scholarly journals Influence of Aminoethoxyvinylglycine on Pecan Fruit Retention

HortScience ◽  
2009 ◽  
Vol 44 (7) ◽  
pp. 1884-1889
Author(s):  
Bruce W. Wood ◽  
Leonardo Lombardini ◽  
Richard J. Heerema
Keyword(s):  
Crop Yield ◽  
Field Studies ◽  
Carya Illinoinensis ◽  
Management Tool ◽  
Load Management ◽  
Crop Load ◽  
Ethylene Inhibitor ◽  
The U.S ◽  
June Drop ◽  
Increase Crop Yield

Insufficient fruit retention limits profitability of certain pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars. The present study examined efficacy of aminoethoxyvinylglycine (formulated as ReTain®; Valent BioSciences, Libertyville, IL), a natural ethylene inhibitor, for increasing crop-load through increased fruit retention in pecan trees grown at three distinct locations within the U.S. pecan belt. Several years of field studies found that timely postpollination ReTain® sprays [132 mg·L−1 a.i. (11.7 oz./acre)] to canopies could increase fruit retention of ‘Desirable’ and increase crop yield by 16% to 38% in trees carrying a “moderate to heavy” crop. ReTain® did not detectably increase fruit retention on trees carrying a “light” crop-load. The ReTain®-associated increase in yield of “heavy” crop-load trees did not necessarily decrease subsequent year yield. ReTain® appears to offer commercial potential as a crop-load management tool for ‘Desirable’ through regulation of Stage II drop (i.e., June-drop), but may not be efficacious for all cultivars.

scholarly journals Influence of Aminoethoxyvinylglycine (AVG) on Yield and Quality of Nut Crops from a Commercial Pecan Orchard

HortScience ◽  
2011 ◽  
Vol 46 (4) ◽  
pp. 586-589
Author(s):  
Bruce W. Wood
Keyword(s):  
Management Tool ◽  
First Year ◽  
Alternate Bearing ◽  
Crop Load ◽  
Yield Increase ◽  
Fruit Drop ◽  
Yield Parameters ◽  
Kernel Quality ◽  
Ethylene Inhibitor ◽  
Effect On Yield

Excessive fruit drop (i.e., June drop) can limit orchard profitability of certain pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars. The present study examines efficacy of aminoethoxyvinylglycine (AVG; formulated as ReTain®; Valent BioSciences, Libertyville, IL), a natural ethylene inhibitor, for increasing nutmeat yield in a commercial ‘Desirable’ pecan orchard over a 2-year period. The 30-ha experiment consisted of two treatments (nontreated versus ReTain) in the first year, an “off” year in the orchard's alternate bearing cycle. The second year's study, an “on” year, consisted of four treatments (i.e., “08 nontreated + 09 nontreated,” “08ReTain + 09 nontreated,” “08 nontreated + 09 ReTain,” and “08ReTain + 09 ReTain”). AVG, as ReTain [132 mg·L−1 a.i. (11.7 oz/acre)], was applied as two post-pollination canopy sprays (937 L·ha−1) 2 weeks apart in both years. During the “off” year, ReTain increased nut yield parameters with ReTain increasing kernel yield by 36% (704 kg·ha−1 versus 516 kg·ha−1) over that of nontreated trees. In the subsequent “on” crop year, the trees exhibiting a ReTain-associated previous year yield increase of ≈36% exhibited a reduction in yield of ≈25%, thus largely negating the previous season's yield increase over a 2-year alternate bearing cycle. Additionally, ReTain-treated trees during the “on” year failed to exhibit an increase in yield parameters over that of the nontreated control. As a result of a lag effect on subsequent year yield parameters, ReTain offers potential as a crop-load management tool for ‘Desirable’ orchards in “off” years such as a year of relatively high nutmeat price followed by a year of relatively low price. There appears to be no positive effect on yield when used in a heavy crop-load “on” year of an alternate bearing cycle. Thus, ReTain might have benefit for stabilizing alternate bearing in ‘Desirable’ pecan orchards. Kernel quality (defined as percentage of nut weight as kernel) of individual nuts from “on” year trees was not as sensitive to units of yield increase as for individual nuts of “off” year trees, thus implying that the rate of assimilate partitioning to individual reproductive structures in “off”-year trees is not as great as that in “on”-year trees.

scholarly journals Heritability and Phenotypic Correlations of Six Pecan Nut Characteristics

1993 ◽  
Vol 118 (3) ◽  
pp. 415-418 ◽  
Author(s):  
T.E. Thompson ◽  
J.F. Baker
Keyword(s):  
Least Squares ◽  
Environmental Variability ◽  
Kernel Weight ◽  
Carya Illinoinensis ◽  
Breeding Program ◽  
Alternate Bearing ◽  
Crop Load ◽  
Phenotypic Correlations ◽  
Heritability Estimates ◽  
The U.S

Heritability estimates for pecan [Carya illinoinensis (Wangenh.) K. Koch] nut weight, nut buoyancy, nut volume, nut density, kernel weight, and percentage kernel were determined from 8748 nut samples representing 152 families collected during 25 years in the U.S. Dept. of Agriculture (USDA) pecan breeding program at Brownwood, Texas. Measurements were corrected for year-to-year environmental variability using least-squares constants of individual year effects. Adjusted values were then regressed on midparent means. Generally, heritability (h2) estimates were low to moderate: nut weight 0.35, nut buoyancy 0.18, nut volume 0.35, nut density 0.03, kernel weight 0.38, and percentage kernel 0.32. The low values are probably due to the extreme alternate bearing tendency of this species, since crop load affects pecan nut characteristics so directly. Phenotypic correlations among these traits showed that larger or heavier nuts had significantly higher kernel weight, buoyancy, and percentage kernel. Nut density increased with higher nut and kernel weight, but decreased with nut volume.

scholarly journals Physiology of Methylotrophs Living in the Phyllosphere

2021 ◽  
Vol 9 (4) ◽  
pp. 809
Author(s):  
Hiroya Yurimoto ◽  
Kosuke Shiraishi ◽  
Yasuyoshi Sakai
Keyword(s):  
Plant Growth ◽  
Crop Yield ◽  
Environmental Conditions ◽  
Sole Source ◽  
Current Understanding ◽  
Methylotrophic Bacteria ◽  
Cellular Mechanisms ◽  
Diurnal Cycles ◽  
Promote Plant Growth ◽  
Increase Crop Yield

Methanol is abundant in the phyllosphere, the surface of the above-ground parts of plants, and its concentration oscillates diurnally. The phyllosphere is one of the major habitats for a group of microorganisms, the so-called methylotrophs, that utilize one-carbon (C1) compounds, such as methanol and methane, as their sole source of carbon and energy. Among phyllospheric microorganisms, methanol-utilizing methylotrophic bacteria, known as pink-pigmented facultative methylotrophs (PPFMs), are the dominant colonizers of the phyllosphere, and some of them have recently been shown to have the ability to promote plant growth and increase crop yield. In addition to PPFMs, methanol-utilizing yeasts can proliferate and survive in the phyllosphere by using unique molecular and cellular mechanisms to adapt to the stressful phyllosphere environment. This review describes our current understanding of the physiology of methylotrophic bacteria and yeasts living in the phyllosphere where they are exposed to diurnal cycles of environmental conditions.

Effects of the bioregulators ACC, 6-BA, ABA, and NAA as thinning agents on Gala apples

2020 ◽  
Vol 100 (2) ◽  
pp. 185-201 ◽  
Author(s):  
Michelle H. Cortens ◽  
John A. Cline
Keyword(s):  
Abscisic Acid ◽  
Fruit Quality ◽  
Fruit Set ◽  
Load Management ◽  
Environmental Concerns ◽  
Naphthaleneacetic Acid ◽  
Management Options ◽  
Crop Load ◽  
Southern Ontario ◽  
Malus Domestica Borkh

Gala apple (Malus domestica Borkh.) trees are prone to heavy cropping but respond to chemical fruitlet thinners to reduce crop load and improve fruit quality. Environmental concerns over the fate of the chemical fruitlet thinner carbaryl is widely acknowledged, but crop load management options are limited. In southern Ontario, Gala trees were treated with new thinning compounds or combinations to determine post-bloom thinning efficacy and resulting fruit quality. Treatments included 6-benzyladenine (6-BA) combined with naphthaleneacetic acid (NAA) or abscisic acid (ABA), and 1-aminocyclopropane-1-carboxylic acid (ACC) alone applied at 9 mm in 2014 and 17 mm in 2015. The treatment NAA + 6-BA produced unacceptably small “pygmy” fruit when applied at 17 mm fruitlet diameter. ABA at 150 and 300 mg L−1 and ACC at 150 mg L−1, when applied at 17 mm fruitlet diameter, resulted in acceptable fruit set, crop load, and quality results in comparison with the carbaryl thinner in 1 yr. The bioregulators ACC and ABA combined with 6-BA showed commercial potential for thinning Gala fruit but require further evaluation.

EFFECT OF IRRIGATION AND CROP LOAD MANAGEMENT ON FRUIT NUTRITION AND QUALITY FOR AMBROSIA/M.9 APPLE

2010 ◽  
pp. 63-72 ◽  
Author(s):  
D. Neilsen ◽  
G.H. Neilsen ◽  
L. Herbert ◽  
S. Guak
Keyword(s):  
Load Management ◽  
Crop Load

Simulation of Competition for Photosynthetically Active Radiation Between Common Ragweed (Ambrosia artemisiifolia) and Dry Bean (Phaseolus vulgaris)

Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 545-554 ◽  
Author(s):  
David Chikoye ◽  
Leslie A. Hunt ◽  
Clarence J. Swanton
Keyword(s):  
Leaf Area ◽  
Crop Yield ◽  
Photosynthetically Active Radiation ◽  
Growth And Development ◽  
Field Studies ◽  
Weed Competition ◽  
Yield Losses ◽  
Dry Bean ◽  
Common Ragweed ◽  
Active Radiation

The influence of weeds on crop yield is not only dependent on weed-related factors such as density and time of emergence, but also on environmental and management factors that affect both the weed and crop through time. This study was undertaken to develop the first physiologically based dry bean model that would account for the influence of weed competition. The specific objective was to develop a model that would account for the influence of weed competition on crop yield, and to use this model to test the hypothesis that crop yield losses resulted from competition for photosynthetically active radiation (PAR). To this end, a model that simulated the growth and development of dry bean was developed. The model performed daily calculations and simulated the phenology, leaf area expansion, dry matter production and distribution, and grain yield of dry bean based on weather and management information, but assumed adequate water and nutrients. The model was calibrated without weed competition at two locations and yr, and for these situations, adequately described the growth and development of the crop. Simulations were then run for five common ragweed densities and two times of emergence. Common ragweed leaf area was read into the model from input files and used to simulate weed shading. Shading of the dry bean canopy by common ragweed accounted for about 50 to 70% of the yield losses observed in field studies when weeds emerged with the crop. Weed shading did not account for the yield reduction measured from weeds that emerged at the second trifoliate stage of crop growth. The agreement between model predictions and field studies was consistent with the hypothesis that competition for PAR was a principal factor in weed-crop interaction. The ability to account for differences in weed densities, management, and environmental conditions suggested that modeling was a useful tool for evaluating the interaction among weeds and crops.

scholarly journals Optimizing Fruit-Thinning Strategies in Peach (Prunus persica) Production

Horticulturae ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 41 ◽  
Author(s):  
Mary Sutton ◽  
John Doyle ◽  
Dario Chavez ◽  
Anish Malladi
Keyword(s):  
Fruit Development ◽  
Fruit Size ◽  
Fruit Weight ◽  
Load Management ◽  
Growth Responses ◽  
Crop Load ◽  
Fruit Number ◽  
Fruit Thinning ◽  
Adverse Weather ◽  
One Year

Fruit size is a highly valued commercial trait in peach. Competition among fruit and among other sinks on a tree reduces potential growth rate of the fruit. Hence, crop-load management strategies such as thinning (removal of flowers or fruit) are often practiced by growers to optimize fruit size. Thinning can be performed at bloom or during early fruit development and at different intensities to optimize fruit growth responses. Responses to thinning may be cultivar and location specific. The objective of the current study was to fine-tune thinning strategies in the southeastern United States, a major peach producing region. Timing and intensity of thinning were evaluated across multiple cultivars over three years. Thinning at bloom or at 21 d after full bloom (DAFB) improved fruit size in comparison to unthinned trees in ‘Cary Mac’ and ‘July Prince’, respectively, in one year. Bloom-thinning reduced fruit yield (kg per tree) in the above cultivars in one year, suggesting that flower thinning alone may not be a viable option in this region. Intensity of thinning, evaluated as spacings of 15 cm and 20 cm between fruit, did not differentially affect fruit weight or yield. However, fruit diameter decreased quadratically with increasing fruit number per tree in ‘Cary Mac’, ‘July Prince’ and ‘Summer Flame’. Similarly, fruit weight decreased quadratically in response to increase in fruit number per tree in ‘Cary Mac’ and ‘July Prince’. Further, yield-per-tree decreased with increasing fruit size in ‘Cary Mac’ and ‘July Prince’. Importantly, these relationships were cultivar specific. Together, the data suggest that achieving a target fruit number per tree is an effective strategy for crop-load management to optimize fruit size in southeastern peach production. The target fruit number per tree may potentially be achieved through a combination of flower and fruit-thinning during early fruit development. Such an approach may provide flexibility in crop-load management in relation to adverse weather events.

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