scholarly journals Cranberry Yield and Fruit Quality Reduction Caused by Weed Competition

HortScience ◽  
1994 ◽  
Vol 29 (10) ◽  
pp. 1127-1130 ◽  
Author(s):  
Kim D. Patten ◽  
John Wang
Keyword(s):  
Fruit Quality ◽  
Fruit Size ◽  
Linear Component ◽  
Regression Equations ◽  
Weed Species ◽  
Quadratic Polynomials ◽  
Canopy Density ◽  
Perennial Weed ◽  
Weed Density ◽  
Best Fit

The relationships between canopy density of three perennial weed species (Potentilla pacifica Howell, Aster subspicatus Nees, and Lotus corniculatus L.) and `Mcfarlin' and `Stevens' cranberry (Vaccinium macrocarpon Ait.) yield and fruit quality were evaluated. Yield was more severely affected by weed interferences than fruit size or color. Best-fit regression equations for the effects of weed density on yield, fruit size, and color were linear or quadratic polynomials with a strong linear component. For each bog, the slope of the linear relationship between yield and weed density was more negative as the mean yield of weed-free controls increased. `Stevens' fruit size and yield were more sensitive and fruit color was less sensitive to changes in P. pacifica population density than those of `McFarlin'.

Relationships between soil, forage, and grazing parameter effects on weed incidence in Missouri pastures

2019 ◽  
Vol 34 (3) ◽  
pp. 408-415
Author(s):  
Gatlin Bunton ◽  
Zachary Trower ◽  
Kevin W. Bradley
Keyword(s):  
Soil Ph ◽  
Tall Fescue ◽  
Perennial Grass ◽  
Weed Species ◽  
Perennial Weed ◽  
Soil P ◽  
Weed Density ◽  
Growing Seasons ◽  
Unit Increase ◽  
Grass Weed

AbstractDuring the 2015, 2016, and 2017 growing seasons, a survey of 63 pastures in Missouri was conducted to determine the effects of selected soil and forage parameters on the density of common annual, biennial, and perennial weed species. Permanent sampling areas were established in each pasture at a frequency of one representative 20-m2 area per 4 ha of pasture, and weed species and density in each area were determined at 14-d intervals for a period from mid-April until late September. The parameters evaluated included soil pH, phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), sulfur (S), zinc (Zn), manganese (Mn), and copper (Cu) concentrations, as well as tall fescue density, forage groundcover density, and stocking rate. An increase of 1 unit in soil pH was associated with 146 fewer weeds per hectare, the largest reduction in weed density in response to any soil parameter. Increased soil pH was associated with the greatest reduction in perennial grass weed density, along with an average reduction of 1,410 brush weeds per hectare for each 1-unit increase in soil pH. Common ragweed, a widespread weed of pastures, could be reduced by 3,056 weeds ha−1 when soil pH was 1 unit greater. A 1-ppm increase in soil P was correlated with a decrease of 206 biennial broadleaf weeds per hectare. Perennial broadleaf weed density was reduced in soils with greater concentrations of P, K, and Ca. Additionally, for every 1% increase of tall fescue and forage groundcover, there was a decrease of 18 and 38 perennial broadleaf weeds per hectare. The results from this research indicate that the density of many common weed species can be reduced with higher soil pH and adjustments to soil macro- and micronutrient concentrations, especially P.

scholarly journals INTERACTION OF TRAINING SYSTEM, SUMMER PRUNING AND ROOT PRUNING ON YIELD AND CANOPY DENSITY OF PEACH

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1168g-1168
Author(s):  
W.C. Olien ◽  
R.E. Williamson ◽  
C.E. Hood ◽  
D.R. Decoteau ◽  
D.C. Coston
Keyword(s):  
Fruit Quality ◽  
Fruit Size ◽  
Training System ◽  
Interactive Effects ◽  
Root Pruning ◽  
Parallel Study ◽  
Negative Effects ◽  
Canopy Density ◽  
Training Systems

Factorial combinations of ± root pruning (RP) and ± summer pruning (SP) were initiated in 1991 as subplots within a Redhaven/Lovell study of orchard training systems: Open Center (OC), Y-Trellis (YT), Central Leader (CL), and Meadow Orchard (MO) established in 1985. Root pruning was imposed at bloom (March 28) at 76 cm from the trunk to a depth of 45 cm. Summer pruning consisted of preharvest removal of water sprouts (June 5). Canopy density, quantified by transmittance of PAR radiation through the canopy, was greatest in OC and MO and least in YT and CL systems. SP and RP treatments further reduced canopy density by 35 to 80%. There were no main or interactive effects of SP and RP on 1991 yields or fruit quality, and also no interactive effects of orchard systems with SP and RP. Thus, SP and RP reduced canopy density without negative effects on fruit. RP, however, advanced harvest date by ca 4 days. A parallel study was also initiated in 1991 to determine the effects of root pruning distance (30, 60, 90 cm from the trunk, or no RP) on canopy density, yield, and fruit quality of mature, OC-trained Redhaven/ and Jefferson/Lovell. Reduction in canopy density without loss of yield or fruit size was obtained at a RP distance between 60 and 90 cm.

Environmental Variability Associated by Economic Thresholds for Soybeans

Weed Science ◽  
1991 ◽  
Vol 39 (4) ◽  
pp. 564-569 ◽  
Author(s):  
Troy A. Bauer ◽  
David A. Mortensen ◽  
Gaila Wicks ◽  
Thomas A. Hayden ◽  
Alex R. Martin
Keyword(s):  
Environmental Variability ◽  
Soybean Seed ◽  
Field Studies ◽  
Regression Equation ◽  
Significant Source ◽  
Yield Reduction ◽  
Crop Loss ◽  
Regression Equations ◽  
Weed Species ◽  
Weed Density

Field studies were conducted in 1986, 1987, 1988, and 1989 to determine the stability of crop loss functions across site by year environments. Environment was a significant source of variation for the soybean crop loss function as influenced by velvetleaf, but not as influenced by tall waterhemp and common sunflower. Weed density was a highly significant source of variation for all weed species studied. Regressions between percent soybean seed yield reductions and weed populations were linear. The velvetleaf interference regression equations were divided into two groups, those with high soybean-yielding intercepts and those with low-yielding intercepts, to explain the variance observed across environments. The regression equation for the high-yielding intercept group was Ŷ = 4.24X while the low-yielding group was Ŷ = 2.14X, where Y is percent soybean yield reduction and X is weed density per 10.7 m of soybean row. Tall waterhemp and common sunflower regression equations were determined to be Ŷ = 1.37X and Ŷ = 6.52X, respectively. Confidence intervals were used to account for the variance associated with the mean regression equation for each model and to develop economic threshold models that include risk aversion principles.

scholarly journals The ‘Tommy Atkins’ mango genome reveals candidate genes for fruit quality

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ian S. E. Bally ◽  
◽  
Aureliano Bombarely ◽  
Alan H. Chambers ◽  
Yuval Cohen ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Fruit Quality ◽  
De Novo ◽  
Mapping Population ◽  
Mangifera Indica ◽  
Consensus Sequence ◽  
Fruit Size ◽  
Hybrid Population ◽  
High Molecular Weight Dna ◽  
Tropical Fruit

Abstract Background Mango, Mangifera indica L., an important tropical fruit crop, is grown for its sweet and aromatic fruits. Past improvement of this species has predominantly relied on chance seedlings derived from over 1000 cultivars in the Indian sub-continent with a large variation for fruit size, yield, biotic and abiotic stress resistance, and fruit quality among other traits. Historically, mango has been an orphan crop with very limited molecular information. Only recently have molecular and genomics-based analyses enabled the creation of linkage maps, transcriptomes, and diversity analysis of large collections. Additionally, the combined analysis of genomic and phenotypic information is poised to improve mango breeding efficiency. Results This study sequenced, de novo assembled, analyzed, and annotated the genome of the monoembryonic mango cultivar ‘Tommy Atkins’. The draft genome sequence was generated using NRGene de-novo Magic on high molecular weight DNA of ‘Tommy Atkins’, supplemented by 10X Genomics long read sequencing to improve the initial assembly. A hybrid population between ‘Tommy Atkins’ x ‘Kensington Pride’ was used to generate phased haplotype chromosomes and a highly resolved phased SNP map. The final ‘Tommy Atkins’ genome assembly was a consensus sequence that included 20 pseudomolecules representing the 20 chromosomes of mango and included ~ 86% of the ~ 439 Mb haploid mango genome. Skim sequencing identified ~ 3.3 M SNPs using the ‘Tommy Atkins’ x ‘Kensington Pride’ mapping population. Repeat masking identified 26,616 genes with a median length of 3348 bp. A whole genome duplication analysis revealed an ancestral 65 MYA polyploidization event shared with Anacardium occidentale. Two regions, one on LG4 and one on LG7 containing 28 candidate genes, were associated with the commercially important fruit size characteristic in the mapping population. Conclusions The availability of the complete ‘Tommy Atkins’ mango genome will aid global initiatives to study mango genetics.

Studies on the flowering biology of red sorrel (Rumex acetosella) ramets from lowbush blueberry (Vaccinium angustifolium) fields in Nova Scotia, Canada

Botany ◽  
2015 ◽  
Vol 93 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Scott N. White ◽  
Nathan S. Boyd ◽  
Rene C. Van Acker ◽  
Clarence J. Swanton
Keyword(s):  
Nova Scotia ◽  
Combined Effects ◽  
Perennial Species ◽  
Weed Species ◽  
Vaccinium Angustifolium ◽  
Perennial Weed ◽  
Flowering Response ◽  
Lowbush Blueberry ◽  
Rumex Acetosella

Red sorrel (Rumex acetosella L.) is a ramet-producing herbaceous creeping perennial species commonly found as a weed in commercially managed lowbush blueberry (Vaccinium angustifolium Aiton) fields in Nova Scotia, Canada. Flowering and seed production occur primarily in overwintering ramets of this species, indicating a potential vernalization requirement for flowering. This study was therefore initiated to examine the role of vernalization, photoperiod, and pre-vernalization stimulus on ramet flowering. Red sorrel ramets propagated from creeping roots and seeds collected from established red sorrel populations in lowbush blueberry had an obligate requirement for vernalization to flower. Ramet populations maintained under pre- and post-vernalization photoperiods of 16 h flowered following 12 weeks of vernalization at 4 ± 0.1 °C, whereas those maintained under constant 16, 14, or 8 h photoperiods without vernalization did not flower. Vernalization for 10 weeks maximized, but did not saturate, the flowering response. Pre-vernalization photoperiod affected flowering response, with increased flowering frequency observed in ramet populations exposed to decreasing, rather than constant, photoperiod prior to vernalization. This study represents the first attempt to determine the combined effects of vernalization and photoperiod on red sorrel flowering, and the results provide a benchmark for the future study of flowering and sexual reproduction in this economically important perennial weed species.

scholarly journals The impact of location, row direction, plant density and rootstock on the sunburn damage of apple cultivars

2005 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Racskó ◽  
J. Nagy ◽  
Z. Szabó ◽  
M. Major ◽  
J. Nyéki
Keyword(s):  
Solar Radiation ◽  
Leaf Area ◽  
Fruit Quality ◽  
Plant Density ◽  
Fruit Size ◽  
Quality Parameters ◽  
Apple Seedling ◽  
Apple Cultivars ◽  
The Impact ◽  
Crab Apple

The effect of row direction (N-S, E-W), plant density (conventional and intensive) and rootstock (M9, MM106 and crab apple) on the sensitivity of 41 apple cultivars to sunburn injury was studied at 6 locations (Derecske, Kálmánáaza, Nagykutas, Nagylapos, Siófok, Tornyospálca). During the observations the cultivars had rootstock-specific properties in respect of sunburn-susceptibility. Accordingly, the injury was decreased in the order: M9, MM106 and seedling rootstocks. The differences in sensitivity depend on the canopy of trees, caused finally by the growing vigour of rootstocks. Accordingly, the highest value of sunburn injury was observed on M9 rootstock, because this rootstock has a dwarfing effect upon the scion cultivars. Thus, vegetative area of these trees grow very slowly and the foliage is not enough compact to protect the fruit from solar radiation. The size and density of the foliage increased in the order: M9, MM 106 and crab apple seedling as rootstock. Moreover, relationships were demonstrated between the diameter of upper part of the crown, the leaf area, the number of fruits per tree and the injury of sunburn. Authors categorized the cultivars in respect of values of sunburn incidence: 1. „Not sensitive", II. „Moderately sensitive" and HI. „Strongly sensitive" categories were constituted. Generally, Topaz and Gala cultivars showed low damage (or were free from symptoms), in contrast to this, Golden mutants suffered relatively much. The most sensitive cultivar was Jonica on all the three rootstocks. We searched for relationship between the fruit quality parameters and the frequency of sunburn. Significant correlation was found in the cases of fruit size and the extent of cover-colour. The latter is interpreted with the fact that the best coloured fruits are found on the periphery of crown as a consequence of more intense irradiation.

scholarly journals The effect of nitrogen supply on specific yield and fruit quality of apple (Malus domestica Borkh.)

2005 ◽  
Vol 11 (2) ◽  
Author(s):  
J. Racskó ◽  
J. Nagy ◽  
Z. Soltész ◽  
M. Soltész ◽  
P. T. Nagy ◽  
...  
Keyword(s):  
Fruit Quality ◽  
Dry Matter ◽  
Shape Index ◽  
Matter Content ◽  
Nitrogen Supply ◽  
Specific Yield ◽  
Dry Matter Content ◽  
Canopy Density ◽  
Apple Cultivars

The aim of the present study was to determine the effect of nitrogen supply on yield and fruit quality of apple cultivars and to explore the relationships between canopy density and the different fruit quality parameters. The experiments were carried out at Kálmánháza, in Eastern Hungary in a private orchard in 2003-2004. The response of four apple cultivars ('Elstar', 'Gala Prince', 'Granny Smith', 'Idared') to different nitrogen dosages was studied. The assessed and calculated indices were: yield, fruit diameter, fruit height, shape index, fruit mass, firmness, dry matter content and colouration. The results indicated that nitrogen fertilization has a significant effect on the yield and fruit quality of apple cultivars. The calculated specific yield values were reduced by the application of nitrogen via the increase in the volume of the canopy. An opposit trend was observed for fruit diameter, fruit height and fruit weight, which increased with increasing nitrogen supply. The reduced shape index caused flattening of fruits. However, the improvement of fruit quality via increasing nitrogen dosage is only virtual, since these dosages increase the fruit size, but firmness, dry matter content and colouration are diminished, which decreases the value of the fruits on the market. The authors also studied the relationships between canopy density responsible for assimilation and light supply of the fruits and the different fruit quality parameters. The closest linear inversely proportional relationship was found in the case of colouration. There was a negative linear relationship between canopy density and firmness or dry matter content. The relationship between canopy density and fruit mass could be described by a quadratic polinomial function.

scholarly journals CITRUS FRUIT QUALITY CLASSIFICATION BASED ON SIZE USING DIGITAL IMAGE PROCESSING

2019 ◽  
Vol 48 (5) ◽  
pp. 95-101
Author(s):  
Ulzii-Orshikh Dorj ◽  
Uranbaigal Dejidbal ◽  
Hongseok Chae ◽  
Lkhagvadorj Batsambuu ◽  
Altanchimeg Badarch ◽  
...  
Keyword(s):  
Fruit Quality ◽  
Fruit Size ◽  
Citrus Fruit ◽  
Citrus Fruits ◽  
Single Tree ◽  
Quality Classification ◽  
Comparative Results ◽  
Vision Algorithm ◽  
Tree Fruits ◽  
Actual Size

A new computer vision algorithm for citrus fruit quality classification based on the size of a single tree fruits was developed in this study. The image properties of area, perimeter, and diameter for the citrus fruits were measured by pixels. In order to estimate citrus fruit size in a realistic manner, the ratios of diameter, perimeter and area in pixel values in relation to the actual size of one fruit were determined. The total of 1860 citrus fruits were grouped based on diameter, perimeter, and area in pixels. The results of the grouping of citrus fruits by diameter, perimeter and area were compared with the results of the survey research into citrus fruit size as conducted by the Jeju Citrus Commission. Comparative results reveal that the image of the citrus fruit diameter in pixels demonstrate a more accurate size than the other two pixel values, i.e. perimeter and area.

scholarly journals Effects of Rootstock, Tree Density and Training System on Early Growth, Yield and Fruit Quality of Blush Pear

HortScience ◽  
2021 ◽  
pp. 1-8
Author(s):  
Lexie McClymont ◽  
Ian Goodwin ◽  
Desmond Whitfield ◽  
Mark O’Connell ◽  
Susanna Turpin
Keyword(s):  
Fruit Quality ◽  
Vegetative Growth ◽  
Fruit Size ◽  
Growth Yield ◽  
Substantial Effect ◽  
Training System ◽  
Tree Density ◽  
High Density ◽  
Marketable Yield ◽  
And Training

Vegetative growth, orchard productivity, fruit quality and marketable yield were evaluated for rootstock (D6, BP1 and Quince A), tree density (741–4444 trees/ha), and training system (Open Tatura trellis, two-dimensional vertical and three-dimensional traditional) effects on young trees of the blush pear cultivar ‘ANP-0131’. ‘ANP-0131’ is a vigorous scion and vegetative growth, precocity, and yield were influenced by the selected rootstocks. Tree density and training system treatments exerted a substantial effect on canopy radiation interception while increasing tree density improved yield. Increasing tree density from 2222 (high density) to 4444 (ultra-high density) trees/ha did not improve cumulative yield. Crop load affected fruit size, such that “marketable” yield (yield of fruit weighing between 150 and 260 g) was greatest for trees on D6 rootstock and trained to Open Tatura trellis at high and ultra-high densities.

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