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 HARVEST AGE EFFECT ON YIELD OF ERECT BLACKBERRIES

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1170b-1170
Author(s):  
John R. Clark ◽  
James N. Moore
Keyword(s):  
Age Effect ◽  
The Other ◽  
First Year ◽  
Average Weight ◽  
Average Yield ◽  
Yield Increase ◽  
Berry Weight ◽  
Second Year ◽  
Effect On Yield

Yield and average berry weight were measured for first year fruiting (on semi-erect canes) and second year fruiting (erect canes) to compare harvest age effect for erect blackberries established from root cuttings. cultivars were `Cheyenne', `Choctaw', `Navaho' and `Shawnee' and 4 plantings were included in the comparison. One of the four plantings had an average yield of 27% more in the first year as compared to the second year. The other plantings had higher yields in the second year as compared to the first ranging up to a 100% increase. Yield was 23% higher for the second year when all plantings were averaged. Average yield increase by cultivar in the second year compared to the first was: 'Choctaw' 37%, 'Cheyenne' 27%, 'Navaho' 22% and 'Shawnee' 20%. Berry weight was not affected by harvest age except in one planting, where average weight was higher for first year fruiting.

scholarly journals Influence of Elevating Tree Potassium on Fruit Drop and Yield of Pecan

HortScience ◽  
2010 ◽  
Vol 45 (6) ◽  
pp. 911-917
Author(s):  
Bruce W. Wood ◽  
Lenny Wells ◽  
Frank Funderburke
Keyword(s):  
Dry Weight ◽  
Field Studies ◽  
Stage Ii ◽  
First Year ◽  
Leaf Analysis ◽  
Beneficial Effects ◽  
Nutrition Management ◽  
Fruit Drop ◽  
Kernel Quality ◽  
K Concentration

Excessive Stage II fruit drop (i.e., June drop) often limits profitability of certain pecan [Carya illinoinensis (Wangenh.) C. Koch] cultivars. Anecdotal evidence indicates that one cause of drop is linked to a nutrient element deficiency. This study examines the consequences of improving tree potassium (K) nutrition on fruit drop, nutmeat yield, and kernel quality (i.e., % kernel) in ‘Desirable’ orchards in which generally accepted foliar analysis standards indicate satisfactory tree K nutritional status (i.e., 0.75% or greater to 2.5% K/dry weight). Multiyear field studies of two such orchards found that elevating leaf and fruit K concentration through soil banding of potash over drip irrigation emitters: 1) increased fruit retention by reducing Stage II fruit drop; 2) increased in-shell nut yield; and 3) increased nut quality by increasing percentage kernel. Potash applied through soil banding elevated foliar and fruit K concentration by ≈ 0.1% to 0.4% units within a few months post-application depending on the amount applied; however, the beneficial effects of a single potash soil band application diminished after the first year. A comparison of the K concentration of retained fruit versus abscised fruit during the Stage II fruit drop window found that retained fruit possessed endogenous K concentrations of 1.2% to 1.7% (dry weight basis) in one orchard and 1.45% to 1.9% in a second orchard, whereas aborted fruit possessed K at 0.65% to 1.2% in one orchard and 0.75% to 1.2% in a second orchard, respectively, thus establishing ≈ 1.25% K as a “drop threshold” under conditions of this study. The total K concentration of retained fruit is typically 0.25% to 0.50 K/dry weight greater than dropped fruit. Considerable K-associated late-spring fruit drop can occur in ‘Desirable’, although early- to midsummer leaf analysis indicates trees were K-sufficient, hence implying that young fruit likely possesses a higher K requirement than does foliage. These K-associated benefits to trees meeting accepted K sufficiency criteria is evidence that K nutrition management of ‘Desirable’ pecan merits r-evaluation and possibly pecan K nutrition in general.

scholarly journals Mechanical Crop Load Management (CLM) Improves Fruit Quality and Reduces Fruit Drop and Alternate Bearing in European Plum (Prunus domestica L.)

Horticulturae ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 52
Author(s):  
Sebastian Lammerich ◽  
Achim Kunz ◽  
Lutz Damerow ◽  
Michael Blanke
Keyword(s):  
Fruit Quality ◽  
Sugar Content ◽  
Fruit Size ◽  
Load Management ◽  
Alternate Bearing ◽  
Crop Load ◽  
Fruit Drop ◽  
Small Fruit ◽  
Class 1 ◽  
Slender Spindle

(1) Background: With ca. 10 million tons of annual production worldwide, the plum (Prunus ssp.) ranks as a major fruit crop and can suffer from small fruit size, premature fruit drop and alternate bearing, which are addressed in this paper using a range of crop load management (CLM) tools. (2) Methods: Sixty 10-year-old European plum cv. “Ortenauer” trees on dwarfing St. Julien INRA GF 655/2 rootstock (slender spindle; 4.25 × 2.80 m) in a commercial orchard near Bonn (50°N), Germany, were thinned in 2 years and flower intensity assessed in the following year. Thinning was performed either mechanically (type Bonn/Baum) or chemically, with ATS (ammonium thiosulfate) or ethephon (Flordimex), or by a combination of mechanical and chemical methods, to improve fruit quality and the proportion of Class 1 fruit. Adjacent un-thinned trees served as controls. (3) Results: Natural fruit drop in June was reduced from 290 fruits per tree in the un-thinned controls to 265 fruits after ATS blossom treatment, and to 148 fruits after mechanical thinning at 380 rpm at a 5 km/h tractor speed at full bloom. The un-thinned control trees developed a large number of small, undersized fruits. The yield of Class 1 fruits increased per tree from 47% in the un-thinned controls, up to 69% after crop load management. Sugar content and fruit firmness were unaffected. (4) Conclusions: The study has shown that fruit quality (i.e., fruit size) and financial returns could be improved by either mechanical (380 rpm at 5 km/h) or chemical thinning, or a combination of both.

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.

EFFECTS OF INORGANIC NITROGEN AND PHOSPHORUS FERTILIZERS ON SELECTED SITES OF NATIVE GRASSLAND IN WESTERN CANADA

1965 ◽  
Vol 45 (3) ◽  
pp. 229-237 ◽  
Author(s):  
M. R. Kilcher ◽  
S. Smoliak ◽  
W. A. Hubbard ◽  
A. Johnston ◽  
A. T. H. Gross ◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Total Yield ◽  
First Year ◽  
Western Canada ◽  
Phosphorus Fertilizer ◽  
Nitrogen And Phosphorus ◽  
Native Grass ◽  
Yield Increase ◽  
Native Grassland ◽  
Better Than

N, P, and N + P at 60, 26, and 60 + 26 lb per acre were applied on native grass sites during three successive years at seven, locations in Western Canada. Single applications of the N fertilizer resulted in 3- or 4-year total yield increases of 300 to 600 lb per acre at six locations. At Summerland the 3-year increase was nearly 1400 lb. Phosphorus fertilizer by itself provided very little yield increase. N + P gave yield increases that were only slightly better than those from N alone.Residual responses to fertilizer were important, especially in the 12- to 16-in. rainfall locations. Only about one-third of the total yield increase occurred in the first year, with the remainder coming in the subsequent seasons.Weeds, where present, showed a marked response to fertilizer N in the first season; in subsequent years the response largely disappeared.

scholarly journals Influence of increasing doses of nitrogen on feed productivity of perennial grasses

2019 ◽  
pp. 19-24
Author(s):  
Svetlana Vasil'evna Ivanova ◽  
Olga Vasil'evna Kurdakova ◽  
Aminat Msostovna Konova ◽  
Anna Yurievna Gavrilova
Keyword(s):  
Dry Matter ◽  
The State ◽  
Perennial Grasses ◽  
Nitrogen Fertilizers ◽  
First Year ◽  
Yield Increase ◽  
Green Mass ◽  
State Register ◽  
Second Year ◽  
First Year Of Life

In the course of the experiment, the effect of increasing doses of nitrogen fertilizers on the yield of clover of the meadow variety Nadezhny, entered in the State Register of Breeding Achievements in 2012, was analyzed. A comparison is also made of this influence with the timothy of the meadow variety Leningradskaya 204. It was established that the pre-sowing introduction of mineral nitrogen for clover and timothy has influenced the productivity of these crops, but the nature of this effect varies depending on the type of grass. The introduction of N20 against the background of P30K90, which provided an increase in control of 51.2% for green mass and 33.6% for air-dry matter, was optimal for meadow clover of the first year of life. For grassland clover second year of life, the best option was N0P30K90, which gave an increase of 56.6% to the control on green mass and 50.6% on air-dry matter. A further increase in the dose of nitrogen on the options caused a decrease in yield increase. Timothy meadow for two years of life was traced responsiveness to the provision of nitrogen. The most productive in all respects was the option N120P30K90.    

Sulphur and phosphorus fertilizers increase the yield of barrel medic (Medicago truncatula) five-fold in native pasture on a traprock soil

1989 ◽  
Vol 29 (4) ◽  
pp. 527 ◽  
Author(s):  
NM Clarkson ◽  
IF Swann ◽  
NP Chaplain
Keyword(s):  
Medicago Truncatula ◽  
Elemental Sulfur ◽  
Nitrogen Concentration ◽  
Nutrient Concentrations ◽  
Phosphorus Concentration ◽  
First Year ◽  
Yield Increase ◽  
Barrel Medic ◽  
Yield And Quality ◽  
Native Pasture

A single application of sulfur and phosphorus in the first year produced a 5-fold yield increase in barrel medic (Medicago truncatula cv. Jemalong), every year for 3 years, on traprock country in southern inland Queensland. In the first year, the yield of medic increased from 400 (untreated) to 1300 kg/ha with sulfur alone (at 40 kg/ha), and to 2300 kg /ha with sulfur and phosphorus together (both at 40 kg/ha). In the second and third years, sulfur and phosphorus together increased yields from 300 to 1400 kg/ha, and from 800 to 4000 kg/ha, respectively. The experiment tested factorial combinations of sulfur and phosphorus, both at 0, 10 and 40 kg/ha, 3 sources of sulfur (gypsum, superphosphate fortified with elemental sulfur and called 'super and sulfur', and elemental sulfur) and agricultural limestone at 2500 kg/ha. Seed and fertiliser were broadcast into a native pasture at the start of the experiment. Elemental sulfur was inferior to gypsum and 'super and sulfur' in the first year, but equally effective thereafter. There was no response to lime. Fertilising with sulfur and phosphorus together increased the sulfur concentration in medic tops from 0.10 to 0.23%, the phosphorus concentration from 0.19 to 0.23%, and the nitrogen concentration from 2.12 to 2.82%. Nutrient concentrations in plant and soil were examined as an aid to diagnosing deficiencies at other sites. We concluded that adequately fertilising medic with sulfur and phosphorus can greatly improve pasture yield and quality, and allow higher stocking rates on traprock country.

Shot-hole borer (Xyleborus fornicatus Eichh.) of tea in Ceylon II.—The effect of chemical control on the yield and manurial response of tea

1968 ◽  
Vol 57 (4) ◽  
pp. 619-641
Author(s):  
J. E. Cranham ◽  
P. Kanapathapillai ◽  
A. Kathiravetpillai
Keyword(s):  
Field Trials ◽  
First Year ◽  
Percentage Increase ◽  
Nitrogen Application ◽  
The Third ◽  
Prolonged Effect ◽  
Second Year ◽  
The Difference ◽  
Significant Regression ◽  
Effect On Yield

In 1960–65, six field trials were carried out on tea estates in Ceylon to assess the effect on yield, and on the response of the crop to fertilizer, of dieldrin sprays applied after pruning to control shot-hole borer (Xyleborus fornicatus Eichh.). Periodic sampling was carried out to assess the numbers of borers and their galleries. Yields were recorded by weekly or fortnightly weighings of the green leaf plucked, over pruning cycles of two to four years.The pattern of the yield increases on the sprayed plots was related to the difference in attack between the sprayed and unsprayed plots. Increases were, in general, small in the first year and much larger in the second year, reaching peak values of 32–58 per cent. (on the yields of successive three-monthly periods recorded) in the late second year, and declining thereafter through the third year as the difference in attack declined. Over the first two years there were marked yield increases in eight of the nine pruning cycles, and these ranged from 11·7 per cent, to 26·3 per cent. There was significant regression (P<0·001) of the percentage increase in yield on the maximum difference in gallery counts. Yield increases in the third year of pruning cycles were also considerable and the results evidence a prolonged effect of the heavy borer attack occurring in the second year.In one trial there was a significant interaction between the effects of dieldrin spraying and of nitrogen supplied. Control of the borer greatly improved the crop response to nitrogen. Nitrogen application increased the yield but resulted also in a proportionately larger loss of crop from borer attack. There was a small but significant increase in the number of borer galleries on the plots receiving nitrogen.The evidence on the size and pattern of crop losses caused by the borer suggests that these occur both from shoot breakages and from the direct effect of galleries on the growth of stems.The significance of the results in relation to estate practice, and the economics of spraying, are briefly discussed.

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