ABSTRACT. Curves of crop growth and nutrient extraction and export are essential to develop fertilization strategies and management plans to maximize yield and reduce environmental impacts. Our study aimed to evaluate dry matter production and both extraction and export of macronutrients by arrowroots (Maranta arundinacea L.) to be used in further crop fertilization plans. To this purpose, two experiments were carried out in field conditions using the varieties Viçosa and Seta. The experimental design was randomized with four replications and nine periods of analysis, which were defined as days after planting (105, 135, 165, 195, 225, 255, 285, 315, and 345 DAP). Dry matter, extraction, and export of macronutrients by arrowroot seed-rhizomes, aerial parts, roots, and storage roots (rhizomes) were determined. The exports of N, P, K, Ca, Mg, and S of storage rhizomes of the variety Viçosa were 104.6, 51.83, 412.24, 15.85, 36.14, and 64.36 kg ha-1, while those of the seta variety were 160.6, 71.62, 521.31, 17.57, 60.09, and 160.41 kg ha-1, respectively. Both varieties proved to be efficient soil macronutrient extractors, mainly for K. The variety Seta had higher shoot, root, seed-rhizome dry matter contents, as well as greater macronutrient extractions and exports.

ABSTRACT. A diagrammatic scale with five levels (0, 0.1 - 2.0, 2.0 - 6.0, 6.0 - 10, and 10 - 14) was developed and evaluated to measure the symptoms of heat injury in a coffee seedling canopy. The scale was constructed to increase assessment efficiency and align the estimations more closely with the actual values. Two assessments with the diagrammatic scale and one without were conducted with an interval of seven days. The evaluators using the proposed scale presented estimates with better levels of precision, accuracy, reproducibility, and repeatability than those using a conventional method. The proposed diagrammatic scale was shown to provide a reliable estimate for assessing the symptoms of heat injury on the canopy of in Coffea arabica L. seedlings. Therefore, it is possible to standardize heat injury evaluation methods using this diagrammatic scale, allowing for data comparisons with different cultivars.

ABSTRACT. One of the main objectives of sugarcane plantations is to increase their longevity without decreasing agricultural productivity. In the present study, we analyzed the proteome of the axillary buds of ‘RB966928’ to investigate possible changes in the number of proteins at different cutting stages. Using tryptic digestion followed by ultra-performance liquid chromatography coupled with high-resolution time-of-flight mass spectrometry, 122 proteins were identified from the proteome of the axillary buds of ‘RB966928’. Of the 122, respectively 97 and 95 proteins were detected at the first and fifth cutting stages, of which 27 and 25 proteins were unique to the respective stage. Proteins that prevent the misfolding of polypeptides generated under stress were exclusively detected at the first cutting stage. Meanwhile, proteins associated with stress responses and disease resistance were exclusively detected at the fifth cutting stage. The present proteomic analysis in the regrowth cycles and axillary bud development of ‘RB966928’ significantly advanced our understanding of the biological processes linked to the reduction of agricultural productivity of sugarcane with the advancement of cutting age. Absence of proteins to tolerate adverse growth conditions at the fifth cutting stage may be related to reduced agricultural productivity, in addition to environmental stress, soil compaction, nutrient availability, cultural practices, and pests or pathogen attacks at different phenological stages of crops.

ABSTRACT. In no-till (NT), liming and urea fertilization are performed on the soil surface, which can increase nitrogen (N) losses via ammonia volatilization. On the basis of N fertilization management, gypsum application provides a promising alternative for improving N uptake by plants. Therefore, the objective of this study was to evaluate the N behavior loss by NH3-N volatilization, the soil pH at a depth of 0 - 0.05 m, leaf N content, and N uptake by second-season corn after lime and gypsum application in a Rhodic Ferralsol under NT. Overall, the treatments consisted of a 4 × 4 factorial arrangement with four lime rates (0, 2.6, 5.4, and 8.1 Mg ha-1) and four gypsum rates (0, 4, 8, and 12 Mg ha-1). During the study period, second-season corn was cultivated for two years and fertilized with urea, for which the N losses through ammonia volatilization, soil pH, leaf N content, and N uptake values were quantified. The losses through ammonia volatilization were subjected to nonlinear regression using a logistic model, and the other variables were subjected to linear regressions. The lime applied by broadcasting on the soil surface in the NT increased the pH of the topsoil and increased N losses via NH3-N volatilization in the second-season corn. Further, the N losses in the NT treated with lime accounted for 58% of the applied N, which increased by 2.3 to 2.5% for each Mg ha-1 of lime applied. Therefore, lime or gypsum application did not improve the status of N in second-season corn in soils with low acidity and no S deficiency.

ABSTRACT. This study examined biochemical changes associated with chilling injury (CI) in sweet potato roots stored at low temperatures and reconditioned at ambient temperature. Sweet potato cultivars BRS Amélia and BRS Rubissol were stored at 6 or 13°C for 4 days at ambient temperature (“ambient reconditioning”: 21 ± 2°C). CI on the outer surface of the roots occurred earlier in BRS Amélia than in BRS Rubissol. The CI index on the inner surface of the BRS Amélia was higher when it was stored at 6°C for 40 + 4 days. BRS Amélia showed higher proline content and electrolyte leakage when stored at 6°C. Ascorbate peroxidase was induced by storage at 6°C for 30 + 4 days in BRS Amélia and from 40 + 4 days in BRS Rubissol. The malondialdehyde and phenolic compounds of BRS Rubissol increased during storage at 6°C. CI in both cultivars was associated with increased peroxidase and polyphenol oxidase activities. Storage of sweet potato cultivars at 6°C for 50 + 4 days caused severe damage to the roots. Cultivars BRS Amélia and BRS Rubissol showed similar symptoms of CI and can be characterized as being sensitive to low temperatures.

ABSTRACT. Banana (Musa spp.) is one of the main fruits consumed worldwide. However, finger drop, is a physiological disorder that causes many postharvest problems, which eventually reduces market value and consumer acceptance. Therefore, the objective of the study was to evaluate the anatomical changes that occur in the pedicel rupture area (drop zone) of bananas diploids (BB França) and tetraploid (BRS Pioneira) in three ripening stages. The levels of gene expression involved in the natural ripening process and in the development of finger drop, was also investigated. The accumulation of their mRNAs and those of expansin (EXP1), pectate lyase (PEL1) and xyloglucan endotransglucosylase/hydrolase protein (XTH4) genes already isolated from bananas were measured by quantitative polymerase chain reaction in three ripening stages. BB França presented a higher resistance to finger drop due to the presence of some specific morphoanatomical characteristics, such as larger parenchymal cells and greater deposition of lignin. In contrast, there was degeneration of the pedicel parenchymal tissue of the BRS Pioneira genotype, forming large empty spaces during the ripening of the fruits, mainly in stage 6, which contributed to the finger drop. The diploid BB França is a strong candidate for use in banana breeding programs aimed at fruit drop resistance. This will certainly improve the quality of banana varieties. Moreover, PEL1 proved to be an excellent candidate gene for functional studies of finger drop in bananas.

ABSTRACT. There are few new black oat cultivars in Brazil; therefore a reduced number of cultivars are available for the most varied production regions. Strategies aimed at studying genetic variability, such as mutation induction, of the few cultivars available on the market represent alternatives to increase the variety in this sector. The objective of the present study was to prepare a scientometric analysis of studies of the genetic improvement of black oats (Avena strigosa L). The literature review was performed using data from the Web of Science (WoS) from 1945 to 2020. Initially, 859 articles were analyzed, which after refinement, were reduced to 404 for further analysis. This study provides a new method for quantitatively visualizing information regarding the development of this area over time. After searching and refining with the aid of the CiteSpace software (5.6 R4), graphic representations were developed of the scientific journals, authors, countries, subject categories, organizations, and individual publications extracted from the WoS. The results of the analysis indicated a growing trend in the number of publications on the genetic improvement of black oats, as well as the number of citations over the years studied.

ABSTRACT. French lavender (Lavandula dentata L.) is of great ornamental, medicinal, and aromatic interest. It is generally propagated vegetatively using stem cuttings. When using artificial lighting, a specific light composition can modify the entire plant phenology and is a factor that can be managed in controlled conditions. This study evaluated the rooting of stem cuttings and growth of lavender under four spectral LED lights. The LED lights used were: T0 (white LED, Roblan®), T1 (AP67 Milky, Valoya®), T2 (NS1, Valoya®), and T3 (AP673L Milky, Valoya®). The first phase evaluated the rooting of stem cuttings and initial development. The plants were then transferred to plastic pots to evaluate plant growth. In both rooting and growing phases, the plant morphological characteristics and water and light efficiencies were evaluated. Nutrient-uptake efficiencies were also evaluated after the growing phase. It was observed that cuttings rooted under the influence of T1 showed greater height. After the growing phase, plants under T3 showed better results in electricity use efficiency, water use efficiency, and nutrient-uptake efficiency and less nitrate leaching. They also presented more uniform growth with a compact canopy. Thus, T1 was better for the stem cuttings rooting phase, while T3 was better for growth and energy efficiency.

ABSTRACT. The center of origin and domestication of Piper nigrum L. are in high rainfall regions. But when grown in regions with irregular or insufficient rainfall, irrigation becomes essential. This study evaluated the impact of irrigation levels on the physiological and growth characteristics of black pepper plants, cv. Bragantina. It was carried out from April 2019 to May 2020, using automatic activation irrigation. We used emitters with different flow rates to apply water depths corresponding to 100, 81, 62, and 42% of the crop water requirement. The parameters evaluated comprised main stem length (MSL), stem diameter (SD), number of leaves (NL), leaf area (LA), chlorophyll contents, chlorophyll-a fluorescence, and some photosynthetic parameters. The treatments significantly influenced (p < 0.05, F-test) MSL and NL. Plants submitted to the control treatment showed MSL (65.8%) and NL (123%) greater than those irrigated with the smallest volume (p < 0.05, F-test). However, the treatments had no significant effect on SD. Moreover, chlorophyll b levels decreased by 26% and chlorophyll a/b ratio increased by 22% at 120 and 180 DAT, respectively. Some photosynthetic parameters such as FV/FM, ABS/RC, and DI0/RC were affected by water deficit at 120 DAT. Our results suggest the sensitivity of black peppers to water deficit and contribute to the proper management of this crop.

ABSTRACT. To overcome the challenges encountered in banana cultivation, such as the high cost of production due to high water consumption by the banana plant, efficient management practices are being adopted. The use of agricultural forecasting techniques is an alternative that has been gaining attention in rural areas. One way to manage and improve agricultural productivity is the use of technologies that allow the monitoring of production. The implementation of computational tools as software to aid processes, such as irrigation management, is gradually taking up space in the agricultural sector. In this light, herein, the present study aimed to develop a model using STELLA 8.0 software to estimate the growth and productivity of irrigated banana (Musa sp.). For this, the physiological processes and water demand were calculated using reference evapotranspiration (ET0) and culture evapotranspiration (ETc) in the first banana cycle for the climatic conditions of the Jaíba Project (Jaíba, Minas Gerais State, Brazil). The data of the climatic conditions were obtained from the National Institute of Meteorology. It was verified that the average monthly ET0 was 5.78 mm day-1. In addition, the water requirement of the plant corresponded to a blade equivalent to 65% of ET0. The verified productivity was 8.93 t ha-1, which is considered adequate for the simulated conditions. The model responded efficiently to the proposed application and was characterized as a prognostic tool of reality through simplified representation.

ABSTRACT. This study aimed to investigate the potential of rhizobacteria isolated from tomato plants to control Sclerotinia sclerotiorum and induce the activity of pathogenesis-related enzymes in Micro-Tom tomato plants. Three rhizobacterial isolates were evaluated to determine the most efficient antagonist agent, which was later identified by gene sequencing as Bacillus amyloliquefaciens PKM16. The antagonistic effects of B. amyloliquefaciens against S. sclerotiorum were assessed in vivo and in vitro using live and autoclaved cultures at concentrations of 0% (control), 20%, 30%, and 40% (v/v). The residual effects of four treatments (20% live culture, 20% autoclaved culture, a Bacillus subtilis-based commercial product, and autoclaved distilled water) on tomato plants inoculated with S. sclerotiorum were determined. The same treatments were also used to assess the myceliogenic germination of sclerotia and induction of plant defense enzymes (peroxidase, catalase, polyphenol oxidase, phenylalanine ammonia-lyase, and β-1,3-glucanase) in tomato plants. The live culture had a residual effect for 4 days and inhibited sclerotial germination by approximately 30%. Furthermore, live and autoclaved bacterial growth cultures stimulated enzyme activity. Therefore, B. amyloliquefaciens PKM16 was antagonistic to S. sclerotiorum, effectively inhibiting mycelial growth and activating defense mechanisms in Micro-Tom tomato plants.

ABSTRACT. The objective of this study was to develop segregating wheat populations for resistance to gibberella through the introgression of synthetic wheat genes in traditional cultivars and to present the results using the backcross method. In addition, to evaluate these populations in F1RC2, agronomic aspects and type II and III resistance to Fusarium head blight (FHB). The cultivars BRS Guamirim and BRS 179 were used as male parents and three synthetic wheat cultivars (CIGM90.909, CIGM92.1666, and CIGM93.298) as female parents, both previously characterized for the reaction to FHB. Crossing and backcrossing methodological procedures were performed to provide adequate controlled conditions. The F1 (winter 2016), RC1 (summer 2016/2017), and RC2 (winter 2017) populations were developed through emasculation and pollination procedures. In the winter of 2018, segregating populations were evaluated in the field using a randomized block design. In the three generations developed in a greenhouse, it was observed that the best crossbreeding combinations, verified by the number of grains, were obtained with the male parent BRS 179. Under field conditions, all segregating populations were considered moderately susceptible and susceptible to type II resistance. In type III resistance, all segregating populations, except for CIGM90.909/BRS 179 and BRS 179, showed values above 50%. Thus, it was evident that the crossings performed with the male parent BRS 179 generated better resistance to the disease.

ABSTRACT. This study aimed to evaluate the nutrition of commercial soybean crops in an agricultural frontier region using the diagnosis and recommendation integrated system (DRIS) and compositional nutrient diagnosis (CND) methods, as well as identify sufficiency ranges. The study was performed by collecting leaf samples (third trifoliate leaf without petiole) at flowering from commercial soybean crops in the states of Piauí and Maranhão, Brazil, and evaluating the crop yield by analyzing macro- and micronutrients in the plant tissue of 98 samples. The DRIS and CND methods were applied based on the cataloged data, followed by the generation of norms, analysis of relationships between yield and nutrients (selecting high-yield crops by the cumulative function of the data), generation of sufficiency ranges, and comparison of methods. The relationships obtained by the DRIS and CND indices with the yield and nutrients were significant, indicating that both methods can be employed for the evaluation of leaf nutrients in soybean. The sufficiency ranges from the DRIS and CND methods presented superior nutrient ranges in relation to the values proposed in the literature for macronutrients, except for nitrogen, and greater range amplitudes for micronutrients.

ABSTRACT. The germplasm of Passiflora L. is conserved through seed banks and field collections. Dormant seeds, seeds with low viability, and high-cost field collections make it difficult to maintain germplasm banks, and in vitro conservation can be a complementary alternative. The aim of this study was to investigate the survival of nodal segments of Passiflora edulis Sims ‘UENF Rio Dourado’ over 180 days of slow growth in vitro by reducing the mineral salt and sucrose concentrations and changing the incubation conditions (temperature and light intensity). The experiment was conducted in a completely randomized design with a 2 × 3 × 3 factorial arrangement consisting of two temperatures (20 ± 2°C and 27 ± 2°C), three concentrations of MSM mineral salts (100% MSM, 50% MSM, and 25% MSM), and three sucrose concentrations (10, 20, and 30 g L-1). Evaluations were performed at 60, 90, 120, 150, and 180 days for survival, number of leaves, and plant color (using a color scale where 1 = dark green, 2 = light green, and 3 = yellow). After 180 days of culture, mineral salt, sucrose concentration, and incubation temperature affected plant survival, regeneration, and acclimatization. During the 180 days, it was possible to slow the growth of nodal segments of passion fruit ‘UENF Rio Dourado’ in culture medium with 25% MSM mineral salts plus 10 g L-1 sucrose, at an average temperature of 20°C without compromising plant survival, regeneration, and acclimatization.

ABSTRACT. Cohesive Oxisols are widely used for cultivating eucalyptus in the Coastal Tablelands of the northeastern region of Brazil. However, mechanization and plant cultivation in these soils are difficult because of their cohesive layers. Therefore, the objective of this study was to identify better combinations between tillage systems and types of fertilization to improve the physical attributes of cohesive soil, with the aim of improving eucalyptus growth. The experimental design was completely randomized in a 4 × 2 factorial scheme (soil preparation × fertilization). The tillage systems tested were: i) conventional tillage (CT) - one plowing combined with two harrowings, ii) minimum tillage (MT) - subsoiling down until 0.57 m depths in the planting line, iii) no-tillage type 1 (NT1) - planting in 0.3 m-deep pits, and iv) no-tillage type 2 (NT2) - planting in 0.6 m-deep pits. The types of fertilization tested were mineral (MF) and organic fertilization (OF). The diameter of the soil aggregates was reduced after being subjected to any combination of cohesive soils. Furthermore, OF provided the best levels of plant-available water, attenuating the adverse conditions of the cohesive layer. MT, NT1, and NT2 improved the soil physical attributes when compared to CT. Therefore, the combination of either NT1 or NT2 with OF, followed by the combination of either NT1 or NT2 with MF, was determined to be the best way to cultivate eucalyptus on cohesive soils.