Pruning of the main stem of Marigold: effect on capitula yield

ABSTRACT The purpose of this work was to evaluate the influence of cutting the apex of the main stem of marigold plants on floral capitula yield. The experiment was carried out in a randomized complete block design, with five replicates. The following removal stages of the main stem apexes were studied: control (without pruning), up to 10 leaves, up to 15 leaves and visible flower bud. Three harvest periods were also evaluated: July, August and September, composing a factorial experiment in a 4x3 arrangement. The diameter, number, fresh matter and the dry capitula were evaluated. The most significant effect of cutting the apex of the main stem on fresh and dry matter of the capitula was obtained when the technique was performed at the time the plants had up to 15 leaves and visible flower bud. The harvesting performed in September showed to be the most promising, since it presented the larger diameter, higher number and higher fresh matter and the dry capitula.

Obtenção e caracterização morfoagronômica de linhagens de pimenta do tipo Jalapeño Amarelo

RESUMO O gênero Capsicum, de grande importância mundial, ocorre tanto nos países tropicais como nos de clima temperado. De um total de 31 espécies, apenas cinco são consideradas domesticadas, as demais, semidomesticadas ou silvestres. Nos últimos anos, as pimentas passaram a ter maior demanda pelo mercado e, consequentemente, os trabalhos relacionados à caracterização, melhoramento e obtenção de novas cultivares receberam mais atenção dentro de instituições públicas de ensino e de pesquisa, assim como no setor privado. Este trabalho foi desenvolvido na Embrapa Hortaliças, com objetivo de caracterizar morfoagronomicamente linhagens de pimenta do tipo Jalapeño Amarelo, atividade essencial para o desenvolvimento de cultivares. Primeiramente foram identificadas três plantas segregantes da cultivar comercial do tipo Jalapeño Vermelho, que apresentaram frutos de coloração amarela. Com base nesse material, o trabalho foi desenvolvido em duas fases: na primeira, obtenção de linhagens homozigotas pelo método de Descendência de Uma Única Semente (do inglês Single Seed Descent); na segunda, caracterização das linhagens obtidas através de cinco descritores morfológicos de Capsicum propostos pelo IPGRI (1995) e posterior avaliação qualitativa das linhagens em campo, sendo usado o teste Scott-Knott para a análise estatística. Conclui-se que o método de melhoramento utilizado foi satisfatório, visto que, em 30 meses de trabalho, as linhagens avançaram cinco gerações (S5). A caracterização morfológica e a avaliação qualitativa permitiram identificar diferenças significativas entre as linhagens. As linhagens promissoras identificadas neste trabalho foram CNPH 25.368, CNPH 25.373, CNPH 25.374, CNPH 25.375 e CNPH 25.377.

Concentração de capsaicinóides em pimenta Tabasco com doses de CO 2 aplicadas via irrigação

RESUMO O trabalho teve como objetivo avaliar os efeitos de diferentes doses de dióxido de carbono (CO2), aplicadas via irrigação por gotejamento na determinação da concentração de capsaicinóides nos frutos da pimenta cv. Tabasco (Capsicum frutescens) visando proporcionar frutos mais ardentes e maior produção dessas substâncias para o mercado de molhos picantes. Os tratamentos aplicados foram 0; 82,6; 92,6; 123,8; g CO2/L. O delineamento experimental utilizado foi de bloco casualizados com 4 tratamentos e 8 repetições. Foram coletados 20 frutos de pimenta na maturação máxima, porém antes do início do murchamento, apresentando cor vermelha nas colheitas, totalizando 12 amostras. Para cada amostra, foram analisadas duas repetições de capsaicina e dihidrocapsaicina. As análises foram realizadas por cromatografia líquida com detecção por ultravioleta no CROMA, na USP em São Carlos. A concentração de capsaicina nos frutos foi reduzida conforme a concentração de CO2 aplicado aumentava, até um valor mínimo de 297 mg/kg de fruto para 123,8 g CO2/L. O mesmo comportamento foi observado em relação à dihidrocapsaicina, com o mínimo de 108,46 mg/kg de fruto para 123,8 g CO2/L. Conclui-se que quanto maior a concentração de CO2 aplicado via água de irrigação por gotejamento, menor a concentração nos frutos das substâncias capsaicinóides analisadas. Entretanto, uma vez que a produtividade aumenta com o aumento das doses de CO2, o rendimento total dessas substâncias por planta foi maior, mesmo que não tenha proporcionado aumento da concentração desses capsaicinoides nos frutos.

Production and quality of strawberry cultivated under different colors of low tunnel cover

ABSTRACT Strawberry is a crop of great economic and social importance. Its fruits are appreciated both for their flavor and nutraceutical potential. Some studies confirm that light quality influences plant physiology. Thus, the aim of this study was to investigate if changes in light spectrum, provided by low tunnels, can improve vegetative traits, as well as, production and fruit quality of strawberry. The authors used six tunnel covers (red, yellow, blue, green, transparent and opaque and one control, without cover), and two cultivars: a short photoperiod cultivar (Camarosa) and a neutral photoperiod cultivar (Albion). Experiment was evaluated in two seasons: production and plant development first; and then, post-harvest quality. Overall, Camarosa showed higher vegetative growth, lower production, and better fruit quality than Albion. Due to the complexity of physiological and biochemical responses, each trait evaluated showed a specific response to light changes. The red, blue, yellow and green covers did not show any significant improvement comparing with transparent and opaque covers. Thus, the authors suggest the use of the latter ones which have already been used commercially.

Tomato growth analysis across three cropping systems

ABSTRACT The objective of this work was to analyze the growth of the Upiã tomato cultivar in the Vertical, Crossed Fence and Viçosa cultivation systems, in order to obtain explanations for the productive gains achieved in the Viçosa system. The experiment was conducted in Viçosa, Minas Gerais State, Brazil, from August 21st to December 5th, 2012, in the scheme of subdivided plots, being the plots represented by the cultivation systems: Vertical, using tape, 1.0×0.5 m spacing; Crossed Fence, staked with bamboo, 1.0x0.5 m spacing; and Viçosa, using tape, 2.0x0.2 m spacing. The subplots were composed by the sampling times of the plants: 15, 30, 45, 60 and 75 days after transplanting. The experimental design was in randomized blocks, with four replications. Each plot was composed by three lines of 10 plants, making a total of 30 plants per plot, being evaluated the four central plants of each plot. We evaluated the dry matter of leaves (MSF), stem (MSC), inflorescences (MSI), fruits (MSFr) and total (MST). Using the foliar area index, measured by digital scanners and the previously obtained dry masses, we determined the physiological growth indices: foliar area index (IAF), specific foliar area (AFE), relative growth rate (TCR), and net assimilation rate (TAL). The Viçosa system altered the growth pattern of the tomato, quantified by the growth analysis, in comparison to Crossed and Vertical Fences. The prolongation of the second growth phase for the dry matter of fruits could possibly explain the productive gains obtained in the Viçosa system. Additional studies are required in order to clarify the relationship between the duration of the second phase of fruit dry matter growth, the physiological indexes AFE, IAF and TAL with the size and fruit yield of the tomato.

Agronomic characteristics of tomato plant cultivar Santa Cruz Kada grafted on species of the genus Solanum

ABSTRACT In this study were evaluated gas exchanges, fruit production and fruit quality of tomato Santa Cruz Kada grafted onto different species of the genus Solanum, using two grafting methods. For the grafted tomato cultivation, the authors used a randomized complete block design, in a 8x2 factorial scheme, evaluating eight rootstocks: accessions of mini tomatos (0224-5, RVTC 57, RVTC 20 and 6889-50); wild tomato species Solanum habrochaites var. hirsutum (PI-127826); Solanum pennellii (LA716); Solanum sessiliflorum (cubiu); and tomato cultivar Santa Cruz Kada (self-grafting, control), and two grafting methods {cleft grafting (FC) and approach grafting (EC)}. The authors verified a significant interaction between rootstock x grafting method. The S. pennellii rootstock provided the best results for physico-chemical characteristics, when grafted using the cleft method. However, the same method, along with cubiu rootstock, presented lower fruit production. Considering the gas exchange and productive characteristics, S. habrochaites as rootstock for tomato Santa Cruz provided the best results for photosynthetic yield and water use efficiency, and for the commercial fruit production characteristic, both grafting methods, and for the average mass of commercial fruits when grafted using FC, with about 5.03 kg/plant and 163.5 g/fruit, respectively. In relation to the grafting methods, the cleft showed to be the most suitable.

Performance of mini-tomato hybrids in different training systems with different number of stems

ABSTRACT At present, Brazil is among the world's largest tomato producers. This production is directed both for the industry and for fresh consumption. Among the different tomato groups, production of mini-tomatoes has grown in recent years because of their high commercial value and mainly greater price stability. However, there are few studies investigating the proper management of this group, as it is recent in the country. The aim of the present study was to evaluate the viability of mini-tomato hybrids in different training systems, in greenhouse conditions. The experiment was set as a randomized block design in a 2×2×4 factorial arrangement with two numbers of stems (one and two stems per plant), two training systems [conventional (vertical) and horizontal], and four hybrids [AF 18196 (Sakata Seed); AF 13106 (Sakata Seed); Nina (Takii Seed) and Cocktail Mascot (Agristar/Top Seed Premium)], with three replicates and four plants per plot in the usable area. The evaluated variables were production per plant, fruit weight, transverse and longitudinal fruit diameter, number of fruits per plant, number of clusters per plant, number of fruits per cluster, precocity, production cycle, chlorophyll index, soluble solids, and crop cycle. The most promising hybrids are AF 13106 (2.71 kg/plant), AF 18196 (2.63 kg/plant) and Mascot (2.38 kg/plant), managed with two stems (2.63 kg/plant), in the vertical system (2.94 kg/plant).

Performance of modern and old, European and national potato cultivars in different environments

Little information on the comparative yield of the main potato cultivars (Solanum tuberosum subsp. tuberosum) used in Brazil is available. The objective of this study was to evaluate the performance of modern and old, European and Brazilian potato cultivars in different environments. Two experiments were carried in the field in 2013, in Brazil: in Guarapuava, in the state of Paraná, from January to April; and in Brasília, the Federal District, from August to November. Treatments consisted of six cultivars (origin, year of release): Bintje (European, 1910), Monalisa (European, 1982) and Agata (European, 1990); Baronesa (Brazilian, 1955), Catucha (Brazilian, 1995) and BRS Clara (Brazilian, 2010), arranged in complete blocks at random, with four replications, in both areas. Growth cycle, total and commercial yield (number of tubers and mass), tuber average weight and tuber dry matter content were evaluated. We observed significant differences in yield among cultivars, both in Guarapuava and in Brasilia. We also observed that increases in yield in Brazil are possible, the modern cultivars having higher yield potential than old cultivars. No significant differences in yield were detected between European and Brazilian cultivars, in none of the growing zones. We suggest that the use of imported cultivars by Brazilian potato growers is related to factors not associated to yield.

Harvest seasons and pruning management in pepper: production and pungency of the fruits

ABSTRACT Changes in plant architecture, such as apical pruning and harvesting at the right time, are management practices to obtain not only greater fruit production, but mainly quality and pungent fruits, preferred by the consumer market. We evaluated the effect of management of pruning and harvest seasons on growth, production and pungency of fruits conducted in the field. Nine seasons of harvest were studied {90, 101, 116, 131, 146, 161, 176, 191, 206 and 221 days after transplanting (DAT)} and two management systems (pruning and no pruning). The treatments were arranged in a factorial design (9x2) with split plot in a randomized block design with three replications. The agronomic traits analyzed were: height, chlorophyll, leaf area, soluble solids, number of fruits and pepper yield. The content of capsaicin and dihydrocapsaicin was determined using fruits harvested in two seasons (146 and 161 DAT) and in management systems (pruning and no pruning), in a factorial scheme (2x2), in a randomized complete block design with five replications. Growth and production traits did not differ significantly for pruning and no pruning managements, with an average of 71.8 fruits/plant and productivity of 429.7 g/plant. The agronomic traits were adjusted to the quadratic model. The maximum yield (529.09 g/plant) and the maximum number of fruits per plant (95.34) were estimated at 164.83 and 163.21 DAT, respectively. The use of pruning resulted in fruits with a higher content of capsaicin (363.89 mg/kg) and dihydrocapsaicin (198.27 mg/kg) at 161 DAT. Pruning management results in more pungent and better quality fruits for industry, and the maximum production of BRS Mari pepper was estimated at 164.83 DAT, important information for pepper producers, in order to schedule the harvests.

Heterosis and combining ability for ornamental chili pepper

ABSTRACT Ornamental use of Capsicum genus chili peppers has expanded due to easy seed propagation, short germination period, diversified fruit colors and harmony of potted plants. The ornamental plant sector requires cultivars adapted to different cultivation conditions in pots and gardens. Breeding programs can use heterosis and combining ability information, aiming to commercially explore hybrids or develop populations for lineage selection with desirable characteristics. However, the ornamental chili pepper field lacks studies with this data. In this study, combining ability of C. annuum accessions was determined for ornamental purposes and hybrid combinations were identified based on heterosis values. Fifteen hybrids were obtained from diallel crosses of six genotypes of C. annuum, from March to September 2014, under greenhouse conditions, grown in five-liter pots in experimental design of randomized blocks with 10 repetitions and one plant per plot. Morpho-agronomic characterization was conducted based on eight quantitative descriptors: plant height (before and after fruiting); canopy diameter; days to flourishing; days to fruiting; fruit length and diameter, and number of fruits per plant. Both additive and dominance effects play important role in controlling the studied characters, indicating hybrid exploitation as well as development of superior lineages from the progress of segregating generations. Negative heterosis values resulted in reduction in height, time for flourishing and fruiting, as well as fruit diameter and length, which are desirable for ornamental Capsicum breeding program. Considering an ideotype for ornamental chili pepper cultivars, the hybrids UENF 1626 x UENF 1750, UENF 1750 x UENF 2030 and UENF 1626 x UENF 2030 can be recommended for cultivation with ornamental purposes.