Availability of floral resources in yellow passion fruit cultivars

The reproductive strategies and resources available in the flower are characteristics that stimulate research studies on the genetic improvement and fruit yield of commercial cultivars. In this sense, this study aimed to study the floral biology aspects of passion fruit cultivars in Tangará da Serra region, Mato Grosso State, Brazil at different evaluation times. The experiment was carried out with eight cultivars of yellow passion fruit from an ex situ germplasm bank of the State University of Mato Grosso. The floral resources (pollen and nectar) were evaluated in a completely randomized, factorial arrangement (8 cultivars x 5 evaluation times), with five replications. Throughout anthesis, the pollen viability, stigma receptivity, and sugar volume and concentration in the nectar were evaluated. The evaluations were carried out in 1-h intervals, between 1:30 and 5:30 p.m. The highest nectar volume production was at 2:30 p.m., decreasing gradually thereafter at the later evaluation times, for all cultivars. Pollen viability increased from the first to the second evaluation time and then decreased gradually until the last evaluation. Stigma receptivity was higher than 90% in all cultivars, at all evaluation times. BRS Rubi do Cerrado and FB 200 were the most promising cultivars for nectar volume and concentration, pollen viability, and stigma receptivity characteristics.The reproductive strategies and resources available in the flower are characteristics that stimulate research studies on the genetic improvement and fruit yield of commercial cultivars. In this sense, this study aimed to study the floral biology aspects of passion fruit cultivars in Tangará da Serra region, Mato Grosso State, Brazil at different evaluation times. The experiment was carried out with eight cultivars of yellow passion fruit from an ex situ germplasm bank of the State University of Mato Grosso. The floral resources (pollen and nectar) were evaluated in a completely randomized, factorial arrangement (8 cultivars x 5 evaluation times), with five replications. Throughout anthesis, the pollen viability, stigma receptivity, and sugar volume and concentration in the nectar were evaluated. The evaluations were carried out in 1-h intervals, between 1:30 and 5:30 p.m. The highest nectar volume production was at 2:30 p.m., decreasing gradually thereafter at the later evaluation times, for all cultivars. Pollen viability increased from the first to the second evaluation time and then decreased gradually until the last evaluation. Stigma receptivity was higher than 90% in all cultivars, at all evaluation times. BRS Rubi do Cerrado and FB 200 were the most promising cultivars for nectar volume and concentration, pollen viability, and stigma receptivity characteristics

Tolerance of pineapple cultivars to natural flowering induction in the state of Mato Grosso

Natural flowering in pineapple crops can cause significant economic losses to growers, resulting in uneven fruiting, which hinders phytosanitary operations and the scaling of fruit harvest. The objective of this work was to evaluate the tolerance of eight pineapple cultivars to natural flowering induction in Tangara da Serra, Mato Grosso, Brazil.  The cultivars BRS-Ajuba, BRS-Imperial, BRS-Vitoria, Gigante-de-Tarauaca, IAC-Fantastico, Jupi, Perola, and Smooth-Cayenne were evaluated. Planting was carried out in May of 2018, in a randomized block design, with five replications and 20 plants per plot. Plant height, D-leaf length, and percentage of induced plants were evaluated. The surveying period of plants naturally induced was between May and September 2019. In this period, the plants were between 12 and 16 months of age, with adequate D-leaf lengths and plant heights for the occurrence of flowering induction. There were days with night-time temperatures below 15 °C; the lowest photoperiod was in June. The cultivars Smooth-Cayenne, BRS-Imperial, and IAC-Fantastico were tolerant to the natural induction, which resulted in uneven fruiting, causing losses to growers.Natural flowering in pineapple crops can cause significant economic losses to growers, resulting in uneven fruiting, which hinders phytosanitary operations and the scaling of fruit harvest. The objective of this work was to evaluate the tolerance of eight pineapple cultivars to natural flowering induction in Tangara da Serra, Mato Grosso, Brazil.  The cultivars BRS-Ajuba, BRS-Imperial, BRS-Vitoria, Gigante-de-Tarauaca, IAC-Fantastico, Jupi, Perola, and Smooth-Cayenne were evaluated. Planting was carried out in May of 2018, in a randomized block design, with five replications and 20 plants per plot. Plant height, D-leaf length, and percentage of induced plants were evaluated. The surveying period of plants naturally induced was between May and September 2019. In this period, the plants were between 12 and 16 months of age, with adequate D-leaf lengths and plant heights for the occurrence of flowering induction. There were days with night-time temperatures below 15 °C; the lowest photoperiod was in June. The cultivars Smooth-Cayenne, BRS-Imperial, and IAC-Fantastico were tolerant to the natural induction, which resulted in uneven fruiting, causing losses to growers

Genetic divergence in snap bean based on agronomic traits and resistance to bacterial wilt

The objectives of this research were to estimate the genetic divergence among genotypes of bush snap beanwith based on morphoagronomic descriptors and evaluation of resistance to bacterial wilt; to determine the relative importanceof the distinguishing traits of genotypes and to indicate potential parents to establish a snap bean breeding program forresistance to bacterial wilt. Two experiments were conducted, the first in the field and the second in a greenhouse, both with 15genotypes in a randomized block design with three replications. Seven traits were studied in the field experiment: days toflowering; days to harvest; mean pod length; number of pods; number of pods per plant; total pod weight and number of seedsper pod. In the greenhouse, the reaction of bacterial wilt was assessed based on two variables, one based on a descriptivegrade scale and the other based on the Area Under the Disease Progress Curve (AUDPC). For the evaluation of genotyperesistance to bacterial wilt the isolate Feij – 2634 of Curtobacterium flaccumfaciens pv. flaccumfaciens was inoculated. Thestatistics of pseudo t2 indicated the formation of four groups by the UPGMA method, the same number of groups as indicatedby the use of canonical variables. The traits that contributed most to genetic divergence were days to harvest, pod length, poddiameter and AUDPC

Morphological and molecular characterization of native Heliconia sp. accessions of the Amazon region

Heliconias are tropical plants with ornamental potential. These plants are particularly used in the floriculture industry because of their exotic colors and shapes. Species characterization is important for the selection of genotypes for the ornamental plant market and subsequent application in studies of genetic improvement. The aim of this study was to estimate the genetic divergence of Heliconia densiflora and Heliconia psittacorum accessions based on quantitative morphological and molecular markers. The mor- phological and molecular descriptors revealed genetic variability among the accessions evaluated. The greatest genetic variability was observed among H. psittacorum accessions, whose sample number was also larger compared to H. densiflora. Morphological characterization was efficient in differentiating the two Heliconia species, especially to characteristics such as bract and inflores- cence length, postharvest durability, and flower stem diameter, which contributed most to the divergence in this study. On the other hand, molecular characterization identified one H. densiflora individual that was grouped with the H. psittacorum genotypes. The results showed that ISSR markers can differentiate closely related H. densiflora and H. psittacorum individuals. The materials evaluated can contribute to the maintenance of local genetic diversity through the germplasm bank of the local breeding program of ornamental tropical plants

Agronomic performance and fruit sensory and quality analyses of pineapple cultivars

The objective of this study was to assess the agronomic performance and fruit sensory and quality characteristics in traditional and modern pineapple cultivars grown in Tangara da Serra, MT, Brazil. The experiment was conducted in a randomized block design, with five replications and 20 plants per plot. Planting was carried out in double rows with spacing of 1.2×0.4×0.4 m, in May 2018. The evaluated cultivars were BRS-Ajuba, BRS-Imperial, BRS-Vitoria, Gigante-de-Tarauaca, IAC-Fantastico, Jupi, Perola, and Smooth-Cayenne. Gigante-de-Tarauaca exhibited the highest fruit weight but presented low soluble solids content and soluble solids to titratable acidity ratio (SS/TA); thus, it is not recommended for fresh fruit market. Jupi exhibited fruit weights (>1500 g) suitable for the market and soluble solids above 12 °Brix, but SS/TA below 20. Considering the modern cultivars, BRS-Ajuba presented the highest fruit weight, but BRS-Imperial and IAC-Fantastico were the most attractive to consumers, as well as the traditional cultivar Perola. However, BRS-Imperial and IAC-Fantastico yield small fruits, which reduces their per-unit value in the market, as pineapples are typically valued based on their sizes.The objective of this study was to assess the agronomic performance and fruit sensory and quality characteristics in traditional and modern pineapple cultivars grown in Tangara da Serra, MT, Brazil. The experiment was conducted in a randomized block design, with five replications and 20 plants per plot. Planting was carried out in double rows with spacing of 1.2×0.4×0.4 m, in May 2018. The evaluated cultivars were BRS-Ajuba, BRS-Imperial, BRS-Vitoria, Gigante-de-Tarauaca, IAC-Fantastico, Jupi, Perola, and Smooth-Cayenne. Gigante-de-Tarauaca exhibited the highest fruit weight but presented low soluble solids content and soluble solids to titratable acidity ratio (SS/TA); thus, it is not recommended for fresh fruit market. Jupi exhibited fruit weights (>1500 g) suitable for the market and soluble solids above 12 °Brix, but SS/TA below 20. Considering the modern cultivars, BRS-Ajuba presented the highest fruit weight, but BRS-Imperial and IAC-Fantastico were the most attractive to consumers, as well as the traditional cultivar Perola. However, BRS-Imperial and IAC-Fantastico yield small fruits, which reduces their per-unit value in the market, as pineapples are typically valued based on their sizes

Agriculture calendar for the maize crop in Sinop, Mato Grosso State, Brazil

This study aimed at determining an agriculture calendar for the maize crop in Sinop, Mato Grosso State, Brazil, by evaluating rainfall, air temperature and evapotranspiration. Based on the thermal requirements of the maize hybrid, the heat unit accumulation or degree-day methods were used to determine the occurrence of phenological stages, considering the highest (30ºC) and lowest (10ºC) temperatures. The growing season was determined by analyzing the variation of the total 10-days average rainfall and evapotranspiration for that locality. The calendar was established according to the thermal requirements to complete the phenological stages, rainfall distribution during these stages and probability of occurring at least five dry days per 10-days period. The best sowing time took place between the 30th and 32nd 10-days period, at the end of October and beginning of November

Secondary pollen presentation and foral traits of Heliconia psittacorum

The secondary presentation of pollen consists of a foral mechanism where the presentation of pollen occurs in other foral structures in addition to the anther, in order to increase the precision of the dispersion of the pollen by the vectors. This study aims to describe the temporal dynamics of secondary pollen presentation, and morphological and morphometric characteristics in stages of pre- anthesis and anthesis in genotypes of fve natural Heliconia psittacorum populations. For the study of foral morphometry traits of length of the fower, stamen, stigma and height of flament insertion in the petal in bud and fower were measured. The foral morphology of pre-anthesis buds and fowers in anthesis, the presence or absence of characteristics such as herkogamy, region of flament insertion in the petal, region of stylar hairs, and of secondary pollen deposition were evaluated. Treatments of controlled pollinations, self-pollination, geitonogamy, cross-pollination, natural pollination and growth to pollen tube were sampled. Floral herkogamy and pollen transfer to the adhered hairs in the stylar region were clearly observed during anthesis, constituting the frst record of occurrence of secondary pollen presentation in Heliconiaceae. Pollen tube growth was inhibited in the stigmatic, style and basal regions of the pistil. Natural fruiting produced little or no fruit. The positioning of the stamens above the stigma, pollen viability and stigma receptivity during anthesis of H. psittacorum fowers may favor self-pollination. The stylar hairs observed in all H. psittacorum populations’ help in the retention of pollen grains. The low fruiting rate in controlled and natural pollinations suggest that the main propagation form of H. psittacorum in the study areas is based on asexual reproduction

Melon cultivation under agrotextile increases production and reduces phytosanitary products

Abiotic and biotic factors influence the productivity and quality of melon fruit; therefore, the protection of plants using agrotextile mesh is a solution that can be agronomically viable, as it reduces the use phytosanitary pesticides and allows for greater productivity and, consequently, quality. The objective this study was to evaluate the influence of coverage time with an agrotextile (0, 21, 26 and 31 days after transplanting (DAT)) in melon hybrids ‘Gold Mine’, ‘Soleares’, ‘Lual’ and ‘Natal’ on productivity and fruit quality attributes. The plants that were protected with agrotextile mesh for 21 and 26 DAT had higher productivity (53.5 and 52.1 t ha−1). Among the hybrids, all excellent plots produced above 42.4 1 t ha−1. Of the observed hybrid quality parameters, 'Natal' protected for 21 DAT showed a better total phenol content and a higher maturation index, and 'Soleares' protected for 21 DAT showed a higher DPPH antioxidant activity and flavonoid content.Abiotic and biotic factors influence the productivity and quality of melon fruit; therefore, the protection of plants using agrotextile mesh is a solution that can be agronomically viable, as it reduces the use phytosanitary pesticides and allows for greater productivity and, consequently, quality. The objective this study was to evaluate the influence of coverage time with an agrotextile (0, 21, 26 and 31 days after transplanting (DAT)) in melon hybrids ‘Gold Mine’, ‘Soleares’, ‘Lual’ and ‘Natal’ on productivity and fruit quality attributes. The plants that were protected with agrotextile mesh for 21 and 26 DAT had higher productivity (53.5 and 52.1 t ha−1). Among the hybrids, all excellent plots produced above 42.4 1 t ha−1. Of the observed hybrid quality parameters, 'Natal' protected for 21 DAT showed a better total phenol content and a higher maturation index, and 'Soleares' protected for 21 DAT showed a higher DPPH antioxidant activity and flavonoid content

Selection gain in the intrapopulation genetic breeding of yellow passion fruit

O objetivo deste trabalho foi estimar o ganho de seleção associado a características agronômicas de importância no melhoramento intrapopulacional do aracujazeiro‑amarelo. O experimento foi realizado em campo, no Município de Terra Nova do Norte, MT, com a avaliação de 111 famílias de irmãos completos (FIC) e seis cultivares comerciais, utilizadas como testemunhas. Utilizou-se o delineamento de blocos ao acaso, com três repetições e quatro plantas por parcela. Foram avaliadas as seguintes características: produtividade, comprimento, diâmetro e peso médio dos frutos, percentagem e peso de polpa, espessura de casca e teor de sólidos solúveis. Para verificar a existência de variabilidade genética entre os genótipos, estimaram-se os parâmetros genéticos da população com base na média das famílias. Os 30 genótipos com o menor valor da soma de postos, de acordo com o índice de seleção de Mulamba & Mock, foram selecionados para estimar os ganhos genéticos. Observaram-se altos valores médios para as características e parâmetros genéticos avaliados nas 26 FIC e nas quatro testemunhas selecionadas. O uso do índice de seleção proporciona ganhos genéticos positivos em produtividade, percentagem e peso de polpa, comprimento, diâmetro e peso de frutos, e espessura de casca.The objective of this work was to estimate the selection gain associated to traits of agronomic importance, in the intrapopulation genetic breeding of yellow passion fruit. The experiment was carried out in the field, in Terra Nova do Norte, MT, Brazil, by evaluating 111 full‑sib families (FSF) and six commercial cultivars, used as controls. The experimental design was a randomized complete block, with three replicates and four plants per plot. The following traits were evaluated: productivity, fruit length, diameter and weight, pulp percentage and weight, skin thickness, and soluble solid content. In order to determine the genetic variability between genotypes, the population’s genetic parameters were estimated based on the means of the families. The 30 genotypes with the lowest sum of ranks, according to Mulamba & Mock’s selection index, were selected to estimate genetic gains. High mean values were observed for the evaluated characteristics and genetic parameters in the 26 FSF and in the four controls selected. The selection index provides positive genetic gains as to: productivity, pulp percentage and weight, fruit length, diameter and weight, and skin thickness