Resumo em Inglês:

ABSTRACT Improving the effectiveness of pesticide application for controlling insects, mites, and pathogens in coffee cultivation has been a major challenge for coffee farmers, researchers, and consultants. The present study aimed to assess the deposition and distribution of a brilliant blue tracer in the coffee canopy using Jacto’s Arbus 2000 Super Export EL and Kuhn’s Twister 2000 air blast sprayers at different application speeds (5 and 7 km h-1). The experiment was conducted using a randomized block design, with a 2 × 2 factorial arrangement (two sprayer models and two application speeds), with six replicates. After spraying, leaves were collected, and the deposition of the tracer was assessed using spectrophotometry. The canopy was divided into lower, middle, and upper heights, and subdivided into external and internal crown positions. The percentage difference in spray deposition between positions was termed relative spray deposition. Spray deposition in the internal crown differed only in the upper third section between sprayers. In the external crown, the application speed affected the deposition of tracer dye for both sprayers, whereas, in the internal crown, the application speed only affected the deposition of tracer dye in the upper crown section only when using the Arbus sprayer.

Resumo em Inglês:

ABSTRACT This research is related to the evaluation of vegetative growth parameters, initial yield and incidence of pests and diseases of twelve Arabica coffee cultivars submitted to the subtropical humidity environment of Vale do Ribeira Paulista, Brazil. The experiment was performed in the Experimental Campus of the UNESP in Registro, in a randomized block design, with three replications. Stem diameter, number of plagiotropic branches, plant height, number of internodes of plagiotropic branches, length of the first plagiotropic branch, incidence of brown eye spot and phoma leaf spot on coffee leaves, infestation by leaf miner and the yield of cultivars were evaluated. The results obtained allowed to conclude that: i) cultivars Catuaí Amarelo IAC 62, Catuaí Vermelho IAC 99 and Mundo Novo IAC 379-1 were higher than the others, with yield above the national average in 2020 and percentage of flat beans below 10%; ii) all cultivars evaluated showed a similar level of increment of variables that indicate plant growth and reproductive development; iii) the cultivation environment is favorable to infestation by the leaf miner and unfavorable to the incidence of rust; iv) The prevailing climatic conditions in the Vale do Ribeira Paulista is suitable for the production of Arabica coffee.

Resumo em Inglês:

ABSTRACT Brazil is the largest Coffea arabica L. producer and exporter in the world market. In view of the need for nitrogen fertilization, the objective of this work was to evaluate the use of digital images of coffee leaves as a function of nitrogen concentration and cultivars, as well as to evaluate the most adequate sampling of this technique to predict leaf nitrogen. The experiment was set in a greenhouse, at UNESP - Experimental Campus of Registro-SP, using 12L pots with medium sand. A completely randomized design was adopted, in a 4 x 2 factorial scheme, with four concentrations of N (0, 50, 100 and 200 mg dm-3), and two coffee cultivars (Mundo Novo and Obatã), with ten replications. The variables evaluated were: hue, dark green color index (DGCI), leaf area and leaf nitrogen content. The hue and DGCI were influenced by N concentration, cultivar and are dependent on the day after treatment application and the number of leaves used. The use of five leaves per replication was more adequate to estimate leaf N content. Hue, DGCI and leaf area were higher in Obatã depending on the day after application of the treatment and N concentration.

Resumo em Inglês:

ABSTRACT Seedling production is an important step in growing vegetables. The study of relationships between variables has applications in practically all areas of study and is useful in identifying relationships among quality variables in vegetable seedlings. Thus, this work aims to estimate linear relationships between biometric variables in lettuce seedlings. The seedlings were grown in expanded polystyrene trays (n = 4) with 128 and 200 cells each. Leaf area, stem diameter, shoot height, length, area, volume of the root, dry and fresh shoot mass variables were measured and evaluated with Pearson's correlation analysis, multicollinearity diagnosis, condition number and the variance inflation factor, path analysis and canonical correlations. The results show linear relationships between the variables. For the 128 cell trays, there was a relationship between the total fresh mass and fresh shoot mass variables and between the total fresh mass and dry shoot mass variables. For the 200-cell trays, significant correlation was observed between the characters total fresh mass and fresh shoot mass variables and between root area and root volume variables, indicating that the greater the total fresh mass, the greater the fresh shoot mass and the greater the root area, the greater the root volume.

Resumo em Inglês:

ABSTRACT The objective of this work was evaluating the nitrogen fertilization splitting on the performance of green corn, grown in rainfed system. The experiment was carried out in Forquilha, Ceará state. Two varieties of corn (Sweet and Gorutuba) were used in the experiment, grown in five types of nitrogen fertilization in the crop cycle (one; three; six; nine and twelve applications). The variables evaluated were: plant height, stem diameter, number of leaves of the plant, plant fresh mass, plant dry mass, ear mass plant-1, marketable ear mass plant-1, marketable husked ear mass plant-1, marketable unhusked ear mass plant-1, number of ear plant-1, number of marketable ear plant-1, length of husked marketable ear, length of marketable unhusked ear, diameter of marketable husked ear, diameter of marketable unhooked ear, number of rows marketable ear-1 and number of grains row-1 of marketable ear. The data were subjected to analysis of variance by the F test (P < 0.05) and the treatment means were compared by the test of Tukey (P < 0.05) and subjected to regression analysis. It was observed that the split of nitrogen fertilization promoted the development of the two varieties of corn studied. It was found that the split, performed in six applications, provided greater vegetative and reproductive development of the corn varieties.

Resumo em Inglês:

ABSTRACT Flower stems of the Heliconiaceae family are gaining more and more space in the Brazilian market of ornamental plants and further knowledge about quality, productivity, and postharvest management is necessary. The objective of the present study was to evaluate heliconiaceae cultivated in full sun in the central-west region of Brazil in terms of agronomic traits and to determine the post-harvest durability of floral stems submitted to cold storage. Accessions of Heliconia bihai cultivar Caribea, H. bihai cultivar Iris Red, and H. rauliniana were evaluated. Quantitative and qualitative morphological characteristics and the total number of flower stems produced and number of marketable stems were obtained. Postharvest longevity was tested in a cold chamber at 16 ºC and 19 ºC and at ambient temperature of 26 ºC. Morphological characteristics such as the length, diameter and fresh mass of flower stems, inflorescence length, and postharvest durability of the inflorescences were the most affected. The most important variables were the quality of flower stems, productivity of marketable stems, and postharvest durability. The studied heliconias presented agronomic characters within the commercialization standards, highlighting H. bihai (Caribea) which presented the highest productivity. The best storage temperature for all accessions evaluated was 16 °C.

Resumo em Inglês:

ABSTRACT Although acerola (Malpighia emarginata D.C.) has been suggested to be a climacteric fruit, little is known about its sensitivity to exogenous ethylene. The objective of the study was to evaluate the quality changes of acerola fruit at two harvest maturity stages in response to external ethylene application. ‘Flor Branca’ and ‘Junko’ acerolas were harvested at the maturity stages 1 (green fruit with density>1 g cm-3) and 2(green fruit with density <1 g cm-3) and were treated with 0 or 1,000 µL L-1 of ethylene for 24 hours at 12 ºC.The fruit were stored at 12 ºC with relative humidity of 90-95% for 14 days. Both cultivars harvested at the maturity stage 2 showed skin color change from green to red during storage, which was not observed in fruit harvested at the maturity stage 1.External ethylene had no effect on 'Flor Branca' and 'Junko' acerolas respiration rate, flesh firmness, skin color, weight loss, soluble solids (SS), titratable acidity (AT), SS/AT ratio, and ascorbic acid contents. The classification of green acerolas by density was an effective approach to determine fruit harvest maturity for fresh consumption.

Resumo em Inglês:

ABSTRACT “Purple top” is an emerging disease that affects solanaceous crops, reported mainly on Solanum tuberosum (potato). Additionally, Bactericera cockerelli has been reported as the insect vector of Candidatus Liberibacter solanacearum (CaLso), a pathogen that has been associated with this disease. However, the information about this disease in Andean fruit species such as Solanum betaceum (tree tomato), S. quitoense (naranjilla) and Physalis peruviana (cape gooseberry) is almost nil. This study was carried out in the Tumbaco Experimental Farm of INIAP to describe the phenotypic symptoms caused by this disease. Molecular diagnosis by PCR method was carried out to diagnose the causal agent associated with the symptomatology. The main symptoms observed were purple color leaves, smaller apical leaves, inward curvature edge leaves, over-sprouting, yellowish and stopped plant growth; however there also were asymptomatic plants. P. peruviana was the most susceptible species because showed 100% of incidence. CaLso was identified as the causal agent associated with this disease. These results contribute to understanding the expression of this disease in Andean fruit crops. However, more studies related to epidemiology, diagnostic methods, mixed infections, vector-pathogen interaction and disease control are required in order to generate information that allows a complete knowledge of this pest.

Resumo em Inglês:

ABSTRACT The cultivation of Cotton (Gossypium hirsutum) is trending in an upward expansion at Minas Gerais state, Brazil. Due this growth, the breeding program has been demanded for the knowledge about the genetic diversity and correlation between morpho-agronomic traits, to start interesting crosses. The objective of this work was to study the genetic diversity and the correlation network between morpho-agronomic traits of cotton genotypes. Two cotton accessions and five commercial cultivars: FM993, FMT701, FM910, DP604 and DP604BG were evaluated for 16 traits. The results revealed divergence between the genotypes. Unweighted pair-group method arithmetic average (UPGMA) analysis allocated the genotypes in three clusters, with DP604 and Accession 2 being the most divergent. The correlation network helped to visualize the association between traits, presenting a negative correlation between anthracnose with plant height (-0.465), plant vigor (-0.486) and main root length (-0.437). Also, even with some genotypes presenting a higher number of reproductive branches, the correlation for this trait with number of bolls showed a high significant value (0.68). Thus, the genotypes showed wide genetic diversity for the composition of future crosses in cotton breeding programs. The correlation network allowed the visualization of a medium to high correlation pattern for the morpho-agronomic traits.

Resumo em Inglês:

ABSTRACT The production of green maize is considerable important for various regions of Brazil. It is vital that breeding programs of public institutions seek to meet the needs of this market sector, which has a relevant social role, mainly on small properties. The aim of this study was to estimate the inbreeding depression and the genetic components (m + a and d) of characters associated with green maize production and quality in three populations of different genetic basis: the variety UFG-Samambaia (P1), and two populations formed by crossing the commercial hybrids (P2 e P3). The S1 progenies of each population, the three S0 populations, and two checks were evaluated in a 14 × 14 triple lattice design. Agronomic and ear quality traits were evaluated. Genetic variability and greater inbreeding depression were observed for most of the traits among the P1 progenies. In P2 and P3, greater inbreeding depression was observed for male flowering, ear weight without straw, ear diameter, ear weight, female flowering, breakage and lodging, and grain color. The traits of ear quality, important for green maize production, had greater inbreeding depression than the agronomic traits, indicating that inbreeding depression and exploitation of heterosis should be considered in the selection process for these traits.

Resumo em Inglês:

ABSTRACT One of the limiting factors for pecan production is the incidence of disease caused by Fusarium spp. which are a threat to orchards in the south of the country. Therefore, the study aimed to confirm the pathogenicity and evaluate the morphophysiological and molecular characteristics of Fusarium spp. associated with pecan in Rio Grande do Sul and Paraná. For this, samples of symptomatic plant material were collected, and potentially pathogenic isolates were evaluated for pathogenicity, by immersing the roots of the plants in a spore suspension of Fusarium spp. In addition, the severity of the disease was assessed using a rating scale according to the symptoms expressed by the plants. The isolates were also analyzed for morphophysiological variability, through evaluations of mycelial growth, colony and aerial mycelium pigmentation, and characteristics of reproductive structures. Molecular characterization was performed which amplify the region of the 1-alpha elongation factor and sequencing. Nineteen isolates were obtained, which were considered pathogenic, however, there was variability in their aggressiveness and morphophysiological characteristics. In addition, the sequencing was used to identify different species. Therefore, species of Fusarium are responsible for the occurrence of wilt in pecan in southern Brazil.

Resumo em Inglês:

ABSTRACT This work aimed to evaluate the efficacy of fungicides for controlling anthracnose (Colletotrichum gloeosporioides) on peach palm (Bactris gasipaes var. gasipaes) seedlings in nursery beds and in newly planted peach palms in the field. The nursery experiment included two fungicide combinations: [thiophanate-methyl + chlorothalonil (TM + C) and pyraclostrobin + epoxiconazole (P + E)], three application intervals (7, 14, and 21 days), and an additional nontreated control. The two field experiments with newly planted peach palms tested the fungicide combinations TM + C at 15-day intervals for 12 months after transplanting, comparing to the control without fungicide application. The severity of anthracnose was assessed, and it was used for calculating the area under the disease progress curve (AUDPC). The fungicides TM + C and E + P applied at 7-days intervals were effective in the control of anthracnose in peach palm seedlings, resulting in the lowest severities and AUDPC. The fungicide TM + C reduced the maximum disease severity and AUDPC under field conditions. However, differences in the final severity of anthracnose and stem diameter were not significant compared to the control. Therefore, the use of fungicides for control of anthracnose in the field is not necessary.

Resumo em Inglês:

ABSTRACT The aim of this study was to evaluate the damages caused by Diceraeus (=Dichelops) melacanthus in maize plants subjected to bioinoculation with or without imidacloprid seed treatment. In this study, five different combinations of bioinoculants and imidacloprid seed treatment were applied to maize seeds in a completely randomized design. The bioinoculants used were Azospirillum brasilense and Bradyrhizobium japonicum. From emergence, the plants were subjected to infestation with the stink bug D. melacanthus (one stink bug/plant), with permanence up to 21 days after emergence. After this period, the phytotechnical parameters (shoot and root) of the corn plants were evaluated. In general, plant height was higher when imidacloprid was applied, suggesting compatibility with bioinoculants. The chlorophyll a content was higher when bioinoculants were applied, regardless of whether imidacloprid was present. Finally, the results indicate that the bacteria A. brasilense and B. japonicum do not induce resistance to the level of D. melacanthus infestation used in the present study. Therefore, these bacteria can be used in combination with imidacloprid, allowing for greater plant height, higher chlorophyll a content, and reduced damage caused by D. melacanthus.

Resumo em Inglês:

ABSTRACT Some vegetables have the ability to accumulate cadmium (Cd)at levels that are toxic to most other plants. The objective of thisstudy was to evaluate the Cd accumulation and its toxic effects on edible vegetables. Three species were tested: watercress (Barbarea verna); chicory (Cichorium endivia); rocket (Eruca sativa) and four Cd doses (0; 1.5; 3.0; 6.0 mg kg-1), with three replications. We evaluated Cd concentration, fresh and dry mass and SPAD index. We calculated tolerance index (TI), translocation index (TR) and the transfer coefficient (TC). Rocket, chicory and watercress are susceptible to Cd contamination and chicory presented visual symptoms of toxicity (chlorosis and mass loss). The Cd contents above those allowed were 0.6; 0.56 and 1.03 mg kg-1 in rocket, watercress and chicory, respectively, these values were reached by applying doses from 1.5 mg kg-1 for rocket and 3 mg kg-1 for watercress and chicory.

Resumo em Inglês:

ABSTRACT The objective was to evaluate the quality of sunflower seeds classified according to their thickness and passed through the seeder-fertilizer dosing system under variation of the travel speed. A lot of M734 was classified by thickness passing the seeds through a set of oblong-hole sieves and two thicknesses were selected. A portion of the seeds with only the commercial classification was also reserved, named as non-classified. The biometric evaluation was done and the sowing was carried out at 5.0, 6.5, 8.0, 9.5 and 11.0 km h-1. The quality of the seeds was evaluated through: germination and first germination count, average time and percentage of emergence in sand, accelerated aging and tetrazolium test. The classification by thickness reduce the coefficient of variation of the length, width, thickness, and mass but seeds classification does not affect seed vigor and viability after sowing under speed variation. In the higher studied speed, the passage of seeds through the dosing mechanism reduces germination. The vigor is affected at 6.5 km h-1 speed by the accelerated aging test. According to the emergence in sand and tetrazolium test, speed variation does not affect the vigor and viability of sunflower seeds.

Resumo em Inglês:

ABSTRACT The incidence of the olive caterpillar Palpita forficifera is among the main phytosanitary problems in olive groves in Brazil, and the use of resistant cultivars can be a useful tool to be incorporated into an integrated management strategy of this pest. The objective of this study was to evaluate the consumption and oviposition of P. forficifera on three olive cultivars in laboratory bioassays, in order to identify a potential antixenosis-type resistance. The cultivars evaluated were Arbequina, Arbosana and Koroneiki. Oviposition free choice tests were carried on young trees of the cultivars, with 7 days old adults. For consumption, detached leaves from the different cultivars were used in no choice and free choice tests with 5th instar larvae. The oviposition of P. forficifera was similar in all three cultivars. As for consumption, in no choice test, Arbequina had a higher dry mass consumed, yet, in free choice tests, no significant difference was observed in the fresh and dry mass consumed on the three cultivars. These results suggest that none of the cultivars expressed antixenosis-type resistance.