Osvaldo Kiyoshi Yamanishi

Global blueberry production has been increasing annually. The cultivation area in Brazil has expanded with the introduction of new low-chill cultivars, particularly those from the Southern Highbush group. Assessing the nutritional status of plants from different cultivars is essential for successful cultivation. In this context, the objective of this study was to evaluate the nutritional status of Southern Highbush blueberry cultivars (Biloxi and Emerald) under tropical climate conditions of Brasília, Distrito Federal, Brazil. The experiment was conducted in 2023 and 2024 at the Fruit Production Sector of the Biology Experimental Station (EEB) of the University of Brasília (UnB). The region's climate is classified as Aw, tropical savanna, with dry winters and rainy summers, according to the Koppen-Geiger classification. The experiment was conducted in a randomized block design, with 10 replications and 10 plants per experimental unit, totaling 200 plants. The treatments evaluated consisted of two cultivars: Emerald and Biloxi. Leaves were analyzed for nutrient contents: macronutrients included nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S), expressed in grams per kilogram (g kg-1); and micronutrient contents included boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn), expressed in milligrams per kilogram (mg kg-1). The cultivars had a significant (p < 0.01) effect on leaf macronutrient (N, P, K, Ca, Mg, and S) and micronutrient (Fe, Mn, Cu, Zn, and B) contents in both years evaluated. The cultivar Emerald exhibited higher accumulation of N, P, Zn, and Cu, whereas the cultivar Biloxi showed greater accumulation of K, Ca, Mg, S, Fe, Mn, and B in leaf tissues.

Consumer interest in natural antioxidants has risen because their intake is linked to the prevention of chronic diseases. Blueberries (Vaccinium spp.)—rich in flavonoids, vitamin C and other bioactive compounds—are therefore being cultivated beyond temperate regions. In tropical areas, however, the lack of chilling hours may alter fruit physiology, and little is known about how pruning practices modulate quality under these conditions. The objective of this study was to quantify the effects of pruning types and seasons on the antioxidant activity, physical and chemical characteristics (TSS, TTA, TSS/TTA), and ash, moisture, and fiber contents in blueberries of the cultivar Biloxi grown under tropical climate conditions (without chilling hours), in Brasilia, DF, Brazil. The trial followed a randomized-block design with three replications. Plants received either severe pruning removing lateral branches (SPRLB) or severe pruning maintaining lateral branches (SPMLB) in winter, spring, summer or autumn; fruit harvested over the subsequent four weeks was analysed for DPPH radical-scavenging capacity, total soluble solids (TSS), titratable acidity (TTA), TSS/TTA ratio, ash, moisture and fibre contents. Pruning season exerted the strongest effect. Autumn pruning—regardless of type—produced the highest antioxidant activity and elevated TSS. SPRLB increased TTA, whereas SPMLB enhanced the TSS/TTA ratio during warmer seasons. These findings demonstrate that pruning season plays a key role in enhancing blueberry fruit quality under tropical conditions.

Global blueberry production more than quadrupled between 2010 and 2022. One of the factors contributing to this production growth was the development of new cultivars with little or no chilling requirements, capable of thriving in tropical regions. Therefore, the objective of this study was to assess the growth and fruit yield of blueberry plants (Biloxi cultivar) subjected to different pruning types and timings in the Distrito Federal (DF), Central-West region of Brazil. The experiment was conducted in an open field, using a randomized complete block design with 3 replications and 10 plants per plot, totaling 480 plants. The plants were grown in pots using a fertigation system and were subjected to two types of pruning (severe pruning and regular pruning) in the different seasons of the year. The plants were evaluated for vegetative growth, fruit yield, number of fruits per plant, mean fruit weight, and fruit transverse and longitudinal diameters. The results showed that Biloxi blueberry can be grown under the climate conditions of the central region of Brazil, during the four seasons of the year, despite the tropical climate conditions and no occurrence of temperatures lower than 7.2 °C. Higher fruit yields were found when pruning was performed in winter or spring. Severe pruning resulted in higher fruit yields compared to regular pruning in winter. Summer and autumn pruning treatments reduced fruit yield; however, it is an alternative to extend the production window of this crop in Brazil.

Blueberry production is increasing in Brazil, and growers are turning to bio-inputs or biostimulants to be used on their growth. This has been due to the growing concern about sustainability in the food production chain and the necessity to increase the yield. The current experiment aimed at evaluating the effects of Samurai King, EM-1 and Brutal Plus (Minhofértil) biostimulants on the cultivation of Southern Highbush blueberries (V. corymbosum L.), cultivar 'Biloxi'. The parameters evaluated were plant height (cm), diameter of the main stem (mm), number of shoots, chlorophyll content, total number of leaves, leaf length and width. The total mass, number of fruits, average mass per fruit, the transversal and longitudinal diameters, and the total sugars (°Brix) were also measured. In 2020, the treatment of Samurai King + EM-1 showed the highest efficiency for the studied parameters related to fruits and yield but with no significant difference as compared to the other treatments. Regarding the plant growth, treatments 1 (Brutal Plus) and 5 (Brutal Plus + EM-1) were the most efficient. In 2021, treatment 7 (Brutal Plus + Samurai King + EM-1) had the highest yields, except for average mass per fruit and total sugars. In the two years of evaluation, although treatments obtained lower averages than the control, the effect observed was generally positive, revealing the efficiency of products containing microorganisms for the growth of blueberry plants. In conclusion, these bioproducts could remarkably affect plant biomass, production and fruit quality, resulting in better yields.

In Brazil, the nutritional requirements of the blueberry are not sufficiently known, thus requiring further research on the management of mineral fertilization. In this perspective, this work aimed to evaluate physiological attributes of Southern Highbush blueberry plants cv. Biloxi as a function of nitrogen fertigation in Brasília-DF. The experiment was conducted from August 2018 to July 2019, in the Fruit Sector of the Experimental Biology Station of the University of Brasilia (UnB), Federal District. This experiment adopted a randomized block design, with four treatments: 10; 20; 30, and 40 g of N plant-1, 8 replications, and 5 plants per experimental plot. The following variables were measured: net photosynthesis rate (A), transpiration (E), stomatal conductance (gs), internal CO2 concentration (Ci), instantaneous water-use efficiency (WUE), carboxylation efficiency (CE), SPAD index (SPAD) and leaf nitrogen (N). There was an effect of the different nitrogen doses applied on the physiological attributes. The plants of the blueberry cultivar Biloxi increased their photosynthetic rates at doses up to 30 g of N plant-1. Nitrogen rates did not influence stomatal conductance nor did they provide improvements in the carboxylation efficiency of the blueberry plants. Under the conditions of the present work, the highest N leaf contents were obtained with the application of 30 g N plant-1, and values above this concentration did not correspond to higher net photosynthesis rates, transpiration, and CO2 concentration in the leaf mesophyll.

This study aimed to establish an alternative treatment for post-harvest storage of Papaya (Carica papaya L.), var “Tainung 1” and to control major diseases at this stage. Two storage place were evaluated (room temperature and cold room); Six treatments (Control, Samurai 40ml/20l water, Serenade® 40ml/20l water, Sanatizer EUPROOFF® 10ml/20l water, EUPROOFF® + Serenade® + Samurai, Serenade® + Samurai), five storage periods (0, 3, 6, 9 and 12 days) and three seasons (December, January and February). Fruit weight loss (FWL), color index, number and size of lesions were evaluated and used to calculate the disease incidence and average of disease incidence. The FWL and index color of fruits were more affected by monthly variation than the treatments, especially the Samurai one. The growth of disease incidence were slower under cold room. Among the treatments, the Samurai was the most efficient,but if mixed to others products their efficiency was not observed. These results suggest that the using of Samurai only in cold room conditions can be more effective in control of post-harvest diseases of papaya.

The use of cover crop in agricultural fields has been well elucidated, especially regarding nitrogen fixation from legume crops and their function as weed protection. Furthermore, to cover crops can benefit the soil microbial community. This study aimed to evaluate and compare the benefits of mulching and cover cropping systems on soil microbial growth and activity, and their effects on plant mineral nutrition in pomelo (Citrus maxima ) and macadamia ( Macadamia integrifolia ) orchards. The treatments included: 1) control [Glyphosate herbicide (Roundup at 4 l per ha)], 2) manual weed control, 3) mulching with dead leaves from their respective trees (macadamia and pomelo), 4) millet, 5) faba bean, 6) millet + faba bean. All the treatments were applied for 120 days before soil and plant leaves were sampled for analyses. Plant mineral nutrition, soil microbial biomass C (MBC) and soil microbial biomass N (MBN); basal respiration (BRA), arbuscular mycorrhizal fungi (AMF) colonization (COL); number of AMF spores (SPO) in soil; total organic carbon (TOC) and total nitrogen (TN) were evaluated. Plant nutrition was not altered by the treatments; however, the MBC, COL and SPO markedly increased in response to mulching and faba bean + millet treatments. Especially in macadamia soils, these treatments had a great response to soil microbiology. Significant negative correlations were also detected for the COL, SPO, BRA and TOC with the Nutrient Balance Index (NBI). These results indicate that in short-term the cover cropping system is useful to improve the soil microbial growth and AMF formation in soils of pomelo and macadam orchards.

This study aimed to evaluate the performance of 'Feizixiao', 'Nuomici', 'Heiye', 'Kway May Pink' and 'Bengal' lychee cultivars topworked onto bearing 'Bengal' trees. The experiments were carried out in commercial orchard at Rio das Pedras Farm in Jundiaí, state of São Paulo. The experimental design consisted of randomized blocks in a subdivided parcel arrangement, in which the parcel consisted of five cultivars and the sub-parcel consisted of six evaluation periods. Five replicates of three plants per parcel and six grafts per plant, (with two grafts per main branch) were used. The trees were approximately 10 years old propagated by air layering and planted with 6 x 4 m (416 plants/ha) spacing. The following characteristics were evaluated: success rate of the grafts, number of shoots, shoot length, number of nodes, number of leaves and chlorophyll content (SPAD). The control ('Bengal'/'Bengal') had the highest grafting success rate with 89.9%. On the other hand, 'Heiye', 'Feizixião', 'Nuomici' and 'Kway May Pink' had, respectively, 60.6, 55.0, 52.6 and 47.0% grafting success rates. All of the shoot grafts had normal growth with no signs of incompatibility. Therefore, the cultivars studied are compatible with 'Bengal' and may be used on commercial orchards.

Este estudo teve por finalidade avaliar o índice de sobrevivência do enxerto de atemoia 'Thompson' sobre dois porta-enxertos. O delineamento experimental foi em blocos casualizados, em esquema fatorial 2 x 2, dois porta-enxertos [araticum-de-terra-fria (Rollinia sp.) e biribá (Rollinia mucosa)] e dois métodos de enxertia (topo em fenda lateral e topo à inglesa simples), em 6 blocos, 4 tratamentos e 5 plantas por parcela, totalizando 120 plantas. Para as condições locais, verificou-se que a atemoia pode ser propagada com sucesso via enxertia, usando o porta-enxerto araticum-de-terra-fria, com diferença significativa em relação ao biribá. O melhor método de enxertia para araticum-de-terra-fria foi o inglês simples, com índice de sobrevivência do enxerto de 90%. Observou-se baixo índice de sobrevivência do enxerto, utilizando-se de ambos os métodos de enxertia para o porta-enxerto biribá. ________________________________________________________________________________ ABSTRACTThis study aimed to evaluate the survival rate of atemoya 'Thompson' on two rootstocks.The experimental design used was in randomized blocks with factorial scheme 2 x 2 consisting of 6 blocks, 4 treatments and 5 replicates per parcel totaling 120 plants. Two grafting methods (side cleft graft and whip graft) and two rootstocks [araticum-de-terra-fria (Rollinia sp.) and biriba (Rollinia mucosa)] were evaluated for propagation of 'Thompson' atemoya. Scion survival rate was evaluated and analyzed by Tukey test, with 5% of significance level. Atemoya tree under local conditions can be propagated successfully by grafting using araticum-de-terra-fria rootstock. Whip graft was the best grafting method for araticum-de-terra-fria rootstock with 90% survival. Both grafting methods for biriba rootstock resulted in low scion survival rate

O maracujá-roxo (Passiflora edulis), apesar de ser desconhecido no Brasil, pode tornar-se numa fonte de renda alternativa para o agricultor, devido à boa remuneração e aceitação da fruta in natura no mercado europeu. Com o objetivo de avaliar a produção de mudas clonais de maracujá-roxo provenientes da Austrália, foi realizado um experimento no Setor de Fruticultura da Universidade de Brasília entre os meses de maio de 2005 e fevereiro de 2006. O delineamento experimental utilizado foi o de blocos casualizados, com 3 repetições, em arranjo fatorial 7 x 2 x 3, sendo sete porta-enxertos, duas variedades-copa e três épocas de avaliação. A parcela foi formada por 3 plantas úteis. Utilizaram-se como porta-enxertos (PE) as espécies P. serrato digitata, P. nitida, P. coccinea, P. quadrangularis, P. edulis e P. edulis f. flavicarpa híbrido 'EC-2-0' e o híbrido P. coccinea X P. setacea, e como copa (CP), as variedades '96A' e '25' de maracujazeiro-roxo. As estacas enraizadas foram transferidas para sacolas plásticas e mantidas sob nebulização intermitente. A enxertia foi efetuada 30 dias após. As avaliações do índice de pegamento foram efetuadas aos 31 e 61 dias após a enxertia (DAE). As combinações CP/PE (entre "25" e "96 A" X P. nitida), seguidas das combinações ("25" e "96 A" X P. edulis f. flavicarpa híbrido 'EC-2-0'), com 100%, 90%, 90% e 80%, respectivamente, obtiveram alto índice de pegamento aos 61 DAE. A produção de mudas de maracujazeiro-roxo enxertadas nas espécies de maracujazeiro silvestres e comerciais P. nitida, P. quadrangularis, P. edulis f. flavicarpa híbrido 'EC-2-0' e P. edulis é viável do ponto de vista técnico, pois não ocorreram problemas de incompatibilidade, e os enxertos apresentaram alta taxa de pegamento.