Elizabeth Orika Ono

Em geral, estacas lenhosas apresentam bons resultados para o fator de enraizamento na maioria dos porta-enxertos de videira, entretanto, algumas variedades apresentam dificuldades nesse processo. O presente estudo teve como objetivo determinar a influência de reguladores vegetais no enraizamento e brotação de estacas caulinares de porta-enxertos ‘Paulsen 1103’ e ‘SO4’, em casa de vegetação, no Submédio do Vale do São Francisco, no município de Petrolina no Estado de Pernambuco (PE), Brasil. Desta forma, os tratamentos utilizados foram: T1: Controle (água); T2: 500 mg L-1 de AIB; T3: 1000 mg L-1 de AIB; T4: 1500 mg L-1 de AIB e T5: 2000 mg L-1 de AIB. As estacas foram provenientes de plantas matrizes, oriundas de área comercial, segmentadas com 12 a 15 centímetros de comprimento, 01 centímetro de diâmetro, com a presença de 2 a 3 gemas vegetativas na porção apical da estaca. As bases das estacas foram submergidas nas soluções de AIB por um período de 10 segundos. O experimento foi conduzido em delineamento inteiramente casualizado, com 5 tratamentos (concentrações de AIB) com 5 repetições, contendo 10 estacas por repetição, perfazendo um total de 250 estacas para cada porta-enxerto avaliado. Os melhores resultados para a propagação vegetativa dos porta-enxertos de videira ‘Paulsen 1103’ e ‘SO4’ foram verificados em estacas não tratadas com auxina que apresentaram boas porcentagens de enraizamento e brotação.

This study evaluated the agronomic performance and phytochemical stability of the ‘Comet’ hop (Humulus lupulus L.) under contrasting photoperiod management regimes (with and without supplemental lighting) in subtropical conditions over two consecutive crop cycles (2024–2025). The experiment, conducted at the School of Agricultural Sciences (FCA/UNESP, Botucatu, Brazil), followed a split-plot factorial design with ten replications. Supplemental lighting (50 W, 6500 K LED floodlights) extended the photoperiod to 17 h during the vegetative stage. Morphometric, phenological, and phytochemical parameters were analyzed, including α- and β-acid contents and essential oil composition by GC–MS and GC-FID. Supplemental lighting significantly increased plant height (590.9 cm), number of lateral branches (70.1), cone length (3.49 cm), and dry cone mass (374.6 g plant⁻¹) while reducing the insertion height of the first cone (99.0 cm). α-Acid content increased from 9.35% to 11.92%, and essential oil content from 1.34% to 1.90%, while β-acid levels showed no significant variation. Chemical analysis identified 31 compounds, predominantly β-myrcene (65–74%) and sesquiterpenes such as (E)-caryophyllene, α-selinene, and β-selinene, exhibiting remarkable compositional stability across years and treatments. Photoperiod extension delayed floral induction, promoted biomass accumulation, and increased cone yield without altering the characteristic herbaceous–resinous aromatic profile. These findings validate supplemental lighting as a decisive strategy to optimize hop production in subtropical regions, ensuring phenological regularity, higher yield, and consistent chemical quality, thereby strengthening the viability of domestic hop cultivation in Brazil.

The objective of this study was to evaluate the physiological, biochemical, and productive effects of the foliar application of bioregulators, based on auxin, cytokinin, and gibberellic acid, on yellow melon, cultivar DALI^®, plants subjected to different salinity levels in a protected environment to simulate Brazil’s semi-arid conditions. The experiment was conducted using a completely randomized block design, in a 4 × 3 factorial scheme, with four salinity levels (0, 2, 4, and 6 dS m⁻¹) and three doses of the bioregulator, Stimulate^® (0%, 100%, and 150% of the recommended dose), with six weekly applications. The physiological variables (chlorophyll a fluorescence and gas exchange) and biochemical parameters (antioxidant enzyme activity and lipid peroxidation) were evaluated at 28 and 42 days after transplanting, and the agronomic traits (fresh fruit mass, physical attributes, and post-harvest quality) were evaluated at the end of the experiment. The results indicated that salinity impaired the physiological and productive performance of the plants, especially at higher levels (4 and 6 dS m⁻¹), causing oxidative stress, reduced photosynthesis, and decreased yield. However, the application of the bioregulator at the 100% dose mitigated the effects of salt stress under moderate salinity (2 dS m⁻¹), promoting higher CO₂ assimilation rates of up to 31.5%, better water-use efficiency, and reduced lipid peroxidation. In addition, the fruits showed a greater mass of up to 66%, thicker pulp, and higher soluble solids (> 10 °Brix) content, making them suitable for sale in the market. The 150% dose did not provide additional benefits and, in some cases, resulted in inhibitory effects. It is concluded that the application of Stimulate^® at the recommended dose is effective in mitigating the effects of moderate salinity, up to ~3 dS m⁻¹, in yellow melon crops; however, its effectiveness is limited under high salinity conditions, requiring the use of complementary strategies.

Grapes are rich in bioactive compounds, including phenolics and anthocyanins, which exhibit antioxidant properties and offer potential health benefits. The accumulation of these compounds is influenced by agronomic practices, particularly rootstock selection and training systems. This study evaluated the effects of different rootstocks (‘IAC 766 Campinas’ and ‘106-8 Mgt’) and training systems (low and high vertical shoot positioning) on the polyphenolic composition and antioxidant activity in the skins and pulps of Vitis labrusca and Brazilian hybrid grapes. The analyses included total phenolics, total flavonoids, monomeric anthocyanins, and antioxidant activity (DPPH and FRAP assays), as well as the individual polyphenolic profile in grape skins. The results indicated that both rootstock and training system significantly affected the accumulation of bioactive compounds and antioxidant capacity. Grapes trained on high trellises exhibited higher concentrations of bioactive compounds, while those from low trellises showed an enhanced phenolic composition. Among Vitis labrusca varieties, ‘Bordô’ had the highest bioactive compounds, while ‘Isabel’ stood out for specific phenolic acids. In hybrid cultivars, the ‘106-8 Mgt’ rootstock boosted antioxidant compounds, while ‘IAC 766 Campinas’ enhanced flavonoid, anthocyanin, and phenolic acid levels. Malvidin-3-O-glucoside emerged as the predominant anthocyanin. These findings underscore the importance of optimizing rootstock selection and training systems to enhance the phenolic composition and antioxidant potential of grapes.

Climate change imposes significant challenges on viticulture, especially in subtropical regions, where thermal and water stresses impact vine physiology and yield. This study evaluated the effects of two rootstocks (‘IAC 766 Campinas’ and ‘106-8 Mgt’) and two training systems (low and high trellis) on the photosynthesis, biochemical parameters, and productivity of Vitis labrusca (‘Bordô’ and ‘Isabel’). The interaction between rootstock and training system significantly influenced gas exchange, chlorophyll fluorescence, antioxidant enzyme activity, and yield components. In ‘Bordô’, grapevines trained on high trellis and grafted onto ‘IAC 766 Campinas’ showed a 45.1% higher electron transport rate and 39.8% greater total chlorophyll content at flowering compared to the low trellis and ‘106-8 Mgt’ combination. Productivity increased by 49% under this combination. In ‘Isabel’, low trellis combined with ‘IAC 766 Campinas’ enhanced water use efficiency by 50% and SPAD index by 11%. These results highlight that selecting suitable rootstock and training system combinations can optimize physiological efficiency and yield, representing an effective adaptation strategy for viticulture under subtropical conditions.

The increasing incidence of heat stress due to global climate change poses a significant challenge to avocado (Persea americana) cultivation, particularly in regions with intense solar radiation. This review evaluates sun protection strategies, focusing on the efficacy of different sunscreen products such as kaolin, titanium dioxide, and calcium oxide in mitigating thermal stress in avocado trees. The application of these materials was shown to reduce leaf and fruit surface temperatures, improve photosynthetic efficiency, and enhance fruit quality by preventing sunburn and dehydration. Despite these benefits, challenges remain, including the optimal timing and dosage of application, and the potential residue impacts on fruit marketability. The review emphasizes the need for ongoing research to develop more effective formulations and to integrate these sun protection strategies with other agronomic practices. The role of extension services in educating producers about the proper use of these technologies is also highlighted as crucial for the successful adoption of sun protection measures in avocado farming.

The yellow (Passiflora edulis) and sweet (Passiflora alata) passion fruit plants hold significant economic importance in tropical fruit cultivation, valued not only for the quality of their fruit but also for their medicinal properties. Conventional propagation through seeds faces challenges due to irregular and slow germination, affecting the time required for seedling formation and the viability and uniformity of plantations. The use of plant growth regulators has been explored as a strategy to overcome these barriers, improving both the rate and uniformity of seed germination. This study aimed to evaluate the influence of seed imbibition with plant growth regulators on the germination and subsequent growth of yellow and sweet passion fruit seedlings. Gibberellic acid (GA₃) and GA₄₊₇ combined with 6-benzyladenine (GA₄₊₇+6BA) were applied in five different concentrations (0, 250, 500, 750, and 1000 mg L⁻¹ a.i.). The experiments were conducted in both laboratory and greenhouse conditions, following a completely randomized design with a 2 × 5 factorial scheme. The varieties tested were ‘BRS Mel do Cerrado’ for sweet passion fruit and ‘IAC-275’ for yellow passion fruit. Quantitative parameters, such as germination percentage, germination speed index, fresh and dry biomass of roots and shoots, and enzymatic activity, were assessed. The results indicated that GA₃, at higher concentrations, significantly enhanced both germination percentage and speed index in both Passiflora alata and Passiflora edulis when compared to the control. Additionally, seedlings treated with GA₃ showed a marked increase in shoot and root biomass, particularly at concentrations of 500 and 750 mg L⁻¹. Enzymatic assays revealed heightened catalase and peroxidase activities in treated seedlings, indicating improved stress tolerance. In contrast, the GA₄₊₇+6BA treatment showed less pronounced effects on seedling growth. Overall, GA₃ was more effective in enhancing germination and seedling growth in both species, suggesting its potential application in improving the propagation of passion fruit.

Capsicum annuum L. has worldwide distribution, but drought has limited its production. There is a lack of research to better understand how this species copes with drought stress, whether it is reversible, and the effects of mitigating agents such as salicylic acid (SA). Therefore, this study aimed to understand the mechanisms of action of SA and rehydration on the physiology of pepper plants grown under drought conditions. The factorial scheme adopted was 3 × 4, with three water regimes (irrigation, drought, and rehydration) and four SA concentrations, namely: 0 (control), 0.5, 1, and 1.5 mM. This study evaluated leaf water percentage, water potential of shoots, chlorophylls (a and b), carotenoids, stomatal conductance, chlorophyll a fluorescence, and hydrogen peroxide (H₂O₂) concentration at different times of day, water conditions (irrigation, drought, and rehydration), and SA applications (without the addition of a regulator (0) and with the addition of SA at concentrations equal to 0.5, 1, and 1.5 mM). In general, exogenous SA application increased stomatal conductance (gs) responses and modified the fluorescence parameters (ΦPSII, qP, ETR, NPQ, D, and E) of sweet pepper plants subjected to drought followed by rehydration. It was found that the use of SA, especially at concentrations of 1 mM in combination with rehydration, modulates gs, which is reflected in a higher electron transport rate. This, along with the production of photosynthetic pigments, suggests that H₂O₂ did not cause membrane damage, thereby mitigating the water deficit in pepper plants. Plants under drought conditions and rehydration with foliar SA application at concentrations of 1 mM demonstrated protection against damage resulting from water stress. Focusing on sustainable productivity, foliar SA application of 1 mM could be recommended as a technique to overcome the adverse effects of water stress on pepper plants cultivated in arid and semi-arid regions.

Rosemary (Rosmarinus officinalis L.) is a medicinal, aromatic and culinary species widely used worldwide for multiple purposes. As this species presents notable difficulties in root induction, the present study was conducted to identify treatments capable of promoting and accelerating the rooting of apical cuttings. The experiment was carried out in a greenhouse from August to November 2013. The basal portion of the cuttings was treated with indole-3-butyric acid (IBA) at 300, 600 or 900 mg L⁻¹; naphthaleneacetic acid (NAA) at 300, 600 or 900 mg L⁻¹; purple nutsedge bulb extract at concentrations of 25%, 50%, 75% or 100%; Arnica montana CH6; and distilled water as the control. In total, 12 treatments were established, each with three replicates, and each replicate composed of 10 cuttings, forming the experimental unit. Cuttings were maintained in a greenhouse under continuous irrigation for 90 days. Data were subjected to analysis of variance (F-test), and means were compared using Tukey’s test at the 5% significance level. Results indicated that, under the climatic conditions of Botucatu, São Paulo, the application of synthetic or natural plant regulators is not required for the rooting of rosemary stem cuttings, as untreated cuttings exhibited superior performance across all evaluated parameters.

The choice of training system impacts the architecture and physiological characteristics of grapevines, affecting grape production and quality. Continuous studies are necessary to optimize viticulture production in Brazil. This study aimed to evaluate the effects of rootstocks and different training systems on the production and quality of ‘IAC 138-22 Máximo’ and ‘BRS Violeta’ grapevines for juice and wine. The experiment was conducted over two productive cycles (2019/2020 and 2020/2021) in an experimental vineyard at the Advanced Center for Fruit Research as part of the Agronomic Institute (IAC), in Jundiaí, São Paulo, Brazil (23°06′ S, 46°55′ W, and 745 m altitude). For each cultivar, a randomized block design in a 2 × 2 factorial scheme was used, with two rootstocks (‘IAC 766 Campinas’ and 106-8 ‘Mgt’) and two training systems (low and high trellises), with five blocks of three plants per experimental plot. In both cycles, the gas exchange and grapevine production, the chemical characteristics of the grape juice (must), and the chemical compounds in the berry skins were evaluated. The rootstocks and training systems influenced the variables evaluated in both cultivars, with the high trellis system providing the best results. This approach increased the photosynthetic rate, improved water-use efficiency, elevated grapevine production, and enhanced fruit quality. Therefore, its use is recommended for training grapevines. Regarding rootstocks, the best scion–rootstock affinity was found between hybrid grapevines and ‘IAC 766 Campinas’.