Effect of a Single Defoliation and Fruit Thinning on Papaya Fruit Production and Quality

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 497d-497
Author(s):  
Lili Zhou ◽  
David Christopher ◽  
Robert E. Paull

The effect of defoliation and fruit thinning on papaya fruit set, growth, and ripe fruit quality was determined. Three defoliation levels (0%, 50%, 75%) and two defoliation methods (75% leaf cut off from the oldest to the youngest vs. 75% leaves removed in a spiral from the oldest) was compared with fruit thinning experiment on `Sunset' papaya during the warm season. Removal of 75% of the leaves significantly reduced new flower and fruit set, and decreased TSS level in ripe fruit. There was no significant difference between 0% and 50% defoliation in new fruit set, or ripe fruit TSS levels. Removal of leaves in a spiral reduced the number of new flower and fruit set more than the defoliation from the bottom to top. Defoliation of the `Kapoho' variety increased ripe fruit number and significantly reduced ripe fruit TSS and sugar level, dry mass persentage 2 weeks after defoliation. There was no significant difference between defoliated and non-defoliated treatment in fruit production, average fruit mass, and percentage of fruit flesh and seed, seed mass ratio, and seed dry mass during the test period. Fruit thinning increased new fruit set and increased ripe fruit TSS level in Line-8 and `Sunset', but not in `Kapoho'. However, average ripe fruit mass increased in fruit thinning experiment in `Kapoho' but not `Sunset' and Line-8 varieties. Fruit thinning also increased remaining young fruit TSS and sugar levels on the remaining fruit on plants compared to same-aged fruit on control and defoliated plants in Line-8. There was no effect on `Kapoho' young fruit TSS and sugar levels of defoliation. Ripe fruit TSS varied with weather conditions, plant growth conditions, and cultivars. These results indicated that although different cultivars had different responses to artificial defoliation and fruit thinning, source–sink balance and the ratio of fruit to leaf was an important factor in controlling potential fruit production and final fruit quality.

HortScience ◽  
1993 ◽  
Vol 28 (11) ◽  
pp. 1081-1084 ◽  
Author(s):  
Michael W. Smith ◽  
William Reid ◽  
Becky Carroll ◽  
Becky Cheary

Pecan [Carya illinoinensis (Wangenh.) C. Koch] fruit were thinned from `Mohawk' trees in Oklahoma and `Giles' trees in Kansas with a mechanical trunk shaker. All trees bore an excessive crop load before shaking. Fruit thinning improved the kernel percentage, individual nut weight, and kernel grade of `Mohawk', but nut characteristics of `Giles' were not affected by fruit thinning. Cold injury, caused by a sudden temperature drop in November, was positively related to the percentage of fruiting shoots in both cultivars. Fruit set in 1992 was negatively related to the percentage of fruiting shoots in 1991 in both cultivars. Consistent annual fruit set could be induced in `Giles' by fruit thinning, but return fruit set in `Mohawk', even at high levels of thinning, was low. Fruit thinning reduced yield the year of thinning in both cultivars. Thus, `Mohawk' trees should be thinned so that 50% to 60% of shoots bearing fruit at mid-canopy height would remain, and `Giles' trees should be thinned similarly to 65% to 70%.


2018 ◽  
Vol 14 (4) ◽  
pp. 161-166
Author(s):  
Scheila Lucia Ecker ◽  
Clevison Luiz Giacobbo ◽  
Leandro Galon ◽  
Adriana Lugaresi ◽  
Gian Carlos Girardi

The objective of this work was to verify the influence of planting density on productivity and fruit quality of the fig tree. The design was used in three blocks, the plants of the cultivar Roxo de Valinhos were submitted to three planting spacings: 5 x 0.5 m; 5 x 1.0 m; and 5 x 1.5 m. The evaluated characteristics were: length of branches; average weekly growth of branches; fruit size; average fruit weight;soluble solids (°Brix); yield of mature fruits; productivity of green fruits; accumulated productivity; and dry mass of fruits.The length of the branches was not influenced by planting spacing, the plants conducted at lower densities presented higher productivity, both of green fruits and accumulated productivity.Plants submitted to lower planting density produced fruits with higher dry matter, but these were smaller in size, but without significant difference for those submitted to lower density. It wasconcluded that productivity is directly affected by fig planting density, but not all the qualitative aspects of the fruits were affected.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 497e-497
Author(s):  
Lili Zhou ◽  
David Christopher ◽  
Robert E. Paull

The source size and sink strength were modified by continual defoliation and fruit removal in `Sunset' papaya. Flower and fruit set, mature fruit mass, and TSS was recorded weekly. Fruit at four different stages of development were harvested at the end of the experiment. Fruit mass, respiration, sugar content, and sucrose phosphate synthase (SPS), sucrose synthase (SS), and invertase enzyme activities were compared. Continual defoliation resulted in lower new fruit set (25% of control), smaller fruit size (77% of control), and lower TSS (85% of control) in the 24-week experimental period. In contrast, there were 52% and 100% more new fruit when fruit were removed than in the control within the first 8 weeks and 24 weeks, respectively. Larger fruit size, earlier fruit development, lower respiration, and higher sugar contents were observed when fruit were removed at 140, 154, and 175 days from anthesis. No significant difference was found in TSS level in the mature fruit compared to the control. Fruit removal plus defoliation gave the same number and mass of new fruit as the control and slightly lower TSS in mature fruit than in the control. Fruit sugar was higher with increased fruit invertase activity and fruit age. Data confirmed that source–sink balance was critical for fruit set, development, and sugar accumulation in papaya.


2013 ◽  
Vol 13 (3) ◽  
pp. 171-179 ◽  
Author(s):  
Cezary Toma

AbstractThe aim of the research was to establish the density of specimens and shoots as well as the reproductive effort of Hydrocharis morsus-ranae during the whole vegetative period in a Polish oxbow lake. The following specimen features were examined: plant diameter, total length, the number of buds, flowers, young fruit, ripe fruit, turions and leaves and also dry total mass, vegetative mass, generative mass, the bud mass, the flower mass, young fruit mass and ripe fruit mass. The density of Hydrocharis morsus-ranae specimens per square metre ranged from 10 to 170 while the density of shoots ranged from 10 to 545. From one square metre overgrown with Hydrocharis morsus-ranae, a maximum of 389 turions, 50 fruit and 4000 seeds are produced. The maximum of reproductive effort is 97.8% of vegetative mass and 2.2% of generative mass in September 2010. The factors which best explain changeability of the Hydrocharis morsusranae population in time are the length and the diameter of the specimens in the population. Fruiting of Hydrocharis morsus-ranae in Poland is higher than in Canada, where it is an invasive taxon. Hydrocharis morsus-ranae is well adapted to the environment in oxbow lakes of the River Vistula and represents the S-R strategy.


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.


2015 ◽  
Vol 4 (4) ◽  
pp. 18
Author(s):  
Mohamed S. Al Saikhan ◽  
Abdel-Kader A. Sallam

<p>The fruit thinning process is employed for the production of high quality large-sized fruits and prevent the production of compact bunches. It is also one way to reduce the alternate bearing habits in date palm. In this study, seven thinning treatments (i.e. without spraying water after pollination, spraying water at 3 minutes after 3, 4 and 5 h, spraying Ethephon at 0, 500 and 1000 ppm after ten days from pollination) are used for Khalas and Ruzeiz date palm cultivars. The factorial experiment in a randomized completely block design with three replicates was done. The results reveal that, spraying water after mechanical pollination has reduced fruit set% and increased fruit shees%. Most thinning treatments reduced fruit yield/palm in both Khalas and Ruzeiz. Spraying water after 5 h enhanced fruit quality compared with the other thinning treatments in besr and tamr stages. Spraying with ethephon at 1000 ppm gave the increased sugars content and TSS, whereas reduced the moisture content in besr stage. Spraying water after 5 h from mechanical pollination or Ethephon at 1000 ppm after 10 days are suitable for obtaining economic yield with best fruit quality.</p>


1972 ◽  
Vol 12 (54) ◽  
pp. 83 ◽  
Author(s):  
N Veinbrants

Evidence is presented that a single application of the fungicide thiram at 0.12 per cent, applied 14 and 21 days after full bloom on Granny Smith apples, reduced the fruit set highly significantly, and to about the same extent as carbaryl at 0.02, 0.04, or 0.08 per cent applied 14 days after full bloom. Either material resulted in good fruit thinning. Carbaryl caused about the same degree of thinning over a wide range of concentrations, the only significant difference being between 0.02 and 0.16 per cent (P<0.05). Applications of N.A.D. at 25 p.p.m., and N.A.A. at 5 p.p.m. caused more drastic reduction in fruit set than carbaryl at 0.02, 0.04, and 0.08 per cent, or thiram at 0.12 per cent, applied at the same time. Carbaryl resulted in the most uniform fruit thinning, followed by thiram, N.A.D., and N.A.A. All spray treatments improved fruit size, reduced fluctuations in cropping, and significantly increased fruit yields over a period of four years as compared with unsprayed, hand thinned trees.


2004 ◽  
pp. 21-26
Author(s):  
József Racskó

On seven apple cultivars (Gala Must, Gloster, Granny Smith, Idared, Jonagold, Jonathan Csány and Mutsu), the author studied the influence of N-phenyl-phthalamic acid (Nevirol 60 WP) and fertilization on fruit setting and fruit quality.The research results show that by using Nevirol 60 WP and applying fertilization, we can improve the fruit setting and number of fruit per tree. As a result of this process, the yield amount will increase.Nevirol 60 WP has a great effect on the improvement of yield amount, especially by good nutrient supply. There is a significant difference between the reactions of different cultivars. The most sensitive to these treatments were the cultivar Gala Must and Granny Smith. Before using Nevirol 60 WP we have to take into consideration that the increased yield needs a higher nutrient supply; otherwise, fruit mass, diameter and fruit height will decrease, and the yield will frittered away. In the study, the most favourable effect of Nevirol 60 WP was detected under additionally fertilized conditions by the author.


Silva Fennica ◽  
2019 ◽  
Vol 53 (3) ◽  
Author(s):  
Outi Manninen ◽  
Rainer Peltola

Accumulated knowledge about the health benefits of bilberry ( L.) has increased the demand and utilization of wild bilberries. Intensive berry picking by metal rakes is believed to cause damage in bilberry stands in areas under continuous picking pressure, and hence expected to hamper the production of berries in forthcoming years. We conducted an experiment to examine the effect of continuous bilberry picking by metal rake on the number of bilberry flowers and fruits, fruit mass, compensation for biomass loss after picking, and plant functional type abundance in the understorey in northern Finland. Bilberry lost less than 0.5% of its biomass annually during the three-year study period due to rake harvesting. The number of flowers was not significantly affected by damage caused by picking, while both fruit production and fruit set increased without any indication of reduced fruit mass, and biomass loss was fully compensated. Moreover, the relative abundance of plant functional types was not affected by picking during the study. We suggest that the low intensity and timing of damage act as a buffer against the adverse effects of picking on bilberry fruit production. On the basis of this study, it is reasonable to anticipate that there are no indications that current intensive berry picking would not be on a sustainable level.Vaccinium myrtillus


2017 ◽  
Vol 35 (2) ◽  
pp. 271-277
Author(s):  
Roberto CF Queiroga ◽  
Gabriel D Silva ◽  
Auderlan M Pereira ◽  
Ricardo RP Almeida ◽  
Ariano B Silva

ABSTRACT Squashes and pumpkins are known and grown worldwide, including the Tetsukabuto type, a hybrid of Japanese origin. On this work, we evaluated yield and quality of parthenocarpic fruits of hybrid Tetsukabuto developed with the use of 2,4-D doses, in the climatic conditions of the Brazilian semiarid, in the city of Pombal, state of Paraíba, Brazil. The experiment was carried out from February to May 2013, in complete blocks at random and five replications. Treatments corresponded to five 2,4-D doses (0, 90, 180, 270, and 360 mg/L) applied to female flowers, and a control treatment, where fruits developed out of insect pollinated flowers. We evaluated number of flowers per plant, duration of flowering, number of fruits per plant (used to estimate number of fruits per hectare), fruit set index, fruit mass and transversal and longitudinal diameters, pulp thickness and content of soluble solids, total fruit production and yield. Number of fruits per plant and fruit mass increased 269.5 and 15.4%, respectively, with 212.1 mg/L and 360.0 mg/L of 2,4-D, when compared to the control treatment. Increasing the 2,4-D dose from 0.0 to 241.4 mg/L resulted in 38.2% rise in plant production. Correlations were significant only for number of flowers x number of fruits per plant (NF) and NF x yield, with coefficients of 87.5 and 82.7%, respectively. These results indicate that fruit induction using 2,4-D resulted in higher fruit set, independent of the 2,4-D dose applied.


Sign in / Sign up

Export Citation Format

Share Document