Resumo em Inglês:

ABSTRACT The aim of this study was to estimate the percentage of deformed fruits (carpelloid, pentandric, and bananoid), summer sterility, repeatability coefficients, and correlations among the variables for floral abnormalities; and select genotypes withthe lowest incidence of deformed fruits and summer sterility. In theexperiment, which involved 254 plants, traits were evaluated using the digital-phenotypic method and the obtained images were processed and analysed using ImageJ v1.48 software with the Cell Counter plugin. Summer sterility had the highest percentage of occurrence in the evaluated periods. Based on the quantificationof total abnormalities, the 30 genotypes with the lowest incidence offloral abnormalities were selected. Summer sterility is the main problem of the papaya crop in terms of floral abnormalities. The non-significant correlations between the traits: NDF/TNF+NFN (number of deformed fruits/number of fruits + number of fruitless nodes) and NFS/TNF+NFN (number of fruitless nodes/number of fruits + number of fruitless nodes); NDF/TNF+NFN and NFN/SUM(number of fruitless nodes/sum of abnormalities); andNFS/TNF+NFN and NDF/SUM (number of deformed fruits/sum of abnormalities) indicate that the variables are independent of each other. Of the 254 evaluated progenies, at least 30 were identified as having potential for selection, with lower occurrence of total floral abnormalities.

Resumo em Inglês:

ABSTRACT The cultivation of genotypes non-adapted to the cultivation region of interest is among the main factors responsible for low yield. The aim of the present study is to select hybrid maize through GGE biplot analysis and to assess its adaptability and stability in different environments in Northeastern Brazil. Twenty-five hybrid maize cultivars were assessed in ten different environments in Northeastern Brazil in 2012 and 2013 based on the randomized block design, with two replications. The analysis of variance and assessment of genotype adaptability and stability were made through GGE biplot analysis, based on grain yield. Analysis of variance results showed different performances depending on the genotype, as well as genotype/environment interaction. The biplot analysis was efficient on data interpretation and represented 63.73% of the total variation in the first two main components, it also allowed classifying the ten environments into three macro-environments. Most environments were positively correlated. Hybrids 2 B 604 HX, 30 A 95 HX, 2 B 587 HX and 2 B 710 HX were responsive and stable. Hybrid 30 A 16 HX was recommended for macro-environments2 and 3. Cultivar 30 A 68 HX was recommended to environment 1. São Raimundo das Mangabeiras and Nova Santa Rosa counties were discriminating and representative. Nossa Senhora das Dores, Umbaúba, Teresina, Brejo, Frei Paulo, Colinas and Balsa counties were ambiguous and non-recommended for further evaluations.

Resumo em Inglês:

ABSTRACT In the present study it is hypothesized that the germplasm of popcorn of tropical regions shows resistance to FAW, and the multivariate analysis can characterize the main traits of this resistance. Thus, the aim of this study was to identify key traits used to select fall armyworm resistance in popcorn by using factor and cluster analyses. Sixteen biological traits were evaluated at larval and pupae stages: total number of armyworm, time larval period, final mass of caterpillars, total mass of caterpillars, mean mass of caterpillars, pupae period, mass of pupae and some indices used to evaluate the food consumed by the caterpillars. Multicollinearity diagnosis, factor and canonical analysis, and the genetic divergence among the genotypes were performed to implement multivariate analysis. The groups were established according to Mojena (1977). After multicollinearity test, only five traits were retained for further analysis. The factor analysis divided the five traits into two factors: the first factor included time larval period, metabolized food and mass of pupae; the second was composed of total number of armyworm and stool mass. Unweighted Pair Group Method with Arithmetic Mean (UPGMA) grouped the eighteen genotypes in three clusters. The present study provides insights of popcorn resistance to fall armyworm, and the multivariate analytical approach used here is directly applicable to any species and set of traits exhibiting correlation.

Resumo em Inglês:

ABSTRACT Maize is one of the species with greater genetic diversity among cereals and possibly the most diverse crop species known. Accessing this variability is essential for maize breeding, allowing breeders to achieve progress of yield increasing, overcome environmental challenges or deal with pests and diseases. Among the maize diseases, southern rust is one of the most important, causing significant losses in yield and presenting severe epidemics worldwide. In the present study, the AFLP technique was applied to analyze population structure and genetic diversity among 145 tropical maize inbred lines, and to test for preliminary evidence of association between AFLP markers and the reaction to southern rust. Disease severity was evaluated in two crop seasons and the accessions were genotyped through AFLP using four primer combinations. The clusters obtained based on the Jaccard genetic distance and Ward’s hierarchical clustering and those achieved by structure simulations had high concordance and were capable of establish two big clusters, one predominantly of common maize and another of popcorn. The association analysis was performed using four different statistical models. The more complete model containing both population structure and genetic relatedness narrowed the number of significant associations, demonstrating its importance to control false associations. A total of 19 significant marker associations were identified from which three (EactMctg18, EactMctg205, EactMctg169) are interesting candidates for further investigations.

Resumo em Inglês:

ABSTRACT The cultivation of second-harvest with soybean crop after first-harvest with maize crop has become an alternative to aggregate income to farmers in the South region of Brazil. However, there is little information about this cropping system in this region. The aims of this study were to: (i) evaluate the agronomic performance of soybean (Glycine max L.) cultivars growing in second-harvest during the summer; and (ii) evaluate the genetic divergence of the cultivars based on qualitative and quantitative traits. To do this, 18 soybean cultivars were evaluated in three field trials, sown during January in the northwestern region of Rio Grande do Sul state, Brazil. In each experiment, a randomized block design with four replicates was used. Five quantitative traits (representing the agronomic performance of the cultivars) and 12 qualitative traits (morphological descriptors) were assessed aiming at studying the genetic divergence. Variance components and genetic parameters were estimated using mixed models and BLUPs for genotypes were estimated for each quantitative trait. The cultivars FPS Iguaçu RR and BMX Turbo RR have good agronomic performance and are, based on quantitative and qualitative traits, genetically distant. These cultivars have shown agronomic features that allow their cultivation in the second-harvest in the northwestern of Rio Grande do Sul in addition to be potential genitors for future soybean breeding programs.

Resumo em Inglês:

ABSTRACT An alternative to increase yield without raising the production costs and minimizing the dependence of agricultural inputs is the development of maize genotypes presenting high nitrogen (N) use efficiency under low N level conditions. Thus, the objective of this study was to estimate the specific combining ability of maize top-crosses under high and low nitrogen (N) conditions and to select high-yielding hybrids for both conditions. The grain yield of 110 top-cross hybrids was evaluated in 2012 in two locations in the Brazilian Midwest. Partial diallel analysis was performed with the adjusted means of each of the individual top-cross analyses. Specific combining ability (SCA) of the hybrids and their interaction with N levels was estimated for each location. The mean grain yield of the 11 hybrids selected by the highest SCA estimates for high and low N was higher than the controls mean in approximately 330 and 241 kg∙ha-1. These results demonstrate that the selection for each environment was efficient and reveals the possibility of developing new hybrids for the Brazilian Cerrado region.

Resumo em Inglês:

ABSTRACT Parental plants, an F1 interspecific hybrid and the F2 generation from Arabusta coffee plants were investigated for meiotic behavior and viability of pollen to understand part of their reproductive biology that affects their possible use in coffee breeding programs. Both parental plants (C. canephora var. Robusta 4x and C. arabica var. dihaploid Bourbon Vermelho) showed a meiosis diploid-like behavior, despite presenting a small percentage of irregularities, just as occurred for the F1 Arabusta hybrid. On the other hand, all F2 plants showeda higher frequency of anomalies that compromised pollen viability. The highest meiotic indices were registered for three analyzed plants of the F2 generation, and the pollen viability tests revealed the highest values for staining (PVS) and germination in vitro tests (PVG) for three others different F2 plants. The meiotic analysis and pollen viability tests may facilitate the selection of the best genetic resources, reducing the time needed for producing new hybrid cultivars. F2 plants which have high meiotic indices and/or high pollen fertility could be used as pollen donors in crossbreeding programs when there is interest in their functional or morphological characteristics. In contrast, the F2 plants that showed low pollen viability could be exploited as sterile male plants or discarded from a breeding program.

Resumo em Inglês:

ASBTRACT Peach as commercial crop in Brazil is usually grown in open vase training system. However, in the 1970s large orchards changed to the Y-shaped system and higher density of plants. This system is the most used in São Paulo state because it allows orchard densification. However, the longevity of the trees is reduced from 15 to 8 years being the excessive exposure of internal branches to solar radiation the main reason for the reduction. Aiming to offer new alternatives of training system for peach, an experiment was carried out to evaluate the fruiting wall in comparison to Y-shaped, using the cultivar Tropic Beauty budded onto cultivar Okinawa. Ten plants by treatment were used as repetition and microclimatic equipment was installed inside the plant to measure temperature and solar radiation. Values of soluble solids (°Brix) were 9.64 to fruiting wall and 9.59 to Y-shaped, not statistically different. However most of fruit physicochemical characteristics were favorable to the fruiting wall system: fruit weight (g) – 97.56 and 90.44; pulp yield (g) – 92.42 and 85.70; pulp firmness (Kg∙cm–2) – 4.27 and 3.50; titratable acidity (g citric ac.∙100 ml–1) – 0.76 and 0.71; and ratio – 12.79 and 13.58, respectively to fruiting wall and Y-shaped. Solar radiation transmission and maximum daily temperature values for the Y-shaped were higher when compared to fruiting wall at harvest. The obtained data show that the fruiting wall training system could be an alternative to Brazilian’s growers for producing superior fruit quality without yield reduction.

Resumo em Inglês:

ABSTRACT Although Brazil is the sixth producer of mandarins in the world, fresh fruit exports are neglectable, and few cultivars are available for the domestic market. Main harvest season comprises May to November, with Ponkan mandarin and Murcott tangor representing more than 70% of the production. Therefore, there is a need for alternative early season, seedless varieties that should also be preferably resistant to Alternaria brown spot. We investigated the horticultural performance of ten selections of Satsuma mandarin in subtropical conditions in Bebedouro, northern state of São Paulo, Brazil. Clausellina, Okitsu, Unshu SRA-529, Saigon SRA-227, Panaché SRA-579, Salzara SRA-341, Miyagawa SRA-444, Kowano SRA-167, FCAV-59 and A2 60.0 selections were grafted on Swingle citrumelo and evaluated up to 7 years old. Unshu, Miyagawa and A2 60.0 presented the highest tree size. These three selections, in addition to Okitsu and Kowano mandarins, resulted in higher fruit yield for the five first harvests (mean of 31.3 kg∙tree–1∙year–1). Panaché had the smallest yield efficiency. Miyagawa and A2 60.0 selections presented lower alternate fruit bearing in the evaluated period due to their early bearing habit. These same selections had the largest fruits with the earliest maturation; similar to the Okitsu mandarin, but with lower soluble solids and higher juice content. The overall performance of the Satsuma mandarin selections grafted on Swingle citrumelo and drip irrigated was promising under subtropical climate. The Okitsu, Miyagawa and A2 60.0 mandarins were selected because of their highest productive potential and their valuable quality traits for the Brazilian domestic market.

Resumo em Inglês:

ABSTRACT The aim of this study was to identify resistance of tolerance type in Citrus and Poncirus genotypes towards the citrus leafminer (CLM), Phyllocnistis citrella. The quantitative variables leaf and shoot lengths, leaf width, number of larvae and new shoots, and fresh and dry shoots weights, and qualitative variables associated with foliar damage were evaluated in six Citrus-related genotypes infested with CLM. In preliminary trials with lime Rough lemon (C. jambhiri), the variables that best discriminated the infestation effect of CLM were established as the numbers of larvae and new shoots per plant together with the percentages of partially rolled leaves (PRL), rolled leaves (RL) and total damage (TD = RL + PRL). In subsequent tests with all six genotypes, the variables new shoots per plant, percentage of attacked but not rolled leaves (ANRL), RL and TD were found to be significant. Trifoliata Limeira (P. trifoliata) and hybrid C × R4 (C. sunki × P. trifoliata) presented the lowest percentages of RL and TD and the highest values of ANRL. A cluster analysis was performed considering all the variables analyzed and the most tolerant genotypes for CLM, namely hybridsC × R4, C × R315 (C. sunki × P. trifoliata), M × P222 [C. sinensis × Tangor Murcott (C. reticulata × C. sinensis)] and Trifoliata Limeira (P. trifoliata) were grouped apart from the less tolerant genotypes Sunki mandarin (C. sunki) and lime Rough lemon. In conclusion, genotypes Trifoliata Limeira and its hybrid C × R4 are the most tolerant to CLM.

Resumo em Inglês:

ABSTRACT The generation of sewage sludge and the concern with their fate has greatly increased. The objective of this study was to assess the effects of using in natura (SS) or composted sewage sludge (SSC) in comparison with mineral fertilizer (MF) application and a control (CT) treatment on the nutritional status of Guanandi (Calophyllum brasiliense Cambess.) seedlings in a typical Red Oxisol in Brazil. The leaf-level nutritional responses of the Guanandi seedlings to these three different fertilizers and the control were evaluated at 90 and 180 days after planting. Nutritional data of leaf variables were compared between the treatments by means of one-way analysis of variance using the F test and a pair-wise comparison of means done by Tukey’s test. The seedlings that received SS or SSC showed deficiencies in Ca, Mg, and Mn, which were confirmed by a visual diagnosis of their leaf symptoms. However, at 180 days after planting there were significant differences (p < 0.05) for K that was greater for MF, SS and SSC than CT, Mg, with SSC larger than SS, and for S that was greater with SS and SSC uses relative to MF. The results highlight the potential for using SS and SSC, after adding KCl and lime, although the Guanandi was highly demanding of Ca, Mg, and Mn. However, they were able to nutritionally supply seedlings, although the short-term cannot be conclusive as regards the exclusive use of them in place of mineral fertilizers.

Resumo em Inglês:

ABSTRACT Since there is no consensus on phosphogypsum (PG) rates to be used in agriculture, a better understanding of its effects on the soil solution is needed. Cotton root growth was evaluated as related to Al and Ca activity in soil solution affected by PG. The experiment was carried out in rhizotrons filled with30∙dm–3 of soil. PG rates were estimated by multiplying the soil clay content by 0.0, 1.5, 3.0, 6.0 and 12.0, and it was mixed to the sub-soil.In the upper soil layer, limestone was applied. After 90 days, samples were taken for analysis, and cotton was planted. After27 days, plants were harvested. PG increased soil pH and decreased Al content and activity. Without PG, dissolved organic carbon concentration was high in the soil solution, which explains the predominance of carbon Al-complexed with PG application. From 1,680 kg∙ha–1 of PG (corresponding to 6 × clay content), sulphur and calcium had the highest concentrations, increasing the SO4 Al-complexed. Cotton root length decreased in the upper layer and increased in the subsoil up to 2,324 kg∙ha–1 (corresponding to 8.3 × clay content) of PG. Cotton root growth is better related with soil properties than with soil solution attributes, and the present recommendations for PG use based on soil clay content underestimate the rate to be applied.

Resumo em Inglês:

ABSTRACT Consumers around the world appreciate strawberries for their taste. They have low calories and high concentrations of soluble fibers, vitamin C and flavonoids. This paper verified the combined effect of O2, CO2, and N2O levels on ‘Oso Grande’ strawberries stored at 10° C, under controlled atmosphere (CA). Five different gas mixtures were used: 0.03 kPa CO2 + 20 kPa O2, 80 kPa N2O + 20 kPa O2, 90 kPa O2 + 10 kPa N2, 60 kPa O2 +40 kPa CO2, and 20 kPa O2 + 20 kPa CO2 + 60 kPa N2O. The lowest incidence of postharvest decay was observed with treatment20 kPa O2 + 20 kPa CO2 + 60 kPa N2O, followed by 80 kPa N2O +20 kPa O2 and 90 kPa O2 + 10 kPa N2. The treatment 60 kPa O2 + 40 kPa CO2 induced an increase in the production of acetaldehyde and ethanol, and these levels were considered inadequate for human consumption. The first factor, named senescence, displayed a positive correlation with soluble solids, luminosity, hue angle, firmness and incidence of decay. hpsThe second factor, named CA-induced injury, showedhps that total acidity correlated negatively with ethanol and acetaldehyde levels. Hiehpsrarchical cluster analysis indicated that strawberries stored underhps80 kPa N2O + 20 kPa O2hps for 14hps hpsdays more closely resembled the quality of fresh fruit at the moment of harvesthps. ‘Oso Grande’ strawberries stored at 10 ºC under 80 kPa N2O + 20 kPa O2 and 90 kPa O2 +10 kPa N2 were in better conditions, with no metabolic alterations, showing that these are the ideal storage conditions.

Resumo em Inglês:

ABSTRACT Nineteen genotypes of bananas and plantains were analysed in order to differentiate the subgroups and/or groups of consumption or industrial use. Genotypes of banana and plantain from different genomic groups and in three ripening stages (2, 5 and 7) were studied in relation to physical and physicochemical characteristics, including bioactive compounds. Furthermore, with the obtained data analysed by multivariate statistical analyses (Principal Component Analysis) it was possible to relate all analysed characteristic profile of samples with the different genotype. The three ripening stages were differentiate by total soluble solids, titratable acidity, chrome (C*) and the carotenoids contents. ‘Ney Poovan’ contain high total soluble solid content and pulp-to-peel ratio, an interesting result for the promotion of this genotype for in natura consumption. ‘Ney Poovan’, ‘Ouro da Mata’, ‘Pelipita’ and ‘Tiparot’ are sources of antioxidant compounds. The genotypes ‘Pelipita’ and ‘Samurá B’ are promising for the industrial use, mainly for the processing of banana chips, for both green and ripe fruit.

Resumo em Inglês:

ABSTRACT In vineyards, the monitoring of leaf area is used to guide management practices in order to produce grapes with quality and enological potential. Remote sensing has been used to estimate leaf area by means of vegetation indices. This work aimed at determining the temporal evolution of the Normalized Difference Vegetation Index (NDVI) while associating it with leaf area of vineyards in the Serra Gaúcha region, Brazil. To this end, between 10 and 20 plants were evaluated monthly (September to May) in three vegetative seasons. NDVI data were obtained using the remote sensor Greenseeker while the following leaf area related parameters were obtained non-destructively: unit leaf area (ULA), average number of leaves per branch (NLB), plant leaf area (PLA), leaf area index (LAI) and chlorophyll index (CI). Data correlation was assessed by joint temporal analysis and Pearson correlations (p < 0.05). The results indicated that NDVI variation over time is coherent with the leaf area dynamics and expresses biomass variations due to phenology and management actions. The NDVI evolution pattern is described by a quadratic regression equation: the index increases rapidly at first (September to November), followed by a relative stabilization (December to February), and decreases in the final stage (March to May). The correlations were higher in the initial and final stages of the cycle, especially for NLB (r = 0.73 and 0.77), PLA (r = 0.60 and 0.61) and CI (r = 0.48 and 0.84), which are promising parameters for characterizing leaf area in vineyards by remote sensing.