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Background and AimsUrochloa (syn. Brachiaria, and including some Panicum and Megathyrus) is a genus of tropical and subtropical grasses widely sown as forage to feed ruminants in the tropics. A better understanding of the diversity among Urochloa spp. allow us to leverage its varying ploidy levels and genome composition to accelerate its improvement, following the example from other crop genera.MethodsWe explored the genetic make-up and population structure in 111 accessions, which comprise the five Urochloa species used for the development of commercial cultivars. These accessions are conserved from wild materials from collection sites at their centre of origin in Africa. We used RNA-seq, averaging 40M reads per accession, to generate 1,167,542 stringently selected SNP markers that tentatively encompassed the complete Urochloa gene pool used in breeding.Key ResultsWe identified ten subpopulations, which had no relation with geographical origin and represented ten independent gene pools, and two groups of admixed accessions. Our results support a division in U. decumbens by ploidy, with a diploid subpopulation closely related to U. ruziziensis, and a tetraploid subpopulation closely related to U. brizantha. We observed highly differentiated gene pools in U. brizantha, which were not related with origin or ploidy. Particularly, one U. brizantha subpopulation clustered distant from the other U. brizantha and U. decumbens subpopulations, so likely containing unexplored alleles. We also identified a well-supported subpopulation containing both polyploid U. decumbens and U. brizantha accessions; this was the only group containing more than one species and tentatively constitutes an independent “mixed” gene pool for both species. We observed two gene pools in U. humidicola. One subpopulation, “humidicola-2”, was much less common but likely includes the only known sexual accession in the species.ConclusionsOur results offered a definitive picture of the available diversity in Urochloa to inform breeding and resolve questions raised by previous studies. It also allowed us identifying prospective founders to enrich the breeding gene pool and to develop genotyping and genotype-phenotype association mapping experiments.HIGHLIGHTWe clarified the genetic make-up and population structure of 111 Urochloa spp. forage grasses to inform cultivar development.

Made available in DSpace on 2022-05-01T09:31:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Droplet size is one of the most important factors that affect spray deposition and weed control through the use of herbicides. The aim of this study was to evaluate the influence of the droplet size on the spray deposition and control of Euphorbia heterophylla and Urochloa ruziziensis by using glyphosate. The treatments included spraying glyphosate with fine, medium, coarse, very coarse, and ultra-coarse droplet sizes to determine the deposition, uniformity of distribution, visual control, and dry weight reduction (DWR). The treatments were compared with the values of the dose required to achieve 50% DWR or 50% visual control (C50) at 7, 14, 21, and 28 days after herbicide application. Fine and medium droplet sizes afforded high deposition values and low distribution uniformities in E. heterophylla. Fine and medium droplet sizes yielded the lowest C50 on visual control and DWR in E. heterophylla, respectively. The droplet size did not affect the spray deposition on U. ruziziensis plants; however, the larger droplets had less uniformity of distribution. In U. ruziziensis plants, spraying glyphosate with coarse and medium droplet sizes yielded the lowest values of C50 to visual control and DWR, respectively. Universidade Estadual Paulista “Júlio de Mesquita Filho” Faculdade de Engenharia Universidade Estadual Paulista “Júlio de Mesquita Filho” Faculdade de Ciências Agrárias e Tecnológicas Universidade Estadual Paulista “Júlio de Mesquita Filho” Faculdade de Ciências Agronômicas Universidade Estadual Paulista “Júlio de Mesquita Filho” Faculdade de Engenharia Universidade Estadual Paulista “Júlio de Mesquita Filho” Faculdade de Ciências Agrárias e Tecnológicas Universidade Estadual Paulista “Júlio de Mesquita Filho” Faculdade de Ciências Agronômicas

Urochloa (syn. Brachiaria) is the most popular fodder of livestock farmers in Cameroon for hay and seed productions. Farmers in Cameroon have been producing Brachiaria seeds for decades for own uses and surplus are sold to neighbours, and to traders from Cameroon and neighbouring countries. However, there is no information available about qualities of these seeds. Fifteen Urochloa seeds samples were collected from farmers and/or government stations in five regions (Adamaoua, East, North, North West, and West) and analysed for major seed quality parameters along with seeds of improved Urochloa cultivar Basilisk imported from Brazil as a check. Study showed significant differences among treatments for various seed quality parameters tested (P P Urochloa grass seeds produced in Cameroon, and the potential of developing Urochloa grass seed business in the Northern, Adamaoua and Western regions of Cameroon.

Made available in DSpace on 2022-04-28T19:41:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Maize (Zea mays L.) intercropping with forage plants has been adopted with the main goal of promoting benefits on soil physical properties. However, a better understanding of soil chemical attributes and crops nutrition under this system is necessary. The objective was to verify whether intercropping maize with Urochloa ruziziensis (Germ. & Evrard) Crins, a tropical forage grass originating in Africa, associated with N rates, could provide modifications on soil chemical attributes and nutritional status of maize and soybean [Glycine max (L.) Merr.] grown in succession. The experiment was carried out for three agricultural years at field conditions in a Rhodic Hapludox soil under no-till system in the state of Paraná, Brazil. Fall/winter (March–August) maize cropping systems, sole or intercropped with U. ruziziensis, were associated with four nitrogen (N) rates (0, 40, 80, and 120 kg ha–1 N) applied as ammonium nitrate (30% N). The soil chemical attributes were not influenced by the factors studied. The N rates linearly increased phosphorus (P), sulfur (S), and copper (Cu) concentrations in maize leaves by 29, 30, and 49%, respectively, whereas for soybeans, only the concentration of manganese was raised by 15%. Maize leaf calcium was linearly reduced with N rates only when sole cropped, up to 15%. The cropping systems did not influence nutrient concentrations in soybean leaves; however, maize leaf concentrations of P within 80 and 120 kg ha–1 of N, as well as potassium, S, and Cu at all N rates, were reduced in 9, 6.5, 6.5, and 8%, respectively. Institute of Rural Development of Paraná (IDR-Paraná), Rd. Celso Garcia Cid, PR-445, km 375 Portal Ciência do Solo (PCS), Américo Brasiliense St., 232, Room 6 Luiz de Queiroz College of Agriculture (ESALQ) Soil Science Dep. Univ. of São Paulo (USP), Pádua Dias Av., 11 Agrarian Sciences Center Agronomy Dep. Londrina State Univ. (UEL), Rd. Celso Garcia Cid, PR-445, km 380, University Campus Brazilian Agricultural Research Corporation (EMBRAPA), National Soybean Center. Rd. Carlos João Strass College of Agricultural Sciences Dep. of Crop Science São Paulo State Univ. (UNESP), José Barbosa de Barros St., 1780 College of Agricultural Sciences Dep. of Crop Science São Paulo State Univ. (UNESP), José Barbosa de Barros St., 1780

Urochloa grasses have shown promising results for smallholders to cope with feed shortages in tropical Africa. The objective of this study was to evaluate the performance of two Urochloa hybrids, Mulato-I and Mulato-II, in the Ethiopian highlands when managed under different plant spacing and harvesting stages. Treatments included three plant spacings for root splits (0.5m×0.25m, 0.5m×0.5m, and 0.75m×0.75m between rows and plants, respectively) and three harvesting stages: 1) 60 days of growth; 2) 90 days of growth corresponding to 50% bloom, and 3) 120 days of growth (corresponding to full bloom). Experimental plots were laid out in a randomized complete block design with three replications, and observations on the same established stands were made in two consecutive years. Varietal differences were observed in plant height (Mulato-II: 42 cm; Mulato-I: 72 cm), and herbage accumulation (Mulato-II: 3.0 Mg DM ha-1; Mulato-I: 10.6 Mg DM ha-1). Plant spacing also affected the above variables, but year of harvest influenced herbage accumulation. The rate of herbage accumulation tended to be constant, while that of crude protein declined and fiber concentration increased significantly with advancing maturity.Overall, the decline in quality at full bloom stage appears to be compensated by the greater herbage accumulation, suggesting that farmers can have enough time window to harvest theforages. While Mulato-I was superior in herbage accumulation, Mulato-II was found to bebetter in forage quality. The two grasses have potential to supply good quality forage provided proper management practices are applied.

Urochloa (including Brachiaria, Megathyrus and some Panicum) tropical grasses are native to Africa and are now, after selection and breeding, planted worldwide, particularly in South America, as important forages with huge potential for further sustainable improvement and conservation of grasslands. We aimed to develop an optimized approach to determine ploidy of germplasm collection of this tropical forage grass group using dried leaf material, including approaches to collect, dry and preserve plant samples for flow cytometry analysis. Our methods enable robust identification of ploidy levels (coefficient of variation of G0/G1 peaks, CV, typically &lt, 5%). Ploidy of some 348 forage grass accessions (ploidy range from 2x to 9x), from international genetic resource collections, showing variation in basic chromosome numbers and reproduction modes (apomixis and sexual), were determined using our defined standard protocol. Two major Urochloa agamic complexes are used in the current breeding programs at CIAT and EMBRAPA: the ’brizantha’ and ’humidicola’ agamic complexes are variable, with multiple ploidy levels. Some U. brizantha accessions have odd level of ploidy (5x), and the relative differences in fluorescence values of the peak positions between adjacent cytotypes is reduced, thus more precise examination of this species is required. Ploidy measurement of U. humidicola revealed aneuploidy.

Forage grass nutritional quality directly affects animal feed intake, productivity, and enteric methane (CH4) emissions. This study evaluated the nutritional quality, in vitro enteric CH4 emission potential, and optimization of diets based on two widely grown tropical forage grasses either alone or mixed with legumes. The grasses Urochloa hybrid cv. Cayman (UHC) and U. brizantha cv. Toledo (UBT), which typically have low concentrations of crude protein (CP), were incubated in vitro either alone or mixed with the legumes Canavalia brasiliensis (CB) and Leucaena diversifolia (LD), which have higher CP concentrations. Substitution of 30% of the grass dry matter (DM) with CB or LD did not affect gas production or DM degradability. After 96 h of incubation, accumulated CH4 was 87.3 mg CH4 g−1 DM and 107.7 mg CH4 g−1 DM for the grasses alone (UHC and UBT, respectively), and 100.7 mg CH4 g−1 DM and 113.2 mg CH4 g−1 DM for combined diets (70% grass, 15% CB, and 15% LD). Diets that combined legumes (CB or LC) and grass (UHC or UBT) had higher CP contents, gross, and metabolizable energy (GE, ME, respectively) densities, as well as lower concentrations of neutral detergent fiber (NDF) and acid detergent lignin (ADL). The ME and nutritional variables such as NFD, tannins (T), and CP showed a positive correlation with in vitro net gas production, while ruminal digestibility was affected by CP, ADL, T, and GE. Optimal ratios of components for ruminant diets to reduce rumen net gas production and increase protein content were found with mixtures consisting of 60% grass (either UHC or UBT), 30% CB, and 10% LD. However, this ratio did not result in a decrease in CH4 production.

A integração lavoura-pecuária (ILP) consiste na adoção de várias técnicas para melhor aproveitamento de áreas, formação e recuperação de pastagens degradadas. As espécies do gênero Urochloa tem-se destacado na ILP e o tipo de semente utilizada e a profundidade de semeadura são fundamentais para o estabelecimento e produção da forrageira. Objetivou-se nesta pesquisa avaliar a emergência e o crescimento de plantas de Urochloa brizantha cv. Marandu, oriundas de sementes incrustadas ou não, semeadas em diferentes profundidades e solos. O delineamento usado foi o de blocos casualizados, com quatro repetições. Os tratamentos foram arranjados em esquema fatorial 2x5, composto por dois tipos de sementes (incrustadas ou não) semeadas em cinco profundidades (0; 1; 2,5; 5; 10cm) em solos de textura franco argilo arenosa (TFAA) e argilosa (TA). Plantas de U. brizantha oriundas de sementes incrustadas e estabelecidas em solo de TFAA apresentaram maior emergência, mas menor crescimento em relação às plantas provindas de sementes não incrustadas. Em solo de TA, o uso de sementes incrustadas promoveu maior índice de velocidade de emergência, mas menor crescimento das plantas. A semeadura de U. brizantha com sementes incrustadas e não incrustadas a 1,0 e 2,5 cm de profundidade proporcionaram maior velocidade de emergência, independente da textura do solo. Após o corte da forrageira, o maior perfilhamento da rebrota foi observado em plantas oriundas de sementes não incrustadas e semeadas em solo de TA até 2,5 cm de profundidade. Na rebrota, não houve efeito dos tratamentos sobre o rendimento de foragem.

Technologies that promote forage production provide gains of income in beef cattle. The objective of this research was to evaluate forage production, morphological components and nutritive value of pasture of Urochloa hybrid Convert HD364, with application of biostimulant, foliar fertilizers and urea. A completely randomized design with 7 treatments and 3 replications was used. The treatments consisted of T1 (control: no fertilization), T2 (urea), T3 (Fertmicro), T4 (FertN), T5 (biostimulant), T6 (Fertmicro+biostimulant), T7 (FertN+biostimulant). The leaf content and accumulation of macro and micronutrients, accumulation of dry mass and rate of forage accumulation, concentrations of crude protein, neutral detergent fiber, and acid detergent fiber, morphological components were evaluated. The data were subjected to analysis of variance using the Tukey test at the 5% significance level for the comparison of mean values. The use of foliar fertilizers, nitrogen fertilizer and biostimulant promoted accumulation of forage dry mass, leaf, stem and dead material and higher rates of accumulation of dry mass of stem and dead material of Urochloa hybrid Convert HD364.

Integration of forage grasses with grain crops, such as maize, allows maintaining soil cover. The objective of this study was to evaluate the tensile strength, friability, and stability of soil aggregates in the maize and forage grass intercropping under no-tillage system. The study used a completely randomized block design with seven treatments and three replications. Undisturbed soil samples were collected in two seasons (2015 and 2016) at 0–0.10 m and 0.10–0.20 m soil depth. The following properties of soil aggregates were measured: tensile strength (TS), friability (F), gravimetric moisture (GM), weighted mean diameter (WMD), geometric mean diameter (GMD), and aggregate stability index (ASI). The intercropping of maize with Urochloa ruziziensis presented higher WMD and GMD at 0.10–0.20 m soil depth. Moreover, TS at 0.10–0.20 m soil depth was lower in maize without intercropping. The effects of the intercropping system on soil aggregates were better detected by aggregate stability than by TS or F. The intercropping of maize and U. ruziziensis improved soil aggregation to a higher extent than those systems with other forage grasses.

Silvopasture systems using tree legumes have potential to reduce C footprint of livestock systems in the tropics. This 4-year study evaluated productive responses of signal grass (Brachiaria decumbens Stapf.) and the performance of cattle in silvopastoral systems (SPS) in the sub-humid tropical region of Brazil. The experimental design was randomized complete block with three replications. Treatments were: signal grass + Mimosa caesalpiniifolia Benth.; signal grass + Gliricidia sepium (Jacq.); and signal grass monoculture. Cattle were managed under continuous stocking with variable stocking rate. Herbage mass (HM) was greater on signal grass monoculture (5057 kg DM/ha) than in mixed pastures (3292 kg DM/ha, average). There was interaction (P

Aims: The objective of this study was to evaluate the photosynthetic activity and production of Urochloa ruziziensis when inoculated with Azospirillum brasilense in the presence and absence of drought. Study Design: Randomized block design and factorial 2x2. Methodology: The first factor was the presence or absence of seed inoculation with A. brasilense strains AbV5 + AbV6; the second factor was the presence or absence of drought. The variables evaluated were: relative water content (RWC), soil gravimetric moisture, net assimilation rate of CO2, response in function of active photon flux density, apparent quantum efficiency, light compensation point, absolute integrity of membrane, damage to membranes, dry mass aborted leaves, and total dry mass of aerial part. Results: Results demonstrate that plants maintained in drought presented a reduction in all evaluated variables. Under conditions of drought the use of A. brasilense promoted smaller variations in RWC, net assimilation rate of CO2, apparent quantum efficiency, light compensation point, absolute integrity of membrane, and damage to membranes; no variations were observed for dry mass, aborted leaves or total dry mass of aerial part. Conclusion: The inoculation of U. ruziziensis seeds with A. brasilense mitigates drought damage in plant physiology, but it does not mitigate leaf losses or plant productivity.

Considering that nitrogen is the main macronutrient limiting pasture productivity, the aim of this study was to investigate the most appropriate day for nitrogen fertilization of the grasses Brachiaria brizantha BRS Piatã and Panicum maximum BRS Quênia. The experiment was conducted in a greenhouse in the city of Rondonópolis, located in the state of Mato Grosso, Brazil, using a completely randomized design. The treatments consisted of five nitrogen fertilization periods: 0; 2; 4; 6 and 8 days after defoliation. The dry mass of the leaf blade (DMLB), dry mass of stem + sheath (DMSS), dry mass of residue (DMRES) and root dry mass (RDM) were evaluated. The non-structural carbohydrate of the grass roots was also quantified. The later nitrogen fertilization after defoliation reduced DMLB (P< .01) and DMSS (P< .01) of the BRS Piatã palisadegrass, and DMRES of both grasses (P< .01). Higher levels of water soluble carbohydrates were observed when nitrogen fertilization was performed on grass cutting (day 0). Nitrogen fertilization of the BRS Piatã palisadegrass close the time of defoliation is recommended. For Quênia guineagrass, nitrogen can be applied between the cutting day and the eighth day after defoliation. For the root system, there is a higher content of water soluble carbohydrates in the BRS Piatã palisadegrass and greater accumulation of starch in the BRS Quênia guineagrass.

The use of grasses as cover crops in the off-season of cash crops under no-till has been largely adopted. However, soil phosphorus (P) uptake was previously shown to be reduced when ruzigrass is introduced in the rotation, affecting the viability and sustainability of this cropping system. The objective of this study was to assess the effect of ruzigrass on soil P availability and desorption kinetics under different P fertilizer application rates. A long-term field experiment where soybean (Glycine max) has been grown in rotation with ruzigrass (Urochloa ruziziensis) or fallow for 10 years, with the application of 0, 13, and 26 kg ha−1 of P, was evaluated for two consecutive years. Soil P desorption kinetics was assessed using diffusive equilibrium (DET) and gradient in thin films (DGT) techniques, as well as the DGT-induced fluxes in soils model (DIFS). Microbial biomass P (MBP) was assessed to verify if soil solution P (PDET) was reduced due to immobilization by microorganisms. Ruzigrass reduced MBP and PDET especially when P fertilizer was applied. The concentration of labile P (PDGT) was also lower after ruzigrass than in fallow. The soil ability to resupply P to soil solution was lower after ruzigrass regardless of P rates due to a slower desorption in response to the perturbation imposed by DGT. Growing ruzigrass as cover crop in the soybean off-season decreases soil P availability regardless of P fertilizer application rates by fundamentally reducing P mobility and P resupply from soil solid phase into soil solution., Highlights • The use of ruzigrass as cover crop affect soil P availability in the long-term. • Soil P desorption kinetics was assessed using diffusive gradient in thin films (DGT). • The use of DGT provided new insights into P availability, by considering the P diffusion and resupply process. • Ruzigrass decreases P availability by reducing P mobility and resupply from soil solid phase into soil solution.

Made available in DSpace on 2019-10-06T16:18:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-04-15 Urochloa spp. grow vigorously in the dry-season of the tropics, and have been used successfully to provide abundant surface residue as cover crop for no-till soybean (Glycine max). Nitrogen (N) fertilizer application could enhance cover crop biomass production and its ground cover and accelerate residue decomposition, but how these cascading factors affect nutrient availability to the subsequent soybean crop is not known. We evaluated nutrient cycling and soybean nutrition and yield components following different timings of N application to living and desiccated Urochloa cover crops. The experiment was conducted in two growing seasons at Botucatu, São Paulo State, Brazil. Treatments consisted of two cover crop grasses (Urochloa brizantha and Urochloa ruziziensis) and six N management systems [control (no N application); N application at soybean sowing (40 kg N ha −1 ) plus topdressing (60 kg N ha −1 at V5 stage); N application 20 days before desiccation (DBD) of cover crops, N application 10 DBD; N application 5 DBD; and N application 1 day before sowing of soybean, using the rate of 100 kg N ha −1 in the latter four treatments]. Both cover crops produced high amount of shoot biomass (> 9.7 Mg ha −1 ), but U. brizantha was 48% more productive than U. ruziziensis. Nutrient accumulation in cover crop straw was enhanced due to greater biomass production in treatments with N applied 20 and 10 DBD. Soybean grain yield was 17% greater following U. brizantha than following U. ruziziensis. Nitrogen application at different times did not affect soybean grain yield. These results suggest that Urochloa biomass, macronutrient accumulation, and subsequent release rates can be enhanced with N application, but it had little short-term impact on soybean yield components. Department of Crop Science College of Agricultural Sciences São Paulo State University (UNESP), Av. Universitária, Lageado Experimental Farm 3789 Special Academic Unit of Agricultural Sciences Federal University of Goiás (UFG) United States Department of Agriculture Agricultural Research Service Brazilian Agricultural Research Corporation – Embrapa Soybean Department of Crop Science College of Agricultural Sciences São Paulo State University (UNESP), Av. Universitária, Lageado Experimental Farm 3789

The aim of the study was to characterize the type of aneuploidy present in the hybrid Urochloa ruziziensis × Urochloa decumbens and to confirm the origin of the additional chromosomes through comparative analysis of the hybrid and parental karyotypes. C and CMA banding techniques were used for chromosome differentiation. The parental genotypes showed 36 chromosomes. The hybrid presented plants with 36 + 2 chromosomes and plants with 36 + 1 chromosomes. Urochloa ruziziensis (4x) presented four chromosomes with CMA and C bands co-located in the terminal position. In U. decumbens, four chromosomes presented terminal CMA bands, eight chromosomes were distinguished by C banding with pericentromeric and terminal bands, one chromosome with terminal band at both ends and one chromosome presented one C terminal band. For the hybrid, CMA bands were found on five chromosomes and C bands on seven chromosomes, all in terminal position. Aneuploidy was identified in pairs 3' and 4' in the hybrid plants with 36 + 2 chromosomes, characterizing it as double trisomy. The karyotype of hybrid plants with 36 + 1 chromosomes indicated elimination of the additional chromosome identified in pair 4' and maintenance of trisomy on pair 3'. The comparative analysis of karyotypes indicates that the additional chromosomes that characterize the trisomy were inherited from U. ruziziensis (artificial tetraploid).

The effects of cover crop management on the carpogenic germination of Sclerotinia sclerotiorum sclerotia and stem rot disease of soybean were investigated during three seasons (2008/2009 to 2010/2011) in a commercial farm of Goias State, Brazil. Congo grass (Urochloa ruziziensis) annually grown during the fall at different densities (150, 300, 450 and 600 units of pure live seeds) was evaluated as cover crop and compared with a spontaneous weeds treatment. The germination of sclerotia was evaluated during cover crop growth in the spring season and in the summer, during soybean flowering. In general, apothecia density, disease incidence and disease severity index assessed at the 5.2 and 5.5 stages decreased with the increase of cover crop density. Trichoderma harzianum doses did not affect disease variables Soybean yield was not affected by any treatment. Principal component analysis clustered grass-soybean treatments apart from the spontaneous weeds-soybean sequence in all seasons. Carpogenic germination under the Congo grass canopy was negatively associated with apothecia density and disease during soybean growth. Mulching with Congo grass stimulates early carpogenic germination of S. sclerotiorum, enhancing soil disinfestation rather quickly. Adjustments in soybean crop stand are suggested to match improved disease management with higher soybean yields.

This study aimed to assess solar radiation transmission and animal thermal comfort indexes in two silvopastoral systems established with different tree arrangements in a tropical region. This study was conducted between 2014 and 2017 in two silvopastoral systems, one composed by an established Urochloa (syn. Brachiaria) decumbens pasture with Brazilian native trees planted in triple rows spaced 17 m apart, and another by an established Urochloa (syn. Brachiaria) brizantha (Hochst ex A. Rich.) Stapf ‘BRS Piata’ pasture with Eucalyptus urograndis (clone GG100) trees arranged in single rows spaced 15 m apart. In these systems and in a full-sun pasture, photosynthetically active radiation transmission, air temperature, relative humidity, black globe temperature, and wind speed were measured. These variables were used to calculate black globe temperature and humidity index (BGHI) and radiant thermal load (RTL). Higher animal thermal comfort was observed in the silvopastoral systems due to changes in the microclimate induced by the trees; notably, a decrease in solar radiation transmission. Fewer hours of potential animal thermal stress (BGHI>79) were observed in the silvopastoral systems than under the full-sun conditions, with differences up to 3 h per day. The silvopastoral systems presented lower radiant thermal load than the full-sun pasture with differences up to 22% achieved. The assessed silvopastoral systems may help livestock adapt to climate change, since they achieved the limit of BGHI considered to cause stress to animals following an increase of 2.2 °C in air temperature, compared with full-sun pastures.

Urochloa arrecta (Hack.) Morrone & Zuloaga, Darwiniana 31: 69 (1992). Distribution: Ethiopia to S. Africa, Madagascar Specimens: MOSHI Hai area, Hemp, A. 2784 (NHT, UBT)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 243, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Urochloa trichopus (Hochst.) Stapf in D.Oliver & auct. suc. (eds.), Fl. Trop. Afr. 9: 589 (1920). Distribution: Trop. & S. Africa, Arabian Pen., Madagascar Specimens: MOSHI Moshi, Hitchcock, A.S. 24567 (K); Moshi, Swynnerton, R.J.M. H45/46 (K)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 244, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Urochloa panicoides P.Beauv., Ess. Agrostogr.: 52 (1812). Distribution: Egypt to S. Africa and Indo-China Specimens: MOSHI Holili, Hemp, A. 1826 (NHT, UBT); Kirua, Hemp, A. 1747 (NHT, UBT); Moshi, Haarer, A.E. 41A (K); Moshi, Hitchcock, A.S. 24564 (K)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 243, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Urochloa deflexa (Schumach.) H.Scholz, Bull. Mus. Natl. Hist. Nat., B, Adansonia 11: 443 (1989). Distribution: Africa to Arabian Pen., Indian Subcontinent Specimens: MOSHI Himo stream, Hemp, A. 2771 (UBT); Holili, Hemp, A. 1816 (UBT); Kiboroloni, Hemp, A. 2770 (NHT, UBT); Moshi, Davies, R.M. 1014 (K); Moshi, Haarer, A.E. 465 (K); Moshi, Hemp, A. 4467 (NHT, UBT); Moshi, Hitchcock, A.S. 24578 (K)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 243, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Urochloa brizantha (A.Rich.) R.D.Webster, Austral. Paniceae: 233 (1987). Distribution: Trop. & S. Africa, W. Indian Ocean, SW. Arabian Pen. Specimens: MOSHI Kirua, Hemp, A. 1686 (NHT, UBT); Moshi, Haarer, A.E. 742 (K); Mwika, Hemp, A. 2054 (B, NHT, UBT); Rombo, Greenway, P.J. 7835 (K); s. loc., Endlich, R. 33A (NH)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 243, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Urochloa leersioides (Hochst.) A.M.Torres & C.M.Morton, Molec. Phylogen. Evol. 37: 42 (2005). Distribution: Egypt to Mozambique, Arabian Pen. Specimens: MOSHI Holili, Hemp, A. 1867 (NHT, UBT); Kiruru, Haarer, A.E. 436 (K); Kisangiro, Peterson, P. 24200 (K); Machame route, Hemp, A. 5157 (UBT); Moshi, Haarer, A.E. 384 (K); Moshi Airport, Greenway, P.J. 7828 (K, NH)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 243, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Urochloa comata (Hochst. ex A.Rich.) Sosef, Fl. Gabon 5bis: 64 (1999). Distribution: Trop. Africa, SW. Arabian Pen. Specimens: MOSHI Kidia, Hemp, A. 1677 (NHT, UBT); Lerang’wa, Hemp, A. 3055 (NHT, UBT); Mandara Hut (=Bismark Hut), Hitchcock, A.S. 24622 (K); Marangu, Hitchcock, A.S. 24660 (K, NH); s. loc., Volkens, G. 657 (MO); Sanya Juu, Hemp, A. 4454 (NHT, UBT)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 243, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Urochloa xantholeuca (Hack.) H.Scholz, Bull. Mus. Natl. Hist. Nat., B, Adansonia 11: 443 (1990). Distribution: Trop. & S. Africa, Arabian Pen. Specimens: MOSHI Himo, Mkenda, P.M. PM4 (K); Holili, Hemp, A. 1902 (NHT, UBT)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 244, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Urochloa dictyoneura (Fig. & De Not.) Veldkamp, Blumea 41: 418 (1996). Distribution: Nigeria to Ethiopia and S. Africa Specimens: MOSHI Holili, Hemp, A. 1888 (NHT, UBT); Machame route, Hemp, A. 4471 (NHT, UBT); Mengwe, area, Hemp, A. 5222 (NHT, UBT)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 243, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Urochloa serrata (Thunb.) Sosef, Pl. Ecol. Evol. 149: 361 (2016). Distribution: Trop. & S. Africa Specimens: MOSHI Lake Chala, Hemp, A. 1998 (NHT, UBT); Lume River, Hemp, A. 3956 (NHT, UBT); Mrao, Haarer, A.E. 1711 (K); Mwika, Hemp, A. 1242 (NHT, UBT)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 244, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Urochloa brachyura (Hack.) Stapf in D.Oliver & auct. suc. (eds.), Fl. Trop. Afr. 9: 592 (1920). Distribution: Ethiopia to S. Africa Specimens: MOSHI Lerang’wa, Grimshaw, J.M. 94247 (K)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 243, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Urochloa setigera (Retz.) Stapf in D.Oliver & auct. suc. (eds.), Fl. Trop. Afr. 9: 598 (1920). Distribution: Indian Subcontinent to SE. China and Borneo Specimens: MOSHI Kahe, Hemp, A. 6410 (UBT)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 244, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES Wheat blast caused by the fungus Pyricularia oryzae triticum (PoT), is one of the main limiting factors for wheat cultivation in Brazil. One of the main difficulties related to the control of the disease is related to the gaps in knowledge about its epidemiology. These include issues such as how much PoT is being disseminated in the country via seeds, how long it can saprophytically survive in wheat straw, and the importance of intermediate host plants, such as plants of the genus Urochloa (formerly Brachiaria). The objective of the present work was: (a) to evaluate the importance of seeds, wheat straw and plants of the genus Urochloa as inoculum sources for wheat blast in Brazil and (b) to verify the relationship between PoT infection rates in seeds of wheat and levels of quantitative variables linked to the establishment and health of seedlings. The work was conducted at Embrapa Trigo, Passo Fundo, RS. Four hundred and one wheat seed samples collected in 2017, 2018 and 2019, in the states of GO, MG, MS, PR and RS were subjected to cultural (Blotter Test) and molecular (PCR - Polymerase Chain Reaction) detection procedures . The saprophytic survival of PoT was evaluated in three locations, Londrina (PR), Planaltina (DF) and Uberaba (MG). In the 2018 and 2019 harvests, wheat seed samples were collected in Londrina (PR), Patos de Minas (MG), Uberaba (MG), and 66 samples of forage plant leaves that presented symptoms attributed to blast, whose detection was confirmed via wet chamber and PCR. The presence of PoT was observed in 28.2% of the 401 samples collected in the states of RS, PR, MG, GO and MS, showing the presence of the pathogen in wheat seed samples, and whose molecular detection via PCR allowed amplification in samples with 0.5% incidence of the pathogen. The emergence rates, pathogen incidence, presence of symptoms, mortality, abnormality and transmissibility in wheat seedlings are related to the PoT infection rate in seeds. The pathogen can survive in wheat plants for a period of up to 160 days, in Brazilian subtropical and tropical conditions. Plants of the Urolchoa genus have a natural incidence of the pathogen. The results obtained allow a better understanding of several aspects related to the survival and dissemination of PoT in the Brazilian conditions of occurrence of wheat blast. A brusone do trigo causada pelo fungo Pyricularia oryzae triticum (PoT), é um dos principais limitantes à cultura do trigo no Brasil. Uma das principais dificuldades relacionadas ao controle da doença está relacionada às lacunas no conhecimento sobre sua epidemiologia. Inclui-se questões como o quanto PoT está sendo disseminado no país via sementes, o tempo que pode sobreviver saprofiticamente na palha de trigo, e a importância que plantas hospedeiras intermediárias desempenham, como plantas do gênero Urochloa (ex-Brachiaria). Foi objetivo do presente trabalho: (a) avaliar a importância que sementes, palha de trigo e plantas do gênero Urochloa representam como fontes de inóculo para a brusone do trigo no Brasil e (b) verificar a relação entre taxas de infecção de PoT em sementes de trigo e níveis de variáveis quantitativas vinculadas ao estabelecimento e à sanidade de plântulas. O trabalho foi conduzido na Embrapa Trigo, Passo Fundo, RS. Quatrocentas e uma amostras de sementes de trigo colhidas nos anos de 2017, 2018 e 2019, nos estados de GO, MG, MS, PR e RS foram submetidas a procedimentos de detecção cultural (Blotter Test) e molecular (PCR – Polymerase Chain Reaction). A sobrevivência saprofítica de PoT foi avaliada em três locais, Londrina (PR), Planaltina (DF) e Uberaba (MG). Nas safras 2018 e 2019, foram coletadas amostras de sementes de trigo em Londrina (PR), Patos de Minas (MG) e Uberaba (MG) e 66 amostras de folhas de plantas forrageiras que apresentavam sintomas atribuídos à brusone, cuja detecção foi confirmada via câmara úmida e PCR. Foi observada presença de PoT em 28,2% das 401 amostras coletadas nos estados de RS, PR, MG, GO e MS, tendo apresentado presença do patógeno em amostras de sementes de trigo, e cuja detecção molecular via PCR permitiu amplificação em amostras com 0,5% de incidência do patógeno. As taxas de emergência, incidência do patógeno, presença de sintomas, mortalidade, anormalidade e transmissibilidade em plântulas de trigo são relacionadas à taxa de infecção de PoT nas sementes. O patógeno pode sobreviver em plantas de trigo por um período de até 160 dias, nas condições subtropicais e tropicais brasileiras. Plantas do gênero Urolchoa apresentam incidência natural do patógeno. Os resultados obtidos permitem uma melhor compreensão sobre vários apectos relacionados à sobrevivência e à disseminação de PoT nas condições brasileiras de ocorrência da brusone do trigo.

Brachiaria (Trin.) Griseb. (syn. Urochloa P. Beauv.) is a C4 grass genus belonging to the Panicoideae. Native to Africa, these grasses are now widely grown as forages in tropical areas worldwide and are the subject of intensive breeding, particularly in South America. Tolerance to abiotic stresses such as aluminum and drought are major breeding objectives. In this study, we present the transcriptomic profiling of leaves and roots of three Brachiaria interspecific hybrid genotypes with the onset of water stress, Br12/3659-17 (gt-17), Br12/2360-9 (gt-9), and Br12/3868-18 (gt-18), previously characterized as having good, intermediate and poor tolerance to drought, respectively, in germplasm evaluation programs. RNA was extracted from leaf and root tissue of plants at estimated growing medium water contents (EWC) of 35, 15, and 5%. Differentially expressed genes (DEGs) were compared between different EWCs, 35/15, 15/5, and 35/5 using DESeq2. Overall, the proportions of DEGs enriched in all three genotypes varied in a genotype-dependent manner in relation to EWC comparison, with intermediate and sensitive gt-9 and gt-18 being more similar to each other than to drought tolerant gt-17. More specifically, GO terms relating to carbohydrate and cell wall metabolism in the leaves were enriched by up-regulated DEGs in gt-9 and gt-18, but by down-regulated DEGs in gt-17. Across all genotypes, analysis of DEG enzyme activities indicated an excess of down-regulated putative apoplastic peroxidases in the roots as water stress increased. This suggests that changes in root cell-wall architecture may be an important component of the response to water stress in Brachiaria.

The objective of this research was to evaluate a soil recovery strategy in soils that were affected by iron mining tailing using herbaceous species inoculated with Acaulospora morrowiae (arbuscular mycorrhizal fungus (AMF)). Tailings were collected on the banks of the Gualaxo do Norte river, one of the places impacted by the Fundao Dam rupture, where tailing layers that were more than one meter were deposited. The experiment was carried out in a greenhouse, using 6 kg pots of non-sterile reject, in a randomized block design in a 4 × 2 factorial scheme, with four cropping systems (Urochloa ruziziensis single crop–RS; and intercropping cultivation: U. ruziziensis with Crotalaria spectabilis–R + C; U. ruziziensis with Guizotia abyssinica–R + G and U. ruziziensis with C. spectabilis and G. abyssinica–R + C + G), with two AMF inoculation conditions (with 200 A. morrowiae spores per pot, and no inoculation), with three replications and 100 days duration. The R + C and R + C + G systems presented the highest shoot dry matter (SDM) yields. Regarding root dry matter production (RDM), a variation of 9.2 g of pot−1 roots was observed between the R + C and R + G systems. Mycorrhizal colonization (MC) was higher in the cultivation system with the three herbaceous species, being the R + C + G system 52% higher than RS system. Spore density did not vary among treatments. Microbial carbon biomass was higher in the RS and R + G treatments when not inoculated. Basal respiration was also higher when not inoculated. Overall, the R + C + G system was more efficient than other systems in the accumulation of elements. The cultivation system with three herbaceous plants proved to be efficient in establishing itself initially in the iron mining tailings, being a viable alternative for the rehabilitation process.

Made available in DSpace on 2021-06-25T11:12:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-01 Maize intercropping with forage crops and N under no-tillage management have led to discrepant results regarding the impact on crop yield. Therefore, understanding various production systems is necessary to assist producers in decision making. The aim of this experiment was to evaluate whether maize (Zea mays L.) intercropping with Urochloa ruziziensis (R. Germ. and C.M. Evrard) Crins promotes differences in the agronomic performance of maize and if split top-dressing N fertilization in the previous crop (common bean [Phaseolus vulgaris L.]) promotes increase in maize agronomic performance. The experiment was conducted during two agricultural years in southeastern Brazil, with treatments arranged as a split-plot fitted in a randomized block design, with four replications. Main plot was cropping systems (two systems - maize sole and maize intercropped with U. ruziziensis) while subplots comprised 10 combinations of split top-dressed N applications, totaling 90 kg ha−1, applied to the previously cultivated common bean crop. Regardless of the agricultural year, intercropping with U. ruziziensis sown simultaneously with maize reduced maize yield by 12% on average. Intercropping maize and U. ruziziensis increased soil coverage from an average of 64–100% over maize as an only crop. The agronomic performance of maize grown in sole crop or intercropped with U. ruziziensis was not influenced by the effect of top-dressing N fertilization applied in common bean under no-tillage as previous crop. Intercropping maize with U. ruziziensis is a viable option for producers seeking improved soil coverage or grazing opportunities, however, caution is needed since maize yields may be reduced. School of Agricultural and Veterinarian Sciences São Paulo State Univ. (Unesp), Via de acesso Prof. Paulo Donato Castellane, s/n, CEP School of Agricultural and Veterinarian Sciences São Paulo State Univ. (Unesp), Via de acesso Prof. Paulo Donato Castellane, s/n, CEP

Background and AimsDiploid and polyploidUrochloa(includingBrachiaria,PanicumandMegathyrsusspecies) C4tropical forage grasses originating from Africa and now planted worldwide are important for food security and the environment, often being planted in marginal lands. We aimed to characterize the nature of their genomes, the repetitive DNA, and the genome composition of polyploids, leading to a model of the evolutionary pathways within the group including many apomictic species.MethodsSome 362 forage grass accessions from international germplasm collections were studied, and ploidy determined using an optimized flow cytometry method. Whole-genome survey sequencing and molecular cytogenetic analysis within situhybridization to chromosomes were used to identify chromosomes and genomes inUrochloaaccessions belonging to the different agamic complexes.Key ResultsGenome structures are complex and variable, with multiple ploidies and genome compositions within the species, and no clear geographical patterns. Sequence analysis of nine diploid and polyploid accessions enabled identification of abundant genome-specific repetitive DNA motifs.In situhybridization with a combination of repetitive DNA and genomic DNA probes, identified evolutionary divergence and allowed us to discriminate the different genomes present in polyploids.ConclusionsWe suggest a new coherent nomenclature for the genomes present. We develop a model of evolution at the whole-genome level in diploid and polyploid accessions showing processes of grass evolution. We support the retention of narrow species concepts forU. brizantha, U. decumbens, andU. ruziziensis. The results and model will be valuable in making rational choices of parents for new hybrids, assist in use of the germplasm for breeding and selection ofUrochloawith improved sustainability and agronomic potential, and will assist in measuring and conserving biodiversity in grasslands.

The objective of this work was to evaluate the effect of brushwood, black plastic mulch, herbicide, and artificial perch on the natural regeneration of native species in Urochloa grassland. The experiment was conducted between February 2014 and February 2016 in the Dense Ombrophilous Forest, in the municipality of Morretes, in the state of Paraná, Brazil. The treatments were: herbicide, herbicide + perch, black plastic mulch, black plastic mulch + perch, brushwood + herbicide, brushwood + herbicide + perch, and a control treatment. The evaluations were carried out at 4, 8, 12, 18, and 24 months after the installation of the experiment, by counting and identifying regenerating woody species and estimating visually the percentage of herbaceous coverage. Initially, brushwood and black plastic mulch reduced the Urochloa grasses; however, this effect was lost over time due to the rapid growth of the grasses from the edges to the center of the plots. The use of perches in the treatments does not allow a significant increase of other species because of the continued inhibiting conditions for the establishment of seedlings. The herbicide is effective in removing the grasses; however, the recruitment of woody species is only satisfactory when perches are used to attract the dispersing fauna. For a successful ecological restoration of pastures, there is a need for the local elimination of Urochloa grasses. Resumo: O objetivo deste trabalho foi avaliar os métodos galharia, cobertura por plástico preto, herbicida e poleiro artificial na regeneração natural de espécies nativas em área com pastagem de Urochloa. O experimento foi conduzido entre fevereiro de 2014 e fevereiro de 2016 na Floresta Ombrófila Densa, no município de Morretes, no estado do Paraná, Brasil. Os tratamentos foram: herbicida, herbicida + poleiro, cobertura por plástico preto, cobertura por plástico preto + poleiro, galharia + herbicida, galharia + herbicida + poleiro e testemunha. As avaliações foram realizadas aos 4, 8, 12, 18 e 24 meses após a instalação do experimento, com contagem e identificação das espécies lenhosas regenerantes e estimativa visual do percentual de cobertura por herbáceas. Inicialmente, a galharia e a cobertura por plástico preto reduziram as gramíneas Urochloa; entretanto, com o decorrer do tempo, esse efeito se perdeu devido ao rápido crescimento das gramíneas das bordas para o centro das parcelas. O uso de poleiros nos tratamentos não possibilita incremento significativo de outras espécies, em razão da permanência das condições inibidoras ao estabelecimento das plântulas. O herbicida é eficiente para remover as gramíneas; contudo, o recrutamento de espécies lenhosas somente é satisfatório com o uso de poleiros para atração da fauna dispersora. Para o sucesso da restauração ecológica em pastagens, há a necessidade de eliminação local das gramíneas Urochloa.

Topdressing nitrogen (N) rates may alter the second-crop corn performance, and this response may vary if the corn is grown single or intercropped with grass or leguminous species. This study aimed to evaluate the effect of topdressing N rates on the growth and productive performance of second-crop corn grown single or intercropped with ruzigrass (Urochloa ruziziensis) or showy rattlebox (Crotalaria spectabilis). The experiment was carried out in a randomized block design, with a split-plot arrangement and four replications. The plots consisted of corn grown single or intercropped with ruzigrass or showy rattlebox, while the subplots consisted of N rates (0, 60, 120, 180 and 240 kg ha-1). The evaluated variables were: SPAD index at R1; normalized difference vegetation index at V4 and V7; leaf area at R1; leaf and total corn dry mass at R1; grain and total corn dry mass at R6; number of ears per plant and grains per ear; 1,000-grain mass; and grain yield. In the absence of N fertilization and with topdressing of 60 kg ha-1 of N, the intercropping with U. ruziziensis reduces the growth and productive performance of second-crop corn. The topdressing N fertilization for second-crop corn intercropped with U. ruziziensis minimizes the forage competition on corn growth and provides a productive performance similar to monocropping from 120 kg ha-1 of N. The intercropping with C. spectabilis does not change the corn growth and productive performance, as well as the response to the topdressing N rates, when compared to monocropping, in the second crop cultivation. RESUMO Doses de nitrogênio (N) em cobertura podem alterar o desempenho da cultura do milho segunda safra, e essa resposta pode variar se o milho for cultivado solteiro ou consorciado com espécies de gramíneas ou leguminosas. Objetivou-se avaliar o efeito de doses de N aplicadas em cobertura no crescimento e desempenho produtivo de milho segunda safra solteiro e consorciado com braquiária (Urochloa ruziziensis) ou crotalária (Crotalaria spectabilis). O delineamento experimental foi em blocos casualizados, com parcelas subdivididas e quatro repetições. As parcelas foram constituídas pelo milho solteiro, consorciado com braquiária ou com crotalária, e as subparcelas pelas doses de N (0, 60, 120, 180 e 240 kg ha-1). As variáveis avaliadas foram: índice SPAD em R1; índice de vegetação por diferença normalizada em V4 e V7; área foliar em R1; massa seca de folha e total do milho em R1; massa seca de grão e total do milho em R6; número de espigas por planta e de grãos por espiga; massa de mil grãos; e produtividade de grãos. Na ausência de adubação nitrogenada e com uso de 60 kg ha-1 de N em cobertura, o consórcio com U. ruziziensis reduz o crescimento e o desempenho produtivo de milho segunda safra. A adubação nitrogenada de cobertura no milho segunda safra em consórcio com U. ruziziensis minimiza a competição da forrageira sobre o crescimento do milho e proporciona, a partir de 120 kg ha-1 de N, desempenho produtivo similar ao do cereal solteiro. O consórcio com C. spectabilis não altera o crescimento e o desempenho produtivo do milho, bem como a resposta a doses de N aplicadas em cobertura, em relação ao milho solteiro, na segunda safra.

Grazing intensity on palisade grass as a function of grazing height in a crop-livestock integration (CLI) system alters the structural soil quality and water infiltration. This study aimed to verify the magnitude of the stocking rate and shoot and root dry matter of palisade grass at the end of the fifth cattle grazing period of an experiment in the CLI system on the visual evaluation of soil structure (VESS), soil-water infiltration rate, and basic infiltration rate (BIR) as a function of grazing heights on Urochloa brizantha cv. MG 5 Vitória in the northwestern Paraná State, Brazil. The experimental design consisted of randomized blocks with three replications and 1-ha experimental plots on an Oxisol. Four treatments with grazing heights of 10, 20, 30, and 40 cm were used in the CLI system, controlled with variable stocking rates of Purunã cattle in the autumn/winter season on Urochloa brizantha cv. MG 5 Vitória in succession to soybean in the summer. The maximum soil water infiltration was stabilized at 30 cm of grazing height of the palisade grass under continuous grazing in the CLI system. The increase in the stocking rate decreased the shoot dry matter of palisade grass, soil water infiltration, and structural soil quality. A intensidade de pastejo da braquiária em função da altura de pastejo em sistema de integração lavoura-pecuária (ILP) altera a qualidade estrutural do solo e a infiltração da água. Com este trabalho teve-se por objetivo verificar ao final do quinto período de pastejo bovino de um experimento em sistema de ILP, qual a magnitude da carga animal, matéria seca da parte aérea e de raízes de braquiária, sobre a avaliação visual da estrutura do solo (VESS), a taxa de infiltração de água no solo e a velocidade básica de infiltração (VIB) em função da alturas de pastejos em braquiária Urochloa brizantha cv. MG 5 Vitória, na Região Noroeste do Estado do Paraná, Brasil. O delineamento experimental é de blocos casualizados, com três repetições, em parcelas experimentais de 1 ha, em um Latossolo Vermelho distrófico. Foram utilizados quatro tratamentos com alturas de pastejo de 10, 20, 30 e 40 cm em sistema de ILP controlados com carga animal variável de bovinos da raça Purunã no período de outono/inverno, em braquiária Urochloa brizantha cv. MG 5 Vitória em sucessão a soja no verão. A máxima infiltração da água no solo se estabiliza em 30 cm de altura de pastejo da braquiária em pastejo contínuo em sistema ILP. O aumento da carga animal diminuiu a matéria seca da parte aérea de braquiária, infiltração de água e a qualidade estrutural do solo.

The objective of this work was to evaluate the influence of sorghum and cover plant cropping systems before soybean cultivation on the occurrence of weeds during soybean growing in the Brazilian Cerrado. The experiment was carried out in a randomized complete block design, with four replicates. The treatments comprised six cropping systems before soybean: sorghum (Sorghum bicolor), palisade grass (Urochloa brizantha), and Congo grass (Urochloa ruziziensis) as cover plants, alone or intercropped, in addition to fallowing. Weeds were evaluated as to: density, dry matter mass, diversity, importance value, and similarity. The greatest similarity of weeds ocurred in single crops of sorghum, palisade grass, and Congo grass, in comparison with their intercroppings. Congo grass before soybean promoted a greater reduction in weed diversity overtime, when compared with palisade grass. The absence of cover crops before soybean cultivation increased weed infestation during the soybean cycle. The cropping systems with sorghum intercropped with cover crops before the soybean cultivation affect the diversity and the importance value of weed species. Resumo: O objetivo deste trabalho foi avaliar a influência de sistemas de cultivo de sorgo e plantas de cobertura anteriores ao cultivo da soja, na ocorrência de plantas daninhas durante o cultivo da soja no Cerrado brasileiro. O experimento foi realizado em delineamento de blocos ao acaso, com quatro repetições. Os tratamentos consistiram em seis sistemas de cultivo antes da soja: sorgo (Sorghum bicolor), capim-marandu (Urochloa brizantha) e capim-ruziziensis (Urochloa ruziziensis), isolados ou consorciados, além do pousio. As plantas daninhas foram avaliadas quanto a: densidade, massa de matéria seca, diversidade, valor de importância e similaridade. A maior similaridade de plantas daninhas ocorreu nos cultivos solteiros de sorgo, capim-marandu e capim-ruziziensis do que em seus cultivos consorciados. O capim-ruziziensis antes da soja favoreceu maior redução da diversidade de plantas daninhas no decorrer do tempo, quando comparado ao capim-marandu. A ausência de plantas de cobertura no pousio aumentou a infestação de plantas daninhas durante o ciclo da soja. Os sistemas consorciados de sorgo com plantas de cobertura antes do cultivo da soja influenciam a diversidade e o valor de importância das plantas daninhas.

Objective: To evaluate for 10 weeks the growth of five Urochloa cultivars: Camello,Cobra, Cayman, Convert 330, Mavuno and Xaraés; during the North Winds (NS), Dry(DS) and Rainy (RS) seasons in a warm sub-humid environment. Design/Methodology/Approach: The variables were crop growth rate (CGR; kg ha-1 d-1 ) and total dry matter yield (TDM; t ha -1 ); which were analyzed under a completelyrandomized design (Tukey; p=0.05). Results: During NS, Mavuno and Xaraés presented, on average, the highest values ??ofCGR (p

Made available in DSpace on 2022-04-29T08:30:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-09-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Optimizing agronomic efficiency (AE) of nitrogen (N) fertilizer use by crops and enhancing crop yields are challenges for tropical no-tillage systems since maintaining crop residues on the soil surface alters the nutrient supply to the system. Cover crops receiving N fertilizer can provide superior biomass, N cycling to the soil and plant residue mineralization. The aims of this study were to (i) investigate N application on forage cover crops or cover crop residues as a substitute for N sidedressing (conventional method) for maize and (ii) investigate the supply of mineral N in the soil and the rates of biomass decomposition and N release. The treatments comprised two species, i.e., palisade grass [Urochloa brizantha (Hochst. Ex A. Rich.) R.D. Webster] and ruzigrass [Urochloa ruziziensis (R. Germ. and C.M. Evrard) Crins], and four N applications: (i) control (no N application), (ii) on live cover crops 35 days before maize seeding (35 DBS), (iii) on cover crop residues 1 DBS, and (iv) conventional method (N sidedressing of maize). The maximum rates of biomass decomposition and N release were in palisade grass. The biomass of palisade grass and ruzigrass were 81 and 47% higher in N application at 35 DBS compared with control in ruzigrass (7 Mg ha−1), and N release followed the pattern observed of biomass in palisade and ruzigrass receiving N 35 DBS (249 and 189 kg N ha−1). Mineral N in the soil increased with N application regardless of cover crop species. Maize grain yields and AE were not affected when N was applied on palisade grass 35 DBS or 1 DBS (average 13 Mg ha−1 and 54 kg N kg−1 maize grain yield) compared to conventional method. However, N applied on ruzigrass 35 DBS decreased maize grain yields. Overall, N fertilizer can be applied on palisade grass 35 DBS or its residues 1 DBS as a substitute for conventional sidedressing application for maize. Department of Crop Science College of Agricultural Sciences São Paulo State University (UNESP), Av. Universitaria, 33789, Lageado Experimental Farm Department of Microbial Ecology Netherlands Institute of Ecology, Droevendaalsesteeg 10 Ecology and Biodiversity Institute of Environmental Biology Utrecht University, Padualaan 8 University of Sao Paulo (USP-ESALQ), Av. Pádua Dias, 235 Agronomic Institute of Campinas (IAC), Av. Barao de Itapura, 1481, Botafogo Department of Crop Science College of Agricultural Sciences São Paulo State University (UNESP), Av. Universitaria, 33789, Lageado Experimental Farm FAPESP: 2015/17953-6 FAPESP: 2016/12317-7 CAPES: 88881.187743/2018-01

Pasture-based systems are prevalent among small-scale family farms. Many farmers consider that the nutritional value of the plant is more relevant than the canopy structure. This study aimed to analyze the various factors related to plant structure and chemical composition that most influence milk yield per hectare under rotational stocking. The experiment was performed at the Animal Husbandry Experimental Station of the Extreme South of Bahia. Three rotational stocking systems with three forage species [Cynodon dactylon (L.) Pers. cv. Tifton 85, Urochloa brizantha (Hochst. ex A. Rich.) Stapf. cv. Xaraés, and Megathyrsus maximus Jacq. cv. Mombasa] were evaluated. Nine crossbred Holstein x Gyr cows were allocated to a balanced 3 x 3 Latin square design. The cows were rotated in three pastures every 14 days. The experimental period consisted of seven evaluation cycles of 42 days each. Cluster analysis, principal component analysis (PCA), and multivariate linear regression were the statistical techniques used to evaluate plant structure and morphological characteristics, and animal performance. Xaraés palisadegrass and Mombasa guinea grass were similar for all evaluated characteristics (P > 0.05), whereas Tifton 85 was different from them in terms of structural, morphological, and chemical composition characteristics (P < 0.05). In the PCA, 59.1% of the total variance was explained by components 1 and 2 for the structural and morphological characteristics, and forage chemical composition. Forage structural and morphological variables showed better results in the multivariate linear regression analysis for milk yield per hectare. Structural and morphological characteristics were more correlated with Mombasa guinea grass than Xaraés palisadegrass and Tifton 85. The structural and morphological characteristics of forages were the main factors determining milk yield per hectare in exclusively pasture-based systems with animals of low production. Os sistemas baseados em pastagens são predominantes entre os pequenos agricultores familiares. Muitos agricultores consideram que o valor nutricional da planta é mais relevante que a estrutura do dossel. Este estudo teve como objetivo analisar os vários fatores relacionados à estrutura da planta e a composição química que mais influenciam a produção de leite por hectare sob lotação rotativa. O experimento foi realizado na Estação Experimental de Pecuária do Extremo Sul da Bahia. Três sistemas de lotação rotacionada com três espécies forrageiras [Cynodon dactylon (L.) Pers. cv. Tifton 85, Urochloa brizantha (Hochst. Ex A. Rich.) Stapf. cv. Xaraés e Megathyrsus maximus Jacq. cv. Mombaça] foram avaliados. Nove vacas mestiças Holandês x Gir foram distribuídas em um quadrado latino equilibrado 3 x 3. As vacas foram rotacionadas em três pastos a cada 14 dias. O período experimental consistiu de sete ciclos de avaliação de 42 dias cada. Análise de cluster, análise de componentes principais e regressão linear multivariada foram as técnicas estatísticas utilizadas para avaliar as características estruturais e morfológicas das plantas e o desempenho animal. O capim-Xaraés e o capim-Mombaça foram semelhantes para todas as características avaliadas (P > 0,05), enquanto o Tifton 85 foi diferente em termos de características estruturais, morfológicas e de composição química (P < 0,05). Na PCA, 59,1% da variância total foi explicada pelos componentes 1 e 2 para as características estruturais e morfológicas, e a composição química da forragem. As variáveis estruturais e morfológicas das forrageiras apresentaram melhores resultados na análise de regressão linear multivariada para a produção de leite por hectare. Características estruturais e morfológicas foram mais correlacionadas com o capim-Mombaça do que para os capins Xaraés e Tifton 85. As características estruturais e morfológicas das forragens foram o principal fator determinante da produção de leite por hectare em sistemas baseados exclusivamente à pasto com animais de baixa produção.

Made available in DSpace on 2022-05-01T09:47:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Some plant species are able to acquire non-exchangeable forms of K, which improve K availability and cycling in cropping systems, and which may explain the lack of response to K. However, this would not be expected in soils dominated by kaolinite. The aim of this study was to assess non-exchangeable K (Kne) use by three selected plant species grown in a tropical Haplic Plinthosol with low exchangeable K (Ke). A greenhouse experiment was conducted with soybean (Glycine max L., Merr.), maize (Zea mays L.), and ruzigrass (Urochloa ruziziensis) with or without K fertilization for three growing cycles. The crop treatments were compared with a control without plants. In the absence of K fertilization, all the tested plants were able to use non-exchangeable K and non-exchangeable K contributed more than 80% of the K demand of the plants in the first growing cycle, even in this kaolinitic soil. In the first growing cycle, soybean and maize took up more non-exchangeable K than ruzigrass, concomitant with higher dry matter yields. Over the three crop cycles, as both biomass yield and K uptake decreased in the unfertilized systems, the dependence of plants on non-exchangeable K decreased. Unfertilized ruzigrass showed a strong ability to acquire non-exchangeable K from the soil. Over the course of three growing cycles, K application decreased the absolute uptake of non-exchangeable K as well as its fractional contribution to total K uptake by the crops. Department Crop Science São Paulo Western University, Raposo Tavares HWY, Km 572 Department of Crop Science College of Agricultural Sciences São Paulo State University (UNESP) Department of Soil Science University of São Paulo-C.P. Agronomy Department Iowa State University National Laboratory for Agriculture and the Environment USDA Agricultural Research Service, 1015 North University Boulevard Department of Crop Science College of Agricultural Sciences São Paulo State University (UNESP)

Made available in DSpace on 2022-04-28T19:41:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Evaluating the effects of crop successions in no-tillage system (NTS) is essential for the correct recommendation of agronomic practices, such as top-dressing nitrogen fertilization. The aim was to evaluate the effect of the crop succession and the splitting of top-dressing N fertilization on the agronomic performance and economic viability of common bean crop. The experiment was conducted in southeastern Brazil for two agricultural seasons in an area under NTS, using a split-plot in randomized complete block design. The plots represented three cropping successions (maize in sole crop, maize intercropped with Urochloa ruziziensis and U. ruziziensis in sole crop) and the subplots composed of ten combinations of splitting of top-dressing N, at the stages V3, V4 and R5 of the common bean crop. In relation to the single application of the N dose of 90 kg ha-1, the common bean had higher response as a function of the N splitting schemes adopted, regardless of the previous cropping succession. The cropping successions evaluated did not interfere with the seed yield of common bean as subsequent crop, even at the beginning of the establishment of NTS. To obtain higher seed yield and economic viability, the N dose of 90 kg ha-1 indicated for the crop must be split and applied among the phenological stages V3, V4 and R5. Saõ Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences Jaboticabal Via de Acesso Prof. Paulo Donatto Castellane, km 5, s/n. 14884-900 Saõ Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences Jaboticabal Via de Acesso Prof. Paulo Donatto Castellane, km 5, s/n. 14884-900

Determining nitrogen (N) accumulation and export by common bean as a function of straw and of the splitting of this nutrient is very important, aiming at the management and sustainability of agricultural systems. This study aimed to determine the N accumulation and export by common bean as a function of Zea mays and Urochloa ruziziensis grass straw (maize, maize/U. ruziziensis intercropping and U. ruziziensis) and splitting of top-dressing N fertilization. The experiment was conducted in Jaboticabal-SP-Brazil, during the 2012/13 crop season, in a Red Eutrophic Oxisol (Eutrudox) in no-tillage under irrigation. The experimental design was a randomized block with split plots with four replicates, totaling 120 subplots sized in 25m2 each. The plots consisted of the cropping systems prior to common bean: maize, maize/ U. ruziziensis intercropping and U. ruziziensis. The subplots were composed of ten top-dressing N fertilization splitting schemes (NS) at the phenological stages V3, V4 and R5 in different combinations. Common bean grain yield differs among cropping systems and as a function of top-dressed N split application. U. ruziziensis grass as single crop promotes greater N accumulation in common bean shoots compared to maize and its intercropping with U. ruziziensis grass. Regardless the cropping system, top-dressing N application in a single dose (90 kg ha-1) at V4 leads to similar accumulations and exports to those found in the absence of N fertilization. Splitting schemes with N application at the R5 stage increase the exports of this nutrient by common bean in succession to maize and its intercropping with U. ruziziensis grass. RESUMO Determinar o acúmulo e a exportação de nitrogênio (N) pelo feijoeiro em função da palhada e do seu parcelamento é importante visando o manejo e a sustentabilidade dos sistemas agrícolas. O objetivo com esse trabalho foi determinar o acúmulo e a exportação de N pelo feijoeiro cultivado sob palhada de milho ( Zea mays) e braquiária (Urochloa ruziziensis) exclusivos ou em consórcio e em função do parcelamento da adubação nitrogenada em cobertura. O experimento foi conduzido em Jaboticabal-SP-Brasil, durante a safra 2012/13, num Latossolo Vermelho eutrófico típico, sob área irrigada no sistema plantio direto. O delineamento experimental foi em blocos ao acaso com parcelas subdivididas com quatro repetições, totalizando 120 subparcelas dimensionadas em 25m2 cada. As parcelas foram constituídas pelos sistemas de cultivo antecessores ao feijoeiro: milho, milho consorciado com braquiária e braquiária. As subparcelas foram compostas por dez parcelamentos da adubação nitrogenada de cobertura (PN) estádios fenológicos V 3, V4 e R5 em diferentes combinações. A produtividade de grãos do feijoeiro difere entre os sistemas de cultivo e em função do parcelamento do N em cobertura. O cultivo exclusivo de braquiária proporciona maiores acúmulos de N na parte aérea do feijoeiro comparado ao milho e seu consórcio com braquiária. Independentemente do sistema de cultivo, a aplicação de N em cobertura em dose única de 90 kg ha-1 em V4 (terceiro trifólio) proporciona acúmulos e exportações semelhantes àqueles na ausência da adubação nitrogenada. Os parcelamentos com aplicação de N em cobertura no estádio R5 (pré-florescimento) incrementa as exportações desse nutriente no feijoeiro em sucessão ao milho e seu consórcio com braquiária.

Made available in DSpace on 2021-06-25T12:17:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01. Added 1 bitstream(s) on 2021-07-15T14:36:09Z : No. of bitstreams: 1 S0100-204X2021000101902.pdf: 730495 bytes, checksum: bf0945a0cc78ec0022b357a0f39a9017 (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundacao de Amparo a Pesquisa do Estado de Goias (Fapeg) Fundacao de Amparo a Pesquisa e ao Desenvolvimento Cientifico e Tecnologico do Maranhao (Fapema) Biotechnology and Biological Sciences Research Council Nucleus: a virtual joint center to deliver enhanced nitrogen use efficiency via an integrated soil-plant systems approach for the UK and Brazil The objective of this work was to evaluate the economic viability and competitiveness of upland rice (Oryza sativa), compared with flooded rice, in a system with different nitrogen fertilization timing and cover crops in Southeastern Brazil. The treatments consisted of upland rice grown under Urochloa brizantha or Urochloa ruziziensis straw, with the following fertilization: T, 30 kg ha(-1) N at rice sowing + no extra N supply (0 kg ha(-1)); C, 30 kg ha(-1) N at rice sowing + 90 kg ha(-1) N at rice tillering; A2, 30 kg ha(-1) N at rice sowing + 90 kg ha(-1) N one day before rice sowing; and A1, 30 kg ha(-1) N at rice sowing + 90 kg ha(-1) N in the living cover crops. Total operating cost, gross revenue, operating profit, profitability index, and equilibrium price were determined. Upland rice results in a monetary gain for the farmer similar to that of flooded rice when nitrogen is added, regardless of fertilization timing. Under rainfall deficit conditions, upland rice sown on U. brizantha straw shows higher profitability rates than when sown on U. ruziziensis. When there is a possibility of rainfall deficit, U. brizantha, as a cover plant, results in a greater economic security for upland rice producers. Univ Estadual Paulista, Fac Ciencias Agron, Ave Univ 3-780, BR-18610034 Botucatu, SP, Brazil Embrapa Arroz & Feijao, Rodovia GO-462,Km 12,Caixa Postal 179, BR-75375000 Santo Antanio De Goias, Go, Brazil Univ Estadual Paulista, Fac Ciencias Agron, Ave Univ 3-780, BR-18610034 Botucatu, SP, Brazil FAPESP: 2015/503058 FAPESP: 2016/12317-17 FAPESP: 2017/10226-7 Fundacao de Amparo a Pesquisa do Estado de Goias (Fapeg): 2015-10267001479 Fundacao de Amparo a Pesquisa e ao Desenvolvimento Cientifico e Tecnologico do Maranhao (Fapema): RCUK-02771/16 Biotechnology and Biological Sciences Research Council: BB/N013201/1

Made available in DSpace on 2022-04-29T08:33:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 The crop succession and nitrogen splitting fertilization are managements that can affect the common bean technological quality and, consequently, the profitability of producer and the food biological value. The aim of this study was to evaluate whether crop succession and N splitting fertilization promote differences in the technological quality of common bean grains. The experiment was carried out during winter over two agricultural years in southeastern Brazil. A randomized block design was used in a split-plot scheme, with four replications. The plots were composed of three crop successional systems (maize sole, maize + Urochloa ruziziensis, U. ruziziensis sole) and the subplots contained nine combinations of N splitting fertilization at a rate of 90 kg·ha-1 N top-dressing in the phenological stages V3, V4, and R5 of the common bean and a control without fertilization. The evaluated variables were: sieve yield greater than or equal to 12 (SY ≥ 12), crude protein content, cooking time, and hydration ratio. Crop succession promotes differences in the technological quality of common bean; however, the N splitting fertilization did not change the technological attributes of grains. The highest technological quality of common bean was obtained after succession with U. ruziziensis sole, generating large size and crude protein content of grain, followed by the succession with maize + U. ruziziensis intercropping, and finally, the succession with maize sole. Therefore, the crop succession is a fundamental factor for obtaining common bean with higher technological quality, affecting the food biological value and the profitability of producers. Universidade Estadual Paulista “Júlio de Mesquita Filho” Faculdade de Ciências Agrárias e Veterinárias Departamento de Ciências da Produção Agrícola Universidade Estadual Paulista “Júlio de Mesquita Filho” Faculdade de Ciências Agrárias e Veterinárias Departamento de Engenharia e Ciências Exatas Universidade Estadual Paulista “Júlio de Mesquita Filho” Faculdade de Ciências Agrárias e Veterinárias Departamento de Ciências da Produção Agrícola Universidade Estadual Paulista “Júlio de Mesquita Filho” Faculdade de Ciências Agrárias e Veterinárias Departamento de Engenharia e Ciências Exatas