scholarly journals Effect of the number of calcium chloride sprays on 'Jonagold' apple quality

2013 ◽  
Vol 52 (1-2) ◽  
pp. 85-94 ◽  
Author(s):  
Paweł Wójcik

The aim of this study was to examine effect of frequency of calcium chloride (CaCl<sub>2</sub>) sprays on 'Jonagold' apple (<em>Malus domestica</em> Borkh.) quality. The experiment was carried out in 1996-1998 in the Experimental Orchard of the Research Institute of Pomology and Floriculture in Skierniewice. Apple trees were grafied on M.26 rootstock and planted in 1992 at a distance of 4 x 2 m on a sandy loam soil with high available phosphorus, potassium and magnesium contents. Four experimental treatments were applied: (i) three sprays with CaCl<sub>2</sub> solutions at 2, 10 and 18 weeks after full bloom, (ii) six sprays with CaCl<sub>2</sub> at 2, 6, 10, 14, 16 and 18 weeks after full bloom, (iii) nine sprays with CaCl<sub>2</sub> at 2, 4, 6, 8, 10, 12, 14, 16 and 18 weeks after full bloom and (iv) control plot - trees unsprayed with CaCl<sub>2</sub>. The results showed that fruit Ca concentration increased with the number of CaCl<sub>2</sub> sprays during the growing season. Apples nine-times sprayed with CaCl<sub>2</sub> solutions were smaller, less mature at harvest and after storage, had lower titratable acidity and soluble solids contents after storage and were less sensitive to bitter pit, internal breakdown and Gloeosporium-rot compared to other treatments; however these effects were influenced by the growing season. Six CaCl<sub>2</sub> sprays only in one year of the study increased fruit firmness after storage, fruit resistance to bitter pit and internal breakdown. Three CaCl<sub>2</sub> sprays decreased bitter pit incidence; however this effect was found only in one investigated year.

2010 ◽  
Vol 16 (4) ◽  
pp. 343-350 ◽  
Author(s):  
M. Guerra ◽  
P.A. Casquero

Two strategies, summer pruning and postharvest Ca treatment, were studied in apple (Malus domestica Borkh) cv. ‘Reinette du Canada’ in order to analyze its effect on the fruit quality during storage. Summer pruning and Ca treatment reduced external and internal bitter-pits; so after 180 days of storage, both treatments decreased external bitter-pit by 10.0% and 16.7%, respectively. Summer pruning influenced color, firmness, total soluble solids and titratable acidity (TA) of fruit during storage, whereas Ca treatment only affected firmness and TA. Fruit from pruned trees had significant lower K and Mg than those from unpruned trees and Ca treatment increased Ca content. Orchard management, by means of summer pruning, combined with Ca postharvest application would be useful to prevent losses due to bitter-pit during storage in commercial orchards. However, in organic orchards, summer pruning would be the ecological alternative to decrease bitter-pit incidence during storage in high quality apple cv. ‘Reinette du Canada’. K/Ca ratio, on the peel at harvest, turned out to be the best parameter to correlate with external and internal bitter-pits during storage; so this ratio would be useful to predict bitter-pit on long-term storage.


2011 ◽  
Vol 38 (No. 3) ◽  
pp. 120-124 ◽  
Author(s):  
B. Milić ◽  
N. Magazin ◽  
Z. Keserović ◽  
M. Dorić

Ammonium and potassium thiosulfate are used commercially or experimentally as flower thinners because they are considered user, environment and consumer safe. The thinning trials were conducted in 2009 and 2010, on three- and four-year-old Braeburn Mariri Red* trees. The chemicals were applied at 1%, 2% and 3% rates of ammonium and 0.5%, 1% and 1.5% of potassium thiosulfate. Both thinning agents reduced fruit set, but were more efficient in 2009, when applied at 20% full bloom, than in 2010, when they were applied at 80% full bloom. Flower thinning with ammonium and potassium thiosulfate increased the average fruit weight, but the highest chemical rates retarded fruit growth. Ammonium and potassium thiosulfate did not affect fruit shape and firmness, but they increased starch degradation, total soluble solids content and titratable acidity. The treatments increased the percentage of flower buds, except at the highest chemical rates, where leaf damage reduced flower bud formation. Ammonium or potassium thiosulfate application may be recommended as the first step in a chemical thinning program


1983 ◽  
Vol 63 (3) ◽  
pp. 687-693 ◽  
Author(s):  
K. I. N. JENSEN ◽  
E. R. KIMBALL ◽  
J. A. IVANY

The efficacy and relative persistence of dinitramine (N′,N′-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2-4-diamine), ethalfluralin [N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4(trifluoromethyl) benzenamine], and trifluralin (α,α,α -trifluoro-2,6-dinitro-N,N-diproply-p-toluidine) were studied in a series of field trials conducted on a Charlottetown fine sandy loam (P.E.I.) and on a Somerset loamy sand (N.S.). Phytotoxicity, as reflected by weed control and injury to the peas (Pisum sativum L.), was greater on the sandy soil and herbicide rates recommended for the region may reduce yields on light soil types. The margin of crop tolerance was also reduced in one year characterized by an extremely wet growing season. Under field conditions, there was little practical difference in weed control obtained with the three herbicides. Dinitramine and ethalfluralin were more persistent in the Somerset sand than in the Charlottetown sandy loam. The order of decreasing persistence was trifluralin>ethalfluralin>dinitramine, except in the Somerset sand where the persistence of ethalfluralin and trifluralin was similar. Significant detectable levels of all three herbicides remained 320 days after application.Key words: Processing peas, dinitramine, ethalfluralin, trifluralin, residue


1977 ◽  
Vol 88 (2) ◽  
pp. 483-492 ◽  
Author(s):  
D. Wilman

SUMMARYGrazing with sheep was compared with cutting, in each case at three frequencies, four, five and six defoliations per year, on a lucerne—cocksfoot ley. The treatments were applied in one year and their effects measured during that year and at cuts in June and August of the following year. One experiment began in 1963 in the second harvest year of a ley and a second began in 1964, on an adjacent site, in the third harvest year of the ley. Cutting four times in the year allowed lucerne to persist satisfactorily in both experiments. In the 1964 experiment cutting five or six times and grazing rather than cutting had no apparent, serious, adverse effect on the lucerne compared with cutting four times. In the 1963 experiment, however, increasing the number of cuts and grazing rather than cutting had a large adverse effect on the lucerne, and in the most extreme treatment, grazing six times, the proportion of lucerne was reduced to 2 % of total herbage yield the following June compared with 66% on the four-cut treatment. The contrasting results in the two experiments seem associated with weather differences, 1964 being a much drier, more sunny growing season than 1963, and perhaps with the differences in age of sward, individual lucerne plants perhaps having bigger roots with more reserves in 1964 than in 1963. During the treatment year increasing frequency of defoliation tended to increase the N content of both species and grazing compared with cutting generally increased the N content of cocksfoot. During the year following the treatment year the N content of the two species was little affected by the experimental treatments. The implications for farm practice are considered.


HortScience ◽  
2019 ◽  
Vol 54 (9) ◽  
pp. 1532-1539 ◽  
Author(s):  
Corina Serban ◽  
Lee Kalcsits ◽  
Jennifer DeEll ◽  
James P. Mattheis

‘Honeycrisp’ apples are susceptible to bitter pit, a physiological disorder that impacts peel and adjacent cortex tissue. ‘Honeycrisp’ is also susceptible to chilling injury (CI) that can be prevented by holding fruit at 10 to 20 °C after harvest for up to 7 days. This temperature conditioning period reduces CI risk but can enhance bitter pit development. Previous research demonstrated a controlled atmosphere (CA) established during conditioning can reduce ‘Honeycrisp’ bitter pit development without inducing other physiological disorders. The objective of this research was to evaluate the duration of CA needed to reduce bitter pit development. Experiments were conducted in 2014, 2016, and 2017 with fruit obtained from commercial orchards in Washington State and, in 2017 only, Ontario, Canada. Half the fruit were treated with 42 µmol·L−1 1-methycyclopropene (1-MCP) for 24 hours at 10 °C immediately following harvest. The untreated fruit were held at the same temperature (10 °C) in a different cold room. Following 1-MCP treatment, all fruit were conditioned at 10 °C for an additional 6 days, then fruit was cooled to 2.8 °C. During conditioning, fruit were held in air or CA (2.5 kPa O2, 0.5 kPa CO2) established 1 day after harvest, for 1 to 8 weeks, then in air. All fruit were removed from cold storage after 4 months and then held 7 days at 20 °C. Fruit from most orchards/years stored in CA developed less bitter pit compared with fruit stored continuously in air. CA during conditioning also reduced poststorage peel greasiness but CA for 2 weeks or longer enhanced cortex cavity development in some orchard lots. Treatment with 1-MCP did not reduce bitter pit but enhanced development of peel leather blotch and core browning for some orchards/years. 1-MCP–treated fruit slowed the loss of soluble solids content, titratable acidity, and reduced internal ethylene concentration. Results suggest the potential for postharvest management of bitter pit development in ‘Honeycrisp’ apples by CA established during conditioning with minimal development of other postharvest disorders.


1995 ◽  
Vol 120 (6) ◽  
pp. 1010-1017 ◽  
Author(s):  
Peter M Hirst ◽  
David C Ferree

Floral development was studied in buds of `Starkspur Supreme Delicious' apple trees growing on B.9, M.26 EMLA, M.7 EMLA, P.18, and seedling rootstocks. In each of 3 years, buds were sampled from the previous years growth at intervals throughout the growing season and dissected to determine whether the apex was domed, indicating the start of floral development. Number of bud scales and true leaves increased during the early part of the growing season, but remained fairly constant beyond 70 days after full bloom. The type of rootstock did not affect the number of bud scales or transition leaves, and effects on true leaf numbers were small and inconsistent. Final bract number per floral bud was similarly unaffected by rootstock. The proportion of buds in which flowers were formed was influenced by rootstock in only one year of the study, which was characterized by high temperatures and low rainfall over the period of flower formation. Bracts were observed only in floral buds, and became visible after doming of bud apices had occurred. Flowers were formed during the first 20 days in August, regardless of rootstock or year. The appendage number of vegetative buds was constant from 70 days after full bloom until the end of the growing season, but the number of appendages in floral buds increased due to the continued production of bracts. The critical bud appendage number for `Starkspur Supreme Delicious' before flower formation was 20, and was stable among rootstocks and years. Buds with diameters above 3.1 mm were generally floral, but on this basis only 65% of buds could be correctly classified. Spur leaf number, spur leaf area, and spur leaf dry weight were not good predictors of floral formation within the spur bud.


2003 ◽  
Vol 25 (1) ◽  
pp. 59-62 ◽  
Author(s):  
Cassandro Vidal Talamini do Amarante ◽  
Clarice Aparecida Megguer ◽  
Luiz Eduardo Bassay Blum

Apple trees, cultivars Gala and Fuji, were sprayed at full bloom with thidiazuron (TDZ) at the doses of 0, 5, 10, or 20 g (a.i.) ha-1 and fruit were assessed for quality and maturity. In both cultivars, the increase of TDZ dose had detrimental effects on fruit quality, causing a reduction of fruit red surface and an increase of percentage of fruit that was asymmetrical and with calyx-end rot. TDZ caused an increment of calyx-end aperture that might have increased calyx-end rot. TDZ increased density and the length : diameter (L : D) ratio of the fruit. The number of viable seeds was not affected by TDZ. TDZ resulted in a substantial delay of fruit maturity in 'Gala' but not in 'Fuji'. TDZ also reduced soluble solids content (SSC) in 'Gala' and reduced titratable acidity in both cultivars.


2016 ◽  
Vol 5 (2) ◽  
pp. 23 ◽  
Author(s):  
Joyce Chepngeno ◽  
Willis O Owino ◽  
John Kinyuru ◽  
Ngoni Nenguwo

<p>Precooling and postharvest application of calcium chloride (CaCl<sub>2</sub>) on produce has positive effects in maintaining the produce quality during storage. However, there is variation in the response of the produce to different CaCl<sub>2 </sub>concentrations<sub>. </sub>As a result, there is need to establish optimal concentrations of calcium chloride that can extend postharvest life of targeted produce. Fresh good quality produce (tomatoes, carrots, courgettes and African eggplants) of uniform size and maturity were harvested and sampled into four portions. One was a control, hydrocooled with water only at 2±1 <sup>0</sup>C and the others were hydrocooled with water containing CaCl<sub>2</sub> at 0.5%, 1.0% and 1.5%. After hydrocooling, tomatoes, African eggplants and courgettes were stored at 10 <sup>0</sup>C, while carrots were stored at 7 <sup>0</sup>C, all at 95% constant relative humidity, and sampled every two days for quality assessment. Weight loss, chilling injury, vitamin c and beta-carotene loss were reduced by application of calcium chloride. Titratable acidity decrease and increase in total soluble solids and specific sugars was also slowed by application of CaCl<sub>2</sub>.</p>


Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 358
Author(s):  
Tal Goldberg ◽  
Harel Agra ◽  
Ruth Ben-Arie

The effect of ‘Hayward’ kiwifruit maturity at harvest on fruit quality during long-term storage at −0.5 °C was evaluated by harvesting the fruit several times, at different stages of maturity. The progress of maturation on the vine was monitored weekly from 136 DAFB (days after full bloom). Fruit were harvested for storage at three points and stored for 3–6 months in regular air (RA), or for 6–10 months in a controlled atmosphere (CA), with or without prestorage exposure to 1-methylcyclopropene (1-MCP). The softening rate under both storage regimes decreased with the advance in fruit maturation on the vine, as indicated by increasing soluble solids content (SSC), and declining firmness. As a result, the fruit from the first harvest (152 DAFB), which were the firmest at harvest, were the softest at the end of both storage regimes. Delaying harvest also decelerated the decline in acidity during storage, so that fruit picked last maintained the highest titratable acidity (TA) upon removal from storage. The overall fruit quality after shelf life, following prolonged storage in either RA or CA, was improved by delaying harvest to late November (ca. 200 DAFB). The harvest criteria for fruit with the best storage potential were dry matter (DM) > 17%, SSC > 7%, TA 2.0–2.6%, with more than 40% of the DM non soluble. From a commercial aspect the rule should therefore be ‘Last in, last out’ (LILO).


HortScience ◽  
2005 ◽  
Vol 40 (6) ◽  
pp. 1850-1853 ◽  
Author(s):  
Gerry Neilsen ◽  
Denise Neilsen ◽  
Shufu Dong ◽  
Peter Toivonen ◽  
Frank Peryea

Calcium application trials were undertaken in a 'Braeburn' apple (Malus ×domestica Borkh.) orchard with a history of bitter pit development at harvest. In 2000, an early season calcium chloride application strategy was compared with the unsprayed control and a late season application strategy. From 2001–03, the assessment of timing of calcium chloride sprays was extended by comparing effects of five weekly sprays applied during the growing season either early, middle, or late season. Other Ca application strategies tested included sprays of acidified calcium carbonate suspensions and soil application of calcium thiosulphate. In the first experiment, early application of calcium chloride reduced the occurrence of bitter pit at harvest and after 3 months cold air storage, despite having low harvest fruit Ca concentrations. Late sprayed fruit had a higher incidence of bitter pit. In the second experiment, the later calcium chloride was sprayed in the growing season, the higher the fruit Ca concentration at harvest. Despite this, no bitter pit was measured at harvest for 2 years for early and midseason calcium chloride spray regimes. In 2003, when Ca disorders were severe and fruit large, bitter pit was observed despite early season calcium chloride sprays. Soil calcium thiosulphate application and foliar sprays of acidified calcium carbonate suspensions failed to meaningfully augment harvest fruit Ca concentrations and affect bitter pit incidence.


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