Cotton In Mexico Research Articles

Multiple domestication events explain the origin of Gossypium hirsutum landraces in Mexico.

Several Mesoamerican crops constitute wild-to-domesticated complexes generated by multiple initial domestication events, and continuous gene flow among crop populations and between these populations and their wild relatives. It has been suggested that the domestication of cotton (Gossypium hirsutum) started in the northwest of the Yucatán Peninsula, from where it spread to other regions inside and outside of Mexico. We tested this hypothesis by assembling chloroplast genomes of 23 wild, landraces, and breeding lines (transgene-introgressed and conventional). The phylogenetic analysis showed that the evolutionary history of cotton in Mexico involves multiple events of introgression and genetic divergence. From this, we conclude that Mexican landraces arose from multiple wild populations. Our results also revealed that their structural and functional chloroplast organizations had been preserved. However, genetic diversity decreases as a consequence of domestication, mainly in transgene-introgressed (TI) individuals (π=0.00020, 0.00001, 0.00016, 0, and 0, of wild, TI-wild, landraces, TI-landraces, and breeding lines, respectively). We identified homologous regions that differentiate wild from domesticated plants and indicate a relationship among the samples. A decrease in genetic diversity associated with transgene introgression in cotton was identified for the first time, and our outcomes are therefore relevant to both biosecurity and agrobiodiversity conservation.

A new species of Neohydatothrips (Thysanoptera: Thripidae) from India.

With 120 described species (ThripsWiki 2020) Neohydatothrips is the most species-rich genus in the Thripidae subfamily Sericothripinae. Although widely distributed almost 70% of the species are from the New World (Lima Mound 2016), with only seven species recorded from India (Rachana Varatharajan 2017). The biology of most species in the genus remains unknown, but they apparently feed and breed on the leaves and/or flowers of various unrelated plants. A few species are economically important as plant pests as well as virus vectors, such as N. variabilis (Beach) (Zhou Tzanetakis 2013; Lima Mound 2016; Han et al. 2019). N. samayunkur (Kudo) is a pest on flowers and leaves of Tagetes spp. in many countries including India (Nakahara 1999; Bhatti et al. 2003). Even though N. gracilipes (Hood) was described originally as damaging cotton in Mexico, it is associated with weedy species of Sida in several countries including central India (Lima Mound 2016). In southern China, N. flavicingulus Mirab-balou, Tong Yang is reported as damaging leaves of Manglietia fordiana. In California, avocado crops are sometimes damaged by N. burungae (Hood) and this species is also recorded as distorting the young leaves of Passiflora in Colombia (Mound et al. 2019). N. gracilicornis (Williams) is reported as damaging Pinaceae and Betulaceae in Spain and South Italy (Marullo 2009). The purpose of this article is to describe a new species from India that was collected in the flowers of Jasminum sambac (Oleaceae) in Assam, northeastern India. A detailed structural diagnosis of this genus is provided by Masumoto and Okajima (2020).

Agronomic and Environmental Impacts of Bt Cotton in Mexico

Agronomic and Environmental Impacts of Bt Cotton in Mexico

Evaluation of the Impact of Genetically Modified Cotton After 20 Years of Cultivation in Mexico.

For more than 20 years cotton has been the most widely sown genetically modified (GM) crop in Mexico. Its cultivation has fulfilled all requirements and has gone through the different regulatory stages. During the last 20 years, both research-institutions and biotech-companies have generated scientific and technical information regarding GM cotton cultivation in Mexico. In this work, we collected data in order to analyze the environmental and agronomic effects of the use of GM cotton in Mexico. In 1996, the introduction of Bt cotton made it possible to reactivate this crop, which in previous years was greatly reduced due to pest problems, production costs and environmental concerns. Bt cotton is a widely accepted tool for cotton producers and has proven to be efficient for the control of lepidopteran pests. The economic benefits of its use are variable, and depend on factors such as the international cotton-prices and other costs associated with its inputs. So far, the management strategies used to prevent development of insect resistance to GM cotton has been successful, and there are no reports of insect resistance development to Bt cotton in Mexico. In addition, no effects have been observed on non-target organisms. For herbicide tolerant cotton, the prevention of herbicide resistance has also been successful since unlike other countries, the onset of resistance weeds is still slow, apparently due to cultural practices and rotation of different herbicides. Environmental benefits have been achieved with a reduction in chemical insecticide applications and the subsequent decrease in primary pest populations, so that the inclusion of other technologies—e.g., use of non-Bt cotton- can be explored. Nevertheless, control measures need to be implemented during transport of the bolls and fiber to prevent dispersal of volunteer plants and subsequent gene flow to wild relatives distributed outside the GM cotton growing areas. It is still necessary to implement national research programs, so that biotechnology and plant breeding advances can be used in the development of cotton varieties adapted to the Mexican particular environmental conditions and to control insect pests of regional importance.

Agroindustria y algodón en el valle de Mexicali. La Compañía Industrial Jabonera del Pacífico

El valle de Mexicali surgió a principios del siglo XX como parte de la expansión de la frontera agrícola del suroeste de Estados Unidos. No se puede explicar esto sin la participación de capitalistas estadunidenses que se adueñaron de la tierra y del agua del valle de Mexicali, estableciendo las bases de un desarrollo agroindustrial que giró alrededor del cultivo del algodón. Una empresa, subsidiaria de la Anderson, Clayton & Company, tuvo un papel relevante en ese proceso, logrando convertir al valle de Mexicali en uno de los principales productores de algodón de México.

Phenology and Ecology of Wild Cotton (Malvales: Malvaceae) and the Boll Weevil (Coleoptera: Curculionidae) in Tamaulipas, Mexico

The phenology and ecology of wild cotton, Gossypium hirsutum L., and the boll weevil, Anthonomus grandis Boheman, were studied at two sites along the northeastern coast of the state of Tamaulipas, Mexico, during 1986 and 1987. Wild cotton densities in the region were low and the plant occurred in areas least disturbed by agriculture and human settlements. Peak flowering periods of cotton and weevil densities occurred during fall months. Boll weevil infestations were relatively low throughout the sample period (7.1% of the total sampled buds and bolls) and never exceeded 31% of the fruiting forms on any sample date. Weevils were active and often reproductive during winter months, but were seldom found during the dry season (March to May) when cotton plants were generally vegetative or leafless. Within the cotton population, boll weevils were aggregated on large plants and often did not infest flowering and fruiting plants close to infested plants. Weevils failed to recolonize the northern study site after the dry season in 1987 although plants flowered and fruited heavily. The possible importance of these wild cotton and weevil populations to cultivated cotton in Mexico and southern Texas is discussed.

Inheritance of Methomyl Resistance in the Tobacco Budworm (Lepidoptera: Noctuidae)

A methomyl-resistant strain of Heliothis virescens (F.) was collected from cotton in Mexico during 1981. After one generation of laboratory selection, this strain showed about 41,000- to 65,000-fold resistance, depending on the weight of the third instars tested. Larvae that weighed 12–21 mg were harder to kill than those weighing 22–29 mg at the doses tested. Resistance appears to be due to a single autosomal incompletely dominant gene.

Boll Weevil: Egg Hatch Inhibition with Four Formulations of Diflubenzuron123

Four formulations of diflubenzuron containing 141.8 g AI/ha (25% WP in cottonseed oil; 39.8% flowable in Savol®; 25% WP in Savol and water; and 25% WP in Sun Oil 7N® and water) were applied by plane to 2-ha replicated plots of cotton in Mexico for control of Anthonomus grandis Boheman. All treatments were significantly different from the check and were highly effective in inhibiting boll weevil egg hatch. There were no significant differences in effectiveness among treatments.

Cotton in Mexico

Cotton in Mexico

An Early Occurrence of Cotton in Mexico

An Early Occurrence of Cotton in Mexico