Control of Dormancy and Budbreak in Sweet Cherry (Prunus avium L.) cv `Bing' with Surfactant + Calcium Ammonium Nitrate and Hydrogen Cyanamide

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 514c-514
Author(s):  
K.G. Weis ◽  
S.M. Southwick ◽  
J.T. Yeager ◽  
M.E. Rupert ◽  
W.W. Coates

Continuing trials (1995–present) advanced budbreak and flowering with a surfactant and calcium ammonium nitrate (CAN17), and in 1997, hydrogen cyanamide (HCN). Chilling in 1996–1997 was marginal in San Joaquin County (SJ, 830 chill hours, 18 Feb.), and low in San Benito County (SB, 612 chill hours, 21 Feb.). When we used the “45 °F” chilling model, the most effective surfactant + nitrate treatment timings for both locations were similar by chill accumulation (≈72 % to 82% of required chilling for `Bing' = 850–880 chill hours), although the two locations differed in total chill accumulation and date of effective treatment. Full bloom (FB) was advanced by 1 week with 4% HCN in SJ, followed by 2% surfactant + 25% calcium ammonium nitrate applied on 21 Jan. (700 chill hours), compared to the untreated control. Bloom duration (full bloom to petal fall) was compressed most by surfactant and CAN17. Bloom in SB was also most advanced by HCN, followed by 2% surfactant + 25% CAN17 applied on 21 Feb. (612 chill hours). Fruit set was improved in SB by surfactant and CAN17 in mid-February; set was too low, however, for real impact. In SJ and SB, HCN advanced fruit maturity most, followed by surfactant and CAN17 applied 21 Jan.; these fruits were softer. We believe that, in order for treatments to be effective in advancing budbreak and full bloom, some minimum amount of chilling must be accumulated prior to application (perhaps 60% to 75% of chilling requirement). We have also determined that where chilling is well below minimum requirement, higher rates of CAN (25%) are necessary to advance bloom. A further advantage of using Armobreak + CAN is improved N level in buds and bark after treatment (1997).

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 525B-525 ◽  
Author(s):  
K.G. Weis ◽  
S.M. Southwick ◽  
J.T. Yeager ◽  
M.E. Rupert ◽  
R.E. Moran ◽  
...  

In continuing trials (1995-current), we have used a variety of treatments to overcome inadequate chilling, coordinate bloom, improve leaf out and cropping, and advance/coordinate maturity in sweet cherry, cv. Bing. Treatments have included hydrogen cyanamide (HCN, Dormex) and various surfactants or dormant oils combined with calcium ammonium nitrate (CAN17). Chill hour accumulation, (required chilling for `Bing' = 850 to 880 chill hours) has varied greatly in each dormant season from 392 (Hollister, 1995-1996) to adequate, depending both on the season and location (central valley vs. coastal valley). In 1998, 4% HCN advanced budbreak significantly compared to any other treatment, although other chemical treatments also were more advanced than the untreated control. Dormex advanced completion of bloom 11% to 40% more than other treatments, although other dormancy-replacing chemicals were at least 16% more advanced in petal fall than the untreated control. Dormex contributed to slightly elevated truss bud death, as did 2% Armobreak + 25% CAN17. In 1998, fruit set was improved by 2% Armobreak + 25% CAN17 (79%) compared to the untreated control (50%); all other treatments statistically equaled the control. Fruit set was not improved by Dormex, although bloom was advanced by a few days in this treatment. As fruit set was increased by treatments, rowsize decreased (as did fruit weight), as expected, but no treatment resulted in unacceptable size. In 1997, fruit set was also improved by 2% Armobreak + 25% CAN17; however, fruit set was so low overall in that year that no real impact was found. In 1997 and 1998, 4% HCN advanced fruit maturity compared to other treatments, with darker, softer, larger fruit at commercial harvest. These and additional results will be presented.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 603e-603
Author(s):  
K.G. Weis ◽  
S.M. Southwick ◽  
J.T. Yeager ◽  
W.W. Coates ◽  
Michael E. Rupert

The years 1995 and 1996 were low chill years in California with respect to stone fruit dormancy. Advancing reproductive budbreak and flowering was accomplished in `Bing' cherry (Prunus avium) by single-spray treatments of a surfactant {a polymeric alkoxylated fatty amine [N,N-bis 2-(omega-hydroxypolyoxyethylene/polyoxypropylene) ethyl alkylamine]} and potassium nitrate in combination when applied at “tightbud,” ≈ 42 days (1 Feb. 1995) before full bloom and with surfactant and potassium nitrate in combination when 10% green calyx was apparent, 33 days before full bloom. Applying 2% surfactant (v/v) + 6% potassium nitrate (w/v) was most effective in advancing bloom, speeding progression through bloom, and advancing fruit maturity when applied at tightbud stage. Surfactant (2% or 4%) applied with 25% or 35% calcium nitrate (w/v) on 2 Feb. 1996 significantly advanced full bloom compared to nontreated controls. Fruit maturity (1995) was somewhat advanced by surfactant–nitrate treatments, but fruit set and final fruit weight were equivalent among treatments. No phytotoxicity was noted in foliage or fruit. In California, marginal and insufficient winter chilling often causes irregular, extended, or delayed bloom periods, resulting in poor bloom-overlap with pollenizers. As a result, flower and fruit development may be so variable as to have small, green and ripe fruit on the same tree, making harvest more time consuming and costly. Data indicate that this surfactant, in combination with a nitrogenous compound, has potential to advance reproductive budbreak and advance maturity in sweet cherry without reducing fruit set or fruit size. Advancing the ripening time of sweet cherry even 2 to 3 days can increase the price received per 8.2-kg box by $10 to $20.


HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 745-748 ◽  
Author(s):  
Murray Clayton ◽  
William V. Biasi ◽  
I. Tayfun Agar ◽  
Stephen M. Southwick ◽  
Elizabeth J. Mitcham

`Bing' sweet cherry (Prunus avium L.) trees were treated with hydrogen cyanamide (CH2N2) or calcium ammonium nitrate (CaNH4NO3) during dormancy, or gibberellic acid (GA3) 26 days before harvest during three consecutive years. Fruit were evaluated at harvest for sensory taste quality using twenty trained panelists sampling for firmness, sweetness, tartness, and cherry flavor. Nondestructive instrumental firmness preceded destructive sensory firmness on the same untreated and GA3-treated cherries in one year when used as a supplementary evaluation. Sensory firmness was consistently higher in GA3 fruit and to a lesser extent in CH2N2 fruit than in CaNH4NO3 and untreated fruit. Instrumental firmness of GA3 fruit did not increase significantly compared with untreated fruit yet instrumental firmness of each treatment correlated relatively well with perceived sensory firmness. Sensory sweetness and cherry flavor scored very similarly, yet both attributes simultaneously varied between treatments across the years. Perceived sensory tartness of treated fruit was variable among years; yet, on average, was rated among treated and untreated fruit as similar. Under the assumption that elevated sensory firmness, sweetness, and cherry flavor intensity reflects improved sweet cherry quality, GA3 fruit were rated of higher quality than untreated fruit given their increased firmness and similar or occasionally elevated sweetness and cherry flavor intensity. CH2N2 fruit maintained quality similar to that of untreated fruit, despite often having marginally higher firmness, due to similar or reduced ratings for sweetness and cherry flavor intensity. Notwithstanding similar firmness between CaNH4NO3 and untreated cherries, sensory quality of CaNH4NO3-treated cherries was reduced due to their often-diminished levels of perceived sweetness and cherry flavor.


HortScience ◽  
2003 ◽  
Vol 38 (3) ◽  
pp. 407-411 ◽  
Author(s):  
Murray Clayton ◽  
William V. Biasi ◽  
I. Tayfun Agar ◽  
Stephen M. Southwick ◽  
Elizabeth J. Mitcham

During three consecutive years, 'Bing' sweet cherry (Prunus avium L.) trees were treated during dormancy with the dormancy-manipulating compounds, CH2N2 or CaNH4NO3, or were treated with the plant growth regulator GA3 at straw color development. Fruit of a range of maturities, based on skin color, were evaluated for quality following harvest and simulated transit and market storage conditions. At comparable maturities, CH2N2 and GA3 fruit were of similar firmness and were consistently firmer than CaNH4NO3-treated and untreated fruit across years, storage regimes, and maturities. CaNH4NO3 and untreated fruit were of similar firmness. CH2N2-treated cherries were larger than fruit of other treatments, but only marginally with respect to variation in fruit size between years. Contraction of fruit diameter occurred after 3 days storage, but ceased thereafter up to 11 days storage. Soluble solids and titratable acidity varied between years, storage regimes, and maturities. Strong interactions of treatment and year concealed possible treatment effects on these indices. GA3 fruit contained fewer surface pits in one year while CH2N2 fruit suffered less shrivel in another. The earlier harvest date for CH2N2 fruit often avoided higher field temperatures and the resulting promotion of postharvest shrivel. Pitting and shrivel were more prevalent in stored fruit. Brown stem discoloration developed in storage, occurring most frequently in mature fruit, although methyl bromide-fumigated fruit were particularly susceptible. This disorder was more common in GA3 fruit during years of high incidence. Chemical names used: gibberellic acid (GA3); calcium ammonium nitrate (CaNH4NO3); hydrogen cyanamide (CH2N2).


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 690a-690
Author(s):  
Esmaeil Fallahi ◽  
Brenda R. Simons ◽  
John K. Fellman ◽  
W. Michael Colt

Influence of various concentrations of hydrogen cyanamide (HC) on fruit thinning of `Rome Beauty' apple (Malus domestica Borkh.), `Friar,' and `Simka' plums (Prunus salicina Lindley) were studied. A full bloom application of HC at all tested concentrations decreased `Rome Beauty' apple fruit set and yield, and increased fruit weight. Hydrogen cyanamide at 0.25% (V/V) resulted in adequate apple thinning, indicated by the production of an ideal fruit weight. Prebloom and full bloom applications of HC at greater than 0.75% reduced plum fruit set and yield in `Friar.' Full bloom application of HC at 0.25% to 0.50% showed a satisfactory fruit set, yield, and fruit size in `Friar' plum. Full bloom application decreased fruit set and yield in `Simka' plum. Hand thinning, as well as chemical thinning, is recommended for plums.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1122a-1122
Author(s):  
Esmaeil Fallahi ◽  
Michael Colt ◽  
S. Krishna Mohan ◽  
John Fellman

Influence of prebloom and full bloom applications of hydrogen cyanamide on `Simka' and `Friar' plums in Southwest Idaho and `Florda Prince' peach in Southwest Arizona was studied. Prebloom application of 0.5% hydrogen cyanamide caused severe toxicity to the fruit buds in `Friar' lure, while 2% hydrogen cyanamide did not cause toxicity in `Simka' plum. `Simka' fruit was effectively thinned with 1-2% prebloom application. At full bloom, 1.5% hydrogen cyanamide caused severe flower and leaf burning in both `Friar' and `Simka' plums, while concentrations between 0.1% and 1% thinned flowers (fruits) in both of the plum cultivars. Influence of hydrogen cyanamide on final fruit set, fruit size and maturity are also studied. Prebloom or full bloom applications of 2% or 3% hydrogen cyanamide eliminated 95 to 100% of the blooms, while application of this chemical at 1% sufficiently thinned the fruit. Number of commercially packed large peaches in trees receiving 1% hydrogen cyanamide was the same as that in trees thinned by hand, suggesting hydrogen cyanamide as a potential chemical for stone fruit thinning.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 537C-537
Author(s):  
J.G. Williamson ◽  
R.L. Darnell

Two-year-old, container-grown `Misty' southern highbush blueberry plants were sprayed to drip with two concentrations of hydrogen cyanamide (HCN) (20.4 g·L–1 and 10.2 g·L–1) after exposure to 0, 150, or 300 hr of continuous chilling at 5.6°C. All plants were sprayed immediately after chilling and placed in a greenhouse for several weeks. The plants were moved outdoors during flowering to increase cross-pollination from nearby `Sharpblue' blueberry plants. HCN sprays killed some of the more advanced flower buds on shoot terminals and on small-diameter wood from the previous spring growth flush. Significantly greater flower bud mortality occurred for the 20.4 g·L–1 HCN sprays than for the 10.2 g·L–1 sprays. Flower buds subjected to 0 hr of chilling were more susceptible to spray burn than flower buds receiving 150 or 300 hr of chilling. Very little flower bud death occurred with the 10.2 g·L–1 HCN rate on plants receiving 300 hr of chilling. Vegetative budbreak was advanced for both HCN treatments compared to controls, regardless of chilling treatment. HCN-treated plants were heavily foliated at full bloom, while non-treated plants had very few to no leaves during bloom. HCN may be useful for stimulating vegetative growth in some southern highbush blueberry cultivars that suffer from poor foliation during flowering and fruit set.


2014 ◽  
Vol 60 (No. 1) ◽  
pp. 1-7
Author(s):  
K. Kubešová ◽  
J. Balík ◽  
O. Sedlář ◽  
L. Peklová

In field experiments over three vegetation periods (2010–2012) we studied impact of the CULTAN (controlled uptake long term ammonium nutrition) method on yield and yield parameters of kernel maize. The field experiments were conducted at three sites with different soil-climatic conditions. CULTAN treatments were fertilized once with the total amount of nitrogen using an injection machine (at the canopy height of 20 cm) and compared to conventional fertilization with calcium ammonium nitrate application at pre-sowing preparations. In all treatments the amount of nitrogen was the same, 140 kg N/ha. In 2010 at Humpolec site, CULTAN urea ammonium nitrate + inhibitor of nitrification treatment gave by 20.5% higher number of ears compared to CULTAN urea ammonium nitrate treatment. In 2011 at Ivanovice all CULTAN treatments reached statistically significantly higher number of kernels per ear. The higher 1000 kernel weight at CULTAN treatments was observed in 2012 at the Ivanovice site; a statistically significant difference between conventional and CULTAN urea ammonium nitrate + inhibitor of nitrification treatment was observed. Fertilization of maize with nitrogen using the CULTAN method under the conditions of the Czech Republic provides the same yield certainty as the conventional surface application and the CULTAN method of fertilization increases the yield certainty at delayed sowing. Harvest index was statistically significantly influenced by year, fertilization treatment and site.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 455f-455
Author(s):  
Esmaeil Fallahi ◽  
Brenda R. Simons ◽  
Max W. Williams

Effects of hydrogen cyanamide and Wilthin on blossom thinning and the consequences of thinning on fruit set, yield and fruit quality of `Rome Beauty' was studied. A full bloom application of hydrogen cyanamide at the rate of 0.25% (Dormex formulation) or 0.25% of Wilthin both followed by a fruit thinning by Sevin + NAA effectively thinned mature trees of `Rome Beauty' and had a similar effect on fruit set, yield and fruit quality. The effects of these two chemicals at these rates on several aspects of fruit set, yield and quality were similar to the effects of Elgetol. Hydrogen cyanamide, Elgetol and 0.25% Wilthin at full bloom resulted in a higher percentage of single fruit set, thus, less labor for hand thinning. Application of 0.37% Wilthin at 20% bloom or at full bloom resulted in larger fruit size, but induced fruit russetting. Soluble solids of fruit from trees with Elgetol, 0.37% Wilthin at 20% bloom or at full bloom were higher than fruit from other treatments. Hydrogen cyanamide at 0.50% resulted in a satisfactory level of blossom thinning in `Friar' plums.


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