RCAAP Repository

ABSTRACT The aim of this study was to estimate genetic divergence and select BC1F3 populations of dwarf tomato plant within the Santa Cruz segment by computational intelligence techniques. The experiment was conducted in a greenhouse in the Vegetable Crop Experimental Station of the Universidade Federal de Uberlândia (UFU), Monte Carmelo, MG, Brazil. A randomized block experimental design was used with 17 treatments and four replications. The genetic material evaluated comprised thirteen dwarf tomato plant populations obtained by a backcross and two self-fertilizations, plus both parents (recurrent and donor), and two commercial check varieties. The traits evaluated were mean fruit weight (MFW), soluble solids content (SSC), fruit diameter (FD), fruit length (FL), fruit shape (FS), pulp thickness (PT), number of locules (NL), distance between internodes, and acylsugar, β-carotene, and lycopene content. The data were analyzed by means testing, and genetic divergence was measured using Mahalanobis generalized distance by the unweighted pair group method with arithmetic mean (UPGMA) and through computational intelligence using Kohonen self-organizing maps (SOM). Genetic dissimilarity in relation to the donor parent could be confirmed through both methodologies. However, the SOM was able to detect differences and organize the similarities among the populations in a more consistent manner, resulting in a larger number of groups. In addition, the computational intelligence techniques allow the weight of each variable in formation of the groups to be ascertained. Among the BC1F3 populations, UFU-SC#3 and UFU-SC#5 stood out for agronomic traits, and UFU-SC#10 and UFU-SC#11 stood out for quality parameters.

ABSTRACT The expansion of blackberry cropping in subtropical regions is recent, requiring adaptability studies and the development of new cultivars, as well as suitable plant management. Aiming to study adaptability and agronomic performance of blackberry (Rubus spp.) under drastic summer pruning in a subtropical region, the response of four blackberry cultivars (‘BRS Tupy’, ‘Guarani’, ‘Brazos’ and ‘Choctaw’) to N and K fertilization was evaluated during two growing seasons in Jundiaí (Brazil). The experiment used split-plots in a randomized complete block design with four replicates. The plots consisted of combinations of three N rates (75, 150 and 300 kg·ha–1·year–1) and three K rates (50, 100 and 200 kg·ha–1·year–1 of K2O) in factorial arrangement and an additional control treatment without fertilizer application. In the subplots, four cultivars of blackberry were studied. Considering fruit yield, accumulation of phytomass and mineral elements, as well as the nutrient efficiency use, the cultivars that showed greater adaptation to cultivation in a subtropical area under drastic summer pruning management are ‘Brazos’, ‘Guarani’, ‘BRS Tupy’ and ‘Choctaw’, in that order. An annual application of 120 and 67 kg·ha–1 of N and K2O, respectively, is expected to be sufficient to achieve maximum economic yield.

ABSTRACT The objective of this work was to evaluate the effect of pre-storage fruit treatment with nitric oxide (NO) on the quality maintenance of cold stored ‘Cripps Pink’ apples. The following treatments were evaluated: 0 μL·L–1 of NO (control); 10 μL·L–1 of NO for 2 h; 10 μL·L–1 of NO for 4 h; 10 μL·L–1 of NO for 8 h; and 20 μL·L–1 of NO for 2 h. Fruit treated with NO, regardless of concentration and application time, had a greener skin background color than the control, especially those treated with 10 μL·L–1 for 8 h. After 7 days of shelf life (23 ± 3 °C/relative humidity, RH, of 65 ± 5%), fruit treated with 10 μL·L–1 for 8 h and 20 μL·L–1 for 2 h had lower respiration rate and a greener skin background color than the control. Fruit treated with NO, regardless of concentration and application time, had a lower incidence of flesh browning after storage. The use of NO (10 μL·L–1 applied for 8 h and 20 μL·L–1 applied for 2 h) pre-storage maintains the quality of ‘Cripps Pink’ apples, because it delays skin yellowing and reduces flesh browning. Nitric oxide has no effect on the maintenance of flesh firmness in ‘Cripps Pink’ apples.

ABSTRACT In the Amazon region, soil patches with an anthropic A horizon are found, called Indian black earths (IBEs). Indian black earths are highly fertile and, therefore, are deforested by small local farmers to cultivate without basic management that maintains soil and crop sustainability. Therefore, in order to evaluate the effect of using different cultures on the spatial variability of soil chemical attributes, three cultivated IBEs and one IBE under natural forest were selected for georeferencing and sample collection. The collection was made with a mesh system with 88 points per IBE, stratified in three layers: 0–0.05, 0.05–0.10 and 0.10–0.20 m. The soil was sampled, dried in the shade and sieved to obtain the fine earth fraction for analysis of chemical attributes. Descriptive statistical and geostatistical analyses were applied to the results. The use and management of soil influenced the spatial behavior of the chemical attributes of IBEs. The cultivation of Brachiaria over many years favored the reduction of the spatial variability of chemical attributes. The use of cacao and coffee crops also favored the homogeneity of the IBEs in relation to the natural forest, but not as much as for Brachiaria, likely due to the succession of crops that preceded these crops. The IBE in the forest contains a high natural spatial correlation in the first 0.1 m of the surface; however, more than 70% of this correlation is linked to a random variation.

ABSTRACT Tree breeders are prioritizing the increase of the interspecific diversity in the breeding programs due to the pronounced environmental changes, and expansion of the forest frontier to less productive areas. In this scenario, there is a growing interest for species of the genus Corymbia due to their good growth, resistance to biotic and abiotic factors, and industrial properties. Also, Corymbia spp. can cross with each other, generating interspecific hybrids. However, there are great difficulties on defining the best crosses. Thus, the objectives of this study were to evaluate the genetic variability of 64 progenies of Corymbia maculata and 64 progenies of Corymbia torelliana and to use the GGE biplot method to point the most appropriated crosses to broad and specific environments in order to generate stable and productive interspecific hybrids of C. maculata and C. torelliana. The GGE biplot was an efficient method for evaluating the genetic variability between progenies, for visualizing the genotype by environment interaction pattern and for identifying the best crosses in order to generate interspecific hybrids of the species. By adopting a selection intensity of 10%, the recommended progenies to generate interspecific hybrids for the Aracruz municipality (ARA) were 10, 40, 49, 64, 20, 9 and 47 of C. maculata and 24, 56, 41, 64, 43, 31 and 12 of C. torelliana. For Três Lagoas municipality (TLA), the recommended progenies were 11, 17, 1, 48, 7, 63 and 21 of C. maculata and 42, 46, 61, 44, 10, 63 and 28 of C. torelliana.

ABSTRACT The aim of this research was to evaluate the physiological and productive aspects of irrigated cassava crop. The statistical design used was randomised blocks, with six treatments and four replications. The used treatments were irrigation levels, based on the crop evapotranspiration – ETC – (L0 = 0% [rainfed], L1 = 40%, L2 = 80%, L3 = 120%, L4 = 160% and L5 = 200% of the ETC) and the analysed physiological variables were: gas exchange, the quantum efficiency of photosystem II (PSII) and the soil plant analysis development (SPAD) index. The growth and crop productivity were also evaluated through of the leaf area index (LAI), the number and productivity of commercial roots and total biomass. In this research, the total irrigation depth was defined as the irrigation depth plus the effective rainfall. The estimated ETC was 1,030 mm over the 12-month production cycle and the greatest value for LAI and SPAD were 7.6 and 57.4, respectively, obtained in irrigated areas with the level of 80% of the ETC. While, in the areas irrigated with 120% of the ETC, were obtained the highest values of root productivity (93 Mg·ha–1), total biomass yield (149 Mg·ha–1) and photosynthetic rate (22.4 μmol CO2·m–2·s–1). On the other hand, with irrigation equivalent at 200% of the ETC were obtained the greatest values of internal CO2 concentration (245 μmol CO2·m–2·s–1), stomatal conductance (0.35 μmol H2O·m–2·s–1) and effective quantum efficiency (0.68).

ABSTRACT The climate risk zoning was carried out for cowpea cultivated in northeastern Amazonia, Pará state, Brazil. Système d’Analyse Régionale des Risques Agroclimatologiques (SARRA) crop model was used and calibrated from data obtained in field experiments conducted between 2013 and 2016 in Castanhal, state of Pará. Low climate risk areas were defined as those with water requirement satisfaction index (WRSI) greater than or equal to 0.5 during flowering and early grain development and less than 20 mm of total rainfall during grain maturation and harvest for at least 80% of the simulated sowings of the crop. Simulations of the current and future climate conditions were carried out with the regional climate modelling system version 4 (RegCM4) nested with the HadGEM2 global circulation model with RCP 4.5 IPCC-AR4 scenario. The results show that climate changes are likely to reduce the duration of the optimal period for sowing cowpea in the mentioned region.

ABSTRACT Phenology, bunch morphology, and must quality are essential factors to the selection of grapevine cultivars for winemaking. This study aimed to evaluate five grapevine hybrids grafted onto two rootstocks, looking for fruit with the best characteristics for producing wine. The hybrids studied were ‘BRS Lorena’, ‘IAC 21-14 Madalena’, ‘Moscatel de Jundiaí’, ‘Moscato Embrapa’ and ‘SR 0.501-17’ grafted onto ‘IAC 572 Jales’ and ‘IAC 766 Campinas’ rootstock. Phenology was evaluated weekly, and the number of days from pruning to sprouting, flowering, and maturation was calculated. Fruit production, bunch morphology, and must quality were evaluated for each genotype and rootstock. ‘SR 0.501-17’ was classified as a genotype with a medium cycle, with fruit maturing 20 days earlier than the other hybrids, which were, therefore, classified as late-cycling. No interaction was noted between hybrids and rootstocks relative to bunch morphology. The must of ‘Moscato Embrapa’ grafted onto ‘IAC 766 Campinas’ rootstock had higher maturation index than that grafted onto ‘IAC 572 Jales’ rootstock. ‘BRS Lorena’ and ‘SR 0.501-17’ produced smaller berries, must with medium acidity, and higher soluble solid contents, as compared with other hybrids, resulting in the best bunch morphology and must quality for winemaking.

ABSTRACT The agricultural use of biochar has been the focus of much research in the last decade due to the improvement of soil chemical, physical, and biological attributes. Nonetheless, Brazil still has no specific legislation for biochar, limiting its agricultural use. The objective of the present work is to evaluate the use of biochar produced from spent coffee grounds (SCG) and coffee parchment (CP) by slow pyrolysis at 700 °C according to the existing framework of the Brazilian Ministry of Agriculture, Livestock, and Food Supply (MAPA) legislation for organic fertilizer, soil conditioner or plant substrate. Biochar was characterized according to normative instructions No. 17, 31, 61, 7, 5 and 35. Although not required by the addressed legislation, the semitotal content of macro- and micronutrients was also determined. While CP biochar could be used as an organic fertilizer or plant substrate, SCG biochar, due to its higher Ni content and lower than required cation exchange capacity (CEC), did not meet MAPA legislation criteria to allow for its agricultural use. Future regulations can be based on the current standards, and structural attributes, such as total C content, particle size distribution, and complete macro- and micronutrient determination should be included. Further research may also indicate the viability of biochar use as a soil conditioner based on a more representative set of biomasses with a higher CEC. These considerations will help to take advantage of the benefits of biochar to soil, contributing to a circular economy, which is still at a difficult stage in Brazil.

ABSTRACT Soil quality indicators may have different seasonal trends during the year. The hypothesis of this study was that sowing maize and marandu palisadegrass with the presence of grazing animals might cause short-term changes in soil indicator responses. We compared four intercropping techniques: ICLS-1: maize plus marandu palisadegrass sown simultaneously, without herbicide; ICLS-2: maize plus marandu palisadegrass sown simultaneously, with herbicide; ICLS-3: maize plus marandu palisadegrass in lagged sowing (i.e., marandu palisadegrass sown 20 days after maize sowing); ICLS-4: maize plus marandu palisadegrass sown simultaneously (palisadegrass on the rows and inter-rows, with herbicide). Two control treatments in monoculture (i.e., grass and maize monocultures) represented the conventional systems. The soil was sampled three times over a one-year period, for the evaluation of carbon and nitrogen fractions as affected by seasonal variability. Results indicated that ICLS-1 and ICLS-4 enhanced soil quality more quickly during the seasonal variation. The ICLS-2 negatively affected microbial biomass (22%), resulting in reduced labile carbon (43%), carbon management index (33%), and potentially mineralizable nitrogen (20%). Labile carbon and the carbon management index were more sensitive and efficient indicators for verifying soil quality changes in the short-term. Results indicated that there is large variability in these soil indicators during the annual cycle, and further studies are needed to verify the effects of the tested systems on different soil nitrogen fractions and how they affect available nitrogen in the short-term. However, potentially mineralizable nitrogen can provide positive insights for short-term changes in the soil.

ABSTRACT The objective of this work was to evaluate the effects of low, ultra-low, and extremely low partial pressures of O2 in a controlled atmosphere (CA) and 1-methylcyclopropene (1-MCP) on the postharvest quality of ‘Cripps Pink’ apples. The treatments used were 21.00 kPa of O2 (cold storage [CS]), CS + 1-MCP, and CA conditions with 2.00, 1.00, 0.60 and 0.25 kPa of O2, without 1-MCP. All fruit were stored at 1.5 ± 0.2 °C, relative humidity (RH) 92 ± 2%, and partial pressure of CO2 < 0.5 kPa, for 4.5 and 8 months, followed by another seven days of shelf life (20 ± 2 °C/RH of 60 ± 5%). Respiration and ethylene production rates were reduced in all CA conditions and the CS + 1-MCP treatment when compared to the CS without 1-MCP, in both storage periods. The application of 1-MCP delayed ripening and reduced the quality loss of the fruits stored for 4.5 months. The CA with 0.6 and 0.25 kPa of O2 reduced the incidence of superficial scald, decay, mealiness, and skin greasiness, and maintained the background color of the epidermis of the fruits in storage for 8 months. Among the CA conditions, the treatment of 0.25 kPa presented the highest production of ethanol and acetaldehyde in the fruits stored for 8 months. Treatment of 0.6 kPa of O2 kept higher values of total phenolic compounds, in the peel and flesh, in both storage periods. Fruits stored under 0.6 kPa of O2 showed the best quality after 8 months of storage.

ABSTRACT The aim of the present study was to assess the relative competition between white clover (cv. BRS URS Entrevero) and weed species Silene gallica L. through replacement series. The experiments followed a completely randomized design with four replications. The first study showed that the shoot dry mass of both species (white clover and S. gallica) became constant with 16 plants.pot-1 or 400 plants.m-2. In 2017, a study was conducted and it was repeated in 2018 in order to assess white clover competition with S. gallica under different crop: weed proportions pot-1 (100:00; 75:25; 50:50; 25:75 and 00:100). Competitiveness analysis was carried out through diagrams applied to replace experiments and through the relative competition indices. Morphological parameters such as plant height, leaf area and shoot dry mass of the crop and the weed were measured when S. gallica plants bloomed (105 days after species emergence). Results have proven the phenotypic plasticity of temperate-climate foragers such as white clover. This outcome shows that the competitive relationship with Silene gallica changes due to plant proportions composing the association. Therefore, it was possible to conclude that the species show similar competitive ability.

ABSTRACT Nickel (Ni) was the latest element to have its nutritional essentiality recognized for plants (Brown et al. 1987). It is a component of various enzymes, including glyoxalases (family I), hydrogenases, superoxide dismutase and urease (Chen et al. 2009). Inadequate Ni supply promotes changes in the plant metabolism, including processes related to nitrogen metabolism, such as amino acids, urea and ureides metabolisms (Rodríguez-Jiménez et al. 2016; Bai et al. 2006). Legumes that are dependent on N2 fixation (e.g., soybean) have their process impaired by Ni deficiency, because this element is an essential catalytic cofactor of [NiFe]-hydrogenase, an enzyme found in some symbiotic bacteria that recycles the H2 produced by a side reaction of nitrogenase in root nodules formed by the plant-bacteria association (Cammack 1995; Bagyinka 2014). Moreover, Ni has shown the potential to control soybean diseases, such as powdery mildew (Barcelos et al. 2018) and Asian soybean rust (Einhardt et al. 2020a; 2020b).

ABSTRACT Heat stress can impact crop development and yield and amino acids play diverse essential roles in plants. This work aimed to study the long-term effects of foliar spray with L-arginine in antioxidant machinery, physiology, nutrition, productivity and fruit quality of tomato plants subjected to transient heat stresses. Six concentrations of L-arginine were sprayed on the plants: 0 (control), 0.10, 0.25, 0.50, 1.0 and 2.0 g·L–1. The content of hydrogen peroxide (H2O2), a reactive oxygen species, decreased concurrently to the increasing arginine concentration. The ascorbate peroxide (APX) activity had an inverse behavior to that observed for H2O2 content (r = –0.79), not only indicating that arginine is able to modulate APX, but also suggesting that this enzyme plays an important role on the mitigation of H2O2 generation under heat stress. Ascorbate peroxide and catalase (CAT) activities had a positive correlation (r = 0.82), showing that these enzymes may work in tandem. The influence of arginine on photosynthesis activity and gas exchange was generally weak and depended mainly on the plant developmental stage. Yield was increased by 19.8 and 23.1% in plants that received 1.0 and 0.5 g·L–1 of arginine, respectively, when compared to control plants. In conclusion, the use of exogenous L-arginine can protect tomato plants against oxidative imbalance under transient heat within protected environments.

ABSTRACT The present work explores a practical strategy for real-time assessment of foliar-based mineral fertilizers diffusion. Thereby, a dialysis tubing membrane was employed as a leaf cell-proxy for tracing the release of three commercial foliar fertilizer formulations and their correspondent primary compounds, MnCO3, Mg(OH)2, and Cu2O at the field-recommended concentration, by simply measuring changes on conductivity and pH during 96 h. It enabled either modulating fertilizer diffusion kinetics, as well as comparing the commercial formulations to its primary compound ones. Hence, the proposed approach stands out as a fast and effective tool for addressing relevant information about the performance of foliar fertilizer formulation, one of the bottlenecks of programs developing new fertilizer formulations.

ABSTRACT EnlistTM technology is a new trait on soybean and corn conferring tolerance to auxinic-type (2,4-D choline) and graminicides (aryloxyphenoxypropionates – FOPs) herbicides. However, the occurrence of volunteer corn tolerant to 2,4-D and FOPs can become a significant weed on soybean cropping systems, affecting the crop yield and reducing seed quality. This research aimed to evaluate herbicides to EnlistTM volunteer corn control and their effects on plant development, crop yield, and physiological seed quality of EnlistTM soybean. Field experiment was performed in a complete randomized block experimental design with four replicates, using a density of 10 plants·m-2 of EnlistTM volunteer corn. Treatments consisted of herbicides applied at 3-4-leaves stage of volunteer corn with haloxyfop-P-methyl, clethodim, pinoxaden, cloransulam-methyl and imazethapyr regarding to a control with and without volunteer corn. The development and yield components of EnlistTM soybean were evaluated and physiological seed testing performed on soybean’s seeds. Clethodim controlled EnlistTM volunteer corn, whereas haloxyfop-P-methyl, pinoxaden, and cloransulam-methyl showed insufficient control levels (30-35%) at 30 days after spray. Imazethapyr exhibited 84% of control of EnlistTM volunteer corn and injured the EnlistTM soybean, affecting its seed viability. EnlistTM volunteer corn interferences negatively the soybean crop yield, yield components, and affects the plant development pattern.

ABSTRACT A long-term experiment (2013 to 2017) of treated sewage effluent (TSE) levels via fertigation in a humid tropical region was installed in Jaboticabal, state of São Paulo, Southeast of Brazil, to evaluate the impact of TSE on soil fertility and the potential for salinization and heavy metal contamination of an Oxisol. The area was cultivated with Urochloa brizantha under the application of four TSE levels at the irrigation depth (0, 11, 60, and 100% TSE) during the four years of the experiment. The TSE chemical composition was monitored throughout the experimental period. The heavy metal levels and soil fertility were evaluated in the 0-0.10 and 0.10-0.20 m layers at the end of the four years of the experiment. Fertigation using TSE did not increase the concentration of potentially toxic elements (As, Cd, Cu, Hg, Mo, Ni, Pb, Se, and Zn) in the soil due to their low concentration in the effluent. A higher Na concentration was also observed at high TSE levels (60 and 100%). However, the sodium adsorption rate in the TSE was low, generating no potential for soil salinization and sodification. Fertigation with TSE levels increased soil fertility, increasing by more than 10% the P content and base saturation in the soil compared to control. According to the chemical attributes evaluated in the soil and effluent, this long-term study showed that TSE application via fertigation in humid tropical regions on clayey soils cultivated with forage grasses is recommended.

ABSTRACT This study aimed to find sources of resistance to damping-off and to determine the inheritance of resistance in watermelon. Firstly, 72 watermelon accessions were inoculated with CMM 1053 isolate of Rhizoctonia solani. Only two accessions (BGH 29 and BGH 76) were considered moderately resistant to the disease. The inoculated plants without symptoms from accession BGH-29 identified as resistant were self-fertilized and the inbred line S1 was used for the crosses. The reaction to R. solani after inoculation of the segregating populations of the cross and backcrosses between susceptible cultivar Crimson Sweet and the inbred line BGH-29 was evaluated. In other experiment eight S1 lines of watermelon were inoculated with six different isolates of R. solani and the reaction was evaluated by partial diallel analysis using the Griffing’s method IV to obtain estimates of general resistance ability (GRA), general aggressiveness ability (GAA), and specific interaction ability (SIA). According to ratings of the susceptible and resistant parents, generations F1, F2, BC1 (F1 × P1) and BC2 (F1 × P2), resistance to damping-off was conferred by at least nine genes with additive effect and low heritability which indicates polygenic inheritance. The results of the diallel analysis corroborate with the analysis of segregating population, indicating inheritance of resistance was horizontal, since 46.1% of the total sum of squares of the variation observed in the crosses was due to GRA, while the SIA corresponded to only 20.39% of variation. This is the first report about inheritance of resistance to damping-off caused by R. solani in watermelon.

ABSTRACT The aim of this study was to evaluate the effect of new Ca sources sprayed on ‘Fuji Suprema’ and ‘Maxi Gala’ apple trees on nutrient levels in leaves and fruit, as well as on fruit ripening features and quality at harvest time and after cold storage. Experiments were carried out in a commercial orchard planted with ‘Fuji Suprema’ and ‘Maxi Gala’ apple trees in Caçador, Santa Catarina state, Brazil. Application of different Ca sources and untreated trees were evaluated in each experiment. Fruit were harvested at two different ripening stages and analyzed based on the following variables: fruit ripening at harvest time, as well as fruit quality and incidence of physiological disorders after 210-day storage at 1 °C. Calcium applications did not change Ca levels in the leaves and of the whole fruit. Calcium levels in fruit peel increased in cultivars Maxi Gala and Fuji Suprema due to leaf Ca applications. ‘Maxi Gala’ apples recorded higher postharvest incidence of physiological disorders, such as greater loss of fruit firmness than ‘Fuji Suprema’ apples (Due to 1-methylcyclopropene [1-MCP] application on ‘Fuji Suprema’ apples). Calcium applications did not change fruit maturation (starch index and pulp firmness) or apple pulp firmness preservation in both cultivars, although they reduced the incidence of bitter pit disorder in ‘Maxi Gala’ apples. The new sources of Ca tested did not increase Ca contents, nor did they reduced the risk for physiological disorder compared to the standard CaCl2 treatment that has been commercially used for decades as the main Ca fertilizer.

ABSTRACT Biochar derived from coffee waste has been reported as a promising material for heavy metal sorption. However, if the intended use is environmental remediation, knowing the extent to which desorption may occur is critical. Thus, the objective of this work was to evaluate the efficiency of spent coffee ground (SCG) and coffee parchment (CP) biochars pyrolyzed at 700 °C under laboratory conditions, in the sorption of Cd and Pb from aqueous solutions, in a pH range from 2 to 10, and their retention after an induced desorption process with a 2.9 pH acetic acid solution. Both biochars were alkaline, and the initial pH of the solution had a large effect on the sorption capacity of SCG but a small effect on the sorption capacity of CP. The Pb sorption capacity was higher for CP (18.6 mg·g–1) than for SCG (11.4 mg·g–1), while both biochars had low Cd retention capacities (1.18 mg·g–1). Coffee parchment also showed the highest Pb retention (30% to 87%), while for Cd there was no difference between CP and SCG biochars. Our results showed that metal precipitation was the main mechanism for metal immobilization and CP biochar proved to be more reliable than SCG, mainly for Pb, due to its higher sorption capacity and lower metal release by desorption than SCG. These characteristics are particularly important for the use of biochar in environmental remediation. Besides that, the biochar production represents an eco-friendly destination for these feedstocks, contributing to the circular economy.