Effect of timing, concentration and stock/scion combination on chemical control of pre-harvest drop of Navel oranges

1975 ◽  
Vol 15 (74) ◽  
pp. 429 ◽  
Author(s):  
RA Sarooshi ◽  
MC Stannard
Keyword(s):  
Poncirus Trifoliata ◽  
Ethyl Esters ◽  
Dichlorophenoxyacetic Acid ◽  
Phenoxyacetic Acid ◽  
Fruit Drop ◽  
Washington Navel ◽  
Semi Arid Region ◽  
D 20 ◽  
One Year ◽  
2,4 Dichlorophenoxyacetic Acid

The effects of 4-chloro-2-methyl phenoxyacetic acid (MCPA) and some derivatives of 2,4-dichlorophenoxyacetic acid (2,4-D) applied at various concentrations and application times on preharvest drop from several navel orange clones and rootstocks were investigated. The trees were spray irrigated, on light soils and growing in a semi-arid region. Herps Washington navel strain on Poncirus trifoliata rootstock had a small natural drop and fruit drop from this combination was unaffected by spray treatments. Control trees of Leng navels dropped more fruit than those of GVN or Herps Washington navel strains. There were no differences in fruit drop between MCPA and 2,4-D both applied at 20 p.p.m. in mid May. In one year however, the higher concentration of 2,4-D was superior to MCPA applied at 10 p.p.m. in mid May but was not better than 2,4-D at 10 p.p.m. Two sprays of 2,4-D 10 p.p.m. applied one each in mid May and mid June had no advantage over a single spray of 2,4-D 20 p.p.m. mid May. The four forms of 2,4-D used were the sodium and amine salts (low volatile) and the isopropyl and ethyl esters (high volatile). All the forms sprayed in mid May at 20 p.p.m. proved equally effective. In all cases, fruit quality and yield were unaffected by spray treatments over a number of years.

Response of pre-harvest drop of grapefruit on two rootstocks to 2,4-D, MCPA and gibberellic acid

1982 ◽  
Vol 22 (117) ◽  
pp. 337 ◽  
Author(s):  
RA Sarooshi
Keyword(s):  
Gibberellic Acid ◽  
Poncirus Trifoliata ◽  
Dichlorophenoxyacetic Acid ◽  
Phenoxyacetic Acid ◽  
Rough Lemon ◽  
Fruit Drop ◽  
South Wales ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Better Than

Several formulations, concentrations and timings of sprays of 2,4-D (2,4-dichlorophenoxyacetic acid) and MCPA (4-chloro-2-methyl phenoxyacetic acid) were tested for their ability to reduce pre-harvest drop of late hanging Marsh grapefruit growing on rough lemon (Citrus jambheri) and trifoliata (Poncirus trifoliata) rootstocks at Dareton in south-western New South Wales. Gibberellic acid was also tested in several timing combinations with 2,4-D for its ability to improve the quality of late hanging fruit. On rough lemon the established standard treatment of 2,4-D at 20 ppm applied in mid-May was as good or better than all other treatments. On trifoliata this standard spray was again as effective as all others in preventing drop up to mid-November, but a similar spray applied in midJune was more effective from mid-November to mid-December. MCPA applied at 10 or 20 ppm in mid-May was not as effective as the standard spray. The best treatments reduced the average cumulative fruit drop, of 39% on trifoliata and 70% on rough lemon, by at least a half. When gibberellic acid at 10 ppm was added to the standard mid-May spray of 2,4-D, or when it followed it in mid June, it improved the colour and appearance and reduced the rind thickness and puffiness of late hanging fruit.

scholarly journals Integrated Approach to Control of Fruit Drop and Improvement of Yield in Kinnow (Citrus nobilis X Citrus deliciosa)

2017 ◽  
Vol 15 (12) ◽  
pp. 819-829
Author(s):  
Ramesh KUMAR ◽  
Madhu SHARMA ◽  
Shailesh Kumar SINGH
Keyword(s):  
Integrated Management ◽  
Insect Pest ◽  
Integrated Approach ◽  
Economic Loss ◽  
Potassium Nitrate ◽  
Dichlorophenoxyacetic Acid ◽  
Fruit Drop ◽  
D 20 ◽  
Kinnow Mandarin ◽  
2,4 Dichlorophenoxyacetic Acid

Fruit drop is a major problem with Kinnow mandarin in all fruit growing regions of the world. Kinnow growers suffer a greater economic loss when natural fruit drop (98.0 to 99.5 %) is accelerated by pathogenic infection, insect-pest infestation, and physiological or hormonal imbalance due to poor orchard management. The application of fungicides to minimize pathogenic attack; 2,4-D (2,4-Dichlorophenoxyacetic acid) to maintain hormonal balance; and KNO3 (Potassium nitrate) to maintain electrolytic balance and efficient utilization of nutrients for developing resistance against insect infestation has greater potential to reduce fruit drop in Kinnow. The fungicides, namely; Zeneb 75WP (0.25 %), Carzim-50 (0.1 %), Curzate M8 (0.25 %), COPRUS 50WP (0.3 %), and Cyproconazole 25EC (0.1 %), in combination with 2,4-D @ 20 ppm and KNO3 @ 1 %, were applied twice, in September and October, and the number of fruits fallen on the ground were counted to determine fruit drop. It was observed that application of T3 [Curzate M8 (0.25 %) + 2,4-D (20 ppm) + KNO3 (1 %)] was an excellent treatment for the integrated management of fruit drop in Kinnow as it had ensured the lowest (1.90-entomological, 3.53-pathological, and 4.75-physiological) fruit drop percentage with the highest fruit yield (432 fruits per plant).

Adsorption of 2,4-Dichlorophenoxyacetic Acid and Phenoxyacetic Acid on Sibunit

2018 ◽  
Vol 52 (1) ◽  
pp. 53-57 ◽  
Author(s):  
M. D. Vedenyapina ◽  
L. R. Sharifullina ◽  
S. A. Kulaishin ◽  
E. D. Strel’tsova ◽  
A. A. Vedenyapin ◽  
...  
Keyword(s):  
Dichlorophenoxyacetic Acid ◽  
Phenoxyacetic Acid ◽  
2,4 Dichlorophenoxyacetic Acid

Citrus tissue culture: regulation of stylar abscission in excised pistils

1980 ◽  
Vol 58 (11) ◽  
pp. 1257-1261 ◽  
Author(s):  
John W. Einset ◽  
Anne Cheng ◽  
Hamid Elhag
Keyword(s):  
Tissue Culture ◽  
Cell Division ◽  
Dichlorophenoxyacetic Acid ◽  
Navel Orange ◽  
Test Medium ◽  
Fresh Weight ◽  
Valencia Orange ◽  
Washington Navel ◽  
Citrus Tissue Culture ◽  
2,4 Dichlorophenoxyacetic Acid

Lemon pistil explants were obtained by cutting just above the region of the hypogynous disc (A type explant) or at the base of the pistil (B type explant) and cultured on test medium containing Murashige and Skoog salts, 50 g sucrose/L, 100 mg myo-inositol/L, 5 mg thiamine–HCl/L, and 0.5 mg kinetin/L, plus or minus supplements. Under appropriate conditions an abscission zone formed and styles abscised after 6–8 days of culture; in the field stylar abscission occurred 12–15 days postanthesis. Abscission in A type explants was markedly inhibited by 9 μM 2,4-dichlorophenoxyacetic acid but was unaffected by indole-3-acetic, 1-naphthaleneacetic, gibberellic, abscisic, caffeic, or p-coumaric acids. The response to 2,4-dichlorophenoxyacetic acid was reduced in B type explants. In an atmosphere containing 35–200 ppm ethylene, cell division occurred in the zone of stylar abscission producing a proliferating callus, and the content of cellulase increased from 0.6 to 53.7 enzyme units/g fresh weight compared with fresh explants. Stylar abscission was inhibited by 2,4-dichlorophenoxyacetic acid in A type explants of Washington navel orange, Valencia orange, and mandarin pistils, but not of grapefruit pistils. B type explants of Washington navel orange and mandarin pistils were less responsive to 2,4-dichlorophenoxyacetic acid.

scholarly journals Foliar 2,4-D Application after Physiological Fruit Drop Reduces Fruit Splitting of Mandarin

2014 ◽  
Vol 24 (6) ◽  
pp. 717-723 ◽  
Author(s):  
Ockert P.J. Stander ◽  
Karen I. Theron ◽  
Paul J.R. Cronjé
Keyword(s):  
Fruit Development ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Dichlorophenoxyacetic Acid ◽  
Slight Reduction ◽  
Strengthening Effect ◽  
Physiological Disorder ◽  
Growing Seasons ◽  
Fruit Drop ◽  
2,4 Dichlorophenoxyacetic Acid

Various mandarin (Citrus reticulata) cultivars are prone to fruit splitting, a physiological disorder that entails cracking of the rind, starting from the stylar end of the fruit, with eventual splitting of the endocarp and abscission of the fruit. On two mandarin cultivars, Marisol and Mor, foliar applications of 2,4-dichlorophenoxyacetic acid (2,4-D), calcium (Ca), and potassium (K) were evaluated over two growing seasons for efficacy to reduce fruit splitting in Paarl, South Africa (lat. 33°69′S, long. 18°95′E). Foliar treatment of 10 mg·L−1 2,4-D directly after physiological fruit drop (APFD) compared with later dates in January and February, either alone or in combination with K, increased rind thickness and reduced fruit splitting of ‘Marisol’ and ‘Mor’ by up to 50%, without negatively affecting internal fruit quality. Treatments increased rind thickness and rind strength throughout fruit development in addition to fruit diameter, length, and growth rate, with no significant effect on rind coarseness. There was a slight reduction in juice content and titratable acidity (TA), but no effect on the total soluble solids (TSS). Application of 2,4-D APFD is thought to increase rind integrity due to a direct strengthening effect on the rind during early stages of fruit development.

scholarly journals Smooth leaf (spineless) Red Spanish pineapple (Ananas comosus) propagated in vitro

1969 ◽  
Vol 73 (4) ◽  
pp. 301-311
Author(s):  
Lii J. Liu ◽  
Evelyn Rosa-Márquez ◽  
Enid Lizardi
Keyword(s):  
Callus Formation ◽  
Ananas Comosus ◽  
Dichlorophenoxyacetic Acid ◽  
Meristem Culture ◽  
Standard Medium ◽  
Shoot Differentiation ◽  
Low Concentrations ◽  
One Year ◽  
2,4 Dichlorophenoxyacetic Acid

Some 40,000 plantlets of Red Spanish pineapple [Ananas comosus (L. Merr.)] were produced via meristem culture. Of these, approximately 50% were spineless. Some of these spineless plantlets reversed to spiny leaf. However, the percentage of reversion from spineless to spiny was 14.1% and that from spiny to spineless was 32.7%. Of the 2,318 plantlets examined in the laboratory and greenhouse during a 3- to 4-month period, 72.9% of the spiny Red Spanish pineapple remained spiny and 85.8% of the spineless remained spineless. One year after field planting, the spineless Red Spanish remained largely spineless and initiated flowering and fruit settings the same as the spiny ones. The standard medium for in vitro propagation of Red Spanish pineapple was improved by supplementing Murashige and Skoog's basic formula (MS) with 0.1 mg/L, 2,4- dichlorophenoxyacetic acid (2,4-D) + 0.5 mg/L benzyl adenine (BA). The callus formation was improved by adding to the same MS formula 10 mg/L BA + 4 mg/L naphtalene acetic acid (NAA). Similarly, shoot differentiation was improved by adding low concentrations of hormone (0.1 mg/L NAA) to the Abo El-Nil and Zettler (AZ) medium.

OH-Radical Induced Oxidation of Phenoxyacetic Acid and 2,4-Dichlorophenoxyacetic Acid. Primary Radical Steps and Products

2002 ◽  
Vol 106 (29) ◽  
pp. 6743-6749 ◽  
Author(s):  
Robert Zona ◽  
Sonja Solar ◽  
Knud Sehested ◽  
Jerzy Holcman ◽  
Stephen P. Mezyk
Keyword(s):  
Dichlorophenoxyacetic Acid ◽  
Phenoxyacetic Acid ◽  
Oh Radical ◽  
Primary Radical ◽  
2,4 Dichlorophenoxyacetic Acid
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