scholarly journals GA3—INDUCED FRUIT SET OF RABBITEYE BLUEBERRY

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 689c-689
Author(s):  
Raguel Cano—M ◽  
Rebecca L. Darnell

The effects of different GA3 concentrations and application times on fruit set, fruit development period, and fruit quality in rabbiteye blueberry (Vaccinium ashei Reade) were studied. Flower clusters were sprayed with 100 or 250 ppm GA3 at 90% full bloom and again 7 days later, or with 125 ppm GA3 at 90% full bloom and again 7, 21, and 42 days later, under greenhouse conditions. Fruit set was monitored every 10 days and fruit weight, fruit development period, soluble solids, and titratable acidity were measured at harvest. Fruit set in GA3 treatments averaged 69 to 76% compared to an average of 43% for the pollinated control. Weight of GA3 treated berries averaged 1.2, g while that of pollinated berries averaged 2.0 g. However, calculated total yield was greater for the GA3 treatments compared to the pollinated control, averaging 244 and 206 g/treatment, respectively. GA3 increased the fruit development period by 2 to 11 days, depending on the treatment. Soluble solids and titratable acidity were not affected by any treatment.

2006 ◽  
Vol 46 (1) ◽  
pp. 131 ◽  
Author(s):  
U. Bal ◽  
S. Altintas

Trichoderma harzianum was applied to seedling growing media (a peat and soil-based mixture or greenhouse soil) at the time of sowing, at transplanting to vials and at planting. The factorial experiment using 2 seedling growing media, 2 cultivars and 4 dosages of T. harzianum at 0 (control), 4 g/m2, 10 g/m2 and 24 g/m2 showed that the Trichoderma dosage had no significant effect on the yield or fruit quality. None of the 3 factor interactions between the criteria studied, that is, total yield, marketable yield, early yield, individual fruit weight, total soluble solids and titratable acidity, were significant except for fruit diameter. The 3 factor combination of Peat × Belleveu F1 × 10 g/m2 resulted in the highest total yield, marketable yield and early yield with 1552, 1373 and 681 g/plant, respectively. The interaction between media and cultivars was significant for all the yield characteristics studied. However, the main effect of T. harzianum on early yield was the highest at 4 g/m2, producing 527 g/plant in comparison to the control with 374 g/plant. It was, therefore, hypothesised that the positive effect of T. harzianum, observed in the early yield, may be extended to the whole growing period by further applications, that is, by periodical renewal of the T. harzianum population at the root zone.


1999 ◽  
Vol 79 (2) ◽  
pp. 269-275 ◽  
Author(s):  
J. Prohens ◽  
F. Nuez

The introduction of pepino (Solanum muricatum Aiton) as a new greenhouse crop relies on the development of clones that produce high fruit yields with an increased soluble solids concentration (SSC). We have evaluated two breeding strategies aimed at obtaining new, improved clones of this heterozygous vegetatively propagated crop: selection in the segregating generation F1 (hybrids) or in the first generation of selfing (selfings). We recorded the total yield, SSC, fruit weight, shape, firmness, titratable acidity and ascorbic acid concentration in seven populations of hybrids and in five populations of selfings. Four populations of clonal replicates were used to estimate environmental variability. Total yield and its heritability were higher in the hybrids than in the selfings. Expected responses to selection showed that it might be possible to select clones with a yield higher than 80 t ha−1 with selection pressures lower than 5% in some hybrid populations. Heritabilities for SSC were moderate, but clones with a SSC higher than 9.0 °Brix could be selected. We also found an important variation in the other characters studied, indicating that improved clones could be selected for all of them. Values for genotypic correlations between characters were very variable. In most hybrid populations, however, we did not find negative genotypic correlations between yield and fruit quality characters. Our results indicate that new hybrid clones of pepino that exceed present clones in yield and fruit quality might be obtained. Key words: New crops, plant breeding, clonal propagation, hybrids, selfings


2013 ◽  
Vol 41 (1) ◽  
pp. 263
Author(s):  
Emine ÖZDEMİR ◽  
Nurettin KAŞKA ◽  
Kazim GÜNDÜZ ◽  
Sedat SERÇE

In this study, we tested the effects of short day (SD), chilling (Ch) and gibberalic acid (GA3) treatments on the yield and fruit characteristics of ‘Camarosa’ and ‘Sweet Charlie’ plug plants under a freeze-protected greenhouse in Mediterranean conditions for two growing seasons in 2006-2007 and 2007-2008. The treatments included control (ambient day length and temperature); SD (8 h days) and ambient temperature; SD + Chilling (Ch) (18/12°C day/night temperatures); SD + Ch (10°C); SD + Ch (2°C); and, GA3 (10 ppm applied to the plants in November). In each growing season, the plug plants were planted in mid-August using bag culture. Yield, fruit weight, firmness, total soluble solids (SS), titratable acidity (TA), and SS/TA ratio were investigated. Considerable amounts of early yield (March and April) were recovered from ‘Sweet Charlie’; 116 and 72 g/plant in the first and second growing seasons, respectively. ‘Sweet Charlie’ also had consistently higher total yield than ‘Camarosa’ (457 vs. 400 g/plant in the 2006-2007 season and 446 vs. 406 g/plant in the 2007-2008 season). Treatment did not have a consistent effect on the fruit quality traits measured. The results indicated that although SD conditioning, Ch and GA3 treatments may have an effect on the total and early yield of strawberries, these effects may be cultivar-dependent and further regulated by environmental factors. Therefore, we propose that low-chilling varieties be utilized for early fruit production that can initiate flower buds in warmer, longer days.


2012 ◽  
Vol 21 (2) ◽  
pp. 132-140 ◽  
Author(s):  
Li Fan ◽  
Valentine Roux ◽  
Claudine Dubé ◽  
Dennis Charlebois ◽  
Shutian Tao ◽  
...  

The effects of three mulching systems on total yield, average yield per plant, average fruit weight, soluble solids content (SSC), titratable acidity (TA), firmness and oxygen radical absorbance capacity (ORAC) of two newly developed lines (‘Orléans’ and ‘Saint Pierre’), one advanced selection (‘SJ8976-1’) and two commonly used cultivars (‘Jewel’ and ‘Kent’) were evaluated. The studied mulching systems were: plastic mulch (PM), mulch with row cover (PMRC), and matted-row system (MRS). Results showed that plastic mulch with row cover (PMRC) generally increased yield per plant, average fruit weight, SSC, firmness and ORAC, but differences varied within harvest times. No significant differences in total yield and TA were observed under the selected mulching systems. Both PMRC and PM accelerated the harvest periods compared to MRS. ‘Kent’ and ‘Jewel’ had the highest total yield while ‘SJ8976-1’ and ‘St-Pierre’ had the highest average fruit weight. The highest SSC, TA and ORAC were found in ‘Jewel’. There was no interaction between the mulching systems and genotypes, indicating that the effect of production system is independent of cultivars. PMRC seems to be a better growing system, improving fruit quality and increasing the nutritional value of all genotypes. By allowing off-season fruit production in cool climates, PMRC can be an alternative method to the costly high tunnels.


2008 ◽  
Vol 35 (No. 2) ◽  
pp. 83-89 ◽  
Author(s):  
G. Tzortzakis N ◽  
D. Economakis C

The performance and suitability of different substrates for the soilless culture of tomato plants (<I>Lycopersicum esculentum</I> Mill., cv. Belladona) were studied over a 5-month period in a closed soilless culture system employing five different substrates (perlite, pumice or maize and their mixtures with 50% shredded maize stems in an unheated glasshouse). Plants grown in a maize stem-containing medium produced earlier fruits, followed by pumice. Plants grown in pumice and perlite substrates obtained lower total yield; a higher yield was associated with the addition of maize shredded stems. Pumice + 50% maize and 100% maize produced higher total number of fruits per plant. Fruit quality parameters such as mean fruit weight, fruit firmness, total soluble solids, titratable acidity, ascorbic acid and carotenoids were influenced by the treatment, while EC, pH and dry matter content were not. The results suggest that the addition of maize in perlite and pumice could improve inorganic substrates properties for tomato soilless culture, leading to higher yields and better fruit quality.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 408E-408
Author(s):  
Maria J. Sindoni V. ◽  
Frank B. Matta

Several cultivar/rootstock combinations were evaluated for overall performance in Mississippi. This study included postharvest fruit quality during storage as influenced by the various rootstocks. Parameters measured were fruit set, scion and stock trunk cross-sectional area, fire blight tolerance, fruit drop, and maturity indices such as fruit size, firmness, fresh fruit weight, soluble solids content, and juice pH. Cultivar/rootstock combinations were `Earligold'/EMLA 7, `Jonagold'/EMLA 111, `Improved Golden'/EMLA 7, `Improved Golden'/EMLA 111, `Scarlet Gala' /EMLA 7, `Jonafree'/Mark, `Macspur'/M 7A, `Royal Gala'/MM 111, and `Williams Pride'/M 7A. Cultivar and rootstock influenced fruit set. `Royal Gala', `Scarlet Gala', `Improved Golden', and `Earligold' showed maximum fruit set among the various cultivars. MM 111 and EMLA 7 rootstocks increased fruit set. Scion cultivars had the greatest trunk diameter on EMLA 111 and MM 111 and the smallest diameter on Mark. Scion cultivars on Mark and M 7A rootstocks showed less susceptibility to fire blight compared to MM 111 and EMLA 111. Cultivars on EMLA 7 showed moderate susceptibility to fire blight. Cultivars `Jonafree', `Williams Pride', `Macspur', and `Scarlet Gala' were least susceptible to fire blight compared to `Royal Gala'. The remaining cultivars were intermediate in susceptibility to fire blight. Fruit size, firmness, fresh fruit weight, soluble solids content, and juice pH were influenced by cultivar. `Jonagold' and `Williams Pride' produced the largest fruit, while `Jonafree' and `Macspur' yielded the smallest fruit. Total soluble solids were not influenced by cultivar and rootstock combinations. Sugar content of the juice increased as the apples matured and ranged from 12% to 14% among the cultivar/rootstock combinations. Firmness was influenced by cultivar but not rootstock. `Jonafree', `Macspur' had firm fruit, while fruit of `Scarlet Gala', `Williams Pride', and `Earligold' was not as firm. After harvest, the cultivars were stored at 2 °C for ≈4 months under controlled conditions and evaluated for soluble solids content, titratable acidity, pH, and firmness at monthly intervals. Overall, firmness, soluble solids content, and titratable acidity in all cultivars decreased with time in storage. `Improved Golden'/EMLA 7, `Royal Gala'/MM 111, and `Jonagold'/EMLA 111 maintained quality during storage, compared with the remaining cultivars/rootstock combinations, and had a longer storage life.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Molla F. Mengist ◽  
Hamed Bostan ◽  
Elisheba Young ◽  
Kristine L. Kay ◽  
Nicholas Gillitt ◽  
...  

AbstractFruit quality traits play a significant role in consumer preferences and consumption in blueberry (Vaccinium corymbosum L). The objectives of this study were to construct a high-density linkage map and to identify the underlying genetic basis of fruit quality traits in blueberry. A total of 287 F1 individuals derived from a cross between two southern highbush blueberry cultivars, ‘Reveille’ and ‘Arlen’, were phenotyped over three years (2016–2018) for fruit quality-related traits, including titratable acidity, pH, total soluble solids, and fruit weight. A high-density linkage map was constructed using 17k single nucleotide polymorphisms markers. The linkage map spanned a total of 1397 cM with an average inter-loci distance of 0.08 cM. The quantitative trait loci interval mapping based on the hidden Markov model identified 18 loci for fruit quality traits, including seven loci for fruit weight, three loci for titratable acidity, five loci for pH, and three loci for total soluble solids. Ten of these loci were detected in more than one year. These loci explained phenotypic variance ranging from 7 to 28% for titratable acidity and total soluble solid, and 8–13% for pH. However, the loci identified for fruit weight did not explain more than 10% of the phenotypic variance. We also reported the association between fruit quality traits and metabolites detected by Proton nuclear magnetic resonance analysis directly responsible for these fruit quality traits. Organic acids, citric acid, and quinic acid were significantly (P < 0.05) and positively correlated with titratable acidity. Sugar molecules showed a strong and positive correlation with total soluble solids. Overall, the study dissected the genetic basis of fruit quality traits and established an association between these fruit quality traits and metabolites.


2017 ◽  
Vol 39 (4) ◽  
Author(s):  
MATEUS DA SILVEIRA PASA ◽  
BRUNO CARRA ◽  
CARINA PEREIRA DA SILVA ◽  
MARLISE NARA CIOTTA ◽  
ALBERTO FONTANELLA BRIGHENTI ◽  
...  

ABSTRACT The low fruit set is one of the main factors leading to poor yield of pear orchards in Brazil. Ethylene is associated with abscission of flowers and fruitlets. Then, the application of ethylene synthesis inhibitors, such as AVG, is a potential tool to increase fruit set of pears. The objective of this study was to evaluate the effect of AVG, sprayed at different rates and timings, on fruit set, yield and fruit quality of ‘Rocha’ pear. The study was performed in a commercial orchard located in the municipality of São Joaquim, SC, during the growing seasons of 2014/2015 and 2015/2016. Plant material consisted of ‘Rocha’ pear trees grafted on quince rootstock ‘BA29’. AVG was tested at different rates (60 mg L-1 and 80 mg L-1) and timings [full bloom, one week after full bloom (WAFB), and two WAFB), either alone or in combination. The experiment was arranged in a randomized block design, with at least five single-tree replications. The fruit set, number of fruit per tree, yield, estimated yield, fruit weight, return bloom, and fruit quality attributes were assessed. Fruit set and yield were consistently increased by single applications of AVG at 60 and 80 mg L-1 at both one and two weeks after full bloom, without negatively affecting fruit quality attributes and return bloom.


2020 ◽  
Vol 8 (5) ◽  
pp. 551-557
Author(s):  
Gurjot Singh Pelia ◽  
◽  
A K Baswal ◽  

Prevalence of heavy soil is a major problem for fruit cultivation under Punjab conditions consequently leading to deficiency of several micro-nutrients including zinc (Zn), iron (Fe), and manganese (Mn) which adversely affects the growth and productivity. In this view, a study was planned to investigate the effect of foliar applications of zinc sulphate (ZnSO4), iron sulphate (FeSO4), and manganese sulphate (MnSO4) on vegetative growth, reproductive growth and fruit quality of papaya cv. Red lady. Plants sprayed with ZnSO4 (0.4 %) exhibited significantly highest plant height, plant girth, number of leaves, petiole length; initiated an earliest flowering and fruiting; and improved fruit quality viz., fruit weight, fruit length, titratable acidity, soluble solids concentrations, ascorbic acid content, total phenols content, and total carotenoids content as compared with the control and all other treatments. In conclusion, foliar application ZnSO4 (0.4 %) significantly improved plant growth and fruit quality in papaya cv. Red lady.


HortScience ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 99-107 ◽  
Author(s):  
Gregory M. Peck ◽  
Preston K. Andrews ◽  
John P. Reganold ◽  
John K. Fellman

Located on a 20-ha commercial apple (Malus domestica Borkh.) orchard in the Yakima Valley, Washington, a 1.7-ha study area was planted with apple trees in 1994 in a randomized complete block design with four replications of three treatments: organic (ORG), conventional (CON), and integrated (INT). Soil classification, rootstock, cultivar, plant age, and all other conditions except management were the same on all plots. In years 9 (2002) and 10 (2003) of this study, we compared the orchard productivity and fruit quality of `Galaxy Gala' apples. Measurements of crop yield, yield efficiency, crop load, average fruit weight, tree growth, color grades, and weight distributions of marketable fruit, percentages of unmarketable fruit, classifications of unmarketable fruit, as well as leaf, fruit, and soil mineral concentrations, were used to evaluate orchard productivity. Apple fruit quality was assessed at harvest and after refrigerated (0 to 1 °C) storage for three months in regular atmosphere (ambient oxygen levels) and for three and six months in controlled atmosphere (1.5% to 2% oxygen). Fruit internal ethylene concentrations and evolution, fruit respiration, flesh firmness, soluble solids concentration (SSC), titratable acidity (TA), purgeable volatile production, sensory panels, and total antioxidant activity (TAA) were used to evaluate fruit quality. ORG crop yields were two-thirds of the CON and about half of the INT yields in 2002, but about one-third greater than either system in 2003. High ORG yields in 2003 resulted in smaller ORG fruit. Inconsistent ORG yields were probably the result of several factors, including unsatisfactory crop load management, higher pest and weed pressures, lower leaf and fruit tissue nitrogen, and deficient leaf tissue zinc concentrations. Despite production difficulties, ORG apples had 6 to 10 N higher flesh firmness than CON, and 4 to 7 N higher than INT apples, for similar-sized fruit. Consumer panels tended to rate ORG and INT apples to have equal or better overall acceptability, firmness, and texture than CON apples. Neither laboratory measurements nor sensory evaluations detected differences in SSC, TA, or the SSC to TA ratio. Consumers were unable to discern the higher concentrations of flavor volatiles found in CON apples. For a 200 g fruit, ORG apples contained 10% to 15% more TAA than CON apples and 8% to 25% more TAA than INT apples. Across most parameters measured in this study, the CON and INT farm management systems were more similar to each other than either was to the ORG system. The production challenges associated with low-input organic apple farming systems are discussed. Despite limited technologies and products for organic apple production, the ORG apples in our study showed improvements in some fruit quality attributes that could aid their marketability.


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