Comunicata Scientiae

Comunicata Scientiae: a horticulture journal

2019-08-25T15:00:18+00:00

Comunicata Scientiae is a scientific journal created at the Campus "Prof.a Cinobelina Elvas" of the Federal University of Piauí in 2009, which had the first issue published in 2010.
Initially, the journal aimed to disseminate the knowledge generated by the scientific community through the publication of research results and new scientific proposals unpublished and relevant to the Agrarian and Environmental Sciences. With this proposal, the journal had a significant growth in the proposed knowledge areas (Agrarian and Environmental Sciences) and it was indexed in the main databases of the world as SCOPUS (Elsevier), obtaining SJR already in 2011 of 0,187, a value that is currently 0.372, which includes it in the second best category of SCOPUS, the Q2...

Extracts of Tagetes minuta L. front of bacteria regarding bovine mastitis

2019-08-25T15:00:23+00:00

Bovine mastitis is a problem in the context of animal health. However medicinal plants are a management strategy in agroecological production systems. In this context, the plant Tagetes minuta L. plays a leading role, due to its recognition in the popular pharmacopeia. Thus, the objective of this work was to assess the effect of hydroalcoholic extracts of T. minuta from different collection sites compared to ten bacteria related to bovine mastitis. The antimicrobial evaluation was done through the microdilution technique in syrup, in 96 well microplates in triplicate, for the determination of Minimal Bacterial Concentration (MBC) (%). In the microplates, the extracts of T. minuta and the inoculums of the bacteria were placed in addition to the growth control of the bacteria and the control of the extracts, which were incubated for 72 hours at 37°C in an oven. After this time, aliquots of 5μL of each orifice were transferred to plates containing 5% equine defibrinated blood agar and maintained in incubation for 24 hours at the same previous temperature. With this, the growth readings were performed, with the subsequent interpretation of the results by the geometric mean of the MBC (%). The results indicate that there is a difference in sensitivity to microorganisms by the extracts as a function of the collection sites and both present antimicrobial action.

Morphological characterization of vaginal epithelial cells of santa inês ewes subjected to estrus synchronization

2019-08-25T15:00:23+00:00

Vaginal cytology analysis has been used to evaluate the different stages of estrous cycle of several species; it presents a direct correlation with the animal’s hormonal state and provides essential information about the female reproductive tract conditions. Two staining methods were tested to evaluate the vaginal epithelial cell morphology of nulliparous and multiparous ewes during the estrus period. An intravaginal device impregnated with medroxyprogesterone acetate was kept into 10 nulliparous and 10 multiparous ewes for 14 days for estrus synchronization. Then, the progesterone device was withdrawn, and 300 IU of eCG was administered intramuscularly. Vaginal smears were prepared for posterior staining with Panotico or Giemsa stains when estrus was detected. The cells were classified into nucleated superficial, anucleate superficial, intermediate, parabasal, and basal. The Panotico and Giemsa staining of the different cell types studied were satisfactory. A predominance of intermediate epithelial cells (p<0.05) was found after staining. No difference in percentages of the different types of vaginal epithelial cells between nulliparous and multiparous ewes were found. Therefore, both staining methods were efficient, and a predominance of intermediate cells is found in nulliparous and multiparous ewes during the estrus period.

Entomofauna diversity in areas of Caatinga under forest management in the semi-arid region of Ceará

2019-08-25T15:00:23+00:00

The Caatinga is characterised by deciduous plant species. The practice in this ecosystem is the production of firewood which, when carried out with no technical criteria, contributes to a reduction in the biodiversity and degradation of the biome. Forest Management Planning has been approved by the Ministry of the Environment; a lower impact on the environment is expected, as there is still little information on the effect on biodiversity. The aim of this study was to evaluate the diversity of soil fauna in areas that adopt a Forest Management Plan. Five areas were selected that adopt Forest Management Planning: Area T1, unexploited for six months; Area T2, unexploited for 2-3 years; Area T3 unexploited for 5-6 years; Area T4, unexploited for 10-11 years; and the Control Area (unexploited). Four pitfall traps were installed in each area. The Shannon-Weaver (H’) Index, the Pielou Uniformity Index (e) and the Species Richness Index were calculated for the purpose of estimating the existing biodiversity. Total richness varied from 7 to 14 groups for the different collection periods and between the treatments; the highest value for the Shannon Index (0.72) was found during the dry/rainy transition period in the area that had been exploited 5-6 years earlier. The number of specimens is influenced by the various stages of wood exploitation.

Multilevel modelling of the draft force required by seeder-fertilizers

2019-08-25T15:00:23+00:00

The high production costs in agriculture have guiding the adoption of farming systems and new management techniques as well as the sizing of agricultural machinery. In this regard, planning entails knowledge on the efficiency according to the energy requirements parameters, so the farmer shall consider the characteristics of the soil on which the implement operates. The performance assessment of sowing-fertilize machines shows the effect of some variables on the draft requirement, so the experimental conditions, which might lead to different outcomes of implement operation, must be regarded. Therefore, it is necessary obtain metanalytical estimates to integrate the results available in the literature. Grounded on systematic review, this study aimed to model the draft imposed by sowing-fertilizing machines considering fixed effects, mainly soil characteristics, and random effects associated to the selected experiments. It was found that the best models according to information criteria may not always meet the assumptions as normality of the distribution of residuals and homoscedasticity. The variables such as bulk density of soil, stubble conditions, depth of fertilizer placement, and speed could accurately explain the draft requirement with mean squared deviation of 2.93 whereas the referred evaluator for the ASABE standard was 63.51. Forthcoming works may analyze the repeatability of the models considering different seeders under diverse configurations and operation conditions

Drip irrigation system powered by photovoltaic panels

2019-08-25T15:00:22+00:00

The objective of this work was to evaluate the performance of a drip irrigation system with photovoltaic energy without the use of energy storage system. The experiment was conducted at the State University of the West Parana - UNIOESTE, Campus of Cascavel, in the laboratory CASA project, during six days, analyzing the coefficients of uniformity of Christiansen (CUC), coefficient of uniformity of distribution (CUD) for measurement of 16 drippers by sector (Keller method) and later the coefficient of variation (CV). In the energy part, the irradiance and the current generated by the panel were analyzed. The irrigation set was also classified according to the ASABE standard. The statistical quality control of the system was also performed in order to evaluate the quality of the set considered, with the means being compared by the Tukey test at 5%. The coefficients of each treatment reached an excellent level according to their classifications. The main results allowed to evaluate that the flow control by dripper showed a significant effect for the factors analyzed. The system obtained excellent processability according to the analyzes of distribution uniformities. It was also concluded that there was a significant relationship between the coefficients (CUC, CUD and CV) with the process capacity of the flow data.

Evaporative cooling efficiency of pads consisting of vegetable loofah

2019-08-25T15:00:22+00:00

Brazilian agroindustry has presented constant innovations in the use of equipment and materials, among which are those that generate artificial thermal conditioning inside the zootechnical facilities, through a direct evaporative cooling system (DEC). In order to mitigate the effects of high temperatures associated with low air humidity in buildings in the northeastern region of Brazil, the use of DEC systems is evident. Therefore, DEC’s built with evaporative pads constituted of alternative materials, prove to be an interesting and viable alternative. The aim of this work was to evaluate the cooling efficiency of the evaporative pads constituted of vegetable loofah. The experiment was performed at the Campus de Ciências Agrárias, Federal University of the São Francisco Valley (UNIVASF) in Petrolina, Pernambuco state. The experimental design was in randomized blocks, in a 4x4 factorial scheme, with 13 replicates. Air temperature and relative humidity values were collected before and after the passage through the pad for different flow velocities and pad thicknesses, in order to calculate the evaporative efficiency. The variance analysis was significant at 5% probability for the sources of variation of the pad thickness (0.05, 0.075, 0.1 and 0.125 m) and the air flow rate (0.076, 0.264, 0.459 and 0.773 m s-1), and the interactions. The highest efficiency, 57.0% was observed for the interaction between the thickness of 0.125 m and the speed of 0.773 ms-1 as adjusted model.

Neem relative growth under supplementary irrigation with saline waters and biofertilizer

2019-08-25T15:00:22+00:00

An experiment was performed, during the period from January to July, 2016, in a screened environment of the Department of Soils and Rural Engineering of the Agrarian Sciences Center, Federal University of Paraiba (UFPB), Areia, Paraiba, Brazil, with the purpose of evaluating the effects of supplementary irrigation with saline waters over the relative growth of Indian neem seedlings, in soil with bovine biofertilizer. The substrate used was a dystrophic Yellow-Red Latosol. The experimental design was in randomized blocks, with four replications, in a 5x2x3 factorial scheme, referring to the water salinity levels of 0.5, 1.5, 3.0, 4.5 and 6.0 dS m-1, in soils without and with bovine biofertilizer, and in three evaluation periods: at 90, 120 and 180 days after emergence of the seedlings, in order to evaluate the relative growth rate of the studied morphological parameters, evaluated by the relation of the periods from 90 to 120 and 120 to 180 DAE of the plants in height, stem diameter, root dry matter, dry matter of the aerial part and total (root + aerial part) dry matter. The growth of the neem seedlings was compromised by the degenerative action of the salts of the irrigation water, but with lower severity in those plants of the treatments with the bovine biofertilizer.

Morphological characterization and germination of Syagrus schizophylla (Mart.) Glass. (ARECACEAE)

2019-08-25T15:00:22+00:00

The interest in Syagrus schizophylla as an ornamental palm tree and the demand for conservation and preservation of the species led to this research. The objective was to study the physiological characteristics of its germination at different temperatures, as well as the morphological and biometrical characterization of diaspores and seedlings at the initial stages of growth and development. The research was divided into two experiments. In the first one, the aim was to identify the water absorption phases of seeds during germination under five scarification treatments as follows: intact diaspores, scarified diaspores, diaspores with endocarp rupture and intact seeds. In the second experiment, germination was tested at 25, 30 e 25 - 35 ºC; the first germination count, seedling emergence, abnormal seedlings, non-germinated seeds, the emergence curve, the emergence speed index and the mean time of emergence were evaluated. Afterwards, the morphological and biometrical characteristics of diaspores and seedlings were described. The water absorption curve observed under the different scarification treatments showed different water absorption patterns. Emergence percentages were 53, 61 and 47% at 25, 30 and 25 - 35 ºC, respectively. The highest emergence speed index was obtained at 30 ºC. The mean time of emergence was 30 days, approximately, under all the temperatures tested. The diaspores showed a great variability in both shape and size, presenting a globular to ovoid shape with an average length of 2.44 cm and an average width of 1.39 cm. The germination can be classified as hypogeal crypto cotyledonal of the remote-tubular type.

Anaerobic biodegradation of cassava wastewater under different temperatures and inoculums

2019-08-25T15:00:22+00:00

The production of starch generates, as a by-product, the cassava wastewater (manipueira), which can be treated by anaerobic digestion to provide biogas and minimize its polluting potential. The most commonly utilized biomass in the anaerobic digestion is the anaerobic sludge. The literature presents, as an alternative to sludge, bovine manure and ruminal fluids, being scarce the studies with the cassava wastewater. This research evaluated the influence of temperature on the microbial ability of cattle and goat rumen in anaerobically biodegrading the manipueira in substitution to the anaerobic sludge. The cattle and goat rumen specific methanogenic activities (SMA) were compared with that of the anaerobic sludge. Subsequently, by using the inoculum which had the best SMA results, cassava wastewater biodegradability tests were performed, investigating the kinetics of the organic matter removal and methane production at 32 ° C and 39 ° C. The bovine rumen presented better results in the SMA (0,315 g COD-CH4 g VSS.d-1) and methane production (1,026 mL). The temperature of 32 °C did not influence the activity of bovine ruminal inoculum as the kinetics of the biodegradation of the manipueira did not differ for the evaluated temperatures (0.1799 d-1 at 32°C and 0.1781 d-1 at 39°C). Bovine rumen achieved glucose reduction of 76% and 80% and methane yield of 77% and 79% for the tests at 32°C and 39°C, respectively. It is inferred that this type of inoculum might be used in reactors of anaerobic digestion processes for the treatment of the cassava wastewater at the ambient temperature of the semiarid region.

Chemical characteristics of soil cultivated with vine and submitted to nitrogen and organic fertilization at the semiarid of the Rio Grande do Norte State, Brazil

2019-08-25T15:00:21+00:00

A probable reason for the scarce levels of N in the soils of the semi-arid regions would be the low levels of organic matter in these soils. In this way, the aim of the present study was to evaluate the effects of nitrogen and organic fertilization and their interaction on chemical properties of soils cultivated with ‘Isabel Precoce’ vines in the semiarid oh the Rio Grande do Norte State, Brazil. The experiment was carried out at the Experimental Farm of the Federal Rural University of the Semi-arid Region, in Mossoró, RN. The soil in the area is classified as a Distrofic Red Argisol with sandy texture. The research was carried out in two cycles of grape production. The experiment was accomplish in a randomized blocks design, with six repetitions, in a 5 x 2 factorial scheme, corresponding to 5 doses of nitrogen fertilization (0, 30, 60, 90 and 120 kg ha-1), in the absence and presence of organic fertilization 0 and 20 m3 ha-1, bovine manure). Samples of the 0-20 cm layer were collected for the evaluation of macro and micronutrient contents, pH, electric condutivity, organic matter and sum of bases. The N and organic fertilization doses influenced the chemical atributes evaluated. The interaction between nitrogen and organic fertilizer resulted in an increase in nutrient, organic matter and sum of bases content. N doses were responsible for reducing pH levels, resulting in higher amounts of nutrients availability.

Mapping of the current land use in part of the Irrigated Perimeter Nilo Coelho, Petrolina-PE, Brazil

2019-08-25T15:00:21+00:00

The objective of this study was to quantify and spatialize the agricultural composition and current land use in part of the Irrigation perimeter Nilo Coelho from the Landsat 8 satellite digital image classification. At first we performed the unsupervised classification image related to January 2014, identifying the separability within natural vegetation, water bodies, agricultural crops and anthropized areas. Then the supervised classification Maxver model was performed where it was observed that the fruit classes “Grape” (5.41%) “Acerola” (3.75%), “Coconut” (6.14%) “Guava” (6.17%), “Banana” (2.29%) and “Mango” (8.18%) showed dominance in the study area. These classes stood out in terms of yield in the area, pointing out that in that expansion which occurs in an area with agricultural crops in the irrigated Nilo Coelho, crops of mango, coco, guava, acerola, banana and grape also grow. In addition, we observed the emergence of new areas with passion fruit crops, melon, watermelon, corn, beans, onions, pumpkin, sweet potatoes, tomatoes, bell peppers, among other crops. Furthermore, we also found the occurrence of pastures containing buffel and elephant grasses, intercropping or not. The estimated overall accuracy was 80.52%, and the mapping defined as very good, with Kappa index equal to 0.7783.

Sediment Losses in Watersheds in the Western-Center Meso-Region Rio-grandense

2019-08-25T15:00:21+00:00

The permanent monitoring of sediment losses in small-paired watersheds is still incipient, especially in what concerns the search for information that combines variables that are part of an open and dynamic system. In this sense, this work investigated sediment losses in watersheds in the Western Meso-region Rio-grandense from 07/2010 to 12/2012. The auxiliary variables were composed of rainfall, surface and base flow and kinetic energy – in comparison to the morphometry of each microbasin and its use – to the concentration of suspended sediments and total sediment loss. Statistical analysis of the data was based on descriptive statistics, taking into account the indicators of cumulative, average, standard deviation, standard error and variance, as well as regression analysis. The largest mild to smooth corrugate relief area of the smallest river basins is not sufficient to provide lower superficial runoff values. The increase in rainfall directly contributes to the increase in kinetic energy, and leads to greater sediment losses in both small hydrographic basins. The larger area occupied by natural water reservoirs contributes efficiently to the reduction of suspended sediment losses. The watershed with larger area is more susceptible to the triggering of erosive processes than to the smaller area, in 8 (2010), 6 (2011) and 4 (2012) times.

Growth and flowering of colored cotton cultivated in soils of distincts ESP and sheep manure

2019-08-25T15:00:21+00:00

The inadequate management of irrigation has promoted the increase in the area of degraded soils through salinization and/or sodification, especially in irrigated perimeters of the northeastern semiarid, promoting environmental impacts and decrease in crop yield. In this manner, studies that aim to evaluate the tolerance of crops to salts, and/or techniques that minimize the deleterious effects of salt stress are highly viable. Based on this, the present study aimed to evaluate the influence of sheep manure doses over growth and flowering of the colored cotton cv. BRS Topázio, cultivated in soils with different exchangeable sodium percentages. A randomized block design was adopted, in a 5 x 4 factorial scheme, corresponding to the treatments of five exchangeable sodium percentages – ESP: 8.84, 12.55, 18.80, 28.80 and 38.80% and four sheep manure doses: 0, 5, 10 and 15% based on the volume of the soil, with 3 replications. At 90 days after sowing, it could be verified that the increment in the sheep manure doses added to the soil mitigated the negative effect of the ESP over the production of flower buds, beside stimulating plant growth, flower production and reducing the rate of flower abortion, independently of the ESP. The cotton cv. BRS Topázio is tolerant to soil ESP up to 38.8%, and anthesis is anticipated by the increase in exchangeable sodium.

Characteristics of 137 macaw palm (Acrocomia aculeata) fruit accessions from Goias, Brazil

2019-08-25T15:00:20+00:00

Accessions of macaw palm fruits from the State of Goias, Brazil were characterized aiming the identification of groups with similar characteristics and indicate groups with higher agronomic potential, using multivariate tools. Fruit were harvested with completed yellow fruit bunches without whitish scores. The evaluated variables were fruit and almond length, fruit and almond diameters, fruit and dehydrated almond weight, average number of almonds, oil percentage of almond and dried fruit. The genetic diversity of populations was evaluated by Ward’s clustering method and Person´s correlation was obtained to evaluate the relative importance of each characteristic and variance analysis associated with Tukey´s test to verify the group’s effects. The studied population demonstrated great variability. The characteristics that most contributed to the variability were fruit weight and diameter and the almond´s oil percentage. Ward´s group analysis revealed six groups of similarity, being significant for all evaluated characteristics. Group VI stood out for all evaluated characteristics and group III presented the best averages for the almond´s weight and almonds and dried fruit oil percentage.

Carbohydrate content and season collection of cuttings from ‘Roxo de Valinhos’ fig tree

2019-08-25T15:00:20+00:00

Choosing the best season collection of cuttings is essential to have success with propagation, due mainly to carbohydrate content, since is a source of energy for roots and shoots development. In literature, there are no papers that associate the collection season of cuttings with carbohydrate contents in figs. Therefore, the current study aimed to evaluate carbohydrate contents and season collection of cuttings to propagate ‘Roxo de Valinhos’ fig tree. The experiment was conducted in a greenhouse; cuttings were collected in the first week of the following months: June, July, August and September. The design was in completely randomized blocks, with four replicates of 30 cuttings collected per season. The following traits were evaluated: carbohydrate content; percentage of root cuttings, bud cuttings, cuttings without bud and root; number of buds, leaves and roots per cutting; length of the largest root and bud; bud diameter; bud and root dry mass; and root volume. Results indicated high carbohydrate content in cuttings that were collected in August; therefore, the best month to collect cuttings of ‘Roxo de Valinhos’ fig tree in the city of São Manuel, state of São Paulo. This result is due to high percentage of rooted cuttings and better development. Furthermore, carbohydrate content mainly affects root growth; besides that, reducing sugars are the most important feature in the development of cuttings.

Watermelon general and specific combining ability

2019-08-25T15:00:20+00:00

The combining ability of six watermelon genotypes was estimated in a diallel cross scheme (6x6), including genotypes JNY (1), ‘ORA’ (2), ‘KOD’ (3), ‘SOL’ (4), ‘CHG’ (5), ‘PEA’ (6) and all possible hybrids between them. A randomized complete block design (RCB) was used, with 36 treatments, three blocks, and plots with five plants. The following traits were evaluated: days before female flower anthesis, main branch length, fruit mass, number of fruits per plant, yield, fruit length, fruit width, pulp firmness, soluble solids content, average rind thickness, seed length, seed width, and seed mass. The data obtained were submitted to analysis of variance, and a diallel analysis was performed according to Griffing’s experimental method I. According to the general combining ability estimates obtained, genotypes ‘KOD’ (3) and ‘JNY’ (1) were the most likely ones to produce hybrids with smaller-sized fruits and smaller seeds. The reciprocal effects confirmed that the results indicate that these genotypes should be used as pollen donors and pollen recipients, respectively. On the other hand, genotypes ‘ORA’ (2) and ‘CHG’ (5) can be used for the commercial exploitation of sliced watermelons. According to the specific combining ability estimates obtained, the combinations ‘ORA’ (2) x ‘PEA’ (6), ‘ORA’ (2) x ‘JNY’ (1), ‘CHG’ (5) x ‘KOD’ (3), ‘PEA’ (6) x ‘KOD’ (3), and ‘CHG’ (5) x ‘SOL’ (4) stood out as being the genotypes most likely to produce the smallest fruits and smallest seeds.

Yield, quality and nutrient accumulation in watermelon as a function of organo-mineral fertilization

2019-08-25T15:00:20+00:00

The study aimed to assess the yield, nutrients accumulation and fruit quality of watermelon grown under different NPK rates provided by mineral and organic fertilizers. The experiment was performed at the Federal University of Campina Grande (UFCG), Campus Pombal-PB, during the period from June to September 2013. Treatments consisted of three nutrient concentrations N, P and K (50, 100 and 150% of NPK recommendation for watermelon) and five ratios of mineral and organic fertilizer (100/0, 75/25, 50/50, 25 / 75 to 0/100). The experimental design was in randomized blocks, in a 3x5 factorial scheme with four replicates. The NPK rate corresponding to 100% was 120 kg ha-1 respectively for N, P and K. The following variables were evaluated: fruit yield, nutrient accumulation, titratable acidity, soluble solids and ratio between soluble solids and titratable acidity. The concentration of 150% of nutrients was more effective in increasing the yield for the 75/25, 25/75 and 0/100 ratios of mineral and organic fertilizers, and the concentrations of 100 and 150% were the most effective in the accumulation of soluble solids when applied in the mineral and organic fertilizer ratios of 75/25 and 50/50.

Bromatological characteristics of the cowpea in the resistance to Callosobruchus maculatus

2019-08-25T15:00:20+00:00

This work aimed to relate the bromatological characteristics of four cowpea cultivars to the preference and development of Callosobruchus maculatus. For this, oviposition preference, choice and no-choice tests were performed in four cowpea genotypes: Bico de Ouro, BRS Novaera, BRS Guariba and BRS Tumucumaque. In the no-choice test were determined: viability of eggs, duration of the immature stage, biological cycle, viability of the immature stage, population growth rate, weight per insect, biomass consumption and consumption per insect. As to the chemical composition, the seeds were characterized concerning the crude protein content, ash, neutral detergent fiber, acid detergent fiber and organic matter. In the evaluation, there were significant differences within the genotypes, except for the viability of eggs and consumption per insect. The BRS Novaera genotype presented antixenosis resistance to C. maculatus, whereas the Bico de Ouro, BRS Guariba and BRS Tumucumaque genotypes revealed to be susceptible. The chemical composition of the seeds affects the development of C. maculatus, and the crude protein and ash contents of the seeds without integument present a positive influence over the insect development.

Application of controlled-release nitrogen fertilizer in irrigated common bean crops

2019-08-25T15:00:19+00:00

The use of adequate management practices and high nitrogen fertilizer rates have contributed to increase the common bean grain yield, however, the application of nitrogen fertilizer at sowing still requires evaluations for irrigated crops in the Brazilian Cerrado biome region. Thus, the objective of this work was to evaluate the effect of application of different rates of controlled-release nitrogen fertilizer—dimethylpyrazole phosphate (DMPP)—at sowing and as top-dressing on agronomic performance and leaf area index of irrigated common bean crops grown in the Brazilian Cerrado biome region. A randomized block design in a 4×3 factorial arrangement with four replications was used. The treatments consisted of four nitrogen rates (0, 60, 120, and 180 kg ha-1) and three application forms (100% at sowing, 100% as top-dressing, and 50% at sowing + 50% as top-dressing). Irrigation was managed with class A tanks and two-day intervals. The nitrogen applied at the different stages of the crop did not affect the production components of the common bean plants. The highest grain yields were found with the nitrogen rates of 180 kg ha-1 in 2015 (1,756.37 kg ha-1), and 123.98 kg ha-1 in 2016 (1,799.63 kg ha-1).

Correlations and path analysis in soybean progenies with resistance source to cyst nematode (race 3)

2019-08-25T15:00:19+00:00

Path analysis is an important study that slices the correlation coefficients between two variables to evaluate whether the relationship between them is of cause and effect. This study aimed to estimate the phenotypic and genotypic correlations between agronomic traits and perform a path analysis in order to identify variables for indirect selection aiming at a higher grain yield. Fourteen soybean F6 lines from the soybean breeding program of FCAV–UNESP, Jaboticabal, São Paulo, Brazil, were analyzed. The experimental design was a randomized block design with three replications. The agronomic traits plant height at maturity (PHM), first pod height (FPH), lodging (Ld), agronomic value (AV), number of pods per plant (NP), number of seeds per plant (NS), and grain yield (GY) were evaluated. Overall, the genotypic correlations were higher than their corresponding phenotypic correlations. The genotypic correlations between grain yield and the traits agronomic value, number of pods per plant, and number of seeds per plant were positive, significant, and of high magnitude. Path analysis showed that the trait number of seeds per plant had the highest direct effect on grain yield, while the trait number of pods per plant had the highest indirect effect through the number of seeds per plant on grain yield

Seed priming with sodium nitroprusside attenuates the effects of water deficit on soybean seedlings

2019-08-25T15:00:19+00:00

Considering that water deficit is one of the main environmental factors responsible for low soybean yield and that nitric oxide (NO) has been shown to be a fundamental part of plant defense signaling during stress, the aim of the present study was to evaluate the effect of seed priming with nitric oxide on the induction of water deficit tolerance during the initial development of soybean. Thus, seeds were treated with 0 (water only), 50, 100 or 250 μmol.L-1 sodium nitroprusside for 6 hours. Additionally, untreated seeds were used. After drying, the seeds were placed in containers filled with a commercial substrate mixture and vermiculite and irrigated to 100% and 50% field capacity. Biometric and biochemical evaluations (pigment and proline contents) were performed after 14 days. It was concluded that pretreatment of soybean seeds with 50 to 250 μmol.L-1 SNP attenuated the effects of water deficit on stem growth, leaf area, and shoot dry matter and induced carotenoid biosynthesis. The accumulation of proline in the leaves was pronounced in the treatments with 100 and 250 μmol.L-1 SNP, while 100 μmol.L-1 SNP induced proline accumulation in the roots.

Treatment of soybean seeds with molybdenum and inoculant: nitrate reductase activity and agronomic performance

2019-08-25T15:00:19+00:00

The aim of this study was to analyze the effects of molybdenum and inoculant application via seed treatment in soybean, and their role in the nitrate reductase enzyme activity, agronomic traits and physiological quality of the produced seeds. The experiment was conducted at the Federal University of Pelotas (UFPel), Rio Grande do Sul state, Brazil. The treatments were shaped by five doses of molybdenum (zero; 16; 32; 48; 64 g.100kg-1 of seeds) combined with the presence and absence of liquid inoculant (Bradyrhizobium japonicum), at a dose of 200 mL per 100 kg of seeds. The evaluations of nitrate reductase activity, agronomic traits and physiological seed quality were performed in the present work. The measured agronomic traits were: plant height, number of pods per plant, number of seed per plant and thousand-seed weight. Standard germination test was executed to evaluate the produced seed viability. First germination counting, accelerated aging test, cold test, plantlet shoot and root length, plantlet shoot and root dry mass, and field seedling emergence were utilized to measure the seed vigour. Molybdenum, both in presence and absence of inoculant, positively influenced the enzymatic activity, for both vegetative and reproductive stages. The addition of inoculant and molybdenum provided increase in the vigour of the produced seeds. The enzyme activity was positively correlated with the agronomic traits and vigour tests. The addition of inoculant and molybdenum in the seed treatment provides a better expression of nitrate reductase activity and vigour of the produced seeds.

Chemical-bromatological characteristics of forage sorghum varieties irrigated with saline effluents from fish farming

2019-08-25T15:00:19+00:00

The objective of this work was to evaluate the chemical and bromatological characteristics of forage sorghum varieties subjected to different leaching fractions of saline effluents from fish farming in the Semiarid region of Brazil. The experiment was conducted in a randomized block design, in a 3×4 factorial arrangement with four replications, consisting of three forage sorghum varieties (Volumax, F305, and Sudão) and four leaching fractions (0%, 5%, 10%, and 15%) of saline (electrical conductivity of 2.5 dS m-1) effluent from fish farming. The organic matter, dry matter, mineral matter, crude protein, neutral detergent fiber (NDF), acid detergent fiber, lignin, hemicellulose, and cellulose contents of the plants were evaluated. The crude protein contents of the plant components, and mineral matter content of leaves and panicles increased, and the NDF of leaves decreased in treatments with the highest leaching fractions. The F305 variety presented better chemical-bromatological characteristics compared to the other sorghum varieties evaluated.

Quantitative and qualitative analysis of sugarcane productivity in function of air temperature and water stress

2019-08-25T15:00:18+00:00

Climate variables can influence the both productivity and quality of the commercial product of sugarcane crop. This study aimed to evaluate the influence of thermal time, negative degree-days and water deficit on productivity and industrial quality of sugarcane for the Goiás Brazilian Savanna region. The data of productivity and industrial quality were obtained in the field (Plant Centro Álcool®) and climate data in the weather station. Thermal time and the accumulation of negative degree-days in cycles showed significant correlations with the yield. The highest (340 mm) and the lowest (158 mm) accumulated water deficit blade not reflected in lower productivity and greater, respectively. Relative evapotranspiration (rET) was equal at 1.0 in more than 50% of the studied period, in which not were found significant correlations between the rET<1 with the productivity and industrial quality. We found significant correlations between rates of degree-days and negative degree-days with productivity rates; however, there was a low correlation between the water deficit rates and productivity. The total recoverable sugars rates and total soluble solids showed maximum accumulation point only in function of degree-day rates. We conclude that the thermal time has greater influence on yield decrease of sugarcane with different harvest cycles, significantly contributing to the accumulation of sugars in the stem.

Changes in temperature of a Plinthosol cultivated with sugarcane under straw levels

2019-08-25T15:00:18+00:00

Soil temperature is affected by its coverage and influences sugarcane productivity. Changes in temperature were assessed in a Plinthosol cultivated with sugarcane under different straw levels, as well as its reflection in stalk productivity, aiming at determining the maximum amount of straw to be removed for other purposes without damaging soil thermal conditions necessary for the crop. The experimental design was a split-plot randomized block design with four replications, with assessment periods of soil temperature arranged in the main plots, straw levels (0, 4.2, 9.5, 13.0, and 18.4 Mg ha−1) arranged in the subplots, and two measuring depths of soil temperature (0.05 and 0.10 m) arranged in the sub-subplots. Soil temperature was obtained by T-type thermocouples (copper/constantan). Soil thermal amplitude underwent oscillations as a function of straw levels, especially at a depth of 0.05 m. The maintenance of 9.5 Mg ha−1 of straw provided an increase of 11.1% in stalk productivity. Values above 9.5 Mg ha−1 of straw can be removed from the field for other purposes without impairing soil thermal conditions required for the crop.

Trichoderma asperellum efficiency in soybean yield components

2019-08-25T15:00:18+00:00