Repositório RCAAP

One of the main stages in the production system of a crop is the production of quality seedlings since it influences the plants' final performance in the field and their production. The study aimed to evaluate different nutrient solutions in the production of Cambuci pepper seedlings. The design used was a complete randomized design, with six treatments corresponding to the nutrient solutions proposed for the pepper crop by Castellane and Araújo, Claudio Roberto, Hoagland, and Arnon, besides the commercial products Plenan® and Biobokashi®, and a control treatment without fertilization, with six replications. The final evaluation was carried out 45 days after sowing. The following variables were analyzed: stem diameter, plant height, leaf dry matter, shoot dry matter, the number of leaves, relative chlorophyll index ("Spad"), and Dickson quality index. The seedlings subjected to the applications of Claudio Roberto and Hoagland and Arnon solutions have the highest heights and number of leaves, the largest stem diameter, shoot dry matter, leaf area, and Dickson quality index with 2.60 and 2.51 mm, 0.54 and 0.62 g, 38.64 and 41.91 cm2, and 0.107; 0.097, respectively. The Hoagland and Arnon nutrient solution provided the best characteristics to produce Cambuci pepper seedlings.

Precision poultry farming is related to effective monitoring of production stages and product quality. This work evaluated the influence of temperature, air humidity, and luminosity variables on chicken egg production and quality (internal and external), under uncontrolled environment and natural lighting, using precision poultry techniques. One hundred and sixty birds of Embrapa 51 line, reared in cages, were assessed with 24, 30, 50, and 70 weeks of life. Values of temperature, relative humidity, luminosity, and the samples for productivity and egg quality determination were collected in predefined locations in a poultry house belonging to IFMS, Nova Andradina/MS Campus. Spatial maps were generated using the inverse distance weighted interpolation (IDW). Environmental variables show significant correlations with production and internal/external quality parameters of chicken egg raised in uncontrolled environments. The use of spatial maps for environmental characteristics of the poultry house, production, and internal/external chicken egg quality provides better visualization of the variations and correlations among the investigated variables, assisting the process of decision-making related to appropriate management and optimization of the poultry house.

This study aimed to evaluate the decomposition and release of nutrients from the remaining straw of two annual forage species conducted in an integrated crop-livestock system (ICLS). The experimental design used was randomized blocks, in split plots, with three replicates. The managements were allocated in the plots (52 m2): without grazing, one grazing, and two grazings. Subplots were defined by material collection times after the forage’s desiccation (0, 30, 60, 90, and 120 days after desiccation). Dry matter yield, amounts of carbon, nitrogen, phosphorus, and potassium, and half-life time were evaluated. Oat cultivar IPR Esmeralda had the highest initial dry matter yield (6,099 kg ha-1) when not grazed, while triticale cultivar IPR 111 showed the highest average values when subjected to grazing (8,088 kg ha-1). The amounts of N, P, and K released from the remaining dry matter, regardless of the management adopted, decreased over time. Potassium was the nutrient that presented the most accelerated release, with an average half-life of 14 days. When subjected to grazing, triticale is more efficient in nutrient cycling, providing 197, 38, and 231 kg ha-1 of N, P, and K, respectively, with a half-life time of 10, 37, and 25 days, respectively. Forage species can improve the cycling of nutrients and make them available to crops in succession in the ICLS.

The incorporation of organic substrate into the soil can reduce aluminum toxicity in pigeon pea (Cajanus cajan (L.) Millsp.) plants, making it a viable alternative for use by small farmers in acidic soil regions such as the northeast semi-arid regions of Brazil that contain toxic aluminum in the soil. The aim of this study was to evaluate the effect of increasing aluminum doses and different commercial substrate concentrations on the initial growth of the pigeon pea. The experiment was undertaken in a greenhouse using a completely randomized design with a 5 × 3 factorial scheme. The first factor consisted of five doses of aluminum (0, 13.5, 27, 54, and 108 mg L-1) and the second factor consisted of three percentages of commercial substrate Vivato Slim Pro® (0%, 10%, and 20%), with five replicates per treatment, totaling 60 experimental units. The variables evaluated were plant height; total chlorophyll; shoot, root, and total dry matter; and root volume. The use of the commercial substrate attenuated the aluminum toxicity and favored the initial growth of pigeon pea plants, regardless of the concentration used. Thus, the aluminum was detrimental to the initial plant growth at all tested concentrations and showed more pronounced signs of toxicity on the root volume.

The present study aimed to identify the best day time to evaluate the relative chlorophyll index in maize and soybean crops as a function of weather conditions. The experiments were conducted in the 2018/2019 harvest, in January and February, in the experimental area of the State University of Goiás, Ipameri University Unit, in Ipameri-GO. A completely randomized design with three replications and 40 plants per plot was used. The measurements of relative chlorophyll index at 7:00, 10:00, 13:00, 16:00, and 19:00, at the maize stage R1 (silking) and soy stage R2 (full bloom), were evaluated. The replications consisted of alternating days over seven days. The relative chlorophyll index, leaf temperature, air temperature, and relative humidity, and light incidence were evaluated. The data were organized, and regression analysis was performed for all variables. The statistical analysis was processed using the Sisvar statistical analysis software. The maize shows higher values of relative chlorophyll index at times with the highest temperatures. For soybean, the relative chlorophyll index must be measured at temperatures close to 30 ºC. Studies with more species of C3 metabolisms, such as soybeans, should be carried out to standardize an adequate time to read the relative chlorophyll index.

The aim of the study was to test the effects of various concentrations of zinc sulfate (ZnSO4) on the radial growth of Trichoderma harzianum and Leucoagaricus gongylophorus in Petri dishes. In addition, we investigated the acceptance of baits containing live propagules of the encapsulated T. harzianum fungus and baits containing ZnSO4 by foraging leafcutter worker ants, A. sexdens, as well as their effects on the colonies of these ants. For the in vitro test, the design was completely randomized using ten replicates of a 2 × 7 factorial scheme: two species of fungi (T. harzianum and L. gongylophorus) and seven concentrations of ZnSO4. For bait acceptance tests, four treatments were used: baits without the mycelium and ZnSO4 (T1, control), baits containing encapsulated T. harzianum mycelium (T2), baits containing ZnSO4 (T3), and baits containing zinc sulfate and the encapsulated T. harzianum (T4). Each treatment was tested in duplicates using eight colonies. In the in vitro test, a ZnSO4 concentration of 0.25 g/L was sufficient to completely inhibit the development of L. gongylophorus without affecting the development of T. harzianum. In the bait acceptance test, the workers accepted ~55% of the bait combination of ZnSO4 and T. harzianum. This suggests the potential of treatment T4 in controlling leafcutter ants. Moreover, treatment T4 is environmentally friendly. 

In the face of the elevated cost of economic and environmental order to recover degraded soil, the monitoring of the structural quality of the soil through physical and plant indicators is recommended. This way, this work aimed to verify which parameters may be used together with soil penetration resistance (PR), after compression induced by agricultural machinery traffic in Haplustox (LVd) and an Eutrustox (LVef), grown with corn. The experiment was conducted with a randomized block design in a split-plot scheme with four replications. Five treatments and three soil layers (0-0.10; 0.10-0.20, and 0.20-0.30 m) for each soil class were evaluated. The treatments were: NC = conventional preparation without additional compression; C14, C17, and C110 = one pass of a tractor of 4, 7, and 10 Mg, respectively; C310= three passes of the tractor of 10 Mg. The variables evaluated were aggregate stability index, soil density (Ds), soil porosity, PR, and root and height variables, diameter, and kernel yield of the corn crop. PR increased with higher compression in the LVd, and in C14, C17, C110, and C310 in the layer of 0.10-0.30 m in LVef. Ds and root area of the corn are useful to analyze the structural quality of the soil together with the PR.

Effects of casing soil enrichment with soybean flour (SF) and iron (Fe) were explored on yield and quality of edible mushrooms inoculated with plant growth-promoting bacteria in a factorial experiment with four replications. Fe from Fe chelate source was applied at two levels of 0 (Fe0) and 500 mg L-1 (Fe500), SF at three levels of 0% (SF0), 1.5% (SF1.5), and 3% (SF3) of compost dry weight, and bacteria inoculation at two levels (non-inoculation and inoculation of mycelia with P. putida). The maximum fresh yield (20.3 kg m-2), mushroom number (1041), biological efficiency (95.0%), vitamin C (3.74 mg 100 g-1 FW), and yield of protein (6.48 kg m-2) were obtained from SF1.5 + P. putida. But, the maximum tryptophan (1.37 mg g-1 DW), methionine (2.29 mg g-1 DW), and antioxidant capacity (4.25 mg mL-1) were related to SF3 inoculated with P. putida. Furthermore, the maximum carbohydrate (5.64%) was related to Fe500 + SF3. Based on the results, casing soil enrichment with Fe did not have a significant influence on quantitative and qualitative traits of mushrooms, but SF application at the rate of 1.5%, especially when accompanied by P. putida, played a more essential role. Thus, it is recommended to use 1.5% SF along with P. putida to enhance the yield and qualitative traits of edible mushrooms.

Nitrogen fertilization in off-season sorghum may have lower cost-benefit ratios than expected due to the residual effect of previous crops. However, the use of growth-promoting bacteria can be an economical alternative to increase crop yields in Cerrado. The objective was to evaluate the response of grain sorghum to nitrogen fertilization and its inoculation by Azospirillum brasilense. This study aims to evaluate grain sorghum responses to nitrogen fertilization and A. brasilense inoculation. The experiment was carried out in a fully randomized block design and 5 x 2 factorial scheme, with five replications. Treatments consisted of applying N recommendation (120 kg N-urea ha-1) split as follows: 100% at sowing, 100% as topdressing, 25% at sowing and 75% as topdressing, 50% at sowing and 50% as topdressing, and a control (without application), all these with and without A. brasilense seed inoculation. We also assessed the morphological and productivity components of grain sorghum. The application of 100% N at sowing promoted taller plants, while 50% -50% splitting shorter ones. Overall, grain sorghum plants did not respond to A. brasilense inoculation. Moreover, yield components of rainfed sorghum grown in succession to soybeans were not affected by A. brasilense inoculation and N supplied at once or split.

There is a contemporary trend of change in the agricultural sector, aiming at the use of ecologically friendly inputs. This trend can be seen by the constant increase in the demand for organic products. However, as with other technologies, there is a need for studies to evaluate the effectiveness of its use. The present study aimed to evaluate the effects of the application of increasing doses of cattle manure on the development and productivity of chili peppers. The treatments consisted of increasing doses of cattle manure (0; 5; 10; 15; 20 Mg ha-1). The variables plant height, stem diameter, number of plant leaves and length, diameter, and fruit yield were evaluated. It was found that, with the maximum amount of cattle manure, there was an increase of 35.96%, 41.12%, 47.84%, and 161.64% concerning the control treatment, without the cattle manure application. Thus, it was concluded that the use of increasing doses of cattle manure, up to 20 Mg ha-1, is beneficial to the development and production of chili pepper.

The study aimed to define the best conditions to conduct germination tests for Ormosia arborea seeds and assess the viability of seeds using the tetrazolium test. The germination tests were conducted at temperatures of 10, 15, 20, 25, 30, and 35 °C and alternating temperatures of 20-30 °C, in the presence or absence of light. For the tetrazolium test, seeds were immersed in tetrazolium solution 0.075%, at 35 °C for three hours, and then the viability was evaluated. It was verified that the seeds did not present absolute photosensitivity. The tetrazolium test was effective in separating the seeds into two categories concerning seed viability, viable and nonviable. It was concluded that O. arborea seeds germinate in the presence or absence of light in a wide range of temperatures. Temperatures of 25 and 30 ºC and alternating temperatures of 20-30 ºC are indicated to conduct germination tests. The tetrazolium test was effective in assessing seed viability.

Corn (Zea mays L.) is one of the most important cereals grown and consumed in the world not only for its economic value but also due to its importance in human and animal nutrition. This study aimed to assess the initial development of corn as a function of increasing nitrogen doses. The study was carried out in a greenhouse on the Sipal Farm, Confresa, MT, Brazil. The experiment was set up in a completely randomized design, consisting of five treatments (0, 100, 200, 300, and 400 mg N dm−3 soil), with four replications, conducted from April to June 2020. Four seeds of the hybrid K 9606 VIP 3 were sown per 8-L polyethylene pot. The plants were thinned at 7 days after emergence (DAE), leaving only one plant per pot. Morphological components were assessed. A significant effect was found for almost all the analyzed parameters, except for stem diameter and root dry matter. The maximum plant height, shoot fresh matter, leaf area index, shoot dry matter, root fresh matter, and root volume was obtained by applying the maximum agronomic efficiency doses of 248.83, 271.90, 336.91, 279.66, 403.92, and 272.90 mg N dm−3 soil, respectively. Nitrogen doses influenced the initial development of the corn crop.

Avoiding the toxicity effect of chemical fungicides on rhizobacteria is a sustainable alternative for agroecosystem management. Rhizobacteria, whose bioprotective and plant growth-promoter potential have been reported in the literature, lack studies on their performance in integrated management with pesticides. Thus, this study aimed to evaluate the effects of azoxystrobin + cyproconazole on the growth of Bacillus subtilis, Streptomyces seoulensis, and Bradyrhizobium japonicum. Three independent experiments were set up, i.e., one for each microorganism, and carried out in a completely randomized design in a factorial scheme (3 × 6), with three doses (recommended by the manufacturer, half, and twice) and six periods of evaluations (48, 96, 144, 192, 240, and 288 hours), with three replications. Growth inhibition rings were evaluated. Azoxystrobin + cyproconazole at all tested doses is compatible with B. subtilis. The use of azoxystrobin + cyproconazole affected the growth of B. japonicum and S. seoulensis, which were sensitive to all its doses until 288 hours after inoculation.

This study aimed to assess the soil density (Sd) and the total organic carbon contents and stocks in different management systems and implementation times in the municipality of Iguatemi, MS, Brazil. A completely randomized design with four replications was applied to four areas: conventional tillage (CT), reformed pasture (RP), and degraded pasture (DP), in addition to a native forest (NF) area with no anthropic action. Disturbed and undisturbed soil samples were collected at depths of 0–0.05, 0.05–0.1, and 0.1–0.2 m. The determination of Sd and total organic carbon content (TOC) allowed calculating the carbon stock (Cstock), the stratification index (SI), and the carbon stock variation (ΔCstock), with subsequent multivariate analysis. The NF area presented the highest TOC contents at all depths compared to the managed areas, with a value of 17.45 g kg−1 at a depth of 0–0.05 m. The RP and NF areas showed similar SI, which was higher in PD, with a value of 2.54. Except for RP, the other managed areas showed a negative ΔCstock in the soil profile relative to the NF area. The RP and NF areas promoted the maintenance of TOC in the soil, while DP and CT compromised the edaphic quality.

Biological formulations used as inoculants are increasingly present in grasses, especially in corn. Positive results in promoting plant growth, with different associations with diazotrophic bacteria, show these capacities of interaction to act as plant growth regulators, making it a promising alternative with a low environmental impact. Thus, this study aimed to evaluate the efficiency of inoculation and co-inoculation of nodulating and non-nodulating diazotrophic bacteria as promoters of initial growth in corn plants. Therefore, the bacteria Azospirillum brasilense (UFG21 strain), Bradyrhizobium japonicum (commercial product), and their co-inoculation were used in seed treatment. The evaluations consisted of growth measuring of the root system and shoot and evaluating leaf chlorophyll concentration. The results showed a beneficial interaction between the bacteria and the corn plant, with an increase in the root system and chlorophyll content, compared to the control treatment.

The study aimed to evaluate the nitrogen sources and doses application effects on the dry matter production and the sugar and alcohol gross yield of sugarcane (SP80-1816) in the cane-plant cycle in a dystrophic Red Oxisol. The experiment was conducted in the Fazenda Rio Paraiso II field, belonging to Usina Raízen, in Jataí - GO. The experimental design used was randomized blocks, arranged in a factorial scheme (2 x 4), with three replications. The treatments consisted of two nitrogen sources (urea and ammonium nitrate) and four nitrogen doses (0, 60, 120, and 180 kg ha-1). Dry matter variables were analyzed in sub-subdivided plots, as four evaluation periods were added (210, 250, 290, and 330 days after planting). The evaluation periods influenced sugarcane dry matter, and urea favored these variables to the ammonium nitrate's detriment. In contrast, the opposite occurred for stalk yield and sugar and alcohol yields, in which ammonium nitrate provided greater increments. The increase in nitrogen doses provided linear gains in practically all studied variables.

This study aimed to evaluate the quantitative and qualitative aspects of production in different populations of cotton cultivars. Ten cultivars were evaluated annually in four plant populations. A randomized block design with split plots and three replicates was used. The cultivars were placed in plots, and the plant populations were placed in the subplots. The following characteristics were evaluated: fiber percentage, fiber yield (kg ha-1), fiber length (mm), the micronaire index, the short fiber index (%), and fiber resistance (gf tex-1). In general, the effect of cultivar was much more important than that of the plant population. These results agree with those obtained by several other authors who have claimed that cotton has a high capacity to adapt to certain population ranges. Thus, considering current seed prices, smaller populations can be used without affecting productivity.

The use of quality seedlings of eggplant is directly related to the success of their production, with polymers added to the substrate, which work as water conditioners, increase the water retention capacity, and provide better seedling quality. The study aimed to evaluate the use of nanocomposite hydrogel enriched with different proportions of N-urea in the production of eggplant seedlings. The experiment was conducted at the State University of Mato Grosso do Sul, Cassilândia, MS, Brazil, from June to August 2019, under sombrite® 30%. Five treatments were evaluated, using the commercial substrate, Carolina Soil®: 1) commercial substrate without hydrogel; 2) commercial substrate with 0.075g of pure hydrogel (0.00g of N-urea)/15 mL of a substrate; 3) commercial substrate with 0.075g of hydrogel and 10% N-urea/15 mL of a substrate; 4) commercial substrate with 0.075g of hydrogel and 20% N-urea/15 mL of a substrate, and 5) commercial substrate with 0.075g of hydrogel and 40% N-urea/15 mL of a substrate. The experiment was conducted with four replications of 25 seedlings. The emergence speed index, percentage of emergence, height, number of leaves, stem diameter, shoot dry matter, root dry matter, and total dry matter were evaluated, as well as the Dickson Quality Index. The data were subjected to analysis of variance (SPEEDSTAT statistical software) and grouping test of means. A regression analysis was performed to adjust equations for some of the variables. The best seedlings can be obtained using the dosage of 28.83% N-urea with 0.075g of hydrogel per 15 ml of the substrate, according to the DQI adjustment, which includes several traits of the seedlings, thus reflecting on its quality.

The use of soil remineralizers with efficient microorganisms (EM) can represent an effective and sustainable alternative to improve the growth, development, and yield of cultivated plants. Thus, the present study aimed to evaluate the effect of different doses of EM, in the presence or absence of rock dust (RD), on the development of iceberg lettuce, cultivar Lucy Brown. The design used was completely randomized, arranged in a 2 x 5 factorial scheme, with four replications. The treatments consisted of the presence and absence of RD in the substrate composition, combined with five commercial product doses based on EM (0, 2, 4, 6, and 8 L ha-1). At 30 days after transplanting, root and stem length, head circumference, the number of leaves, stem diameter, leaf area, fresh matter of root, stem, leaf, and shoot, and dry matter of root, stem, leaf, and shoot were evaluated. There was an interaction between the factors for most variables of economic importance. The dose of 4.5 L ha-1 of the product based on EM, combined with PR, implied the best performance of iceberg lettuce under the studied cultivation conditions.

This study aimed to estimate the association of P2O5 doses with and without rhizobia inoculation to maximize the agronomic performance and yield of cowpea on an Oxisol in the Cerrado region of Tocantins. The experiments were carried out in two periods during the 2014/2015 growing season at the Experimental Farm of Gurupi belonging to the Federal University of Tocantins, using the variety BRS Novaera. Inoculation was carried out with a standard strain recommended for cowpea. The experimental designs were randomized in blocks in a 2×6 factorial arrangement, with the first factor consisting of the inoculation (presence and absence) and the second factor consisting of six phosphorus doses (0, 30, 60, 90, 120, and 150 kg ha−1 of P2O5), totaling 12 treatments with four replications. Total chlorophyll, leaf P content, flowering, hundred-grain weight, and yield were evaluated. Phosphorus fertilization had a positive influence on the total chlorophyll, flowering, and leaf P content of cowpea on the Oxisol in the Cerrado region of Tocantins. The application of 113.42 kg ha−1 of P2O5 provided a yield of 1,124 kg ha−1 in the first planting period, corresponding to an 83% increase. However, phosphorus fertilization and inoculation increased grain yield in the second period, with the maximum yield reaching 145.94 kg ha−1, obtained with the maximum effect dose of 123.04 kg ha−1 of P2O5, with a yield gain of 257.3%.