Magnitude, timing, and causes of immature fruit loss in Amelanchier alnifolia (Rosaceae)

1989 ◽  
Vol 67 (3) ◽  
pp. 726-731 ◽  
Author(s):  
R. G. St. Pierre
Keyword(s):  
Dry Weight ◽  
Fruit Growth ◽  
Total Loss ◽  
Large Magnitude ◽  
Mature Fruit ◽  
Amelanchier Alnifolia ◽  
Fruit Crop ◽  
Immature Fruit

Despite a consistent and massive yearly bloom, the production of a fruit crop by Amelanchier alnifolia is highly variable. The objectives of this study were to characterize the magnitude and timing of fruit loss in A. alnifolia and to determine the causes of this loss, emphasizing factors that cause damage to flowers and immature fruit. Fruit loss was consistently of a large magnitude; for the 6 years that data were available, a mean of 81% of the potential fruit were lost. Mature fruit to flower ratios varied from 0.02 to 0.46 [Formula: see text]. The number of fruit per infructescence decreased within each season consistently and significantly. The period of decrease was initiated shortly after anthesis and was complete by mid-June, varying from 9 to 34 days [Formula: see text] in length. Fruit growth (mg dry weight) was only 16% complete by the end of the period of fruit loss. Of the abscised fruit collected and examined, a mean of 81% were damaged; 2–90% [Formula: see text] were damaged by a sawfly (Hoplocampa montanicola; Hymenoptera: Tenthredinidae) and 0–68% [Formula: see text] were damaged by frost. From 0 to 21% [Formula: see text] were damaged by other factors including a curculio (Anthonomus spp.) and unidentified insects and fungi. The cause of 19% of the total loss was undetermined.

scholarly journals Association between Fruit Development and Mature Fruit Drop in Huanglongbing-affected Sweet Orange

HortScience ◽  
2020 ◽  
Vol 55 (6) ◽  
pp. 851-857
Author(s):  
Lisa Tang ◽  
Sukhdeep Singh ◽  
Tripti Vashisth
Keyword(s):  
Fruit Development ◽  
Sweet Orange ◽  
Water Status ◽  
Fruit Size ◽  
Substantial Reduction ◽  
Fruit Growth ◽  
Mature Fruit ◽  
Callose Deposition ◽  
Immature Fruit ◽  
Fruit Drop

In the past decade, FL citrus industry has been struck by Huanglongbing (HLB), a disease caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (CLas). Besides tree decline, HLB causes a sharp increase in mature fruit drop before harvest, leading to a substantial reduction in citrus production. The aim of the study was to provide insights in HLB-associated mature fruit drop. For HLB-affected ‘Valencia’ and ‘Hamlin’ sweet orange (Citrus sinensis), trees exhibiting severe symptoms (“severe trees”) had a significantly higher rate of mature fruit drop compared with mildly symptomatic ones (“mild trees”). Interestingly, dropped fruit were smaller than those still attached to tree branches regardless of the symptom levels of trees; overall, fruit of severe trees were smaller than mild trees. The result suggests a negative effect of HLB on fruit growth that may lead to a high incidence to drop subsequently at maturity. This possibility is further supported by the difference in immature fruit size as early as 2 months after bloom between severe and mild trees. Although HLB-triggered phloem plugging due to callose deposition in citrus leaves, which results in disrupted carbohydrate transport, has been documented in literature, the results of the histological analysis demonstrated no consistent pattern of callose deposition in the mature fruit pedicel in relation to the drop incidence. Additionally, sugar concentration in juice was not significantly different between dropped and attached fruit, providing evidence that carbohydrate shortage is not the case for dropped fruit and thus not the predominant cause of HLB-associated mature fruit drop. Notably, the midday water potential was significantly lower for severe than mild trees during the preharvest period (2 weeks before harvest of the current crop) in late March, which was also the second week after full bloom of return flowering. This suggests that altered tree water status due to HLB might limit fruit growth during the initial stage of fruit development (immediately after flowering) and/or increase the incidence of mature fruit abscission, leading to elevated preharvest fruit drop. Together, the results suggest that in the presence of HLB, strategies to increase fruit size and minimize additional stresses (especially drought) for the trees may improve mature fruit retention.

scholarly journals Modeling the Peach Sugar Contents in Relation to Fruit Growth

1996 ◽  
Vol 121 (6) ◽  
pp. 1122-1131 ◽  
Author(s):  
Michel Génard ◽  
Michel Souty
Keyword(s):  
Growth Curve ◽  
Prunus Persica ◽  
Transfer Functions ◽  
Dry Weight ◽  
Fruit Growth ◽  
Data Sets ◽  
Weight Growth ◽  
Using Data ◽  
Good Agreement

The edible quality of peaches (Prunus persica L. Batsch) to a great extent depends on their sweetness, which is related to sugar composition. Our objective was to develop a model to predict carbon partitioning within fruit flesh and to predict the sucrose, sorbitol, glucose, and fructose contents. The model is dynamic and deterministic and was designed to be driven by the flesh dry-weight growth curve, flesh water content, and temperature data. It uses differential equations where the state of the system is defined by variables that describe how much carbon is present as each form of sugar and as other compounds (acids and structural carbohydrates). The rates of change of these amounts of carbon depend on the current values of corresponding variables and on the transfer functions between them. These functions are defined by rate constants or by functions of degree-days after full bloom. The model was calibrated and tested using data sets from treatments that covered several leaf: fruit ratios. The predictions of the model were in fairly good agreement with experimental data. A sensitivity analysis was performed to identify the most influential transfer function parameters. Carbon flows between sugar forms were analyzed. Sucrose, which was the most abundant sugar, and fructose, which is the sweetest, contributed most to fruit sweetness. Simulations were performed to study the effects of changes in fruit growth-curve parameters on sugar contents and concentrations.

scholarly journals Seasonal Partitioning of Leaf and Fruit Potassium and Fruit Dry Matter in French Prune Trees at Various Potassium Levels

1991 ◽  
Vol 116 (6) ◽  
pp. 981-986 ◽  
Author(s):  
F.J.A. Niederholzer ◽  
R.M. Carlson ◽  
K. Uriu ◽  
N.H. Willits ◽  
J.P. Pearson
Keyword(s):  
Dry Matter ◽  
Dry Weight ◽  
Fruit Growth ◽  
Growth Stages ◽  
Dry Matter Accumulation ◽  
Accumulation Rates ◽  
Mature Trees ◽  
Linear Relationships ◽  
Weight Yield ◽  
High K

A study was undertaken to determine the seasonal dynamics of leaf and fruit K content and the influence of tree K status and fruit growth on leaf and fruit K accumulation rates in French prune (Prunus domestics L. cv. d'Agen). Mature trees in a commercial orchard were treated with various rates of K2 SO4. (O to ≈20 kg/tree) in the fall. Fruit dry weight yield per tree at harvest and fruit K content were higher for high-K trees, but fruit percent K (by dry weight) was ≈1.0% for all trees. Leaf scorch and subsequent abscission severely reduced the canopy of K-deficient trees. Significant positive linear relationships between leaf and fruit K accumulation rates existed for the periods of 28 Apr.-28 May (May) and 28 May-7 July (June). A significant negative linear relationship existed between these two criteria from 7 July-3 Aug. (July). May (0.237 mg K per fruit-day) and July (0.267 mg K per fruit-day) mean fruit K accumulation rates were similar, but both were significantly higher (P = 0.001) than those for June (0.140 mg K per fruit-day). Mean leaf K accumulation rates for May (- 0.007 mg K per leaf-day) and July (-0.010 mg K per leaf-day) were similar, but both were significantly (P = 0.001) less than for June (0.005 mg K per leaf-day). Potassium per fruit accumulation was highest in trees with highest K status. Periods of net leaf K efflux and influx did not precisely correlate with fruit growth stages measured by fruit dry weight. The period of lowest fruit K accumulation (28 May-7 July) coincided with the period of maximum dry matter accumulation by the kernel. After 7 July, all increases in fruit dry weight and K content were due to mesocarp growth.

scholarly journals No Evidence of Excessive Leaf Production by Strawberries Grown in the Subtropics

Agriculture ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 197
Author(s):  
Christopher M. Menzel
Keyword(s):  
Dry Weight ◽  
Daily Maximum ◽  
Base Temperature ◽  
Sigmoid Function ◽  
Potential Yield ◽  
Leaf Production ◽  
Breeding Lines ◽  
Immature Fruit ◽  
Linear Pattern ◽  
Number Of Leaves

Fruit growth in most plants is strongly dependent on photosynthates produced in the leaves. However, if there are too many leaves, the lower part of the canopy becomes heavily shaded and yields are reduced. Experiments were conducted to determine if cultivars of strawberry (Fragaria × ananassa Duch.) grown in Queensland, Australia have excessive leaf production for adequate cropping. Seven cultivars and breeding lines were planted from March to May from 2004 to 2016 and the number of fully-expanded leaves, dry weight of the flowers and fruit, and yield/plant recorded (n = 23). Information was collected on daily maximum and minimum temperatures and solar radiation. Increases in the number of leaves/plant over the season followed a linear pattern (range in R2 from 0.81–0.99), with the relationship generally similar or better than a dose-logistic (sigmoid) function (range in R2 from 0.79–0.99). There were strong linear relationships between the number of leaves/plant and growing degree-days (GDDs), using a base temperature of 7 °C (range in R2 from 0.81–0.99). In contrast, there was no relationship between the number of leaves/plant produced each day and average season daily mean temperature (15.7 °C to 17.8 °C) or radiation (13.0 to 15.9 MJ/m2/day) (R2 < 0.10). Potential yield as indicated by the dry weight of the flowers and immature fruit/plant increased up to 40 to 45 leaves/plant (R2 = 0.49 or 0.50) suggesting that the cultivars do not have excessive leaf production. There was no relationship between yield and the number of leaves/plant (R2 < 0.10) because rain before harvest damaged the fruit in some years. These results suggest that the development of new cultivars with more leaves/plant might increase cropping of strawberries growing in the subtropics.

Regulation of ethylene production and ripening by saskatoon (Amelanchier alnifolia Nutt.) fruit

1998 ◽  
Vol 76 (10) ◽  
pp. 1743-1754
Author(s):  
Suzy Y Rogiers ◽  
GN Mohan Kumar ◽  
N Richard Knowles
Keyword(s):  
Ethylene Production ◽  
Acc Oxidase ◽  
Fold Increase ◽  
Dry Weight ◽  
Oxidase Inhibitor ◽  
Aminooxyacetic Acid ◽  
Acid Oxidase ◽  
Amelanchier Alnifolia ◽  
Endogenous Ethylene ◽  
Maturity Class

Changes in respiration and ethylene production were characterized during maturation and ripening of saskatoon (Amelanchier alnifolia Nutt.) fruit. On a per fruit basis, respiration and ethylene production increased 78 and 400%, respectively, as fruit ripened on the plant and trends were consistent with those for climacteric fruits. When estimated on a fresh and dry weight basis, increased rates of ethylene production were still apparent during ripening; however, respiration rate declined. Trends in respiration rates and endogenous ethylene levels of harvested fruit of nine maturity classes, from immature green (class one) to fully ripe and purple (class nine), were consistent with those of fruit growing on the plant. Tissue prints showed that ACC (1-aminocyclopropane-1-carboxylic acid) oxidase was distributed throughout the pericarp of fruit at all nine maturity stages and that the enzyme was most concentrated in the immature stages on a per fruit basis. On a protein basis, ACC oxidase increased progressively with development of cv. Smoky fruit but remained relatively constant over the nine maturity classes of cv. Northline fruit. In contrast, ACC oxidase levels were relatively low in cv. Pembina fruit over the first four maturity classes, increased substantially as fruits developed from class four to five, then remained constant as fruit ripened to maturity class nine. Treating immature harvested Pembina fruit (maturity classes one to three) with ACC effected a 28- to 108-fold increase in ethylene production, compared with an average of only 7-fold for ACC-treated fruit of maturity classes four through nine. Preharvest treatment of class-three fruit with ACC induced ripening to maturity class eight within 5 days, while untreated fruit required 15 days to reach class eight. Vacuum infiltrating class four fruit with alpha-aminooxyacetic acid (AOA) or aminoethoxyvinyl glycine (AVG) inhibited ethylene production and color development substantially. The inhibiting effect of AOA on ripening was eliminated when fruit were infiltrated with equimolar concentrations of AOA and ACC. Cobalt, an ACC oxidase inhibitor, also inhibited ethylene production and ripening. Collectively, our results indicate that ethylene synthesis by preclimacteric fruit is limited by the availability of ACC, ethylene is responsible for initiating ripening, and thus, saskatoon fruit are climacteric.Key words: Amelanchier alnifolia, saskatoon, fruit ripening, ethylene.

scholarly journals Variability in Kernel Oil and Kernel Crude Protein Contents in Sudanese Fruit Accessions of Balanites aegyptiaca (L.) Del.

2017 ◽  
Vol 60 (3) ◽  
pp. 134-140
Author(s):  
Nour Ahmed Osman-Bashir ◽  
Salah Ahmed-Ali Elhussein
Keyword(s):  
Crude Protein ◽  
Dry Weight ◽  
Physicochemical Characteristics ◽  
Mature Fruit ◽  
Balanites Aegyptiaca ◽  
Kernel Oil ◽  
A Value ◽  
Potential Source ◽  
Total Fatty Acids ◽  
Different Parts

Balanites fruits (Balanites aegyptiaca) as a potential source of steroidal sapogenins, chemicalsin demand by the pharmaceutical industry was studied. This report focuses on two potential fruit productsother than sapogenins, namely, balanites kernel oil (BKO) and kernel total protein. The oil content ofbalanites kernels obtained from thirteen mature-fruit accessions collected from different parts of Sudanwas high, reaching a value above 40% of kernel dry weight in several accessions. Kernel total proteinaveraged 31.2%. Some physicochemical characteristics of the oil and of its component lecithin fractionwere determined. Linoleic acid was the predominant fatty acid in BKO, reaching 56.0% of total fatty acids.

scholarly journals Model Selection for Nondestructive Quantification of Fruit Growth in Pepper

2012 ◽  
Vol 137 (2) ◽  
pp. 71-79 ◽  
Author(s):  
A. Maaike Wubs ◽  
Yun T. Ma ◽  
Ep Heuvelink ◽  
Lia Hemerik ◽  
Leo F.M. Marcelis
Keyword(s):  
Dry Matter ◽  
Simulation Models ◽  
Dry Weight ◽  
Matter Content ◽  
Fruit Growth ◽  
Dry Matter Content ◽  
Sigmoid Function ◽  
Fresh Weight ◽  
Data Set ◽  
Weight Growth

Quantifying fruit growth can be desirable for several purposes (e.g., prediction of fruit yield and size, or for the use in crop simulation models). The goal of this article was to determine the best sigmoid function to describe fruit growth of pepper (Capsicum annuum) from nondestructive fruit growth measurements. The Richards, Gompertz, logistic, and beta growth functions were tested. Fruit growth of sweet pepper was measured nondestructively in an experiment with three different average daily temperatures (18, 21, and 24 °C) and in an experiment with six cultivars with different fruit sizes (20 to 205 g fresh weight). Measurements of fruit length and fruit diameter or circumference were performed twice per week. From these, fruit volume was estimated. A linear relationship related fruit fresh weight to estimated fruit volume, and a Ricker or polynomial function related fruit dry matter content to fruit age. These relations were used to convert estimated fruit volume into fruit fresh and dry weights. As dry weight increased until harvest, fitting the sigmoid function to the dry weight data was less suitable: it would create uncertainty in the estimated asymptote. Therefore, the sigmoid functions were fitted to fresh weight growth of the fruit. The Richards function was the best function in each data set, closely followed by the Gompertz function. The fruit dry weight growth is obtained by multiplication of the sigmoid function and the function relating fruit dry matter content to fruit age.

scholarly journals Optimizing Continuous Canopy Shakers for Late Season `Valenica' Harvest

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 885A-885
Author(s):  
Richard S. Buker* ◽  
Jackie K. Burns ◽  
Fritz M. Roka
Keyword(s):  
Operating Conditions ◽  
Tree Size ◽  
Mature Fruit ◽  
Fruit Removal ◽  
Crop Load ◽  
Immature Fruit ◽  
Late Season ◽  
Southern Site ◽  
Mechanical Harvester

Continuous canopy shakers (CCS) were developed in the late 90's and have been used to commercially harvest citrus in Florida. A viable mechanical harvester in Florida must be able to selectively remove mature `Valencia' fruit. A study was conducted to evaluate the effect of operating conditions on mature and immature fruit removal during the 2003 harvest season. The study was conducted in the southern flat woods and northern ridge areas. The study treatments were completely random and replicated four times. The CCS treatments were 145, 215, 230, and 245 cycles per minute (cpm) and a hand picked control. The harvest occurred on 17 and 19 June at the southern and northern sites, respectively. Mature fruit removal linearly increased from 95.7% to 97.9% between 145 and 245 cpm, respectively. Varying the operating ranges significantly influenced mature fruit removal in the southern flat woods site. The trees at the southern site were taller (>4m), and had a larger crop load. At the northern ridge site where trees were smaller, varying the CCS operating ranges did not significantly influence mature fruit removal. Immature fruit removal was influenced by the operating ranges. Immature fruit removal was increased at least 22% over hand picked controls. The results were interpreted to indicate the frequency of CCS is dependent on tree size. The initial selectivity of the CCS was not equal to hand picking.

scholarly journals Modification of Carbohydrate Content in Developing Tomato Fruit

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 551E-551
Author(s):  
Arthur A. Schaffer ◽  
Marina Petreikov ◽  
Daphne Miron ◽  
Miriam Fogelman ◽  
Moshe Spiegelman ◽  
...  
Keyword(s):  
Carbohydrate Metabolism ◽  
Metabolic Pathways ◽  
Tomato Fruit ◽  
Starch Synthesis ◽  
Mature Fruit ◽  
Immature Fruit ◽  
Natural Genetic Variation ◽  
Structural Carbohydrate ◽  
Source Sink ◽  
The Impact

The carbohydrate economy of developing tomato fruit is determined by wholeplant source–sink relationships. However, the fate of the imported photoassimilate partitioned to the fruit sink is controlled by the carbohydrate metabolism of the fruit tissue. Within the Lycopersicon spp. there exists a broad range of genetic variability for fruit carbohydrate metabolism, such as sucrose accumulation and modified ratios of fructose to glucose in the mature fruit and increased starch synthesis in the immature fruit. Metabolic pathways of carbohydrate metabolism in tomatoes, as well as natural genetic variation in the metabolic pathways, will be described. The impact of sink carbohydrate metabolism on fruit non-structural carbohydrate economy will be discussed.

scholarly journals PERFORMANCE OF 18 JALAPENO VARIETIES IN WHOLE PACK AND SAUCE

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 515E-516
Author(s):  
Paul Wilson
Keyword(s):  
Cultural Production ◽  
Heat Content ◽  
Dry Weight ◽  
Fruit Weight ◽  
Fresh Market ◽  
Mature Fruit ◽  
Surface Color ◽  
Processed Products ◽  
Red Peppers ◽  
Fruit Surface

Jalapeños are versatile peppers with both green and mature-red peppers used fresh and in processed products. Peppers can be dried, pickled whole in brine or as salted mash for sauces. Mature fruit can also be smoked and dried to produce chipotle which can be used in several ways including preparation of sauces. Although there are many individual cultivars of jalapeño peppers available, little is known of their processing characteristics. Most food processors still rely on fresh-market supplies rather than contracting specific cultivars which might provide better processing characteristics. A study was begun in Summer 2005 at LSU to provide information concerning the processing characteristics of commonly available jalapeño cultivars. Over a 3-year period, each cultivar will be evaluated in fresh form, as pickled whole fruit, as salted mash and as smoked chipotle. Besides good cultural production qualities, pepper cultivars that will be manufactured into processed products should have 1) acceptable and consistent heat content, 2) good stable color and, 3) consistent/suitable size (for whole pack). Seventeen jalapeño cultivars were evaluated in fresh green, brine-cured green and mature-red state for fruit surface color, average fruit weight, dry weight, and percent seed.

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