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Growth and Photosynthetic Pigments of Cotton Cultivars Irrigated with Saline Water  [PDF]
Elka Costa Santos Nascimento, Ronaldo do Nascimento, André Alisson Rodrigues da Silva, Carlos Vailan de Castro Bezerra, Mateus Costa Batista, Luana Lucas de Sá Almeida Veloso, Márcia Cristina de Araújo Pereira, Hallyson Oliveira
Agricultural Sciences (AS) , 2019, DOI: 10.4236/as.2019.101007
Abstract: The cultivation of cotton is a relevant socioeconomic activity in the Brazilian agricultural scenario. In the Brazilian Northeast, however, production is limited by low rainfall, requiring water supplementation, a problem for the cotton cultivation practiced in the semi-arid region, due to the presence of saline ions in several water sources, from where the water is used for irrigation. It is necessary to identify cultivars that better tolerate saline stress in order to provide subsidies for their cultivation under such conditions. In this sense, the objective was to evaluate the tolerance of cotton cultivars to salinity. The experiment was conducted in a greenhouse, belonging to the Natural Resource Technology Center of the Federal University of Campina Grande, Campus I, Campina Grande, Brazil, in a completely randomized design in a 2 × 5 factorial scheme, with four replications, totaling 40 experimental units (BRS 368 RF and BRS SAFIRA) submitted to five saline levels (1.5, 3.0, 4.5, 6.0 and 7.5 dS·mˉ1). Irrigation with water saline of EC from 1.5 dS·mˉ1 affects adversely the growth of cotton cultivars, causing reductions in plant height, stem diameter, leaf area and number of leaves. Saline stress reduced the levels of the photosynthetic pigments of the cotton plants studied.
Scaling Leaf Measurements to Estimate Whole Canopy Gas Exchanges of Cotton  [PDF]
Dennis C. Gitz III, Jeffrey T. Baker, Robert J. Lascano
American Journal of Plant Sciences (AJPS) , 2016, DOI: 10.4236/ajps.2016.714178
Abstract: Diurnal leaf and canopy gas exchanges of well-watered field grown cotton were measured. Our objective was to scale leaf-level values of transpiration and net assimilation to the whole canopy level using estimates of canopy leaf area. Single leaf gas exchange measurements were made with two portable photosynthesis systems and canopy measurements with four open Canopy Evapo-Transpiration and Assimilation (CETA) chamber systems. Canopy leaf area was measured at the end of the experiment and estimated during gas exchange by fitting values to a growth curve. Leaf level measurements were arithmetically scaled to estimate canopy level gas exchange based on canopy leaf area and then compared to the measured values. Scaled values of single leaf transpiration were very similar to canopy transpiration measurements, although both whole canopy transpiration and assimilation were overestimated around mid-day. We conclude that canopy cotton transpiration of well-watered field grown plants could be estimated within 5% throughout the day by scaling leaf level measurements to the whole canopy using measured canopy leaf area. Estimating canopy assimilation from leaf level measurements remains problematic.
Physiological quality of wheat seeds submitted to saline stress
Duarte, Gisela Loureiro;Lopes, Nei Fernandes;Moraes, Dario Munt de;Silva, Rodrigo Nascimento da;
Revista Brasileira de Sementes , 2006, DOI: 10.1590/S0101-31222006000100017
Abstract: the objective of this experiment was to determine the influence of different salt levels (zero, 15, 30, 45 and 60mm nacl) on seed physiological quality of two wheat cultivars (brs 177 and brs 179). summarize methodology. the results allow the following conclusions: the physiological quality (germination and vigor) of wheat seeds, cultivars brs 179 and brs 177, decrease with the increase of the salinity. the wheat seeds cv. brs 179 performs better than brs 177, mainly in higher salt concentrations (3 45mm of nacl). the electric conductivity of wheat seeds increases in function of the increment of the saline concentrations.
Within-plant distribution of cotton aphid (Hemiptera: Aphididae) in cotton cultivars with colored fibers
Fernandes, Francisco S.;Ramalho, Francisco S.;Malaquias, José B.;Nascimento Junior, José L.;Correia, Ezequias T.;Zanuncio, José C.;
Anais da Academia Brasileira de Ciências , 2012, DOI: 10.1590/S0001-37652012005000040
Abstract: we describe the vertical and horizontal distribution of the cotton aphid aphis gossypii glover within a cotton plant in two cotton (gossypium hirsutum linnaeus) cultivars (brs safira and brs rubí) with colored fiber over the time. measurements of aphid population dynamics and distribution in the cotton plants were recorded in intervals of seven days. the number of apterous or alate aphids and their specific locations were recorded, using as a reference point the location of nodes on the mainstem of the plant and also those on the leaves present on branches and fruit structures. the number of apterous aphids found on the cultivar brs safira (56,515 aphids) was greater than that found on brs rubí (50,537 aphids). there was no significant difference between the number of alate aphids found on the cultivars brs safira (365 aphids/plant) and brs rubí (477 aphids/plant). there were interactions between cotton cultivar and plant age, between plant region and plant age, and between cultivar and plant region for apterous aphids. the results of this study are of great importance in improving control strategies for a. gossypii in the naturally-colored cotton cultivars brs safira and brs rubí.
Effect of silicon and acibenzolar-s-methyl on colored cotton plants infested or not with Aphis gossypii Glover (Hemiptera, Aphididae)
Alcantra, Eliana;Moraes, Jair Campos;Antonio, Alex;Alvarenga, Roberta;Fran?oso, Jonas;
Revista Brasileira de Entomologia , 2011, DOI: 10.1590/S0085-56262011005000011
Abstract: effect of silicon and acibenzolar-s-methyl on colored cotton plants infested or not with aphis gossypii glover (hemiptera, aphididae). the aphid aphis gossypii is an insect pest that causes damage mainly at the beginning of the cotton plant development. the effect of resistance inductors silicon and acibenzolar-s-methyl (asm) on the development of colored cotton plants were researched in the presence and absence of a. gossypii. three colored cotton cultivars were sown in pots and individually infested with 25 apterous aphids, 13 days after the application of the inductors. fifteen days after plant emergence, the silicon was applied at a dosage equivalent to 3 t/ha and acibenzolar-s-methyl in 0.2% solution of the product bion 500?. after 21 days of infestation the following parameters were evaluated: plant height, stem diameter, dry matter of aerial part and root, and total number of aphids replaced. it was verified that the plant height was reduced in the presence of aphids and all variables were negatively affected by the application of asm. however, silicon did not affect plant development.
Study on characteristics of colored cotton fiber development

WANG Xue de,LI Yue you,

浙江大学学报(农业与生命科学版) , 2002,
Abstract: Pigment matter in fiber cells of brown or green cotton could be extracted by HNO 3/ethanol distillation, and its content could be estimated by absorbance reading at 412 nm for distillation solution Pigment matter in brown or green cotton fiber cells could be obviously detected when fiber cells grown up to about 15 days post anthesis (DPA), reaching a maximum content at 20 DPA Fiber color change from white to brown in the boll of brown cotton was not found until 30 35 DPA, and brown color was very stable and even deepening in the sunlight However, fiber in the green cotton boll began to be colored green at 20 DPA, after this, fiber color was gradually deepened with fiber development, but easy to fad in the sunlight Cellulose content in brown or green cotton fiber was significantly lower than in white cotton fiber, which might be caused by accumulation of fiber pigment matter Between 15 and 30 DPA, the pH in white fiber cells lowered rapidly, while that in brown or green fiber cells slowly It was suggested that a rapid or slow decline for fiber cell pH during this period might bring some effects on fiber cell elongation, secondary wall synthesis and color change Comparing with white fiber, quality of brown or green colored fibers was lower, such as shorter length and weaker strength, which possible reason was discussed in the paper
Study on extraction and quantification of fiber pigment matter in colored cotton

WANG Xue de,LI Yue you,

浙江大学学报(农业与生命科学版) , 2002,
Abstract: Pigment matter in mature fibers of brown or green cotton was extracted by organic solvent (ethanol, aether and dimethylbenzene), acid and alkaline solution, and HNO 3/ethanol. The comparison of three extraction methods showed that pigment matter in colored fiber cells could be effectively extracted out only by HNO 3/ ethanol distillation. There was a maximum absorbance peak at 412 nm for fiber pigment solutions from HNO 3/ ethanol distillation. Absorbance readings of sample solutions at this wavelength were associated with fiber color and its intensity, for brown or green fibers increased with fiber color deepening (0.063 4 0.990 0) and for white fibers only had a negligible quantity (0.007 2). Therefor, it was suggested that the HNO 3/ethanol distillation method for extraction and quantification of fiber pigment be in favor of comparison of the color intensity for colored cotton varieties. When brown or green fibers were treated with acid or alkaline solutions, fiber color not only changed with pH value and but also restored to original color at pH7. There was a negative relationship between pigment and cellulose content in colored fibers.
Weed control via intercropping with gliricidia: I. cotton crop
Silva, P.S.L.;Silva, J.C.V.;Carvalho, L.P.;Silva, K.M.B.;Freitas, F.C.L.;
Planta Daninha , 2009, DOI: 10.1590/S0100-83582009000100013
Abstract: the majority of cotton grown commercially in the world has white lint, but recently, there has been a growing interest in colored lint cotton in several countries, including brazil. the use of naturally-colored fiber reduces chemical pollution. the objective of this paper was to evaluate cotton cultivar fiber yield in response to weed control via intercropping with gliricídia. cultivars brs-verde (greenish fibers), brs-rubi (reddish brown fibers), brs-safira (brown fibers), and brs-187 8h (white fibers) were submitted to the following treatments: no hoeing, two hoeings (at 20 and 40 days after transplanting), and cotton intercropped with gliricídia. in the intercropped treatment, gliricídia was planted between rows of cotton plants, using one seedling pit-1, in pits spaced 50.0 cm apart. twelve weed species predominated in the experiment, many of them belonging to the poaceae family. weeds occurred at different frequencies and in a non-uniform manner in the experimental area. cultivars did not influence weed dry matter. intercropping with gliricídia reduced weed dry matter but did not prevent reductions in cotton fiber and seed cotton yield, which were higher in hoed plots. cultivar brs safira had the highest fiber yield, but no differences were observed between cultivars regarding to seed cotton yield.
Employing Canopy Hyperspectral Narrowband Data and Random Forest Algorithm to Differentiate Palmer Amaranth from Colored Cotton  [PDF]
Reginald S. Fletcher, Rickie B. Turley
American Journal of Plant Sciences (AJPS) , 2017, DOI: 10.4236/ajps.2017.812219
Abstract: Palmer amaranth (Amaranthus palmeri S. Wats.) invasion negatively impacts cotton (Gossypium hirsutum L.) production systems throughout the United States. The objective of this study was to evaluate canopy hyperspectral narrowband data as input into the random forest machine learning algorithm to distinguish Palmer amaranth from cotton. The study focused on differentiating the Palmer amaranth from cotton near-isogenic lines with bronze, green, and yellow leaves. A spectroradiometer was used to acquire hyperspectral reflectance measurements of Palmer amaranth and cotton canopies for two separate dates, December 12, 2016, and May 14, 2017. Data were collected from plants that were grown in a greenhouse. The spectral data were aggregated to twenty-four hyperspectral narrowbands proposed for study of vegetation and agriculture crops. Those bands were tested by the conditional inference version of random forest (cforest) to differentiate the Palmer amaranth from cotton. Classifications were binary: Palmer amaranth and cotton bronze, Palmer amaranth and cotton green, and Palmer amaranth and cotton yellow. Classification accuracies were verified with overall, user’s, and producer’s accuracy. For the two dates combined, overall accuracy ranged from 77.8% to 88.9%. The highest overall accuracies were observed for the Palmer amaranth versus the cotton yellow classification (88.9%, December 12, 2016; 83.3%, May 14, 2017). Producer’s and user’s accuracies range was 66.7% to 94.4%. Errors were predominately attributed to cotton being misclassified as Palmer amaranth. The overall results indicated that cforest has moderate to strong potential for differentiating Palmer amaranth from cotton when it used hyperspectral narrowbands known to be useful for vegetation and agricultural surveys as input variables. This research further supports using hyperspectral narrowband data and
Effect of frozen saline water irrigation in winter on soil salt and water dynamics, germination and yield of cotton in coastal soils
冬季咸水结冰灌溉下滨海重盐碱地土壤水盐动态 及对棉花出苗和产量的影响

ZHANG Xiu-Mei,GUO Kai,XIE Zhi-Xi,FENG Xiao-Hui,LIU Xiao-Jing,
,郭 凯,谢志霞,封晓辉,刘小京

中国生态农业学报 , 2012,
Abstract: A three-year field experiment was conducted to investigate soil water and salt dynamics, cotton emergence, seedling salt content and cotton seed yield in coastal soils (Xiaoshan, Haixing County of Hebei Province) under frozen saline water irrigation in winter. The irrigation water salinity and volume were 8.15~14.27 g·L-1, and 180 mm, respectively. After saline ice melt-water infiltration in spring, the soil was mulched with plastic film to prevent further soil salinization via evaporation. The results showed that soil salt and water contents at sowing in 2009, 2010 and 2011 were respectively 0.32%, 0.29% and 0.17% and 26.2%, 25.0% and 24.2% under saline ice water irrigation. This implied that longer saline ice water irrigation had better soil desalination effect, providing suitable soil water and salt conditions for cotton growth. While cotton germination rate was above 85% under saline ice water irrigation treatment, few cotton seeds emerged under the control treatment (no irrigation and no mulching) due to high soil salinity. Seedling sodium content decreased by 57.6%~64.5% under saline ice water irrigation but potassium and calcium contents remained higher than the control. This prevented mono-ion problems in cotton plants, which further enhanced normal metabolism in cotton plant tissues. Salt content of the topsoil decreased further with the arrival of rainfall, which further ensured normal cotton growth. Overall, cotton seed yield reached 2 643.8~3 607.7 kg·hm-2 with that of the succeeding year higher than preceding year. The above findings showed that frozen saline water irrigation in winter improved cotton growth in coastal soils in north China.
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