Greater Fruit Set Research Articles

Evaluation of Agronomic Performance and Fruit Quality of Four Genotypes of Bell Pepper under Greenhouse Conditions

Aims: The objective of this experiment was to evaluate agronomic performance of four pepper genotypes under greenhouse conditions, and to determine the nutritional content of their fruits.
 Study Design: Was with the completely randomized model with four treatments (genotypes P-01, P-02, P-03 and P-04) and four repetitions each. The comparison of means was by Tukey ≤.05.
 Place and Duration of Study: Experimental greenhouse "The Bajío” Buenavista, Plant Breeding Department of the Universidad Autónoma Agraria Antonio Narro. between March 2021 to December 2021.
 Methodology: Four genotypes of bell pepper were evaluated (P-01, P-02, P-03 and P-04), through the quantification and determination of morphological variables, yield, as well as the physicochemical and nutritional quality of the pepper fruits.
 Results: Significant statistical differences were identified in the number of fruits per plant, highlighting P-03, P-04 with 13.81 and 13.53 fruits, in fruit length, the P-01 genotype exceeded the rest of the genotypes by more than 16.5 %. For physicochemical evaluations there were no significant differences, however, there was a 10 % increase in firmness and mesocarp thickness in the P-03 and P-04 genotypes. Regarding carotenoids, P-03 had 52 % more than the rest of the genotypes, the P-01 genotype stood out in antioxidant capacity with 6 and 15 % for ABTS and FRAP, while the P-02 genotype stood out in a 26 % for DDPH. The color of the fruits turned out to be yellow red, highlighting P-03 and P-02 in terms of luminosity.
 Conclusion: Due to the length of the fruits, the genetic potential of the P-03 genotype could be exploited, while due to the number of fruits harvested per plant, the genotypes with the greatest potential are P-02 and P-04. The variables with differences between treatments can lead to the selection of genotypes of better commercial quality and greater fruit set.

Hand pollination and natural pollination by carpenter bees (Xylocopa spp.) in Passiflora edulis Sims. f. flavicarpa Deg. (yellow passion fruit)

We investigated the fruit set and quality of yellow passion fruit subjected to hand and natural pollination by carpenter bees (Xylocopa spp.) in the Philippines. We also recorded the foraging behavior of the bees. A quadrat measuring 6 m x 7 m was marked in a yellow passion fruit plantation for the investigation. Two groups of 20 flowers that had been either hand pollinated or visited by the bees were followed to determine fruit set and quality. The hand pollinated flowers had significantly greater fruit set (15/20 versus 7/20), fruit weight, transverse diameter, longitudinal diameter, peel weight, number of seeds, and juice yield. Flowers that were self-pollinated by hand produced no fruit. Bee flower visit times and patterns were also investigated. The carpenter bees started visiting the passion fruit flowers from 7:00 AM to 5:00 PM, with peak visitation at 1:00 PM. The greatest mean duration of flower visits was observed at 11:00 AM (304 s), which coincided with the observed peak hour of flower opening. We observed random distances in the flight patterns of the carpenter bees, which was independent of flower distances (Kolmogorov-Smirnov test; µ=3.34 < σ2=7.91 vs. µ=2.40 > σ2=1.20). We conclude that passion fruit farmers can utilize supplemental hand pollination to increase yield when the main pollinators such as Xylocopa spp. are not available in sufficient numbers.

Effect of pollen doses on fruit formation and oil production in two hybrid palm genotypes (Elaeis oleifera H.B.K. Cortes x Elaeis guineensis Jacq.)

OxG oil palm hybrids (Elaeis oleifera x Elaeis guineensis) produce a small number of male inflorescences, with an irregular, slow anthesis phase and low-viability pollen that affect natural pollination, making the agronomic practice of assisted pollination necessary for plantations in order to guarantee the formation of the majority of bunch fruits. In the hybrids “Coarí x La Mé” and “(Sinú x Coarí) x La Mé”, the influence of several doses of pollen (0, 0.01, 0.05, 0.1, 0.15 g/inflorescence) on bunch weight, normal and parthenocarpic fruits, fruit set and oil/bunch potential was studied. A completely randomized experimental design was used with four replicates and nine inflorescences/replicate. The bunch weight was higher with the 0.05 g/inflorescence dose and lower with the natural pollination. The greatest fruit set was obtained with the dose of 0.1 g/inflorescence, and the oil/bunch percentage was higher with 0.05 g/inflorescence and lower with 0.01 g/inflorescence. The results confirm the need for assisted pollination in these new hybrid materials.

Boron foliar application, branch girdling and plant growth regulators on yield and fruit quality of 'Garber' pear trees.

The aim of this study was to evaluate the influence of boron foliar application, branch girdling and plant growth regulators on the performance of pear trees cv. Garber. The experiment was arranged in a randomized block design with three replications. Treatments consisted of different boron rates (220, 440, 660 and 880 mL 100 L-1), branch girdling, and the plant growth regulators Promalin® (benzyladenine + gibberellins AG4+7) (560 mL 100 L-1) and Biozyme * TF (200 mL 100 L-1). The percentage of fruit set, stem length, fruit length, fruit diameter, flesh firmness, soluble solids and yield were assessed. The greatest fruit set was observed with Promalin® in both years and also boron and Biozyme * TF in the second year. The use of Promalin® increased peduncle length, fruit height but negatively affected soluble solids. Yield was also increased by this plant growth regulator and boron. Concluding, Promalin® improves fruit set, yield, and fruit quality and boron positively influence yield.

Effects of arbuscular mycorrhizae on tomato yield, nutrient uptake, water relations, and soil carbon dynamics under deficit irrigation in field conditions

Plant strategies to cope with future droughts may be enhanced by associations between roots and soil microorganisms, including arbuscular mycorrhizal (AM) fungi. But how AM fungi affect crop growth and yield, together with plant physiology and soil carbon (C) dynamics, under water stress in actual field conditions is not well understood. The well-characterized mycorrhizal tomato (Solanum lycopersicum L.) genotype 76R (referred to as MYC+) and the mutant nonmycorrhizal tomato genotype rmc were grown in an organic farm with a deficit irrigation regime and control regime that replaced evapotranspiration. AM increased marketable tomato yields by ~25% in both irrigation regimes but did not affect shoot biomass. In both irrigation regimes, MYC+ plants had higher plant nitrogen (N) and phosphorus (P) concentrations (e.g. 5 and 24% higher N and P concentrations in leaves at fruit set, respectively), 8% higher stomatal conductance (gs), 7% higher photosynthetic rates (Pn), and greater fruit set. Stem water potential and leaf relative water content were similar in both genotypes within each irrigation regime. Three-fold higher rates of root sap exudation in detopped MYC+ plants suggest greater capacity for water uptake through osmotic driven flow, especially in the deficit irrigation regime in which root sap exudation in rmc was nearly absent. Soil with MYC+ plants also had slightly higher soil extractable organic C and microbial biomass C at anthesis but no changes in soil CO2 emissions, although the latter were 23% lower under deficit irrigation. This study provides novel, field-based evidence for how indigenous AM fungi increase crop yield and crop water use efficiency during a season-long deficit irrigation and thus play an important role in coping with increasingly limited water availability in the future.

Produção de néctar e visitas por abelhas em duas espécies cultivadas de Passiflora L. (Passifloraceae)

A atividade dos polinizadores é afetada pela disponibilidade de recursos. Flores que produzem mais néctar podem ser mais visitadas e assim apresentar maior produção de frutos. O efeito da produção de néctar na atividade dos polinizadores foi testado em duas espécies cultivadas de maracujá, Passiflora alata Curtis e Passiflora edulis Sims, em Morretes, Paraná. Botões foram ensacados e o néctar acumulado das flores foi coletado em intervalos de 1 h. Em P. alata o volume e a concentração de solutos no néctar aumentaram durante o período de antese, associados com o aumento da temperatura. Em P. edulis, o volume aumentou durante o período diurno da antese, e decresceu após as 18 horas. A concentração de solutos no néctar permaneceu constante. A taxa média de visitação de Xylocopa frontalis (Olivier) em P. alata foi de 1,7 visitas/100flores/hora e em P. edulis foi de 6,6 visitas/100flores/hora, sendo constante durante a antese. A taxa média de visitação de Bombus morio (Swederus) em P. alata foi de 5,8 visitas/100flores/hora, sendo mais alta no início da antese. A constância das visitas de X. frontalis deve estar associada à produção contínua de néctar em ambas as espécies de maracujazeiros. Como as espécies são xenogâmicas, a manutenção das visitas é importante para propiciar o fluxo de pólen entre indivíduos e assim garantir boa produção de frutos.

Floral Biology and Breeding System ofAngadenia berteroi(Apocynaceae): Why Do Flowers of the Pineland Golden Trumpet Produce Few Fruits?

Angadenia berteroi is a tropical perennial subshrub with large yellow flowers that sets very few fruits in its native pine rockland habitat. To learn more about the breeding system of this rare species, we collected seeds from two populations and grew plants for greenhouse study. The flowers open before sunrise. They have a complex floral arrangement (the anthers form a conical structure surrounding the stigma, which has a secondary pollen presentation) that promotes outcrossing from visits by long-tongued pollinators. Hand-pollinations show that A. berteroi is mostly self-incompatible, with greatest fruit set, fruit length, and seedling emergence resulting from crosses between unrelated individuals. The low fruit set observed in natural populations may be due to low visitation by pollinators, matings between closely related individuals, or both.

Trends in the reproductive biology of Venezuelan Melochia (Malvaceae) species

The breeding system, floral morphology, morph frequency, biomass allocation to floral whorls, pollination and reproductive efficiency were examined in four distylous and three monomorphic Melochia species. Monomorphic species were self-compatible and distylous species were self-incompatible. Flowers of homomorphic species were longer than those of distylous species. Herkogamy was significantly higher in pin than in thrum morphs of the two distylous species, and monomorphic species exhibited the lowest values of herkogamy. Pollen/ovule ratios were similar between monomorphic and dimorphic species, irrespective of the self-incompatibility level. Biomass allocation to flowers was biased toward non-sexual structures, attraction and support. Androecium biomass and androecium/gynoecium biomass ratio were larger in thrum than in pin flowers of distylous species indicating maleness in the thrum morph and femaleness in the pin morph. There was no clear difference between fruit set of monomorphic and dimorphic species; however, the greatest fruit set was found in the monomorphic species, M. pyramidata, which is a self-compatible species. Fruit set was significantly higher in pin than in thrum morphs in three out four distylous species and fecundity was only significantly higher in pin morphs of M. caracasana and M. parvifolia. Melochia species have generalist pollination systems. According to the taxonomic classes and number of pollinator species, M. caracasana and M. parvifolia have similar generalist pollination systems. Our comparative analyses of the characters between floral morphs of distylous species and the relationship with these characters in monomorphic species allow divergences and similarities to be established and different evolutionary trends to be postulated in the breeding systems of Melochia species. Specifically, M. parvifolia and M. caracasana are apparently biased toward monomorphy and dioecy, respectively.

Comunicação científica qualidade de frutos da pereira-japonesa colhidos em duas regiões de Santa Catarina, Brasil

O trabalho foi desenvolvido em Caçador (1067 unidades de frio -UF- durante a vernalização) e em São Joaquim (1999 UF), nas safras de 2006/07 e 2007/08, com objetivo de comparar a qualidade de frutos produzidos por diferentes cultivares de pereira-japonesa, nos dois locais, e colhidas em diferentes estágios de maturação. A deficiência na quantidade e na qualidade do frio durante a vernalização ocasionou a brotação de flores sem a presença de folhas até a fase "J" na cv. Kousui, afetando a fase inicial de desenvolvimento dos frutinhos. Também propiciou reduzido número de gemas florais por planta e baixa quantidade de flores por gema. Região com adequada quantidade de horas de frio durante a vernalização exige raleio mais intenso devido ao maior número de frutos por planta. A colheita de frutos antes de atingirem o ponto ideal de maturação fisiológica implica a produção de frutos de menor peso, menor teor de sólidos solúveis totais, maior firmeza e menos saborosos. Já os frutos colhidos após o ponto de colheita ideal podem apresentar os distúrbios fisiológicos "pingo-de-mel" e "degenerescência interna por senescência da polpa". O teor de SST foi definido mais pelo genótipo da cultivar, mas para algumas variou entre os anos. As cvs. Housui e Kousui tendem a apresentar maior °Brix que a cv. Nijisseiki. Melhor qualidade comercial foi apresentado por frutos da cv. Housui. O número de sementes por fruto variou entre cultivares e anos. A cv. Housui apresentou baixa fecundidade quando analisada pelo número médio de sementes produzidas por fruto (&lt;3,0); a cv. Kousui apresentou baixa fecundidade em São Joaquim, mas fecundidade intermediária (3,1 a 5,0 sementes por fruto) em Caçador; a cv. Suisei apresentou fecundidade intermediária, e a cv. Nijisseiki apresentou alta fecundidade (&gt;5,1 sementes por fruto),

The maintenance of mixed mating by cleistogamy in the perennial violet Viola septemloba (Violaceae)

The production of both potentially outcrossed (chasmogamous) and obligately self-fertilized (cleistogamous) flowers presents a clear exception to the prediction that the only evolutionarily stable mating systems are complete selfing and complete outcrossing. Although cleistogamy has evolved repeatedly, the reason for its stability is not known for any species. We tested the hypothesis that the production of cleistogamous and chasmogamous flowers by a perennial violet constitutes adaptive phenotypic plasticity. We manipulated the season of flowering for each flower type and determined fruit set and the germination percentage of seeds produced by cleistogamous and chasmogamous flowers to test the hypothesis that adaptive plastic response to seasonal environmental variation makes mixed mating stable. Cleistogamous flowers had greater fruit set in all seasons and produced seeds with germination percentages as great as or greater than those from chasmogamous flowers. The consistent advantage of cleistogamous flowers is clearly not consistent with a role of adaptive plastic response to seasonal variation. The biomass cost of seed production by chasmogamous flowers was nearly three times that for cleistogamous flowers. Explaining why chasmogamous flower have not been eliminated by natural selection requires that this difference be balanced by an advantage to chasmogamous flowers that has not yet been identified.

COLORED SHADING NETS INCREASE YIELDS AND PROFITABILITY OF HIGHBUSH BLUEBERRIES

COLORED SHADING NETS INCREASE YIELDS AND PROFITABILITY OF HIGHBUSH BLUEBERRIES

Reproductive ecology of 21 coexisting Psychotria species (Rubiaceae): when is heterostyly lost?

Heterostyly is a genetic polymorphism in which plant populations are composed of two or more morphs that differ in stigma and anther heights. The polymorphism promotes intermorph pollen transfer, thus outcrossing. Heterostyly has been reported in 28 angiosperm families and is frequently lost in heterostylous lineages. To assess ecological factors related to shifts from heterostyly to monomorphy, we examined the reproductive ecology of heterostylous tropical shrubs of Psychotria. Among 21 species at Barro Colorado Island and the nearby Parque Nacional Soberania, Panama, 14 species were heterostylous while seven were monomorphic. A molecular phylogeny and the existence elsewhere of heterostylous populations indicated that the breakdown of heterostyly had occurred independently. Heterostylous and monomorphic species were visited by the same bee species, although visit frequencies were lower in monomorphic species. Monomorphic species had significantly lower population density and greater fruit set than did heterostylous species. Autonomous autogamy made a large contribution to fruit set in monomorphic species and was only rarely observed in heterostylous species. The results indicate monomorphic and heterostylous species produce more seeds through selfing and outcrossing, respectively. The limitation of outcrossing as a result of low population density may be related to the breakdown of heterostyly and the evolution of selfing. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93, 125‐134. ADDITIONAL KEYWORDS: Barro Colorado Island ‐ breeding system evolution ‐ Panama ‐ pollination ‐ rarity ‐ self-fertilization ‐ tropical forest.

Mixed mating in Banksia media

Differential exclusion of vertebrates and invertebrates from the inflorescences of Banksia media R.Br. on the south coast of Western Australia showed the species to be partially self-compatible. Access by invertebrates increased fruit set and additional access by vertebrates resulted in even greater fruit set. Honeyeater birds and marsupial nectarivores were abundant and widespread in the study area and most carried the pollen of Banksia media while it flowered. However, although B. media had the floral characteristics attributed to vertebrate pollination, self-pollination and pollination by insects clearly also play major roles in seed production. Banksia media regenerates solely from seed released after fire and we suggest that its mixed mating strategy is a compromise between inbreeding depression and risk of elimination from areas prone to occasional fires.

Proximate factors affecting fruit set and seed mass of Styrax obassia in a masting year

We studied the relative importance of pollen limitation and resource limitation as proximal factors affecting fruit set and seed mass in a sub-canopy tree, Styrax obassia Sieb. et Zucc. in a masting year. We selected four individual trees and three branches of each tree for pollination and artificial defoliation experiments. The pollination experiment contained natural, self and cross-pollination treatments for each branch. Artificial defoliation rates in branches were 0%, 30%, and 60%. Pollen limitation seems not to have affected fruit set, because cross-pollination did not result in greater fruit set than did natural pollination. S. obassia appears to be partially self-incompatible as fruit set obtained by self-pollination was decreased compared to natural fruit set. Fruit set in both 60% and 30%-defoliated inflorescences was not statistically different from that of non-defoliated ones. Mean seed mass varied among trees and was affected by the pollination experiment. Thus, we conclude pollen quantity did not limit fruit set although its quality may affect seed mass, but stored resources may be a factor because limitation of current resources did not affect fruit set and seed mass of S. obassia.

Continuous Fluorescent Illumination Enhances Growth and Fruiting of Pepper.

Prolonging the photoperiod to continuous illumination (CI) implies a longer photosynthetic period which might be ideal for better plant growth. Pepper (Capsicum annuum L.) were grown in a nutrient culture system under a 12-h photoperiod for 6 weeks. Another group of plants was grown under a 12-h photoperiod for 3 weeks and then grown under a 24-h photoperiod (12/24-htreatment) for 3 more weeks. All seedlings were exposed to a low photosynthetic photon flux (PPF) of 120μmol·m-2s-1. The plants in the 12/24-h treatment gained more shoot dry weight, produced more leaves with heavier specific leaf weight (SLW), and had greater fruit set than those grown under a 12-h photoperiod. In a replicated experiment, the response was enhanced when a third group of plants was exposed to CI for 9 weeks just after germination. The higher shoot dry weight, and lack of further accumulation of starch in new leaves under CI indicate that the extensive carbon fixed under CI at low PPF was utilized effectively for pepper plant growth.

Pollination Requirements of Three Highbush Blueberry (Vaccinium corymbosum L.) Cultivars

The effects of pollination treatments on fruit set and five berry characteristics [mass, diameter, number of apparently viable seeds (well-developed, plump with dark seed coat), total seed number (includes apparently viable and partially developed seeds), and harvest date] were examined on three highbush blueberry cultivars. Pollination treatments included unpollinated, open pollinated, emasculated, and three hand pollinations that used pollen from the same flower, from the same cultivar, or from a different cultivar. Berries matured earliest and were smallest with the most apparently viable seeds in `Northland', `Patriot' had the greatest fruit set and smallest seed number, and `Bluecrop' matured the latest. Fruit set was greater, berry size larger, seed number smaller, and maturation later in 1990 than 1991. For all three cultivars, berries were generally smallest, latest maturing, and had the fewest seeds when pollination was prevented and were largest with the most seeds and earliest maturing in open visitation. Emasculation resulted in berries similar to those from unpollinated flowers. For berry characteristics, cross-pollination was of benefit for `Patriot' and possibly `Northland' but not `Bluecrop'. Thus, commercial highbush blueberry planting designs must be based on the pollination requirements of the particular cultivar. `Northland' berries almost always had seeds, while `Patriot' showed high levels and `Bluecrop' low levels of parthenocarpy.

Effects of temperature and pollination on growth, flowering and fruit set of the non-astringent persimmon cultivar ‘Fuyu’ under controlled temperatures

SummaryA controlled temperature room experiment evaluated the effects of four day/night tem-perature treatments on flowering, fruit set and growth of ‘Fuyu’, the most important non- astringent persimmon cultivar grown in Australia. Fruit set of hand-pollinated flowers at 17/12°C and 22/17°C was similar and averaged 53.6 and 54.9%, respectively. In contrast, fruit set of hand-pollinated flowers at 27/22°C and 32/27°C was significantly reduced by 58 and 77%, respectively. For the three higher temperature treatments, fruit set of non- pollinated flowers was very low (<4.0%) compared with fruit set at 17/12°C, which averaged 50.2%. The greater fruit set of non-pollinated flowers at 17/12°C may have been due to a combination of increased flower size and reduced vegatative growth under these conditions. Higher shoot starch concentrations at anthesis were recorded with decreasing temperature, presumably due to reduced growth (17/12°C, 3.1%; 22/17°C, 1.9%, 27/22°C, 0.85%, 32/27°C, 0.90).

CRANBERRY VARIETY FRUIT YIELD AND YIELD COMPONENETS

Accurate estimates of yield and yield components for parental selection would facilitate cranberry breeding efforts. A study was designed to obtain value estimates for traits related to yield. Ten commonly-cultivated varieties grown in a replicated planting, were evaluated in 1991 and 1992 for fruit yield per unit area (FY), average berry weight (BW) and number of berries per unit area, or berry concentration (BC). Averaged over all varieties, FY was significantly greater in 1992. BC was responsible for higher yields in 1992. Regression analysis revealed that BC accounted for more of the variation in FY than did BW in both years. BW accounted for some variation, however, in 1991 when FY was lower. Varieties differed significantly in FY, BW and BC. Hybrid varieties bad significantly greater FY and BW than wild selections. Variation for yield components exists among varieties tested, suggesting genetic gain is possible for yield with additional breeding efforts. In particular, greater fruit set should be emphasized as a breeding objective.

Effect of Transplant Age and Pruning Procedure on Yield and Fruit-set of Bell Pepper

Abstract In 1976, pruning and transplanting at 11 weeks increased the number of early marketable fruit from all cultivars compared to 11-week, nonpruned plants and plants transplanted at 8 weeks, whether pruned or not. Eight-week, nonpruned plants produced larger fruits than 11-week plants in early season regardless of cultivar. Effect of transplant treatments on fruit-set varied with cultivar. The greatest fruit-set was on 8-week, nonpruned ‘Bell Boy’ transplants and the least on 8-week, nonpruned ‘Emerald Giant’ transplants. Eleven-week-old transplants generally set more fruit than 8-week transplants, regardless of cultivar.

Effects of pollen and nitrogen availability on reproduction in a woodland herb, Lysimachia quadrifolia.

Relationships between pollen loads, resource availability, and fruit and seed production were determined for Lysimachia quadrifolia ramets in two adjacent sites (the scrub site and the open site) in 1982, 1983, and 1984. Pollen loads limited % fruit set and seed production in the open site in 1982 and 1983. Reproduction in the scrub site was resource limited in 1982, as shown by an increase in % fruit set when one-half of the flowers on a ramet were removed prior to fruit initiation. In the scrub site in 1983, pollination of one-half of the flowers on a ramet decreased the % fruit set of the remaining, unpollinated flowers. Fruit production in the same site was limited by pollen in 1984. Addition of nitrogen fertilizer to the scrub site in 1984 had no effect on fruit and seed production. There was more variation in fruit set between sites than between years. There was no trend to greater fruit set or number of seeds/fruit on early flowers compared to late flowers on the same ramet. Correlations between measures of reproduction were positive or insignificant. These results demonstrate year-and site-specific variation in the factors that limit plant reproduction.