Exploring the impact of cover crops in integrated pest management: pest and natural enemies population dynamics in no-tillage cotton production.

Conservation agriculture plays an important role in the sustainability of production systems, notably for globally significant crops such as cotton. This study explores the integration of the no-tillage system (NTS) with integrated pest management (IPM) by incorporating cover crops. The aim is to assess the impact of these living or dead covers on the management of insect populations, the indices diversity of phytophagous insects and natural enemies, and to investigate the population fluctuation of these arthropods, considering a variety of crops in the NTS before and after cotton planting. The trial, conducted over two consecutive cropping seasons in Mato Grosso do Sul State, Brazil, employed a randomised block design with four repetitions. The treatments included cover crops with the highest potential for use in the region, such as millet (Pennisetum glaucum glaucum L.), corn (Zea mays L.), brachiaria (Urochloa ruziziensis), black velvet bean (Stizolobium aterrimum), forage sorghum (Sorghum bicolor L.), and white oats (Avena sativa L.) and a mix of white oats with brachiaria. The results indicated that the black velvet bean stands out as the most effective cover crop, providing the best performance in terms of non-preference to the attack of the evaluated pest insects. Conversely, brachiaria proves to be more susceptible to infestations of Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae), and Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae). The study underscores the relevance of the judicious choice of cover crops in IPM and in promoting agricultural biodiversity, creating a strategic tool to enhance the sustainability and efficiency of the cotton production system in the context of the NTS.

Novel powdery mildew of cotton (Gossypium hirsutum) caused by Phyllactinia gossypina sp. nov. in Brazil.

Cotton (Gossypium hirsutum, Malvaceae) is the most important fiber crop in the world. There are published records of many fungal pathogens attacking Gossypium spp., causing numerous diseases, including powdery mildews. Recently, in 2022, non-cultivated spontaneous G. hirsutum plants bearing powdery mildews symptoms were found at roadsides in two municipalities of the state of Minas Gerais (Brazil): Varginha and Ubá. Such localities are situated ca. 260 km apart, suggesting a broader distribution of this fungus-host association in Brazil. Samples were taken to the laboratory, and an Ovulariopsis-like, asexual stage of Phyllactinia, was identified forming amphigenous colonies, that were more evident, white and cottony, abaxially. Morphological and molecular data- of the ITS and LSU regions- have shown that colonies from those two samples were of the same fungus species, belonging to a previously unknown species of Erysiphaceae (Ascomycota). The fungus fits into the Phyllactinia clade and is described herein as the new species Phyllactinia gossypina sp. nov. This new species belongs to the 'basal Phyllactinia group', a lineage that includes species known only from the Americas. This report expands the list of pathogenic fungi on cotton. It is early to anticipate whether this new powdery mildew represents a threat to cultivated cotton, which is a major crop in Brazil. Nevertheless, further studies about its infectivity to commercial cotton varieties are recommended, since all known Erysiphaceae are specialized obligate plant parasites and several species cause major losses to important crops.

Assessing the predictive capability of N, P, and B diagnosis in cotton crop.

The compositional nutrient diagnosis-CND method is a standard tool for evaluating plant nutritional status. Adjustments are crucial to elevate accuracy. The effectiveness of such methodological refinements should be rigorously assessed through accuracy tests that are benchmarked against the prescient diagnostic analysis-PDA methodology. The objective of this investigation was to refine the CND technique for a more precise evaluation of N, P, and B nutrient status in cotton. The study's database encompasses 144 data points pertaining to crop yield and foliar nutrient concentrations from cotton plantations in the Cerrado biome of Brazil. Subsequently, the CND norms were established through rigorous calibration. Three separate nutrient-dose trials, each featuring four levels of N, P and B, were carried out to assess plant true nutritional status. Adjustments were made to the nutrient responsiveness range-NRr (0.5 and 1.0), while yield response-YR were scrutinized at threshold levels (5% and 10%). The prerequisites for achieving high diagnostic accuracy were nutrient specific. For N, maximal accuracy was linked only to the YR parameter (YR = 10%). For P, the most precise outcomes were attained with a NRr = 0.5 and YI = 5%. For B, highest diagnostic accuracy when the NRr = 1.0 and YI = 10%. These insights highlight the need to fine-tune the CND method for reliable nutritional evaluations and cotton crop productivity optimization.

Monitoring cotton squares with opened and/or yellowed bracts to determine the need and efficency of chemical control against the cotton boll weevil.

The technique of terrestrial sampling of boll weevil (BW) populations is expensive and inefficient over large areas, but may be cheaper and more efficient without involving the manipulation of cotton squares. The aim of this study was to develop a technique to sampling cotton squares based on the observation of opened and/or yellowing bracts to determine the need and efficacy of chemical control of BW in cotton crops. The first experiment aimed to estimate the ratio between the number of cotton squares with opened and/or yellowed bracts and that of squares with BW oviposition punctures. The second experiment, aimed to determine the efficacy of chemical control for BW by sampling cotton squares with opened and/or yellowed bracts. The ratio between the number of opened and/or yellowed bracts and the number of cotton squares with oviposition punctures was 2:1. The level and efficiency of chemical control of BW, based on the percentage and sampling of cotton plants with opened and/or yellowed bracts, was 5% and did not differ from the one based on the observation of cotton plants with 10% cotton squares with oviposition punctures by BW females. The control level based on sampling cotton plants with open and/or yellowing bracts was 5%. The efficiency of chemical insecticides using this economic threshold against the BW did not differ from that based on sampling cotton plants with 10% of cotton squares with oviposition punctures by BW females. This indicates that the chemical control of cotton boll weevil can be carried out based on cotton squares with open and/or yellowed bracts.

Genetic Variability Among U.S.-Sentinel Cotton Plot Cotton Leafroll Dwarf Virus and Globally Available Reference Isolates Based on ORF0 Diversity.

The aphid-transmitted polerovirus, cotton leafroll dwarf virus (CLRDV), first characterized from symptomatic cotton plants in South America, has been identified in commercial cotton plantings in the United States. Here, the CLRDV intraspecific diversity was investigated by comparative sequence analysis of the most divergent CLRDV coding region, ORF0/P0. Bayesian analysis of ORF0 sequences for U.S. and reference populations resolved three well-supported sister clades comprising one U.S. and two South American lineages. Principal component analysis (PCA) identified seven statistically supported intraspecific populations. The Bayesian phylogeny and PCA dendrogram-inferred relationships were congruent. Population analysis of ORF0 sequences indicated most lineages have evolved under negative selection, albeit certain sites/isolates evolved under positive selection. Both U.S. and South American isolates exhibited extensive ORF0 diversity. At least two U.S. invasion foci were associated with their founder populations in Alabama-Georgia and eastern Texas. The Alabama-Georgia founder is implicated as the source of recent widespread expansion and establishment of secondary disease foci throughout the southeastern-central United States. Based on the geographically restricted distribution, spread of another extant Texas population appeared impeded by a population bottleneck. Extant CLRDV isolates represent several putative introductions potentially associated with catastrophic weather events dispersing viruliferous cotton aphids of unknown origin(s).

Global gene expression profile and functional analysis reveal the conservation of reproduction-associated gene networks in Gossypium hirsutum.

KEY MESSAGE: Lastly, the bZIP gene family encompasses genes that have been reported to play a role in flower development, such as bZIP14 (FD). Notably, bZIP14 is essential for Flowering Locus T (FT) initiation of floral development in Arabidopsis (Abe et al. 2005). Cotton (Gossypium hirsutum L.) is the world's most extensively cultivated fiber crop. However, its reproductive development is poorly characterized at the molecular level. Thus, this study presents a detailed transcriptomic analysis of G. hirsutum at three different reproductive stages. We provide evidence that more than 64,000 genes are active in G. hirsutum during flower development, among which 94.33% have been assigned to functional terms and specific pathways. Gene set enrichment analysis (GSEA) revealed that the biological process categories of floral organ development, pollen exine formation, and stamen development were enriched among the genes expressed during the floral development of G. hirsutum. Furthermore, we identified putative Arabidopsis homologs involved in the G. hirsutum gene regulatory network (GRN) of pollen and flower development, including transcription factors such as WUSCHEL (WUS), INNER NO OUTER (INO), AGAMOUS-LIKE 66 (AGL66), SPOROCYTELESS/NOZZLE (SPL/NZZ), DYSFUNCTIONAL TAPETUM 1 (DYT1), ABORTED MICROSPORES (AMS), and ASH1-RELATED 3 (ASHR3), which are known crucial genes for plant reproductive success. The cotton MADS-box protein-protein interaction pattern resembles the previously described patterns for AGAMOUS (AG), SEEDSTICK (STK), SHATTERPROOF (SHP), and SEPALLATA3 (SEP3) homolog proteins from Arabidopsis. In addition to serving as a resource for comparative flower development studies, this work highlights the changes in gene expression profiles and molecular networks underlying stages that are valuable for cotton breeding improvement.

Seed sensor position on seeder performance at varying speeds / Influência da posição do sensor de sementes da semeadora em diferentes velocidades de trabalho

The uniformity of seed distribution and sowing speed directly impact crop quality and productivity. This experiment assessed how the position of the sowing monitoring sensor influences the distribution of cotton seeds using a pneumatic meter at different operating speeds. The experiment employed a completely randomized two-factor factorial design on a static simulation bench. The first factor involved the sensor installation sites (upper, middle, and lower portions of the conductor tube and conveyor belt), while the second factor encompassed simulated speeds of 3.0, 5.0, 7.0, 9.0, and 11.0 km/h. Parameters such as frequency of double, flawed, and acceptable spacing, coefficient of variation, and precision index were measured based on five replications of 250 consecutive spacing. The results indicated that the sensor's placement significantly influences reading accuracy. Optimal results were observed when the sensor was positioned at the final portion of the conductor tube, providing more accurate seed deposition, and facilitating decision-making.

A uniformidade de distribuição de sementes no solo e a velocidade de semeadura estão diretamente relacionados à qualidade e produtividade da lavoura. O objetivo do experimento foi avaliar a influência da posição de instalação do sensor de monitoramento de semeadura, em relação a leitura realizada em bancada de ensaio, durante a distribuição de sementes de algodão com dosador pneumático, submetido a diferentes velocidades operacionais. O experimento foi conduzido em bancada estática de simulação, com delineamento inteiramente casualizado, fatorial duplo, sendo o primeiro fator o local de instalação do sensor (porção superior, média e inferior do tubo condutor e esteira condutora) e o segundo as velocidades simuladas de 3,0; 5,0; 7,0; 9,0 e 11,0 km h−1. Os parâmetros mensurados para a avaliação da distribuição das sementes foram a frequência de espaçamentos duplos, falhos e aceitáveis, seu coeficiente de variação e índice de precisão, mensurados a partir de cinco repetições de 250 espaçamentos consecutivos. Os resultados obtidos foram que a posição de inserção do sensor de monitoramento interfere diretamente na eficiência da leitura, a qual tende a ser mais assertiva quando o sensor é posicionado na porção final do tubo condutor, demonstrando com maior acurácia a real deposição e assim facilitando a tomada de decisão.

Cotton leaf curl Multan betasatellite impaired ToLCNDV ability to maintain cotton leaf curl Multan alphasatellite / O enrolamento da folha de algodão Multan betassatélite prejudica a capacidade de ToLCNDV de manter o enrolamento da folha de algodão alfassatélite Multan

Alphasatellites (family Alphasatellitidae) are circular, single-stranded (ss) DNA molecules of ~1350 nucleotide in size that have been characterized in both the Old and New Worlds. Alphasatellites have inherent ability to self-replicate, which is accomplished by a single protein, replication-associated protein (Rep). Although the precise function of alphasatellite is yet unknown, and these consider dispensable for infectivity, however, their Rep protein functions as a suppressor of host defence. While alphasatellites are most frequently associated with begomoviruses, particularly with monopartite than bipartite begomoviruses, they have recently been found associated with mastreviruses. The in planta maintenance of alphasatellites by helper geminivirus is still an enigma, with no available study on the topic. This study aimed to investigate whether a widely distributed bipartite begomovirus, tomato leaf curl New Delhi virus (ToLCNDV), can maintain cotton leaf curl Multan alphasatellite (CLCuMuA) in the presence or absence of cotton leaf curl Multan betasatellite (CLCuMuB). The findings of this study demonstrated that ToLCNDV or its DNA A could maintain CLCuMuA in Nicotiana benthamiana plants. However, the presence of CLCuMuB interferes with the maintenance of CLCuMuA, and mutations in the CP of ToLCNDV further reduces it. Our study highlighted that the maintenance of alphasatellites is impaired in the presence of a betasatellite by ToLCNDV. Further investigation is needed to unravel all the interactions between a helper virus and an alphasatellites.

Alfassatélites (família Alphasatellitidae) são moléculas de DNA circulares de fita simples (ss) de ~1350 nucleotídeos de tamanho, que foram caracterizadas tanto no Velho como no Novo Mundo. Os alfassatélites têm capacidade inerente de autorreplicação, o que é realizado por uma única proteína, a proteína associada à replicação (Rep). Embora a função precisa dos alfassatélites ainda seja desconhecida, e estes sejam considerados dispensáveis ​​para infectividade, entretanto, sua proteína Rep funciona como supressora da defesa do hospedeiro. Embora os alfassatélites sejam mais frequentemente associados a begomovírus, particularmente com begomovírus monopartidos do que bipartidos, eles foram encontrados recentemente associados a mastrevírus. A manutenção in planta de alfassatélites por helper geminivirus ainda é um enigma, sem estudos disponíveis sobre o tema. Este estudo teve como objetivo investigar se um begomovírus bipartido amplamente distribuído, o tomate leaf curl New Delhi virus (ToLCNDV), pode manter o alfassatélite Multan do enrolamento das folhas de algodão (CLCuMuA) na presença ou ausência do betassatélite Multan do enrolamento das folhas de algodão (CLCuMuB). Os achados deste estudo demonstraram que ToLCNDV ou seu DNA A poderia manter CL CuMuA em plantas de Nicotiana benthamiana. No entanto, a presença de CLCuMuB interfere na manutenção de CLCuMuA, e mutações no CP de ToLCNDV a reduzem ainda mais. Nosso estudo destacou que a manutenção de alfassatélites é prejudicada na presença de um betassatélite por ToLCNDV. Mais investigações são necessárias para desvendar todas as interações entre um vírus auxiliar e um alfassatélite.

The synergistic effects of soil-applied boron and foliar-applied silicon on cotton fiber quality and yield.

Studies of boron (B) and silicon (Si) synergy in cotton crops have shown promising results; however, the focus was on the foliar application of B and Si. Nonetheless, B is an element with little mobility in the plant and its best form of application is in the soil. Thus, the objective of this study was to evaluate the synergistic effect of soil applied B and foliar applied sSi on fiber quality and crop yield of cotton. For this purpose, a field experiment was carried out using cotton cultivar FM 985 GLTP. The soil's B in the experimental site is classified as low for cotton cultivation. The experiment was conducted in a randomized complete-block design, in a 3 × 2 factorial scheme, with three doses of B: 0.0 kg ha-1 (deficiency), 2.0 kg ha-1 (recommended dose), and 4.0 kg ha-1 (high dose) in the absence and presence (920 g L-1) of Si, with four replications. One week after the 4th application of Si, B and Si leaf content was determined. At boll opening, crop yield was estimated, and fiber quality analysis was realized. Boron deficiency reduced cotton yield, in 11 and 9%, compared to the application of 2 and 4 kg ha-1 of B, respectively. The presence of Si, however, increased plant yield in 5% in the treatments with 0 and 2 kg ha-1 of B, respectively. Cotton fiber length and elongation were not influenced by the B doses and Si presence. Fiber breaking strength was increased in 5% by the presence of Si and was not influenced by B deficiency. Micronaire was 8% smaller in the treatment with 0 kg ha-1 of B and 6% smaller in the absence of Si. Short fiber index was 4% greater in the plants of the treatment with 0 kg ha-1 of B. The results of this study reports that the complementation with Si via foliar application increases fiber quality by enhance breaking strength and micronaire. In conclusion, the interaction between soil-applied B and foliar-applied Si is beneficial for cotton cultivation, resulting in high cotton yield with better fiber quality.

Changes in the levels of immunological markers after treatment in patients with allergic rhinitis / Cambios en los niveles de marcadores inmunológicos después del tratamiento en pacientes con rinitis alérgica

Introduction: Monitoring changes in the levels of immune markers is of great significance in evaluating the effectiveness of treatment in patients with allergic rhinitis. Objectives: Determine the change in the concentration of immune markers after treatment in patients with allergic rhinitis caused by cotton dust. Methods: A descriptive, single-group, comparative before and after intervention study on 52 patients with allergic rhinitis caused by cotton dust. Comparison of immunological markers results before and after 36 months of treatment. Results: Total IgE concentration after treatment decreased, the median decreased from 1227.756 U/mL to 676.805 UI/mL. Serum levels of IgG, IgG4, and IgG1 in patients after treatment increased compared to before (p< 0.001). The cytokines also changed in the direction of no longer responding toward allergy. Median IL-17 decreased from 1.752 mg/dL to 0.417 mg/dL. Conclusion: In patients with allergic rhinitis after specific sublingual desensitization treatment, IgE levels and cytokines such as IL-6 and IL-17 are significantly reduced and IgG, IgG4 and IgG1 levels are increased after treatment(AU)

Introducción: El monitoreo de los cambios en los niveles de marcadores inmunes es de gran importancia para evaluar la efectividad del tratamiento en pacientes con rinitis alérgica. Objetivos: Determinar el cambio en la concentración de marcadores inmunes después del tratamiento, en pacientes con rinitis alérgica causada por polvo de algodón. Métodos: Estudio descriptivo, monogrupo, comparativo antes y después de la intervención, en 52 pacientes con rinitis alérgica por polvo de algodón. Se compararon resultados de marcadores inmunológicos antes y después de 36 meses de tratamiento. Resultados: La concentración de IgE total después del tratamiento disminuyó, la mediana disminuyó de 1227,756 U/mL a 676,805 UI/mL. Los niveles séricos de IgG, IgG4 e IgG1 en pacientes, después del tratamiento, aumentaron (p< 0,001). Las citocinas también cambiaron en dirección a ausencia de respuesta a la alergia. La mediana de IL-17 disminuyó de 1,752 mg/dL a 0,417 mg/dL. Conclusión: En pacientes con rinitis alérgica, después del tratamiento específico de desensibilización sublingual, los niveles de IgE y citocinas como IL-6 e IL-17 se reducen significativamente y los niveles de IgG, IgG4 e IgG1 aumentan(AU)

Ruminal responses, digestibility, and blood parameters of beef cattle fed diets with different oilseeds.

It aimed to evaluate the effects of different whole oilseeds in lipid-rich diets on nutrient intake, apparent digestibility, ingestive behavior, and ruminal and blood parameters of steers. A control diet (without oilseed) and four diets containing whole oilseeds (cotton, canola, sunflower, and soybean) were tested. All diets used the whole-plant corn silage at 400 g/kg as roughage. Five diets, being a control diet (without oilseed) and four diets containing whole oilseeds (cotton, canola, sunflower, and soybean), were tested. All diets used the whole-plant corn silage at 400 g/kg as roughage. Five rumen fistulated crossbreed steers, in a 5 × 5 Latin square design were distributed using five periods of 21 days. The steers fed cottonseed and canola diets had lower dry matter intakes (6.6 kg/day). Steers showed higher averages of time in rumination for treatments with sunflower, soybean, and cottonseed (406, 362, and 361 min/day, respectively). There was no treatment effect for the ruminal pH and ammonia (NH3) variables. There was an effect of the treatment on the volatile fatty acid concentrations. The animals that received soybean showed a higher plasma urea concentration (50.7 mg/dL). Animals fed the control diet showed lower serum cholesterol levels (111.8 mg/dL) than those fed diets containing whole cottonseed, canola, sunflower, and soybean (152.7, 137.1, 146.9, and 138.2 mg/dL, respectively). We recommended using whole soybean or sunflower seeds to formulate lipid-rich diets with 70 g/kg of ether extract for crossbreed steers in the feedlot.

Performance of cotton expressing Cry1Ac, Cry1F and Vip3Aa19 insecticidal proteins against Helicoverpa armigera, H. zea and their hybrid progeny, and evidence of reduced susceptibility of a field population of H. zea to Cry1 and Vip3Aa in Brazil.

The genetically modified cotton DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 expressing Cry1Ac, Cry1F and Vip3Aa19 from Bacillus thuringiensis Berliner (Bt) has been cultivated in Brazil since the 2020/2021 season. Here, we assessed the performance of DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 cotton expressing Cry1Ac, Cry1F and Vip3Aa19 against Helicoverpa armigera (Hübner), Helicoverpa zea (Boddie), and their hybrid progeny. We also carried out evaluations with DAS-21023-5 × DAS-24236-5 cotton containing Cry1Ac and Cry1F. In leaf-disk bioassays, DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 was effective in controlling neonates from laboratory colonies of H. armigera, H. zea and the hybrid progeny (71.9%-100% mortality). On floral bud bioassays using L2 larvae, H. zea presented complete mortality, whereas H. armigera and the hybrid progeny showed <55% mortality. On DAS-21023-5 × DAS-24236-5 cotton, the mortality of H. armigera on leaf-disk and floral buds ranged from 60% to 73%, whereas mortality of hybrids was <46%. This Bt cotton caused complete mortality of H. zea larvae from a laboratory colony in the early growth stages, but mortalities were <55% on advanced growth stages and on floral buds. In field studies conducted from 2014 to 2019, DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 cotton was also effective at protecting plants against H. armigera. In contrast, a population of H. zea collected in western Bahia in 2021/2022 on Bt cotton expressing Cry1 and Vip3Aa proteins, showed 63% mortality after 30 d, with insects developing into fifth and sixth instars, on DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 cotton. We conclude that H. armigera, H. zea, and their hybrid progeny can be managed with DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 cotton; however we found the first evidence in Brazil of a significant reduction in the susceptibility to DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 cotton of a population of H. zea collected from Bt cotton in Bahia in 2021/2022.

Ramularia leaf spot: PCR-based methods reveal widespread distribution of Ramulariopsis pseudoglycines and limited presence of R. gossypii in Brazil.

Whilst Brazil is the fourth largest cotton producer globally, incidence of ramularia leaf spot (RLS) has decreased yield. In 2017-18 and 2018-19, ca. 300 fungal samples were collected throughout Brazil. Hyphal tip cultures were obtained for amplification of the RNA polymerase II (RPB2), 28S rRNA, the ribosomal DNA internal transcribed spacers (ITS), actin (ACT), elongation factor (EF1-α) and histone H3 (HIS3) genomic regions. Additionally, sequences of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were obtained by nanopore sequencing and the EF1-α region was selected as a marker for rapid recognition of Ramulariopsis species. Clade assignments based on the concatenated-sequence tree were identical to those in tree generated by RPB2-sequences, as well as in an RPB2 haplotype network and an ISSR (TGTC)4 dendrogram, in identification with species-specific primers and based on morphological comparisons. Out of 267 examined isolates, 252 were identified as Ramulariopsis pseudoglycines, indicating this species as the most widespread causal agent of cotton RLS in the Brazilian growing regions. Species-specific primers developed in the study that target the EF1-α gene provide an opportunity for extensive RLS sampling worldwide to study the distribution of Ramulariopsis species. Such data will aid breeders and plant pathologists in cotton disease resistance development and fungicide resistance avoidance.

Pyruvic acid as attenuator of water deficit in cotton plants varying the phenological stage.

The lack of water during crop growth causes damage to any production system, especially when it occurs during the initial establishment or beginning of the reproductive stage. Although cotton can be properly managed in regions with water limitation, its yield is affected at different levels according to the genetics of the cultivar adopted. Exogenous application of some organic components has shown a stress-mitigating effect and can be a valuable procedure to enhance the yield of water stress-sensitive cultivars. The objective of this work was to evaluate the benefits of exogenous application of pyruvic acid (100 µM) in cotton plants under water deficit varying the phenological stage of the crop. The experiment was conducted in a greenhouse, where the plants were grown in pots and subjected to seven days of water suspension, initiated individually in stages V2 and B1. Each pot contained two plants. The treatments adopted were: T1 - control, T2 - water suppression; and T3 - water suppression + pyruvate application. The design was randomized blocks in a factorial scheme (3 × 3) with three replicates. The reductions in gas exchange and growth of the cultivars BRS Seridó, CNPA 7MH and FM 966 were more significant in the reproductive stage, especially for FM 966, which was more sensitive. Pyruvate application reduced the effects of water suppression on boll production by 31% in BRS Seridó and 34% in CNPA 7MH and FM 966.

Characterizing the vector competence of Aphis gossypii, Myzus persicae and Aphis craccivora (Hemiptera: Aphididae) to transmit cotton leafroll dwarf virus to cotton in the United States.

Cotton leafroll dwarf virus (CLRDV) is a yield-limiting, aphid-transmitted virus that was identified in cotton, Gossypium hirsutum L., in the United States of America in 2017. CLRDV is currently classified in the genus Polerovirus, family Solemoviridae. Although 8 species of aphids (Hemiptera: Aphididae) are reported to infest cotton, Aphis gossypii Glover is the only known vector of CLRDV to this crop. Aphis gossypii transmits CLRDV in a persistent and nonpropagative manner, but acquisition and retention times have only been partially characterized in Brazil. The main objectives of this study were to characterize the acquisition access period, the inoculation access period, and retention times for a U.S. strain of CLRDV and A. gossypii population. A sub-objective was to test the vector competence of Myzus persicae Sulzer and Aphis craccivora Koch. In our study, A. gossypii apterous and alate morphs were able to acquire CLRDV in 30 min and 24 h, inoculate CLRDV in 45 and 15 min, and retain CLRDV for 15 and 23 days, respectively. Neither M. persicae nor A. craccivora acquired or transmitted CLRDV to cotton.

Methane emission, milk yield and behavior of ewes kept on pastures or supplemented with concentrate based on corn grain or whole cottonseed / Emissão de metano, produção de leite e comportamento de ovelhas mantidas em pastagem ou suplementadas com concentrado à base de milho grão ou caroço de algodão

This study aimed to evaluate methane emission, milk yield and behavior of ewes kept exclusively on irrigated pasture of Tifton 85 grass (Cynodon spp.) or supplemented with ground corn or whole cottonseed (WCS) based concentrates. Twelve Lacaune x Santa Ines ewes (43.07±0.83 kg of body weight, 77±24 days after parturition, on average) were distributed in replicated 3x3 Latin square. Treatments consisted of three diets: pasture (no concentrate supplementation); corn (pasture + corn-based supplement); whole cottonseed (pasture + whole cottonseed-based supplement), offering 0.5 kg/ewe/day. The WCS group showed the highest concentrate dry matter intake (DMI) (p=0.049) and crude protein (CP) intake (p=0.001) compared to the others. There was no difference on total DMI (p=0.115) for the tested diets. Animals exclusively kept on pasture had the greatest forage DMI (p=0.004), lowest CP digestibility (p=0.015), showed longer grazing time (p=0.01) and shorter idle time (p=0.01) compared to the supplemented groups. Milk yield (0.36 kg/ewe/day) (p=0.15) and methane emission (33.12 g/ewe/day) (p=0.95) were similar for all three evaluated groups. Supplementation with concentrate based on corn or whole cottonseed does not improve productive performance nor decrease methane emission. However, lactating ewes kept exclusively in pasture show longer grazing time, without changes in milk yield and methane emission.

Objetivou-se avaliar a emissão de metano, a produção de leite e o comportamento de ovelhas mantidas exclusivamente em pastagem irrigada de Tifton 85 (Cynodon spp.) ou suplementadas com concentrados à base de milho grão ou caroço de algodão. Doze ovelhas Lacaune x Santa Inês (43,07±0,83 kg de peso corporal e 77±24 dias após a parição, em média) foram distribuídas em quadrados latinos 3x3 replicados. Os tratamentos consistiram em três dietas: pastagem (sem suplementação concentrada); milho (pastagem + suplemento à base de milho); caroço de algodão integral (pastagem + suplemento à base de caroço de algodão), oferecendo 0,5 kg/ovelha/dia. O grupo caroço de algodão apresentou maior consumo de matéria seca (CMS) (P=0,049) e consumo de proteína bruta (PB) (P=0,001) em relação aos demais. Não houve diferença no CMS total (P=0,115) para as dietas testadas. Os animais exclusivamente em pastagem apresentaram maior consumo de forragem (P=0,004), menor digestibilidade da PB (P=0,015), maior tempo em pastejo (P=0,01) e menor tempo em ócio (P=0,01), em relação aos grupos suplementados. A produção de leite (0,36 kg/ovelha/dia) (P=0,15) e a emissão de metano (33,12 g/ovelha/dia) (P=0,95) foram semelhantes nos três grupos avaliados. A suplementação com concentrado à base de milho grão ou caroço de algodão não melhorou o desempenho produtivo e não reduziu a emissão de metano. Entretanto, as ovelhas lactantes mantidas exclusivamente em pastagem apresentaram maior tempo em pastejo, sem alterações na produção de leite e na emissão de metano.

Enhancing a SARS-CoV-2 nucleocapsid antigen test sensitivity with cost efficient strategy through a cotton intermembrane insertion.

Lateral flow antigen tests have been widely used in the Covid-19 pandemic, allowing faster diagnostic test results and preventing further viral spread through isolation of infected individuals. Accomplishment of this screening must be performed with tests that show satisfactory sensitivity in order to successfully detect the target protein and avoid false negatives. The aim of this study was to create a lateral flow test that could detect SARS-CoV-2 nucleocapsid protein in low concentrations that were comparable to the limits of detection claimed by existing tests from the market. To do so, several adjustments were necessary during research and development of the prototypes until they were consistent with these criteria. The proposed alternatives of increasing the test line antibody concentration and addition of an intermembrane between the conjugate pad and the nitrocellulose membrane were able to increase the sensitivity four-fold and generate a new rapid test prototype called "lateral flow intermembrane immunoassay test" (LFIIT). This prototype showed an adequate limit of detection (2.0 ng mL-1) while maintaining affordability and simplicity in manufacturing processes.

Physiology and production components of cotton plants under salt stress and salicylic acid application / Fisiologia e componentes de produção do algodoeiro sob estresse salino e aplicação de ácido salicílico

The use of saline waters in irrigated agriculture has become a reality in several regions of the world. However, this practice may cause limitations to growth and development, depending on the tolerance level of the crop. Applying strategies that minimize salt stress in crops is therefore essential, and, in this respect, salicylic acid can act as an antioxidant and enhance the plant's tolerance to salt stress. The objective of this study was to examine the effects of foliar application of salicylic acid on the physiology and production components of naturally colored cotton cv. BRS Jade grown under salt stress. The plants were cultivated on lysimeters in outdoor conditions at the Agro-Food Science and Technology Center, Federal University of Campina Grande, located in Pombal - PB, Brazil. The experiment was laid out in a randomized block design with a 5 × 5 factorial arrangement consisting of five irrigation-water electrical conductivity levels (ECw: 0.3, 1.8, 3.3, 4.8, and 6.3 dS m-1) and five concentrations of salicylic acid (SA: 0, 1.5, 3.0, 4.5, and 6.0 mM), with three replicates. Irrigation with water with salinity levels from 0.3 dS m-1 reduced gas exchange, the synthesis of photosynthetic pigments, and the number of bolls in cotton cv. BRS Jade. Salinity levels from 0.3 dS m-1induced stomatal closure and reduced transpiration, CO2 assimilation rate, the levels of photosynthetic pigments, and production components of cotton cv. BRS Jade. The salicylic acid concentrations of 2.6 and 2.7 mM increased CO2 assimilation rate and stomatal conductance, respectively, in the cotton plants. Foliar application of salicylic acid did not mitigate the effects of salt stress on gas exchange, the synthesis of photosynthetic pigments, or production components of cotton.

O uso de águas salinas na agricultura irrigada vem se tornando uma realidade em diversas regiões do mundo, entretanto, dependendo do nível de tolerância da cultura ocorrem limitações no crescimento e desenvolvimento. Dessa forma, o uso das estratégias que minimizem o estresse salino nas culturas é fundamental, nesta perspectiva, o ácido salicílico pode atuar como antioxidante e contribuir na tolerância das plantas ao estresse salino. Neste sentido, objetivou-se avaliar os efeitos da aplicação foliar de ácido salicílico na fisiologia e nos componentes de produção do algodoeiro naturalmente colorido cv. BRS Jade cultivado sob estresse salino. As plantas foram conduzidas em lisímetros sob condições de céu aberto, no Centro de Ciências e Tecnologia Agroalimentar pertencente à Universidade Federal de Campina Grande, Pombal-PB. O delineamento utilizado foi em blocos casualizados, em esquema fatorial 5 × 5, sendo cinco níveis de condutividade elétrica da água de irrigação - CEa (0,3; 1,8; 3,3; 4,8 e 6,3 dS m-1) e cinco concentrações de ácido salicílico - AS (0; 1,5; 3,0, 4,5 e 6,0 mM) com três repetições. A irrigação com água a partir de 0,3 dS m-1 reduziu as trocas gasosas, a síntese de pigmentos fotossintéticos e o número de capulhos do algodoeiro cv. BRS Jade. A irrigação com água a partir de 0,3 dS m-1 induziu o fechamento estomático e diminuiu a transpiração, a taxa de assimilação de CO2, os teores de pigmentos fotossintéticos e os componentes de produção do algodoeiro cv. BRS Jade. As concentrações de ácido salicílico de 2,6 e 2,7 mM proporcionaram aumento na taxa de assimilação de CO2 e condutância estomática, respectivamente, das plantas de algodão. A aplicação foliar de ácido salicílico não amenizou os efeitos do estresse salino sobre as trocas gasosas, a síntese de pigmentos fotossintéticos e os componentes de produção do algodoeiro.

Mpp23Aa/Xpp37Aa Insecticidal Proteins from Bacillus thuringiensis (Bacillales: Bacillaceae) Are Highly Toxic to Anthonomus grandis (Coleoptera: Curculionidae) Larvae.

The beetle Anthonomus grandis Boheman, 1843, is the main cotton pest, causing enormous losses in cotton. The breeding of genetically modified plants with A. grandis resistance is seen as an important control strategy. However, the identification of molecules with high toxicity to this insect remains a challenge. The susceptibility of A. grandis larvae to proteins (Cry1Ba, Cry7Ab, and Mpp23Aa/Xpp37Aa) from Bacillus thuringiensis Berliner, 1915, with toxicity reported against Coleopteran, has been evaluated. The ingestion of different protein concentrations (which were incorporated into an artificial diet) by the larvae was tested in the laboratory, and mortality was evaluated after one week. All Cry proteins tested exhibited higher toxicity than that the untreated artificial diet. These Cry proteins showed similar results to the control Cry1Ac, with low toxicity to A. grandis, since it killed less than 50% of larvae, even at the highest concentration applied (100 µg·g-1). Mpp/Xpp proteins provided the highest toxicity with a 0.18 µg·g-1 value for the 50% lethal concentration. Importantly, this parameter is the lowest ever reported for this insect species tested with B. thuringiensis proteins. This result highlights the potential of Mpp23Aa/Xpp37Aa for the development of a biotechnological tool aiming at the field control of A. grandis.

Genetic polymorphism detection in brazilian perennial cottons (Gossypium spp.) using an ISSR marker system and its application for molecular interspecific differentiation.

BACKGROUND: The semi-domesticated Brazilian perennial cotton (Gossypium spp.) germplasm is considered a source of variability for creating modern upland cotton varieties. Here we used Inter-simple Sequence Repeat (ISSR) markers to detect intra and interspecific genetic polymorphism in Gossypium hirsutum L. r. marie-galante and Gossypium barbadense L. and to use molecular data to assessing genetic diversity and molecular discrimination of these species. METHODS AND RESULTS: The sets contained 12 G. barbadense genotypes and 16 G. hirsutum genotypes from a Brazilian collection. The 11 ISSR primers were used for genotyping yielded 101 bands (polymorphism = 47.5%) and were classified as moderately informative (PIC = 0.304). The ISSR markers exposed a greater diversity in G. hirsutum (P = 24.72%; HE =0.071 and I = 0.111) as compared to G. barbadense (P = 17.98%, HE = 0.043 and I = 0.070). The AMOVA analysis showed that 89.47% of the genetic variation was partitioned within species which is supported by Nei's genetic differentiation (Gst = 0.598) and gene flow (Nm = 0.338), suggesting that strong reproductive barriers between species. The UPGMA Cluster Analysis, Principal Coordinate Analysis and Bayesian Model-Based Structural Analysis divided the 28 genotypes into two main clades consistent with the taxonomical delimitation. CONCLUSION: The ISSR marker system offers a new approach to determining molecular differences between two cotton species (G. hirsutum L. r. marie-galante and G. barbadense L.). This study can expand the molecular marker resources for the identification and improvement of our knowledge about the genetic diversity and relationships between perennial cotton genotypes.