Revista Ceres

In vitro seed germination, seedling development and aclimattization of Actinocephalus polyanthus (bong.) Sano, an endemic everlasting flower species

2025-08-21T10:56:43-03:00

Actinocephalus polyanthus (bong.) Sano (Eriocaulaceae) is an everlasting endemic endemic to Brazil with great potential for use in landscaping and as a cut flower on the national and international markets. In order to ensure that its use as an ornamental plant does not jeopardise populations of the species in areas of natural occurrence, as well as to avoid predatory extraction, the development of protocols for its propagation is extremely important. However, no protocol for the in vitro propagation of Actinocephalus polyanthus has been reported in the literature. The aim of this study was to establish a protocol for the germination, seedling development and acclimatization of A. polyanthus. The use of Wood plant medium culture medium at concentrations of 75 and 100% proved to be the most effective for germinating the seeds, but it was not the best medium for growing the seedlings, given that for the growth phase the medium was MS at the highest concentrations, also 75 and 100% salt concentrations, for acclimatization the use of a shading screen proved to be the most effective and the use of washed sand or carolina soil were the best substrates

Etiology, incidence, and severity of downy mildew infecting quinoa crops in Cauca, Colombia

2025-09-02T08:29:46-03:00

Downy mildew, caused by Peronospora variabilis, is one of the most limiting diseases affecting quinoa (Chenopodium quinoa) cultivation worldwide. In Colombia, there are few studies on this pathosystem. Therefore, the objective of this research was to determine the etiology, incidence, and severity of downy mildew in quinoa-producing areas in the department of Cauca. Commercial crops in the municipalities of Bolívar, La Vega, Silvia, and Totoró were visited to determine the incidence and severity of the disease, and symptomatic tissue samples were collected for studying the causal agent. The pathogen was morphologically identified using taxonomic keys and confirmed through phylogenetic analysis of the ITS and COX regions. To validate Koch’s postulates, inoculations were performed using a sporangiospore suspension on healthy quinoa leaf tissue. Downy mildew was detected in all four municipalities, with incidence ranging from 3.3% to 96.7% and severity between 0.8% and 66.3%. Morphometric and molecular analyses confirmed the identity of P. variabilis. Pathogenicity was verified 10 days after inoculation by observing symptoms and signs on the tissue. This study presents the first confirmed report of downy mildew caused by P. variabilis in quinoa crops in Colombia.

First record of Crypticerya brasiliensis (Hemiptera: Monophlebidae) on pequi trees (Caryocar brasiliense, Caryocaraceae) in the Brazilian Cerrado

2025-10-03T08:29:41-03:00

Crypticerya brasiliensis (Hempel, 1900) (Hemiptera: Monophlebidae) is a scale insect that has recently been observed in some native and exotic plants from the Brazilian Cerrado. This study reports for the first time the occurrence of C. brasiliensis in pequi trees (Caryocar brasiliense Camb., Caryocaraceae). Infestations were found in two pequi trees located in the urban area of Brasília, Distrito Federal, Brazil. This is the first report of the occurrence of a monophlebid associated with the Caryocaraceae family.

First record of Cadra cautella (Walker, 1853) (Lepidoptera: Pyralidae) infesting Brazil nut (Bertholletia excelsa) in Nova Califórnia, Rondônia, Brazil

2025-11-03T15:29:02-03:00

This study presents the first record of Cadra cautella (Walker, 1853) (Lepidoptera: Pyralidae) infesting Brazil nut kernels (Bertholletia excelsa Humboldt & Bonpland) in the Nova Califórnia district, Porto Velho, Rondônia, Brazil. In April 2024, microlepidopterans were found in stored Brazil nuts. A sample of infested nuts was collected and sent to the Entomology Laboratory at Embrapa Acre. From these samples, six adult lepidopterans emerged, which were identified as C. cautella, a cosmopolitan pest that infests food products during storage. This polyphagous insect causes significant damage to stored products by creating holes and galleries in the kernels, which favors the development of filamentous fungi and contamination by mycotoxins, rendering the nuts unsuitable for consumption. Identifying pests and understanding their economic impact is essential for developing control strategies and preventing losses. This record represents an initial step toward studies to mitigate infestations in Brazil nuts and preserve the quality of stored products.

Nutrient Omission in Corn Plant Development Cultivated in Nutrient Solution

2025-08-21T11:36:07-03:00

Correções do artigo publicado anteriormente.

Influence of 6-benzylaminopurine and culture medium on the regeneration of axillary shoots of Psidium cattleyanum Sabine cultivars Ya-cy and Irapuã

2025-09-02T08:58:21-03:00

Psidium cattleyanum, commonly known as araçá, is a fruit tree valued for its nutritional benefits and is increasingly consumed fresh and processed. However, the genetic variability within its populations makes selecting and propagating individuals with desirable traits challenging. This study aimed to optimize the in vitro shoot regeneration from axillary buds of Irapuã and Ya-cy cultivars using a complete MS culture medium and half-strength MS basal salts (MS/2), supplemented with 6-benzylaminopurine (BAP). Apical shoots from in vitro germinated plantlets were placed on MS or MS/2 medium, supplemented with 2.2, 4.4, or 8.8 µM BAP, and a control without BAP. For the Irapuã cultivar, the highest shoot regeneration rate was achieved on MS/2 medium with 2.2 µM BAP during the third subculture, resulting in 100% of the explants producing shoots. In contrast, the Ya-cy cultivar showed the best results on MS/2 medium with 4.4 µM BAP, yielding up to 78.3% shoot formation in the first subculture. Both cultivars were rooted on MS/2 culture medium without plant growth regulators, with cv. Irapuã achieving up to 100% rooting and cv. Ya-cy 41.2%. A micropropagation protocol was successfully developed for the Irapuã and Ya-cy cultivars.

Combining genetic potential for early maturitty and grain yield in soybean

2025-05-06T09:40:10-03:00

The aim of the work was to employ general and specific combinatorial capacity to select possible genetic bases and parents that meet the agronomic ideotype of soybean precocity and grain yield. The experiment was conducted at the Regional University of the State of Rio Grande do Sul. The experimental design used was that of augmented blocks, with interspersed controls, with treatments distributed in four blocks allocated throughout the experiment. To reduce pod insertion height, specific breeding strategies are suggested. For the ideal plant height, line 195 is selected. Lines 262 and 286 are chosen for their early maturity traits, while lines 893 and 661 are selected to improve grain weight per plant. These selections aim to enhance plant growth and yield. The general and specific combining capacity allows the selection of additive and complementary gene constitutions for insertion height of the first pods with the parents Massal Maradona RR 15b70 IPRO, plant height with HO Puricá x HO Jacuí IPRO, precocity through TMG 7262 RR x 15b70 IPRO, grain yield attributes through NS 6700 IPRO x BMX Valente 6968 RSF and DM 7.0 BMX Magna x BMX Ativa RR.

Stability of wheat genotypes for grain yield using the GGE Biplot methodology

2025-11-03T15:09:36-03:00

Wheat plays an important role in global agriculture, being one of the most widely cultivated cereals. Wheat cultivation in each region depends on the stability of grain yield in the given environment. The objective of this study was to identify the most productive and stable genotypes over three years of cultivation in the municipality of Frederico Westphalen, using GGE Biplot analysis. Twelve wheat genotypes were cultivated in a randomized complete block design, with three replicates over three years from 2019 to 2021. The experimental units consisted of six 4-meter rows, spaced 0.17 m apart. Grain yield was measured 3 meters from the four central rows. The data obtained was subjected to analysis of variance, which verified interactions between genotypes and years, and then performed GGE Biplot analysis. The grain yield of the wheat genotypes was influenced by the environmental conditions during the three years of cultivation. The genotypes UFSMFW 1-07 and USFMFW 1-04 were more productive in specific years, with the best performance for grain yield and stability being that of the genotype UFSMFW 1-08.

Leaf extracts of Clusia fluminensis Planck & Triana with allelopathic potential

2025-06-30T08:15:20-03:00

Our goal was to evaluate the bioherbicide effect of ethanol extract and its fractions of increasing polarity derived from the leaves of Clusia fluminensis, on the germination and initial growth of Lactuca sativa (lettuce) and Megathyrsus maximus (guinea grass), as well as their activity in the catalase, peroxidase, and superoxide dismutase enzymes. For the antioxidant capacity, the DPPH, ABTS, FRAP and phosphomolybdenum tests were used, in addition to the pigment content analysis. Chemical analyses were performed by quantification of total phenol, tannin, and flavonoid contents. The ethyl acetate fraction showed the best result, at concentration 0.75mg/mL, with less influence on lettuces seeds and greater influence on guinea grass seeds. In treatments with ethyl acetate fraction, there was a significant increase in the activity of the three enzymes in lettuce seeds, up to 67% in catalase. The catalase and dismutase enzyme activity decrease in 30% and 19%, respectively in guinea grass seeds. The presence of total phenols, tannins, and flavonoids on the ethyl acetate fraction allow a correlation to the most significant antioxidant activity by the ABTS, DPPH and FRAP assays. The results, therefore, suggest that the ethyl acetate fraction from leaves of C. fluminensis showed phytotoxic potential.

Dragon fruit jelly: exploring the potential of peel in post-harvest loss reduction

2025-05-06T08:57:23-03:00

The aim of this work was to evaluate the potential use of the peel of pitaya fruits for jam production. Four pitaya jelly formulations with different peel proportions used in place of the pulp (0, 20, 40 and 60%) were evaluated. The inclusion of peel in the formulation of red pitaya jelly is viable, and the product quality is maintained, especially at a 20% peel proportion, which is better accepted by tasters than are higher proportions. The 20% substitution of pulp with peel resulted in higher mean consistency and overall impression values than the other formulations. The levels of soluble solids and titratable acidity and the soluble solids/titratable acidity ratio did not significantly differ among the products, with mean values of 64.6%, 1.05%, and 61.67% with 20%, 40% and 60% peel addition, respectively. Substituting pulp with pitaya mesocarp resulted in an increase in jelly pH. The adhesiveness and cohesiveness of the jellies increased as the percentage of peel increased. The microbiological results of this study indicate the absence of microorganisms in the jellies. Thus, the use of peel in jam production can minimize production losses while adding value to the product and reducing waste disposal in the environment.

Impact of leaf age on common fig susceptibility to rust caused by Cerotelium fici

2025-05-06T11:03:32-03:00

Rust caused by Cerotelium fici leads to significant defoliation in common fig trees (Ficus carica). However, studies on its epidemiology remain scarce. The aim of the present study is to investigate common fig rust progress in leaves inoculated at different ages over two growing seasons (dry and rainy) in an experimental fig orchard. Artificially inoculated leaves and those exposed to natural infection showed more severe rust symptoms when they were inoculated earlier - up to 45 days after leaf emergence. Disease severity and leaf longevity (in days) were inversely and directly proportional to leaf age at inoculation time, respectively. Leaves inoculated at earlier presented significantly higher disease progression rates based on number of pustules per cm², broader area under the disease progress curve (AUDPC) recorded for pustule density and higher maximum severity, which was visually estimated as the percentage of lesioned leaf area. Inoculated young leaves abscised 40 to 60 days earlier than the uninoculated leaves, which were protected from natural infection by plastic bags. The uninoculated leaves remained attached to the plants from 90 to 100 days. These findings highlight apical sprouts as primary targets for protective fungicide applications, which must be more intense at early growing season in order control rust in common fig crops.

Rootstocks for ‘Valência’ sweet-orange in Santa Catarina in the context of plant size and spacing reduction

2025-06-09T10:11:57-03:00

Citrus orchards have been planted in higher tree densities, which encourage the use of rootstocks that reduce scion tree size. The performance of low-vigor rootstocks with ‘Valência’ orange is not well known, especially in southern Brazil. The objective of this work is to compare the agronomic performance of ‘Valência’ sweet orange grafted on seventeen rootstocks in western Santa Catarina, Brazil, and analyze the results in light of the search for small trees for orchards with narrower spacing. An experiment was conducted over 10 years for evaluation of seventeen rootstocks, concerning tree size, yield and fruit quality. The rootstocks were classified in Standard (six genotypes, including ‘Swingle’, main rootstock in Santa Catarina), Super-standard (two genotypes), Semi-standard (seven genotypes) and Dwarf (two genotypes). An estimated hectare yield was calculated after a tree spacing adjustment based on tree diameter. In conclusion, the citrandarin ‘San Diego’ forms trees similar in size to the widespread citrumelo ‘Swingle’, but is more productive, and maintains the quality of the fruit. ‘Fepagro C37 Dornelles’ reduces ‘Valência’ tree size, facilitates fruit harvest and induces it to produce big, good quality fruits. Dwarf rootstocks lead to a low hectare yield even in reduced space orchards.

Beneficial rhizobacteria and cover crops on soybean development

2025-06-09T10:36:54-03:00

Soybean cultivation holds national and international significance, necessitating sustainable production practices. This study evaluated the impact of plant growth-promoting rhizobacteria (PGPR) and cover crops on soybean yield components and grain yield. The experiment followed a randomized block design in a 5 × 2 factorial scheme with four replications. Treatments included the application of a PGPR combination (Bacillus sp. + Serratia marcescens) and five cover crops grown in the off-season: rice, corn, millet, Urochloa ruziziensis, and a cover crops mix. Over five agricultural seasons (2019/20–2023/24), we assessed the number of pods per plant, grains per pod, 100-grain mass, and grain yield. Cover crops did not influence yield components or grain yield. However, applying the PGPR mixture (Bacillus sp. BRM 63573 + Serratia marcescens BRM 32114) significantly improved 100-grain mass and grain yield. Among climatic factors, solar radiation was the primary determinant of grain yield variation. These findings highlight the potential of PGPR to enhance soybean production sustainably, while cover crops may require further investigation to optimize their role in this system.

Sources and Application Methods of Potassium Fertilizer for Cotton Cultivation in Cerrado Soil of Western Bahia

2025-06-09T10:48:07-03:00

Potassium (K) fertilization strategies are crucial for maximizing cotton yield and fiber quality in Brazil’s Cerrado region. This study evaluated the effects of K source and application timing on cotton performance in Western Bahia. The experiment followed a randomized block design with four replications. Treatments included pre-planting applications of muriate of potash (MOP), polyhalite (Poly4), and a 50/50 MOP/Poly4 blend; post-planting (topdressing) applications of MOP and Poly4; and a control without K. Seed yield, fiber yield, fiber quality parameters, and macronutrient concentrations were assessed. Potassium fertilization significantly increased seed and fiber yields compared to the control. Among the fertilized treatments, yields and fiber quality were statistically similar. The highest leaf K concentration was observed in the post-planting Poly4 treatment, while both this treatment and the control had the highest Mg concentrations. Sulfur concentrations were higher in all fertilized treatments than in the control. Fiber quality did not differ significantly among treatments, except for the yellowing grade (+b), which was lower in the control. Additionally, cotton classification grades were higher in all fertilized treatments. These results indicate that Poly4 is a viable alternative to MOP for cotton cultivation in Western Bahia, offering additional macronutrients and flexibility in application timing.

Insecticidal properties of Pinus taeda essential oil

2025-06-09T10:59:11-03:00

This study aimed to evaluate the yield of essential oil extracted from different sample and pH compositions, as well as the insecticidal potential of Pinus taeda essential oil. For this, samples composed only of needle and composed of needle and branches were kept in solvent water at different pH (3, 4, 5 and 6). Subsequently, the oils extracted in the different pH treatments were added in a proportion of 25% to Tween® (20%) and sunflower oil (55%) forming a concentrated bioinsecticide solutions at each pH. Solutions were diluted in deionized water to final concentrations of 12.5, 6.2, 3.1 and 0% oil. The samples containing needles and branches, as well as those extracted at pH between 4 and 6, provided a higher yield of essential oil. The bioinsecticide formulations containing the highest concentrations of essential oil extracted at pH 3 showed the best results in the control of S. zeamais. The essential oil of P. taeda has potential for the preparation of bioinsecticides and can be extracted from samples containing needles and twigs in a solvent with pH 3. Bioinsecticide solutions of higher concentrations are more efficient in controlling S. zeamais after 24 hours of exposure.

Encapsulation of Beta vulgaris extract by electrospraying and evaluation of antimicrobial potential

2025-08-26T08:57:05-03:00

Beets are rich in phenolic compounds and betalains that can be used as natural food colorings and have antimicrobial effects. However, these compounds are not very stable, and encapsulation can prolong their stability and action. The aim of this study was to investigate the antimicrobial activity of beetroot extract encapsulated by electrospraying with zein as wall material. The extract and capsules were characterized, as well as the encapsulation efficiency determined. Antibacterial activity was determined against gram-positive bacteria (Listeria monocytogenes, Staphylococcus aureus) and gram-negative bacteria (Salmonella Typhimurium, Escherichia coli) by the disk diffusion method using the minimum inhibitory concentration and the minimum bactericidal concentration. Encapsulation was efficient (92%) forming capsules with high thermal stability and spherical morphology with a regular surface. Beetroot extract and zein capsule with beetroot extract exhibited inhibition halos, inhibitory and bactericidal effects at a concentration of 200 mg mL^-1against Salmonella Typhimurium.

Morphological characterization and genetic divergence among melon accessions

2025-09-02T08:47:53-03:00

Melon, a member of the Cucurbitaceae family, is cultivated in over 100 countries and is a crop of great global importance. The significant morphological variability, encompassing attributes such as size, shape, color, and texture of the rind and flesh, alongside aroma and flavor, indicates the extensive phenotypic diversity the crop manifests. This diversity represents a crucial resource for breeding programs aimed at the species' improvement. Such variation enables breeders to select superior individuals for subsequent crosses, to develop cultivars adapted to diverse environmental and management conditions. The objective of this study was to estimate the genetic divergence between melon accessions for morphological traits. Twenty-four accessions and one commercial cultivar were evaluated. The generalized Mahalanobis distance was used as a measure of dissimilarity. Then, the clustering analysis of the accessions was performed using the Tocher optimization method and the hierarchical agglomerative clustering method (UPGMA). Both the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) hierarchical method and the Tocher optimization agglomerative method yielded the formation of three distinct groups, exhibiting a congruence of 96% between them. It was found that the longitudinal diameter, transverse diameter, and length-width/fruit ratio were the characteristics that presented the highest percentage of contribution to divergence between the accessions evaluated.

Use of geographic and edaphoclimatic information for the selection of soybeans for organic environments in current and future scenarios

2025-11-18T08:43:20-03:00

The objective of this work was to select soybean genotypes for different organic growing environments, based on geographic and soil climatic information and use of predictions of meteorological variables for future scenarios. The experiment was conducted in a randomized block design, in an incomplete factorial scheme, with three agricultural harvests (2019/2020, 2020/2021 and 2021/2022) x 21 environments organics x 18 conventional soybean genotypes, arranged in three replications per environment. The study was di-vided into two agricultural scenarios based on soybean grain productivity, where scenario I was based on variable data on minimum temperature, mean temperature, maximum temperature, precipitation, relative humidity, incident radiation, in addition to geographic variables such as latitude, longitude and altitude. The scenario II was predicted based on data from 2023 to 2040 through climate projections, from the INPE were used.The genotypes LIN 16, BRS 539 and IPR 115 are superior in terms of grain productivity. The BRS 511 genotype had a high genetic average, high responsiveness to improvements in the growing environment and high stability. In the current scenario, latitude, soil pH and soil organic carbon stock are determining factors for the grain yield of genotypes destined for organic management. In the future scenario, the minimum, mean and maximum air temperatures will be the basis for positioning soybeans in organic conditions. The year 2026 will be the most critical for soybean production in southern Brazil due to low precipitation and high temperatures. In this context, it is envisaged to select cultivars that tolerate hot environments and are resilient to water restrictions. To guarantee their potential, it is necessary to provide environments with high fertility, vegetation cover and minimal interspecific competition with other plant species.

Contrasting roles of gibberellin and cytokinin in the in vitro development and acclimatization of pitaya (Selenicereus undatus (Haw.) D. R. Hunt)

2025-11-18T08:59:09-03:00

The use of plant growth regulators is a widely adopted strategy to optimize germination and propagation under in vitro conditions; however, their application can also cause morpho-physiological changes in plants that need to be investigated. The study aimed to evaluate the effect of gibberellic acid (GA) and 6-benzyladenine (BA) supplementation on the in vitro germination, structure, and shoot proliferation of S. undatus, as well as to test different substrates during the acclimatization of the obtained plantlets. Seeds were inoculated in MS medium without plant growth regulators (MS0) and in MS medium supplemented with GA (1.0 and 3.0 mg L^-1) and BA (1.0 and 2.0 mg L^-1). Seeds were also germinated under ex vitro conditions as a control. In vitro culture conditions accelerated germination and initial development of S. undatus. However, GA supplementation did not influence seed germination speed. Greater hypocotyl and epicotyl lengths were obtained in plants grown in a medium supplemented with 1 mg L^-1 GA. Regardless of the concentration, BA led to the emergence of multiple axillary shoots, altering seedling architecture. Furthermore, BA and GA acted antagonistically on the morphoanatomy of the hypocotyls, increasing and decreasing the thickness of this organ, respectively. The treatments supplemented with BA regenerated twice the number of plantlets per seed. The commercial substrate allowed a higher survival rate (~85%) of the plantlets compared to sand (~30%), and it has been recommended for acclimating S. undatus plantlets obtained through in vitro propagation.

Interaction between systemic insecticide and humic substance applied to Conilon coffee seedlings

2025-11-18T09:08:20-03:00

The objective of the study was to evaluate Conilon coffee seedlings treated with a systemic insecticide and a humic substance, both of which have growth-promoting functions. The experiment was conducted in a commercial nursery for the production of Conilon coffee seedlings in the municipality of Linhares, Espírito Santo, Brazil. The experimental design was a randomized block in a 2 x 3 factorial scheme with four replicates. Two clones, A1 and K61, were used, and treatments included the use of insecticides alone or in combination with humic substances. Characteristics of roots, shoots, leaves, and cuttings of Conilon coffee seedlings were evaluated. The combined use of insecticides and humic substances resulted in increases of 39.0%, 47.8%, and 20.5% in shoot length, leaf area, and root volume, respectively, compared to the control. Superior production of leaf and aerial biomass was also observed in clone A1 due to the use of the insecticide in combination with the humic substance. It was concluded that clone A1 has better seedling growth compared to clone K61 and that the use of insecticide in combination with humic substances is recommended for the production of Conilon coffee seedlings.

Variability of photosynthetic performance among improved genotypes of Coffea canephora

2025-06-09T09:00:24-03:00

This study evaluated the variability of photosynthetic performance of 27 improved genotypes of Conilon coffee, cultivated in the Southern of the Espírito Santo State. The photosynthetic performance was based on the measurement of gas exchange rates and chlorophyll in the period most favorable to the photosynthetic activity and in different stages of the reproductive cycle: flowering, fruit initiation, grain formation and fruit maturation; being expressed as the average (weighted by the number of days) along the phenological stages of the third reproductive cycle of the plants. It was possible to verify the existence of sufficient variability to differentiate the photosynthetic performance among the 27 genotypes throughout the reproductive cycle, even starting from a group of already improved genotypes. Among the physiological parameters, the rate of carbon assimilation, stomatal conductance and the transpiration rate stood out as parameters for the study of variability, mainly due to their contributions to the clustering of genotypes. The genotype 108 is highlighted due to its high photosynthetic rate, associated with higher relative content of chlorophyll, as well as reasonable water use efficiency. The genotypes 205, 206 and 305 stood out in terms of water use and carbon assimilation.

Compatibility of mixtures of phytosanitary products recommended for melon and their selectivity for Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae)

2025-05-06T10:02:28-03:00

In pest control, understanding insecticide compatibility and selectivity is crucial to effectively integrate the use of insecticides and parasitoids. The aim of this study was to evaluate the compatibility of mixtures of insecticides and fungicides recommended for melon and their selectivity in Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae). The were evaluated the compatibility of six mixtures: 1) Spinetoram + Pyraclostrobin and Fluxapyroxad; 2) Cyromazine + Pyraclostrobin and Fluxapyroxad; 3) Cyproconazole + Spinetoram; 4) Cyantraniliprole + Abamectin + Metiram and Pyraclostrobin; 5) Spinetoram + Azoxystrobin and Difenoconazole; 6) Abamectin + Cyantraniliprole; and a Control (distilled water). The compatible mixtures were applied to Anagasta kuehniella (Zeller, 1879) (Lepidoptera: Pyralidae) eggs, before and after T. pretiosum parasitism. Was evaluated: mortality of adult T. pretiosum females after exposure to treated eggs, parasitism, emergence and number of parasitoids emerged/egg. Only treatment 4 showed change in physical stability after 5 minutes. In selectivity tests, treatments 1, 3, and 5 caused greater mortality (>47%) of female adults. In pre-parasitism, parasitism (>77%) and emergence (>76%) were observed in all treatments, and all the mixtures were classified as innocuous to the parasitoid in these parameters. In post-parasitism, treatments affected negatively emergence (>51%) and number of parasitoids/egg at the three ages studied. Therefore, all mixtures were considered stable and viable for use with T. pretiosum, as long as they were applied before parasitoid releases.

Terbuthylazine, atrazine, and atrazine + mesotrione for weed control in second-crop maize in Brazil

2025-05-06T09:16:27-03:00

Terbuthylazine, as well as atrazine, is a triazine with the mechanism of action of photosystem II (PSII) inhibitors, effective in controlling weeds in maize crops. The aim of this study was to assess the efficacy of terbuthylazine, atrazine, and atrazine + mesotrione, alone or in mixtures with glyphosate, in weed control for post-emergence application in maize. The experiment was conducted over two growing seasons, evaluating weed control, damage symptoms in maize and maize yield. No damage symptoms were observed in maize, and when differences in yield were observed, they were due to differences in treatment efficacy in weed control. The efficacy of terbuthylazine is akin to that of atrazine in controlling broadleaf weeds (until 93.8%) and tends to be superior in controlling grasses (until 87.5% for terbuthylazine, until 76.3% for atrazine) or Commelina benghalensis (until 91.3% for terbuthylazine, until 82.5% for atrazine). Terbuthylazine or atrazine + mesotrione, alone or in a mixture with glyphosate, were effective in post-emergence weed control in maize, with a broad spectrum of action. Atrazine, alone or in a mixture with glyphosate, was effective in controlling broadleaf weeds (Richardia brasiliensis, Bidens subalternans, and volunteer soybeans).

Management of Meloidogyne incognita in tomato using soil conditioner

2025-05-06T09:56:50-03:00

Soil conditioners have humic acid levels which can control nematodes and promote plant nutrition. The objective of this work was to evaluate different concentrations and doses of commercial soil conditioner Premium® on motility, mortality, hatching, infectivity and reproduction of Meloidogyne incognita in tomato. In order to evaluate motility, mortality, and hatching, second stage juveniles (J2) or eggs were subjected to incubation at different concentrations of soil conditioner. To evaluate infectivity and reproduction, infested soil with M. incognita were mixed to different concentrations of commercial soil conditioner. Thirty-day-old tomato seedlings (cv. Kada) were transplanted into the pots and after 30 days the numbers of galls, egg masses and eggs per gram of root were evaluated. The use of soil conditioner drastically reduced motility at a concentration of 66.67 g L-1 and caused mortality above 98% in M. incognita J2 at 133.33 g L-1. Exposure of eggs to soil conditioner reduced J2 hatching by more than 50% at a concentration of 2.5 g L-1. Highest concentrations of soil conditioner provided lower infectivity and reproduction of M. incognita in tomato. Soil conditioner at a dose of 5.0 g provided greater development of the root system, demonstrating the efficiency of this product.

Temporal analysis of Phoma leaf spot of coffee plants at different altitudes

2025-05-06T10:38:58-03:00

Phoma leaf spot (Phoma spp.) of coffee causes losses of between 15 and 43%, and presents significant variability over time and space, especially in mountain coffee production. Thus, the objective of this study was to evaluate the behavior of this disease at different altitudes and to use time series techniques and regression models to explain disease behavior. The experiment was conducted over two years (from September 2013 to August 2015) with monthly evaluations in a Coffea arabica L. plantation. The incidence and severity progress curves showed irregular behavior most of the time, typical of the disease. Higher altitudes provided higher disease incidence and severity values. Only the incidence and severity progress curves at the altitude of 1143.2 m showed significant autocorrelation over time. Thus, the first-order autocorrelation structure, AR(1), was incorporated in the estimates of the parameters of the linear and nonlinear models. Only the months from February to June/July 2014 were considered, when the disease progressed regularly. The rates obtained for the incidence, overall mean of the 85 points and mean altitude of 1143.2 m, were 5.2 and 4.6%, respectively, while the estimated rates for the severity data under the same conditions were 0.3 and 0.1%, respectively. These values represent the expected increase in incidence and severity each month. The Phoma leaf spot presents complex temporal dynamics, influenced by microclimatic variables associated with altitude.

Efficacy of florpyrauxifen-benzyl and other herbicides in the control of Commelina benghalensis

2025-06-09T09:26:27-03:00

Commelina benghalensis has become one of the main weeds in the second-crop soybean‒corn system, and the use of auxinic herbicides is essential for its control. The objective of this study was to evaluate the control efficacy of treatments applied in off-season management before soybean cultivation using the herbicides florpyrauxifen-benzyl and other synthetic auxins in the control of C. benghalensis. Experiment 1 consisted of the application of florpyrauxifen-benzyl + glyphosate, triclopyr + glyphosate, [halauxifen + diclosulam] + glyphosate, [halauxifen + diclosulam] + glufosinate, [halauxifen + diclosulam] + glyphosate + saflufenacil, and [halauxifen + diclosulam] + glyphosate + carfentrazone; Experiment 2 consisted of the application of florpyrauxifen-benzyl + glyphosate, triclopyr + glyphosate, halauxifen + glyphosate, [halauxifen + diclosulam] + glyphosate, [halauxifen + diclosulam] + glyphosate + glufosinate, and [halauxifen + diclosulam] + glyphosate + carfentrazone. At 60 days after application, florpyrauxifen-benzyl + glyphosate reached 73.8% efficacy in the control of C. benghalensis in Experiment 1 and 92% in Experiment 2, whereas the other treatments presented a maximum control of 55.5%. The application of florpyrauxifen-benzyl + glyphosate effectively controlled C. benghalensis when applied during off-season management before soybean sowing. Florpyrauxifen-benzyl was superior in efficacy to treatments involving the application of other synthetic auxins.

Quizalofop tank mixtures for control the main paddy rice weeds occurring in Southern Brazil

2025-06-09T09:40:00-03:00

Quizalofop-p-ethyl is used in Provisia^TM rice for selecive grass weed control. In southern Brazil, other weeds occur, and an herbicide tank mix is needed to achieve a broad spectrum. This study aimed to evaluate the interaction of quizalofop-p-ethyl with other herbicides used to control the main paddy rice weeds occurring in Southern Brazil. Two greenhouse experiments were performed using Aeschynomene denticulata Rudd (jointvetches), Cyperus iria L. (rice flatsedge), Echinochloa crus-galli L. (barnyard grass), and Oryza spp. (weedy rice). The factorial arrangement to each species comprises: Factor A) Doses of quizalo-fop-p-ethyl (g ha^-1): 0, 120, and 120 plus 120 (applied 14 days after the initial treatment - DAIT); Factor B) Tank mix partner: bentazon (960 g ha^-1), florpyrauxifen-benzyl (30 g ha^-1), quinclorac (375 g ha^-1), saflufenacil (30 g ha^-1), and control. At 42 DAIT, control and shoot dry weight (SDW) were evaluated. Colby’s method compared treatments using Tukey’s HSD and tank mix. No herbicide tank mix reduced or increased the variables evaluated compared to the herbicides applied alone, suggesting a neutral effect. Between the mixtures, in terms of spectrum of weed control, quizalofop-p-ethyl plus florpyrauxifen-benzyl was the best treatment, providing effective control or SDW reduction (≥ 90%) in all tested species.

Pathogenicity and virulence of Bipolaris bicolor on wheat, corn and sorghum

2025-06-30T08:25:58-03:00

The objective was to evaluate the pathogenicity of six strains of Bipolaris bicolor on wheat, corn and sorghum and its virulence when inoculated into healthy plant tissue of wheat under different light regimes at 25 °C. Pathogenicity was evaluated by inoculating mycelial discs in the corp leaves at 25 ºC for six days in a completely randomized design and 6x3 factorial arrangement, with the six strains of B. bicolor and three corps (wheat, corn, and sorghum). Besides, virulence was evaluated in the same conditions, excepting as follow: 6x5 factorial arrangement (six strains of B. bicolor and five photoperiods). The evaluations were performed by measuring the lesioned leaf diameter daily, which was later transformed into the lesioned leaf area (LLA). The results showed the ability of B. bicolor to infect other plant species beyod wheat, that is, the strains proved to be pathogenic on corn and sorghum leaves. Regarding its physiology, the results showed that strains such as virulence differed when inoculated on wheat leaves. The 14 h light regimen showed the greatest significant reduction in disease severity, the point from which the increase in the frequency of luminosity led to an increase in the LLA up to the 20 h light regimen.

Susceptibility of Palmistichus elaeisis (Hymenoptera: Eulophidae) to essential oils from Lippia origanoides Cham. (Verbenaceae) and Cymbopogon citratus (DC) Stapf. (Poaceae)

2025-08-21T11:28:44-03:00

Palmistichus elaeisis (Hymenoptera: Eulophidae) is a parasitoid with potential for use in control of lepidopteran pests; its integrated use with botanical insecticides may be feasible in pest management. Therefore, the objective was to evaluate the susceptibility of P. elaeisis to the essential oils of pepper-rosemary and lemongrass. The experiment was implemented in a completely randomized design, in a 2 (oils) × 4 (concentrations: 0.125, 0.25, 0.5, and 1.0 %) factorial arrangement, with two controls (detergent and deltamethrin). The following traits were evaluated: parasitism (%) - in the F1 generation, emergence (%), the progeny per pupa, the sex ratio, the longevity of the parental generation of males and females, and the egg-adult period of the parental and F1 generation. There were no significant differences for the biological parameters evaluated regarding the essential oils, thus indicating that the oils were innocuous to P. elaeisis. This result was confirmed by the percentage of emergence of the next generation (F1), which was always greater than 85%. The essential oils also did not affect the percentage of parasitism of the F1 generation. Thus, at the dosages tested, the essential oils of pepper-rosemary and lemongrass are selective agents that do not damage P. elaeisis.

Resistance of phylloplane-inhabiting yeast to fungicides

2025-08-26T08:47:37-03:00

Yeasts colonize the surface of plants and act as natural biological control agents, reducing the incidence and severity of diseases. However, fungicide applications can lead to the reduction and/or inhibition of these species in the phylloplane. The objective was to evaluate the sensitivity of yeast strains from the phylloplane against fungicidal products used in agriculture for the control of plant diseases. Thus, strains of different species of yeast from the leaf surface of plants were evaluated in vitro for sensitivity to fungicides, measuring the inhibition zone radius for each yeast strain exposed to fungicidal products. The yeast Zygoascus hellenicus, Rhodotorula aurantiaca, Pichia spp., and Sporobolomyces roseus were insensitive to most of the fungicidal. Regarding the products, those composed of a mixture strobilurins and carboxamides and the multisites were shown to be less toxic to yeast, whereas the compounds chemicals containing the active ingredient of the triazole group were shown to be more toxic. The products acting on only one mechanism of action, the inhibition of respiration, proved to be more selective to yeast. The yeast has natural resistance to most of the fungicidal products; however, some species show significant sensitivity to compounds containing the active principle of the triazole group.

Multispectral images in the monitoring of coffee trees phytotechnical parameters after pruning

2025-05-06T09:48:40-03:00

The objective of this work was to monitor coffee plants (Coffea arabica L.) after pruning through multispectral images obtained with an unmanned aerial vehicle (UAV) containing a Mapir Survey 3 camera and estimate agronomic parameters based on simple regression parametric models. Growth evaluation was performed in 228 sampling points related to the coffee plants. The parameters analyzed were plant height, crown diameter, plagiotropic branch length, and the number of plagiotropic branches after the pruning point. The creation of mosaics was performed through the software Agisoft PhotoScan Professional 1.4.5, and radiometric calibration through Mapir Camera Control, georeferenced by QGIS and normalized by ENVI. Based on the models generated, data analysis permitted estimating coffee plants’ agronomic parameters after decote-type pruning (cutting off the orthotropic branch at 1.5 m and 2.0 m above ground) with high accuracy. Height was measured in April’s flight with the near-infrared band (Precision = 91.87%), crown diameter and plagiotropic branches length in April’s flight with the infrared band (Precision = 89.36% and 82.22%, respectively), number of nodes in February’s flight with the near-infrared band (Precision = 79.48%), and the number of plagiotropic branches after the pruning point in June’s flight with the near-infrared band (Precision = 69.57%).

Irrigation water productivity in grape tomato under different matric potential ranges

2025-05-06T09:31:39-03:00

The knowledge of critical limits of water potential in the substrate (Ψ) allows performing irrigations that do not exceed the capacity of water storage and do not harm crop yield. In this study, substrate water retention curve was determined by inverse modeling and originated two ranges of Ψ used for irrigation scheduling: range 1, upper critical (UPΨ) = -6 kPa and lower critical (LCΨ) = -40 kPa; and range 2, UPΨ = -14 kPa and LCΨ = -40 KPa. These limits were applied in the irrigation scheduling of grape tomato in a fixed form and by changing Ψ according to the crop development stage (DS). The water productivity (WP) was determined as a function of variations in the values and form of application of Ψ. The experiment was carried out in a greenhouse. Plants were cultivated in pots filled with substrate, fertigated by an automated drip irrigation system. Tomato evapotranspiration was determined using a weighing lysimeter. Soil water content was monitored by GS1 and TDR100 sensors. Yield was not significantly affected by the different ranges of Ψ applied. WP was statistically higher in plants subjected to range 2 throughout the crop cycle and in at least one of the DS.

The triangular greenness index indicates the weed control efficacy of stored herbicide spray mixtur

2025-08-21T11:12:13-03:00

Herbicide spray mixture may need to be stored due to mechanical failures, adverse weather conditions, or the use of concentrated spray mixture. Remote sensing has emerged as a valuable tool for assessing pest control efficacy. This study aimed to assess the effect of prolonged storage of spray solution on weed control efficacy using remote sensing. The experiment adopted a randomized block design with four replicates, using a split-plot arrangement. The following factors were analyzed in the present study: four herbicide spray mixture (glyphosate, dicamba, diquat, and 2,4-D) in the main plot, eight storage periods (14, 12, 10, 8, 6, 4, 2, and 0 days before application) in subplots, and seven time points (1, 3, 5, 7, 9, 14, 21, and 28 days after application) in subsubplots. Data analysis involved ANOVA, assumption testing, and Pearson product-moment correlation between methods. The results indicated that stored spray mixture maintain their efficacy in weed control. In addition, the triangular greenness index effectively estimated the weed control efficacy of all herbicides studied, i.e., glyphosate, dicamba, diquat and 2,4-D.

Wheat yield and irrigation water productivity in a Cerrado region of Minas Gerais, Brazil

2025-11-18T08:37:40-03:00

There is significant potential for expanding the wheat production chain in the Brazilian Cerrado. Studies addressing wheat crop performance in this region could help guide this expansion. This study hypothesizes that deficit irrigation can enhance irrigation water productivity without compromising wheat yield in the Cerrado region of Minas Gerais state. The aim was to evaluate the grain crop yield (Y), yield components, and irrigation water productivity (W_IRRI) of two wheat cultivars under different irrigation depths. The field experiment was carried out in a 2 x 5 factorial scheme with two cultivars (BRS 404 and ORS Feroz) in combination with five irrigation levels (120%, 100%, 80%, 60% and 40% replacement of crop evapotranspiration, ETc). The cultivar BRS 404 showed the highest plant height and highest thousand grain weight. ORS Feroz presented the highest number of ears m^-2. W_IRRI and Y, as well as most components of yield, differed significantly depending on the irrigation level. The 54.4% reduction in total net irrigation depth caused a 29.1% reduction in yield but provided a 51.7% increase in irrigation water productivity. The adoption of deficit irrigation proved to be a viable strategy for maintaining reasonable wheat crop yield while conserving water under the experimental conditions.

Phosphate fertilization in a corn-Urochloa intercrop system

2025-05-06T11:16:41-03:00

Corn intercropped with Urochloa contributes not only to increasing soil coverage but also to improving physical, biological, and chemical quality, especially in Cerrado soils that have low phosphorus availability. Therefore, the objective of this work was to evaluate the response of different doses of phosphorus (P) in production systems on the chemical attributes of the soil, and physiological, biometric, and productive parameters of corn. Thus, an experiment was conducted with a randomized block design in a split-plot scheme, with four replications. The plots consisted of two production systems: single corn and intercropped corn. The subplots consisted of three doses of phosphorus. Soil chemical attributes, gas exchange, chlorophyll content, biometric components, and corn productivity were evaluated. The physiological parameters were not affected by the systems and P doses. In the biometric components, there was a significant effect only for stalk diameter, where corn in the single system had a larger diameter in comparison to the intercropped one. There were effects for P contents in the system and dose factors, while for organic matter and carbon only in the dose factor. Production systems and phosphate fertilizer did not influence corn grain productivity

Nutrient Omission in Corn Plant Development Cultivated in Nutrient Solution

2025-06-09T11:15:14-03:00

Macronutrients are essential for plants, and their deficiency results in decreased productivity, hindering the plant from completing its life cycle. The aim of this study was to evaluate the effect and symptomatology of macronutrient omission in maize (Zea mays L.) cultivation. The experiment was conducted in a greenhouse, with the following treatments: T1: no macronutrients; T2: complete except for Nitrogen; T3: complete except for Phosphorus; T4: complete except for Potassium; T5: complete except for Calcium; T6: complete except for Magnesium; T7: complete except for Sulfur; and T8: all nutrients included. Micronutrients were added to the treatments, irrigated with 60% water retention capacity. A Completely Randomized Design was applied, with 5 repetitions per treatment. After 80 days, the analyzed variables were: plant height, number of leaves, stem diameter, fresh mass weight, and dry mass of above-ground and root parts. Analysis of variance was performed, and means were compared using the T-test for multiple comparisons (LSD) at a 5% probability level. Treatments with omission of N, P, and S were the most affected in all evaluated variables. On the other hand, the absence of Ca, K, and Mg nutrients had little impact on plant development.