Gabriel Emiliano Pereira

The present study aimed to evaluate the plant growth curve of two new potato cultivars, to better understand the dynamics of the plant development throughout the growth cycle, and to subsidize management strategies. Field experiments were carried out in Canoinhas-SC, and Pelotas-RS, in the spring 2019. The new potato cultivars BRS F50 - Cecília and BRS F183 - Potira were compared with the standard cultivar widely grown in the country, Asterix. The experimental design was randomized complete blocks with four replications of plots composed of 43 useful plants, plus borders. Destructive samples of four plants per plot were carried out at 28, 42, 56, 70, 84, 98, and 112 days after planting. Morpho-agronomic characters were evaluated throughout the crop cycle, and the determination of tuber yield was done at its end, harvesting 15 plants per plot. Cecília presented a great development of the aboveground plant parts, and a high tuber yield. Potira also showed a good tuber yield, but was late in the plant development cycle, requiring specific studies on differentiated management of this character. In general, genotypes with a greater development of the aboveground plant parts are more productive, however, in this analysis it is not possible to consider only characters related to the leaf production or even the leaf area, but the plant structure as a whole, including stem development.

The carrot is one of the most important and preferred vegetables in Brazil due to its versatility and nutritional significance, especially as a source of vitamins. The selection of carrot genotypes should consider several agronomically important characteristics to allow more suitable and balanced gains. The aim of the present study was to estimate genetic gains in the carrot using different selection indices. Thirty-six carrot genotypes were evaluated in two experiments, the first conducted between 16 November 2017 and 1 March 2018, and the second between 5 March and 18 June 2018 in, Brasilia. In both trials. the experimental design was of randomised blocks with three replications. The plots were sown directly onto the seedbed, which had a total working area of 1.8 m2. The incidence of leaf blight was evaluated 78 to 98 days after sowing, at intervals of seven days, giving a total of four evaluations. The harvest was carried out at 105 days when the characteristics of the yield components were measured. An analysis of variance was applied, together with five selection indices: direct selection, classic, desired gain, weight- and parameter-free, and genotype-ideotype. There were differences between genotypes for most of the characteristics under evaluation. The genotype-ideotype index afforded the greatest gains for the characteristics being evaluated, with an economic weight equal to the coefficients of genetic variation; however other indices were also efficient and offered balanced gains, with the exception of the desired-gain index.

Analyzes of plant growth throughout the crop vegetative cycle are important to know the dynamics of the plant development. Thus the objective of this work was to study the development of potato genotypes throughout the crop cycle, in three environments. Experiments were conducted in Canoinhas-SC, Pelotas-RS, and Brasília-DF, Brazil, in the 2018 crop season. A randomized complete block experimental design with three replicates was used. Traits related to different plant parts of clones F183-08-01 and F50-08-01 and the cv. Asterix were evaluated as a function of time and, at the end of the cycle, for tuber yield. The two clones were found to have high tuber yields, but later development than 'Asterix'; consequently, its management must be adapted to this trait. Leaf mass, leaf number, leaf area index and root mass plus stems were correlated with each other, and leaf area index, leaf number and leaf mass can be quantified through only one of these traits, due to the high correlation between them. There were also positive and significant correlations between the height of the tallest stem and the root plus stem mass and the tuber mass, indicating that more vigorous plants have higher tuber yield.

Las condiciones climáticas del Medio Oeste brasileño restringen el cultivo de la papa a períodos del año en que la humedad del aire es más baja y las temperaturas más cálidas. Por lo tanto, la siembra de papa está restringida a los meses de abril y mayo, lo que proporciona a las plantas las condiciones ideales de desarrollo en un período de mayor susceptibilidad a Ralstonia spp. (Rs), que presenta un mejor desarrollo en condiciones de alta humedad del aire y temperatura. Este trabajo tuvo como objetivo evaluar la adaptación de los genotipos de papa de Embrapa a las condiciones edafoclimáticas de la Región del Distrito Federal (DF) plantadas fuera de la principal temporada de siembra. Se realizaron dos experimentos en Brasilia, DF, en diferentes fechas de siembra en 2017 y 2018. El diseño experimental de bloques aleatorios completos se utilizó con tres repeticiones en 2017 y cuatro repeticiones en 2018. Genotipos F183-08-01, F50-08-01, BRSIPR Bel, Agata, Atlantic y Asterix fueron evaluados en ambos años. Los clones 24-09, 29-19 y 30-09 se agregaron en 2018. El vigor de la planta se evaluó mediante puntajes que varían de 1 a 5. Se utilizó el software SAS en todos los análisis. La producción de tubérculos comercializables del genotipo 30-09 fue mayor que todos los demás genotipos evaluados (25,10 t ha^-1) en condiciones favorables para el desarrollo de Rs. El clon 30-09 funcionó bien y puede ser un genotipo potencial para aumentar el período en el cual es posible cultivar la papa en el Medio Oeste brasileño, especialmente cuando hay un historial de ocurrencia de Rs.

Las condiciones climáticas del Medio Oeste brasileño restringen el cultivo de la papa a períodos del año en que la humedad del aire es más baja y las temperaturas más cálidas. Por lo tanto, la siembra de papa está restringida a los meses de abril y mayo, lo que proporciona a las plantas las condiciones ideales de desarrollo en un período de mayor susceptibilidad a Ralstonia spp. (Rs), que presenta un mejor desarrollo en condiciones de alta humedad del aire y temperatura. Este trabajo tuvo como objetivo evaluar la adaptación de los genotipos de papa de Embrapa a las condiciones edafoclimáticas de la Región del Distrito Federal (DF) plantadas fuera de la principal temporada de siembra. Se realizaron dos experimentos en Brasilia, DF, en diferentes fechas de siembra en 2017 y 2018. El diseño experimental de bloques aleatorios completos se utilizó con tres repeticiones en 2017 y cuatro repeticiones en 2018. Genotipos F183-08-01, F50-08-01, BRSIPR Bel, Agata, Atlantic y Asterix fueron evaluados en ambos años. Los clones 24-09, 29-19 y 30-09 se agregaron en 2018. El vigor de la planta se evaluó mediante puntajes que varían de 1 a 5. Se utilizó el software SAS en todos los análisis. La producción de tubérculos comercializables del genotipo 30-09 fue mayor que todos los demás genotipos evaluados (25,10 t ha^-1) en condiciones favorables para el desarrollo de Rs. El clon 30-09 funcionó bien y puede ser un genotipo potencial para aumentar el período en el cual es posible cultivar la papa en el Medio Oeste brasileño, especialmente cuando hay un historial de ocurrencia de Rs.

Knowledge on the nutritional demands of different potato genotypes is necessary for the development of fertilizing recommendations. This study aimed to determine and compare the macronutrient accumulation curves in the Agata, Asterix, BRSIPR Bel and F183-08-01 potato genotypes, in order to subsidize the split fertilization that could meet the specific demands of each genotype. A randomized block design was used, with the treatments (genotypes × plant stages) arranged in a split-plot scheme, with three replications. The genotypes were grown in plots containing 75 plants each. The subplots within a plot contained four plants each and corresponded to the number of days after planting, when destructive samples of whole plants were collected. The plants from the subplots were harvested at 24, 38, 52, 66 and 80 days after planting, to estimate the dry mass accumulated by different parts of the plant (shoots + roots, tubers and whole plants), as well as to determine the macronutrient accumulation curves. F183-08-01 presented the highest total accumulation of N, Ca, Mg and S (141.37, 29.21, 25.16 and 22.36 kg ha-1, respectively). The highest rates of macronutrient accumulation for all the potato genotypes occurred at 24 days after planting, coinciding with the beginning of the tubers formation.

The knowledge of the plant growth pattern under specific climatic conditions (growth curve) is the basis for exploiting the maximum yield potential of potato genotypes. This study aimed to establish the growth curve, as well as to evaluate the agronomic characteristics, yield and specific gravity of tubers of three potato cultivars and one elite clone, thus providing basic information on the productive characteristics of these genotypes in the Brazilian Midwest. A randomized experimental block design, with three replications, was used. The dry mass accumulated by the tubers varied from 6.28 (Agata) to 9.75 t ha-1 [F183-08-01 (F183)]; the total mass of tubers from 35.33 (BRSIPR Bel) to 58.60 t ha-1 (F183); the mass of marketable tubers from 23.46 (Asterix) to 48.24 t ha-1 (F183); and the leaf area index from 2.86 (Agata) to 10.60 (F183). F183 showed a good adaptation to the cultivation conditions of the Federal District, being strongly recommended for this region.

Potato is responsive to intensive agricultural input use; however, it can be produced in less intensive production systems (such as the organic system) by using appropriate production techniques and genotypes adapted to this system. This study aimed to evaluate the performance of advanced potato genotypes for tuber yield under conventional and organic production systems, in order to select potential genotypes to become new cultivars adapted to these systems. Fifteen advanced potato clones and two controls were evaluated under organic and conventional production systems, in 2016 and 2017, in Brasília-DF, Brazil. The experimental design was randomized blocks with three replicates and plots composed of two rows with 10 plants each, spaced 0.35 m between plants and 0.80 m between rows. Total (mass) and marketable (mass and number of tubers) productivities were evaluated. Variance analysis showed significant differences among genotypes for all traits. Despite the lower average tuber yield in the organic system, selecting genotypes with high potential productivity was possible in this system, such as F158-08-01 and F158-08-02, showing high marketable tuber yield, with values equivalent to the conventional system. Clones F102-08-04, F13-09-07, F-18-09-03, F-183-08-01, F-21-09-07, F31-08-05, F63-10-07 and F97-07-03 also outperformed the control cultivars in organic system. For conventional system, F158-08-01, F158-08-02 and F183-08-01 were superior, and F18-09-03, F21-09-07, F63-10-07, F97-07-03, PCDINV10 and PCDSE090 showed performance similar or superior to the most productive control (cultivar Asterix). Genotypes F158-08-01 and F158-08-02 were superior in both conventional and organic systems, with potential to become new cultivars recommended for both production systems.

Selection of more productive carrot genotypes is fundamental for crop breeding programs aiming to increase productivity and reduce cost production. Thus, the aim of this work was to evaluate gains from direct selection and to measure its effects on other agronomic traits of interest in carrots. Thirty six carrot genotypes were evaluated in two experiments: the first, sown in the second half of November 2016 and the second one in the first week of March 2017. The experimental plots covered a useful area of 1.5 m², in transversal rows and 0.10-m double spacing between single rows x 0.20-m between double rows in a randomized block design with 3 replicates. At 90 days, the incidence of leaf blight was evaluated using a note scale and 100 days after sowing, roots were harvested measuring the number and mass of total, commercial and non-commercial roots of each plot. The direct selection of commercial root mass allowed to estimate indirect and expressive gains for most evaluated traits, allowing to select seven genotypes (populations 758, 751, 737, 736, 735, 744 and 742) which can be released as cultivar or for the formation of a broader genetic-based population.