scholarly journals Mode of Action of Benzyladenine When Used as a Chemical Thinner on Apples

1992 ◽  
Vol 117 (5) ◽  
pp. 775-779 ◽  
Author(s):  
Duane W. Greene ◽  
Wesley R. Autio ◽  
Jeffrey A. Erf ◽  
Zhongyuan Y. Mao
Keyword(s):  
Malus Domestica ◽  
Ethylene Production ◽  
Mode Of Action ◽  
Leaf Surface ◽  
Fruit Size ◽  
Fruit Characteristics ◽  
Crop Load ◽  
Fruit Flesh ◽  
Adaxial Leaf Surface

BA thinned apple (Malus domestica Borkh.) fruits when applied to either the leaves or the fruit, although it was much more effective when applied to the leaves. BA increased fruit size independent of its effects on reducing crop load, but only when applied directly to the fruit. When applied to one of two fruit in a cluster, BA had no influence on abscission, fruit size, or fruit characteristics of the adjacent nontreated fruit. BA reduced fruit flesh Ca only on treated fruit and the response was inversely proportional to the increase in fruit size. More than 60% of the BA applied to a fruit was absorbed during 24 hours, and this amount was considerably larger than penetration through either the abaxial or adaxial leaf surface. BA treatments that thinned also increased ethylene production linearly in both leaves and fruit 24 hours after application, but the magnitude of increase was not considered large enough to be the primary cause for thinning. BA thinned spurs with two or three fruit more than spurs with one fruit, and it did not selectively thin to just one fruit per cluster. Chemical name used: N-(phenylmethyl)-1H-purine-6-amine [benzyladenine (BA)].

Bio-regulators improve fruit size and c olour and reduce crop-load and annual bearing of Honeycrisp™ apples

2005 ◽  
Vol 85 (2) ◽  
pp. 453-455
Author(s):  
C. G. Embree ◽  
D. S. Nichols
Keyword(s):  
Fruit Quality ◽  
Malus Domestica ◽  
Fruit Size ◽  
Fruit Weight ◽  
Fruit Colour ◽  
Full Bloom ◽  
Crop Load ◽  
Fruit Thinning ◽  
Colour Category ◽  
Return Bloom

Honeycrisp™ [Malus × domestica (L.) Borkh.] can be a very profitable cultivar if fruit quality is high. Some crop-load bio-regulators were evaluated for improving fruit quality and annual flowering. Ammonium thiosulphate applied at full bloom reduced crop-load, increased fruit weight, fruit colour and return bloom. Fruitone N® combined with Sevin XLR® reduced the percent of fruit in the 40–60% colour category and also crop-load. Fruitone N® alone reduced crop-load. Key words: Honeycrisp™, fruit thinning, crop-load, return bloom

scholarly journals Characterization of the Kentville Stock Clone Apple Rootstocks. III. Quality and Overall Performance

1993 ◽  
Vol 118 (2) ◽  
pp. 177-180 ◽  
Author(s):  
C.G. Embree ◽  
B.H. Lesser ◽  
A.D. Crowe
Keyword(s):  
Malus Domestica ◽  
Performance Index ◽  
Fruit Size ◽  
Fruit Color ◽  
Tree Size ◽  
Size Group ◽  
Apple Rootstocks ◽  
Crop Load ◽  
Overall Performance

The effects of 30 Kentville Stock Clone (KSC) selections on fruit size and color of `McIntosh' and `Delicious' apples (Malus domestica Borkh.) were monitored over 5 years. Fruit size was influenced by the rootstock and, when averaged over the duration of the study, ranged from 108 to 132 g and 131 to 161 g for `McIntosh' and `Delicious', respectively. Variation in fruit size due to crop load (CL) was greater for `McIntosh' than for `Delicious'. Fruit color was influenced by the rootstock in all years for `McIntosh' and in 3 of 5 years for `Delicious'; it was strongly associated with tree size for `Delicious' only. An overall performance index, which also included price based on quality, was developed, and the best performers in each size group were: semidwarf KSC 18 and 28; semivigorous KSC 7, 11, and 24; and vigorous KSC 3 and 6.

Certain chemical thinning treatments advance maturity of Paulared apple

2001 ◽  
Vol 81 (3) ◽  
pp. 499-501 ◽  
Author(s):  
Charles G. Embree ◽  
Douglas S. Nichols ◽  
John M. DeLong ◽  
Robert K. Prange
Keyword(s):  
Adverse Effects ◽  
Key Words ◽  
Malus Domestica ◽  
Fruit Size ◽  
Fruit Colour ◽  
Apple Trees ◽  
Crop Load ◽  
Malus Domestica Borkh ◽  
Fruit Maturity ◽  
Napthaleneacetic Acid

Mature Paulared (Malus ×domestica Borkh L.)/MM106 apple trees with a heavy bloom were sprayed with carbaryl [Sevin® XLR 1.25 mL L–1 (600 mg L–1 a.i.)], benzyladenine (BA)/gibberellic acids (GA4 + 7) [Accel® 1.22 mL L–1 (23.1 mg L–1/2.31 mg L–1 a.i.)], carbaryl [Sevin® XLR 1.25 mL L–1 (600 mg L–1 a.i.)] + BA/GA4 + 7 [Accel® 1.22 mL L–1 (15.6 mg L–1/1.56 mg L–1 a.i.)] and napthaleneacetic acid (NAA) [FruitoneN® 0.32 g·L–1 (1.13 mg L–1 a.i.)] when fruitlet diameter was 7 mm. Ethephon [Ethrel® 2.29 mL L–1 (549.6 mg L–1 a.i.)] was applied at the 13.5 mm fruitlet diameter stage. Carbaryl alone, NAA and ethephon all resulted in improved fruit size at harvest, whereas BA/GA4 + 7 was ineffective as a thinner and did not alter fruit size at harvest. Of these treatments, only ethephon significantly reduced crop load. Both NAA and ethephon, and especially ethephon, advanced fruit maturity at harvest as indicated by a lower Streif index. Only ethephon increased commercial levels of fruit colour and following-year blossom density. Thus, while ethephon appears promising as a fruitlet thinner and a promoter of maturity for this cultivar, these effects will have to be balanced against possible adverse effects on storage and shelf life. Key words: Crop load, carbaryl, ethephon, apple maturity, Streif index

scholarly journals Early Performance of Four Apple Cultivars on Mark and M.26 Rootstocks

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 792F-793
Author(s):  
James R. Schupp
Keyword(s):  
Malus Domestica ◽  
Fruit Size ◽  
Cross Sectional Area ◽  
Planting Density ◽  
Sectional Area ◽  
Cross Sectional ◽  
Crop Load ◽  
Apple Cultivars ◽  
Early Performance ◽  
Plot Design

To evaluate the interactions between cultivar and rootstock, four apple (Malus domestica Borkh.) cultivars, `Pioneer Mac', `Marshall McIntosh', `Ginger Gold', and `Empire' on two rootstocks, M.26 and Mark, were planted in a split-plot design. After 5 years, `Pioneer Mac' and `Ginger Gold' had larger trunk cross-sectional area (TCSA) on M.26 than on Mark. `Marshall McIntosh' and `Empire' had larger TCSA on Mark than on M.26. Precocity, expressed as both number of flower clusters and yield, was greater for trees on Mark for all cultivars except `Ginger Gold', which had greater flower cluster numbers and yield on M.26. Fruit size was variable from year to year, depending on crop load; however, `Pioneer Mac' and `Ginger Gold' usually produced the largest fruit, while `Empire' consistently produced the smallest fruit—'Ginger Gold' appears to be incompatible on Mark. The results of this study demonstrate that cultivar × rootstock interactions can be significant and need to be considered when rootstock and planting density recommendations are made.

Interaction Between CPPU and NAA on Fruit Thinning and Fruit Development in Selected Apple Cultivars

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 513c-513 ◽  
Author(s):  
Martin J. Bukovac ◽  
Jerome Hull ◽  
John C. Neilsen ◽  
Michael Schroeder ◽  
Georg Noga
Keyword(s):  
Total Yield ◽  
Fruit Size ◽  
Frost Damage ◽  
Fruit Growth ◽  
Soluble Solids ◽  
Seed Number ◽  
Crop Load ◽  
Fruit Thinning ◽  
Carpel Development ◽  
Return Bloom

NAA is used extensively for fruit thinning of apples to increase fruit size and to promote return bloom. In some cultivars, even if thinning is achieved, fruit size at harvest may be less than expected based on crop load. CPPU, N-(2-chloro-4-pyridinyl)-N.-phenylurea, has been shown to increase fruit growth in apples, grapes, and kiwi. We evaluated combinations of NAA and CPPU on thinning, fruit growth and return bloom in Redchief `Delicious', `Elstar', and `Gloster'. CPPU was applied at 5 mgμL–1 (based on 0 to 10 mgμL–1 response curve) in combination with 15 mgμL–1 NAA as high-volume sprays at 7 to 10 mm KFD. Yield and fruit size distribution (on total yield) were used as index of response. In `Delicious', CPPU (3-year study) increased % large (70 mm+) fruit, but in the presence of NAA % large fruit was reduced 2 of the 3 years. CPPU did not induce significant thinning. There were no significant effects on color or soluble solids; firmness was increased slightly and seed number reduced. The L/D ratio was increased and uneven lobe and carpel development was common. CPPU had no significant effect on return bloom in presence or absence of NAA, but NAA increased bloom in both the presence and absence of CPPU. With `Elstar' (2-year study) there was no significant thinning with either chemical, but CPPU increased mean fruit size and % large (70–80 mm) fruit over nonthinned, but not significantly greater than NAA alone. There were no significant differences in firmness, color, soluble solids or seed number. NAA + CPPU did not inhibit fruit growth or cause excessive uneven carpel development. Frost damage reduced crop load in `Gloster' where results were similar to `Elstar' except seed number was reduced by the NAA + CPPU combination.

scholarly journals Daminozide, Root Pruning, Trunk Scoring, and Trunk Ringing Effects on Fruit Ripening and Storage Behavior of `McIntosh' Apple

1991 ◽  
Vol 116 (2) ◽  
pp. 195-200 ◽  
Author(s):  
D.C. Elfving ◽  
E.C. Lougheed ◽  
R.A. Cline
Keyword(s):  
Ethylene Production ◽  
Fruit Size ◽  
Soluble Solids ◽  
Starch Hydrolysis ◽  
Root Pruning ◽  
Full Bloom ◽  
Ethylene Evolution ◽  
Flesh Firmness ◽  
Solids Concentration ◽  
Storage Behavior

A midsummer foliar daminozide (DZ) application (750 mg a.i./liter) to `Macspur McIntosh'/M.7 apple trees (Malus domestics Borkh.) reduced preharvest drop and retarded flesh firmness loss and starch hydrolysis when tested at harvest; DZ also reduced fruit ethylene production at harvest and after 19 weeks of storage at 0.5C. Root pruning at full bloom (May) resulted in increased soluble solids concentration (SSC) and firmer flesh and less starch hydrolysis at harvest, but not consistently each year. Full-bloom root pruning reduced the incidence of stem-cavity browning and brown core, but again not each year. Full-bloom root pruning did not influence ethylene evolution at harvest but did reduce post-storage ethylene evolution in two of three seasons. Full-bloom root pruning generally was less effective than DZ in altering fruit behavior, while root pruning later than full bloom had virtually no effect. Trunk scoring or ringing increased SSC and retarded loss of flesh firmness before harvest and following storage, but had little effect on starch hydrolysis. Scoring or ringing decreased incidence of some disorders and reduced post-storage ethylene evolution, although these treatments had little effect on ethylene production at harvest. Trunk scoring influenced some fruit characteristics more strongly than DZ. Fruit size was not affected by any treatment in any year. Chemical name used: butanedioic acid mono (2,2 -dimethylhydrazide) (daminozide).

scholarly journals Adjuvant Effects on Imazethapyr, 2,4-D and Picloram Absorption by Leafy Spurge (Euphorbia esula)

Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 469-475 ◽  
Author(s):  
W. Mack Thompson ◽  
Scott J. Nissen ◽  
Robert A. Masters
Keyword(s):  
Ammonium Nitrate ◽  
Ammonium Sulfate ◽  
Seed Oil ◽  
Leaf Surface ◽  
Leafy Spurge ◽  
Cuticular Waxes ◽  
Adaxial Leaf Surface ◽  
Abaxial Leaf Surface ◽  
Urea Ammonium Nitrate ◽  
Adjuvant Effects

Laboratory experiments were conducted to identify adjuvants that improve absorption of imazethapyr, 2,4-D amine, and picloram by leafy spurge. Adjuvants (0.25% v/v) included crop oil concentrate (COC), methylated seed oil (MSO), nonionic surfactant (NIS), organosilicones (Silwet L-77®, Sylgard® 309, Silwet® 408), 3:1 mixtures of acetylinic diol ethoxylates (ADE40, ADE65, ADE85) with Silwet L-77, ammonium sulfate (2.5 kg ha−1), and 28% urea ammonium nitrate (UAN, 2.5% v/v). Adjuvants were combined with14C-herbicide and commercially formulated herbicide product. Leaves were harvested 2 DAT, rinsed with 10% aqueous methanol to remove surface deposits of herbicide, and dipped in 9:1 hexane:acetone to solubilize cuticular waxes. Imazethapyr absorption increased by 38 to 68% when UAN was combined with COC, NIS, or MSO. Total absorption of imazethapyr plus COC, MSO, or NIS exceeded 86% 2 DAT when UAN was added. Urea ammonium nitrate reduced the amount of imazethapyr associated with the cuticular wax by 2.0%. Imazethapyr absorption was similar on both the abaxial and adaxial leaf surface when UAN was not added; however, 12% more imazethapyr was absorbed from the abaxial leaf surface than from the adaxial leaf surface when UAN was combined with Sylgard 309. Uptake of 2,4-D ranged from 54 to 78% and was greatest with Silwet 408 and 3:1 mixture of ADE40: Silwet L-77. Picloram absorption ranged from 3 to 19%. Buffering picloram treatment solutions to pH 7 and including 2.5 kg ha-1ammonium sulfate increased picloram absorption to 37%.

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.

WINTER INJURY TO GRAVENSTEIN APPLE STRAINS AS INFLUENCED BY TRUNK SCORING

1985 ◽  
Vol 65 (4) ◽  
pp. 981-984 ◽  
Author(s):  
C. G. EMBREE ◽  
A. D. CROWE
Keyword(s):  
Regression Analysis ◽  
Malus Domestica ◽  
Field Trial ◽  
Fruit Size ◽  
Old Field ◽  
Graft Union ◽  
Lower Trunk

Eleven Gravenstein apple strains (Malus domestica) in an 8-yr-old field trial were trunk scored 4 wk after bloom prior to and following the 1980–1981 test winter that injured many trees in Eastern Canadian orchards. Regression analysis revealed that scores which healed poorly and initial light cropping reduced lower trunk hardiness while growth had no effect. The incidence of injury was greatest below the score but always above the graft union and fruit size was negatively correlated with trunk damage.Key words: Winter injury, Gravenstein apple, trunk scoring, healing, yield, growth

Contributions to the Andean Senecioneae (Compositae)—II. Werneria lanatifolia, a new species from central Andes

Phytotaxa ◽  
2019 ◽  
Vol 422 (2) ◽  
pp. 201-205 ◽  
Author(s):  
JOEL CALVO ◽  
ROSA I. MENESES
Keyword(s):  
New Species ◽  
Leaf Surface ◽  
Central Andes ◽  
Distribution Map ◽  
Adaxial Leaf Surface ◽  
Dichotomous Key ◽  
A New Species

Werneria lanatifolia is described as a new species from the central Andes. It is a minute plant characterized by a lanate indumentum on the adaxial leaf surface and involucre. The new species is compared with the morphologically closest taxa and useful characters for its proper identification are provided. Detailed pictures of living plants, a distribution map, and a dichotomous key including the species allied to W. lanatifolia are also presented.

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