Marcelo Antonio Tomaz

Expanding Coffea canephora cultivation to transitional altitudes offers a promising strategy to sustain coffee production under climate change. This study evaluated 27 genotypes cultivated under two water management regimes (fully and minimally irrigated) at 650 m altitude in Espírito Santo, Brazil, over eight harvests (2018–2025). A split-plot design was analyzed using a three-way mixed model (REML/BLUP) to estimate genetic parameters and predicted genotypic values. Adaptability and stability were assessed using the harmonic mean of relative performance of genotypic values (HMRPGV) and weighted average of absolute scores (WAASB) and integrated into a multi-trait selection index. Significant genotypic and temporal effects were detected, while the interaction between genotypes and water management regimes was non-significant, indicating consistent performance under different water regimes. Broad-sense heritability was moderate, with high selective accuracy. Genotypes 108 and 203 achieved the highest predicted yields (91.4 and 86.8 bags ha⁻¹) and superior adaptability. The multi-trait index identified six outstanding genotypes—108, 203, 201, 306, 303, and 302—combining high yield, broad adaptability, and temporal stability, resulting in an expected genetic gain of 8.17% in relation to the original population. These findings demonstrate that selected C. canephora genotypes are well adapted to transitional altitudes, supporting breeding programs for climate-resilient and high-yielding crops.

This study aimed to determine the nutrient use efficiency of the yacon potato under NPK fertilization at different rates. The experiment followed a randomized block design with four replications and a split-plot arrangement. The main plots consisted of three fertilization levels (60%, 100%, and 140% of the reference dose—50:80:60 kg ha⁻¹ of NPK), with subplots to data collection intervals, performed every 30 days, for a total of 7 collections, generating 21 treatments. The dry biomass of whole plants and tuberous roots was determined. Samples were taken to determine the content of N, P, K, Ca, Mg, Cu, Fe, Mn, and Zn. The biological utilization coefficient (BUC) was calculated by dividing the mean values of dry biomass in kilograms of plant parts by the kilogram of nutrient found in that biomass. The application of 100% of the reference dose led to the highest use efficiency of P, K, Ca, and Mg, and intermediate efficiency for N in yacon tuberous roots and total biomass production throughout the cycle, provides a significant contribution to fertilization planning for this crop. The amount applied which was 100% of the reference dose was 17, 80, and 20 kg ha⁻¹ of N, P₂O₅, and K₂O, respectively, at planting, supplemented with 33 and 40 kg ha⁻¹ of N and K₂O as topdressing.

Tomatoes are the second most cultivated vegetable in Brazil. Despite their importance, nematodes of the genus Meloidogyne can compromise their productivity. Some bacteria have potential for managing these pathogens. Three experiments were carried out, each repeated once. In experiment 1, the efficiency of 20 bacterial isolates obtained from biofertilizers in the mortality of second-stage juveniles (J2) of M. exigua was evaluated. Bacterial isolates B74, B86, B88, and B121 were as efficient as Fluensulfona, with mortality probabilities of up to 82%. Experiment 2 was carried out to verify the compatibility between the seven most promising isolates evaluated in experiment 1. There was no antagonistic effect between the isolates, and they were identified as follows: B74: Bacillus thuringiensis; B75: Bacillus wiedmannii; B84: Bacillus cereus; B85: Micrococcus luteus; B86: Bacillus cereus; B88: Bacillus thuringiensis and B121: Brevibacterium epidermidis. In experiment 3, the effect of the bacterial isolates selected in experiment 2, applied individually or in combination, on the biocontrol of M. exigua parasitizing tomato plants was evaluated. All treatments reduced the population of M. exigua, with the best results obtained by Fluensulfona and isolate B121. There are no reports in the literature on the role of B. epidermidis as a biocontrol agent for M. exigua. It is concluded that isolates B74, B86, B88, and B121 are promising in the biocontrol of M. exigua and can be applied together, as there is no antagonistic effect between them.

Studies on nutrient absorption patterns allow for the identification of periods of peak nutritional demand, the amount of nutrients accumulated in each organ, the quantity exported by harvest, and the necessary replenishment to the soil. These insights are crucial for developing effective fertilization programs for crops. This study aimed to determine the nutrient absorption pattern of macro and micronutrients and the accumulation of biomass in various organs of yacon plants. The experiment was conducted under field conditions, following a randomized block design. The treatments consisted of different plant ages. Seven evaluations were conducted monthly, starting 30 days after transplanting. Twelve plants from the useful area were sampled for each evaluation. The plants were divided into five parts (leaves, stems, rhizophores, roots, and tuberous roots) to determine dry biomass. The samples were analyzed for N, P, K, Ca, Mg, Cu, Fe, Mn, and Zn content. Yacon prioritized the allocation of photoassimilates for biomass production in the following order: tuberous roots, rhizophores, leaves, stems, and fine roots. Nutrient absorption by yacon plants followed this order: Ca > N > K > Mg > P > Fe > Mn > Zn > Cu. Tuberous roots were the main organ for nutrient accumulated, exporting from the system 71, 15, 57, 125, 11, 1.8, 0.87, 0.40, and 0.27 kg há-1 of N, P, K, Ca, Mg, Fe, Zn, Mn, and Cu, respectively. These results provide critical physiological parameters for formulating evidence-based fertilization programs and modeling yacon growth, thereby advancing precision nutrient management. Moreover, integrating these data into agronomic models and sustainability assessments will facilitate the crop’s development as a high-value functional food, supporting both productive and environmental goals.

Objetivou-se analisar a variabilidade do crescimento de nove genótipos de cafeeiro conilon, com diferentes regimes hídricos, cultivados em altitude de transição. O experimento seguiu o esquema de parcelas subdivididas, em delineamento de blocos ao acaso, com quatro repetições. O fator subparcela consistiu em nove genótipos de cafeeiro conilon. O fator parcela correspondeu a dois regimes hídricos, irrigado e não irrigado. Foram avaliadas características de crescimento vegetativo, iniciadas na antese de um ciclo reprodutivo, sendo finalizada no estágio de maturação dos frutos do mesmo ciclo, percorrendo todas as fases do ciclo reprodutivo. A taxa de crescimento do cafeeiro conilon foi influenciada pela variabilidade entre os genótipos e pelo manejo hídrico adotado, onde o comportamento da curva de crescimento vegetativo ao longo do ciclo reprodutivo oscila de forma diferenciada conforme o manejo hídrico. Além disso, as máximas e mínimas para cada característica são fortemente influenciadas pelo material genético, além do manejo da água no solo. A altura da planta, o comprimento do ramo plagiotrópico e a área foliar do ramo plagiotrópicos ao final do ciclo reprodutivo (maturação dos frutos) foram favorecidos pelo manejo irrigado, com ganhos de 7,6%, 9,5% e 13,0%, respectivamente, em relação ao manejo não irrigado. O genótipo 108 sobressaiu os demais ao apresentar copas mais altas, com ramos maiores e mais enfolhados, enquanto os genótipos 101 e 103 estiveram nos grupos com as menores médias para essas características.

The Coffea canephora market has grown significantly, driven by its economic relevance and improvements in beverage quality. Developing varieties adapted to local edaphoclimatic conditions is essential for supporting smallholder farmers, increasing productivity, and ensuring quality in the face of environmental challenges. This study evaluated 27 genotypes under two irrigation regimes using a split-plot design in a completely randomized block arrangement, with four replicates and three plants per plot. Growth and yield parameters were assessed. Genotypes 102, 103, 105, 106, 202, 209, 301, 303, and 305 showed significantly higher yields under full irrigation—up to 60% greater than under minimal irrigation—demonstrating strong responsiveness to water availability. In contrast, genotypes 203 and 206 performed better under minimal irrigation, with 29% higher yields, suggesting lower water requirements or greater drought tolerance. These findings highlight the potential for selecting genotypes suited to transitional altitudes that can benefit from targeted irrigation strategies. The combined use of irrigation and altitude-specific cultivation represents a viable and necessary approach to maximizing genetic potential, optimizing water use, and enhancing the sustainability of C. canephora cultivation in regions facing climate variability.

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.

The objective of this study was to quantify growth efficiency parameters of genotypes of conilon coffee cultivated in intercropping with dwarf coconut, in order to verify the suitability of nutritional parameters to cluster genotypes and aid possible selections to improve efficiency traits. The experiment was developed in a consortium system, following a completely randomized design, testing eight genotypes of conilon coffee (Coffea canephora) randomly distributed along the lines of consortium with dwarf coconut trees (Cocos nucifera), using six replications. Nine parameters of growth efficiency were used, based on the conversion rate of nitrogen in leaves (main sources) to number, size and mass of other plant structures. The results showed that using growth efficiency parameters is adequate to study the variability and to cluster genotypes in groups of different levels of efficiencies. Some parameters seem to be more suitable to quantify the growth efficiency for nitrogen, such as dry matter, number and combined lengths of leaves, the chlorophyll content, and the number of fruits. The phenotypic and genetic variability expressed, even in a restricted group of eight improved coffee genotypes, seems to be enough to allow a selection of genotypes more suitable for intercropping. Considering the evaluated conditions, the genotypes 16, 100, 76 and 153 stand out for this intercropping, as they could be selected to promote gains in several of the growth efficiency parameters for nitrogen.

The aim of this study was to quantify vegetative, reproductive and nutritional characteristics of conilon coffee genotypes intercropped with dwarf coconut, in order to verify the possibility of identifying genotypes with promising performance for consortium systems between genotypes recommended for monoculture. The experiment was developed in a consortium system, following a completely randomized design, testing eight genotypes of C. canephora randomly distributed along the lines of consortium with dwarf coconut trees, using six replications. Twelve characters were evaluated to describe vegetative, reproductive and nutritional aspects of plants. It was possible to identify differences in vegetative, reproductive and nutritional characteristics between genotypes of C. canephora in consortium with dwarf coconut. The phenotypic and genetic variability expressed, even in a limited group of eight genotypes improved and adapted for monoculture, seems to be sufficient to allow a selection of genotypes more suitable for the consortium. Considering the conditions evaluated, genotypes 83, 48, 02 and 153 stand out for this consortium, because their selection could promote gains in several of the characteristics used in this research.

The high phenotypic and genotypic variabilities increases the chances of success in selection of genotypes based on efficiencies for using the available water resources. The objective was to evaluate the productive efficiency of 27 genotypes of Coffea canephora regarding the amount of water made available over the first four reproductive cycles. The experiment followed a split plot scheme, with 27 genotypes and four reproductive cycles, in a randomized block design. Genotypes 108 and 201 stand out for the highest productive efficiencies, using, on average, 2.85 liters of water for each gram of coffee. Less productive genotypes, as 203 and 307, present the lowest efficiencies, using up to 11.24 liters per gram of coffee. Efficient genotypes can save up to 75% of the water required per gram of coffee produced. Genotype 102 have not shown a significant variation in its productive efficiency throughout the harvests, electing it as the most stable among the genotypes. Studying the behavior of genotypes of Conilon coffee for productive efficiency emerges as a tool that can contribute to the selection of genotypes in specific conditions of water use, which can assist in the rational use and conservation of water resources.