continue using synthetic insecticides despite having planted Bt cotton. Outbreaks of stink bug pests are common in the southern USA. Even though these pests' devastating agricultural impact is well documented, the causes and natural preventive measures remain unclear (Zeilinger et al., 2016). Luo et al. (2017) describe lab experiments investigating the effects of soil salinity on the expression of insecticidal proteins produced by Bt cotton and the effectiveness of these proteins in controlling Helicoverpa armigera. The authors noted that soil salinization is a critical factor that influences sustainable agricultural development. Irrigation and poor drainage are the major causes of increased soil salinization. Whereas some crops require alkaline soil for increased yields, others are affected by high salinity. Cotton, for instance, performs well in alkaline soil than less saline soil. Luo et al. (2017) pointed out that cotton bollworm and other pests affect the


6 productivity of cotton despite the presence of favorable soil conditions. Farmers have resorted to the largescale plantation of Bt cotton to tackle the cotton bollworm challenge. The researchers noted that abiotic stress could affect the Bt protein level and its control efficiency in the current study. The abiotic factors that influence Bt cotton's protein level include water deficiency and temperature. However, soil salinity's impact on Bt cotton's control effectiveness against cotton bollworms, affecting the expression of Bt protein, is not well understood (Luo et al., 2017). Summary of Research Findings Findings from the selected research articles show that the introduction of Bt Cotton has led to a significant decline in insecticide usage. Some farmers have, however, continued to use foliar insecticides to manage heliothine pests in several regions across the U.S. The findings also show that crop damage related to the Bt Cotton-targeted pests has also decreased remarkably. Unfortunately, the studies have not evaluated the economic impact of Bt cotton. The researchers reported that Bt genes have been introduced in other crop varieties such as corn for pest control purposes. Corn farmers have continued to report immense benefits from this technology. No major environmental problems have been experienced following the use of these species. The studies also found that increased soil salinity leads to decreased Bt protein content. High soil salinity decreases Bt cotton's insecticidal activity against cotton bollworm. The population of cotton bollworms is high on Bt cotton grown in low and medium salinity soil. These findings indicate that high soil salinity alter Bt cotton's nutritional quality and the defensive trait of plants.

What Remains Obscure?


7 Although transgenic crops have numerous benefits for farmers, they have several potential risks that cannot be overlooked. These risks include outcrossing through pollen drift, food safety, the direct and indirect impact on non-targeted organisms, and horizontal transfer of transgenes to other organisms (Naranjo, 2005). Naranjo (2005) noted that most laboratory studies investigating the effects of exposure to Bt toxins on non-target organisms have been inconclusive. Field studies focus primarily on changes in abundance and diversity of non-target species. Another major concern is the possibility of resistance to Bt technology. Researchers are worried that transgene crops may cause targeted and non-targeted pests to lose susceptibility to Bt toxins. For instance, Fleming et al. (2018) reported a decline in Bt cotton yields in certain regions between 2010 and 2015. The decreased yields were associated with a decline in insect pressure. The researchers postulated that the target insects might have developed resistance to Bt toxins. There is the likelihood that changes in cotton genetics over time altered the susceptibility of heliothines to the toxins. Studies have, however, revealed that resistance to a single transgene might take over 30 years to occur. This period may increase if dual-transgenes are involved. Other studies show that the competitive release of stink bugs in Bt cotton may lead to these pests' outbreak. However, the relative significance of competitive release remains a contentious issue. Extensive ecological risk assessments are needed to generate solid information regarding the ecological mechanisms underlying outbreaks of non-targeted pests (Zeilinger et al., 2016). Further, researchers cannot brush away the issue of the safety of transgenic crops. It is crucial to inform people of the benefits and disadvantages of such crops. More research is needed to produce significant information regarding Bt cotton's safety to the people, animals, and


8 environmental stability. This information will enhance acceptance of Bt cotton across the continuum. Prospects Cotton is an important crop in the United States and other parts of the world. Insect pests have long affected the productivity of cotton. The use of insecticides has not produced the results wanted by farmers. Transgenic Bt cotton offers a long-lasting solution to the pests' menace. Continued research will generate reliable information to rid people of doubts concerning the effectiveness of transgenic Bt cotton. In the future, more people will embrace the use of transgenic crops with minimal fear of adverse health outcomes or devastating environmental consequences.

Conclusion Although research on Bt cotton is not exhaustive on all biosafety aspects, literature shows that Bt cotton effectively prevents pests. Bt cotton reduces the need to use pesticides, thus protecting the arthropod predators. Transgenic Bt cotton improves yields and reduces the number of pests in the field. Studies show that Bt cotton effectively controls cotton bollworm, which causes massive agricultural and economic losses. The effectiveness of Bt cotton is affected by various factors, including soil salinity. Farmers can increase Bt cotton protein content by irrigating their land and reducing soil drainage.


9 References Fleming, D., Musser, F, Reisig, D., Greene, J., Taylor, S., Parajulee, M., ... & Little, N. (2018). Effects of transgenic Bacillus thuringiensis cotton on insecticide use, heliothine counts, plant damage, and cotton yield: A meta-analysis, 1996-2015. PloS one, 13(7), e0200131. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0200131 Luo, J. Y., Zhang, S., Peng, J., Zhu, X. Z., Lv, L. M., Wang, C. Y., ... & Cui, J. J. (2017). Effects of soil salinity on the expression of Bt toxin (Cry1Ac) and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton. PloS one, 12(1), e0170379. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0170379 Naranjo, S. E. (2005). Long-term assessment of the effects of transgenic Bt cotton on the function of the natural enemy community. Environmental Entomology, 34(5), 1211-1223. https://academic.oup.com/ee/article/34/5/1211/429827 Zeilinger, A. R., Olson, D. M., & Andow, D. A. (2016). Competitive release and outbreaks of non‐target pests associated with transgenic Bt cotton. Ecological Applications, 26(4), 1047-1054. https://doi.org/10.1890/15-1314


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