Control of premature fruit drop in Macadamia integrifolia: effects of naphthalene acetic acid application, cincturing, and shoot-tip removal

1980 ◽  
Vol 20 (107) ◽  
pp. 740 ◽  
Author(s):  
RR Williams
Keyword(s):  
Acetic Acid ◽  
Fruit Set ◽  
Shoot Tip ◽  
Naphthalene Acetic Acid ◽  
Fruit Drop ◽  
Macadamia Integrifolia

The effects of NAA application, cincturing and shoot-tip removal on the incidence of premature fruit drop were investigated in orchard-grown trees of Macadamia integrifolia cv. Kakea. A single, post-anthesis application of NAA (1 ppm) increased (P < 0.05) the final set of macadamia fruit by 35%. Limb cincturing combined with shoot-tip removal increased (P < 0.05) initial fruit set and possibly final set. Cincturing alone was less effective and shoot-tip removal had no effect alone.

scholarly journals Reduction of Early Fruit Abscission by Main-branch-girdling in Macadamia Is Related to the Favorable Status of Carbohydrates and Endogenous Hormones

HortScience ◽  
2022 ◽  
Vol 57 (1) ◽  
pp. 40-47
Author(s):  
Wei Hai Yang ◽  
Chao Zhong Lu ◽  
Wei Chen ◽  
Huan Yu Xu
Keyword(s):  
Acetic Acid ◽  
Fruit Set ◽  
Physiological Mechanism ◽  
Zeatin Riboside ◽  
Endogenous Hormones ◽  
Fruit Abscission ◽  
Fruit Drop ◽  
Macadamia Integrifolia ◽  
Horticultural Practice ◽  
Indole 3 Acetic Acid

Fruit abscission occurring severely in the early fruit development affects macadamia yield. Developing effective methods to improve fruit retention is a priority for macadamia cultivation and production. Girdling is an important horticultural practice that has been widely used to increase fruit yield. Previous studies have shown that girdling fails to increase macadamia yield despite enhancing the early fruit set, but few have examined the effect of girdling on its related physiological mechanism. The objective of this study was to investigate the effects of main-branch girdling (MBG) on early fruit retention and also on the levels of carbohydrates and endogenous hormones in the leaves, bearing shoots and fruit of macadamia. Herein, MBG was performed at fruit set using a single-blade knife on 9-year-old macadamia trees (Macadamia integrifolia). Results showed that MBG significantly reduced young fruit drop, concurrent with significant increases in the contents of starch in both the leaves and the bearing shoots and in glucose, fructose, and sucrose levels in the husk and seed. It was suggested that the availability of carbohydrate for fruit retention was improved by MBG. Additionally, MBG increased indole-3-acetic acid (IAA), gibberellin (GA3), and zeatin-riboside (ZR, a type of cytokinin) concentrations and decreased abscisic acid (ABA) contents in the husk and the seed, indicating that MBG reduced the early fruit drop by modifying the balance of endogenous hormones. Therefore, a positive interplay between carbohydrates and endogenous hormones induced by MBG was involved in the reduction of early fruit abscission in macadamia.

scholarly journals Effect of chemical thinning, gibberellic acid and pruning on growth and production of nectarine (Prunus persica (L.) Batsch var. nucipersica) cv. May fire

2017 ◽  
Vol 9 (1) ◽  
pp. 332-337
Author(s):  
Rimpika Rimpika ◽  
N. Sharma ◽  
D.P. Sharma
Keyword(s):  
Acetic Acid ◽  
Gibberellic Acid ◽  
Shoot Growth ◽  
Prunus Persica ◽  
Tree Height ◽  
Naphthalene Acetic Acid ◽  
Crop Load ◽  
Fruit Drop ◽  
Alternative Approach ◽  
Old Trees

The present investigation was carried out on 12-year old trees of nectarine (Prunus persica (L.) Batsch var. nucipersica) cultivar May Fire raised on wild peach seedling rootstocks, Farmer’s orchard at Kotla- Barog in District Sirmour during the years 2014 and 2015. In this experiment, experimental trees were subjected to seventeen different treatments;T1: Pruning to retain 60 fruiting shoots tree-1 (control), T2: Pruning to retain 50 fruiting shoots tree-1, T3: Pruning to retain 40 fruiting shoots tree-1 ,T4: NAA 40 ppm, 2 WAPF (week after petal fall) ,T5: Ethrel 300 ppm, 2 WAPF, T6: GA3 100 ppm, 4 WAPF, T7: GA3 200 ppm, 4WAPF, T8: GA3 100 ppm, 6 WAPF T9: GA3 200 ppm, 6 WAPF, T10: Pruning to retain 50 fruiting shoots tree-1 + NAA 40 ppm (T4), T11: Pruning to retain 50 fruiting shoots tree-1 + Ethrel 300ppm (T5), T12: Pruning to retain 50 fruiting shoots tree-1 + GA3100 ppm (T6), T13: Pruning to retain 50 fruiting shoots tree-1 + GA3 100 ppm (T8),T14: Pruning to retain 40 fruiting shoots tree-1 + NAA 40 ppm (T4), T15: Pruning to retain 40 fruiting shoots tree -1 +Ethrel 300 ppm (T5),T16: Pruning to retain 40 fruiting shoots tree -1 + GA3 100 ppm (T6), T17: Pruning to retain 40 fruiting shoots tree -1 + GA3 100 ppm (T8), pertaining to alternative approach to chemical thinning, chemical thinner were more effective in improving the production of superior grade fruits than reducing the crop load directly by pruning or indirectly by GA 3 (Gibberellic Acid) treatments. Treatments with NAA (naphthalene acetic acid) at 40 ppm when applied two weeks after petal fall reduced the crop load to the greatest extent and improve the yield of superior grade fruits and increase the leaf to fruit ratio and decrease the fruit drop. Pruning to retain 40 fruiting shoots tree-1 + NAA 40 ppm, 2WAPF increased the shoot growth (160.80, 170.20cm), tree height (3.70,4.50 cm), tree spread (2.84,3.60), leaf area (42.71, 40.63 cm) during both the year. However, effect of chemical were less pronounced on trees subjected to severe pruning.

scholarly journals EFFECT OF RACEME THINNING AND GIRDLING ON FRUIT SET OF MACADAMIA NUT

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1105d-1105
Author(s):  
Gary R. Ueunten ◽  
Kent D. Kobayashi
Keyword(s):  
Significant Interaction ◽  
Fruit Set ◽  
Phloem Transport ◽  
Fruit Drop ◽  
Macadamia Integrifolia ◽  
Macadamia Nut ◽  
Days After Anthesis

Premature fruit drop of Macadamia integrifolia is a major limitation to yield. This study investigated the effects of raceme thinning and branch girding on find fruit set of macadamia nut 'Ikaika' and 'Keaau'. Eleven-year old grafted trees grown near Hilo, Hawaii were used. Racemes were thinned to 1, 2, or 4 racemes per branch two weeks after anthesis. The base of half these branches was girdled when the racemes were thinned.Premature fruit drop occurred during the 97 and 151 days following anthesis for `Keaau' and `Ikaika', respectively. Peak fruit drop occurred within 70 days after anthesis for both cultivars. Raceme thinning and girdling had no effect on final fruit set (nuts/branch) of `Ikaika' 151 days after anthesis. There was a significant interaction between raceme thinning and girdling on final fruit set of `Keaau'. Branches with four racemes set more fruit than branches with one or two racemes. Raceme thinning and girdling had no effect on fruit retention (% of initial fruit set retained through final fruit set per branch) of `Ikaika'. There was a significant interaction between girdling and raceme thinning on fruit retention of `Keaau'. Branches with four racemes had greater fruit retention than branches with one or two racemes. Premature fruit drop may be altered on individual branches by altering raceme load and limiting phloem transport of assimilates into the girdled branch.

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