Abstract
Introduction: Date bunch fading disorder has been one of the most important problems, which caused economic damage to date plantation area of Iran. It has been first reported on Mozafti cultivar in Kahnuj area, Kerman province. It has often been observed on soft and mid ripening cultivars such as Mozafti, Mordaseng and Kalote. Furthermore, it usually appears on Mozafti cultivar when fruits change from Khalal to Rutab stage. The most important symptoms of this disorder are sudden wilting of fruits and necrotic strips on the upper surface of the main bunch stalk. Incidence and development of these symptoms increase by high temperature, low relative humidity, and hot and dry wind. Several research studies have been carried out on this disorder so far, but the only research about the effect of nutrition on disorder was performed by Rosta (2003). The aim of the present study was to investigate the effect of calcium and potassium spray on date bunch fading and some traits of date fruit in Rigan region, Kerman province. Materials and Methods: The experiment was conducted based on randomized complete block designs with three replicates in Rigan located in east south of Kerman province, Iran, in 2012. Treatments were: T1: control, T2: spray of calcium nitrate at the concentration of 5 ppm, T3: spray of potassium sulfate at the concentration of 5 ppm, and T4: combined spray of calcium nitrate and potassium sulfate at the concentration of 5 ppm. Treatments were applied at Kimri, Hobabok and Khalal stages. Sampling was performed from 3 date palms (3 bunches from each date palm were selected randomly) at the second date harvest. Totally, the traits of 200 fruits were measured in each date palm. The traits measured in the present study were: fruit length, fruit diameter, fruit weight, stone weight, stone diameter, and bunch fading percentage. Results and Discussions: According to the data of variance analysis, treatments had a significant effect on wet fruit weight, fruit length, fruit diameter, stone weight, stone diameter, and bunch fading percentage at 1℅ level. The highest wet fruit weight, fruit length, fruit diameter, stone weight, and stone diameter were attained in the treatment containing combined application of calcium nitrate and potassium sulfate. Furthermore, the lowest amounts of these traits were obtained in control. The lowest and highest percentage of date bunch fading belonged to the combined treatment of calcium nitrate and potassium sulfate, and control, respectively. In general, application of calcium nitrate and potassium sulfate with each other improved fruit traits and reduced bunch fading percentage. Calcium mobility in the plant takes place mainly in the xylem, together with water. Therefore, calcium uptake is directly related to plant transpiration rate. Conditions of high humidity, cold and low transpiration rates may result in calcium deficiency. Salinity might also cause calcium deficiency because it decreases water uptake by the plant. Since calcium mobility in plants is limited, calcium deficiency appears in younger leaves and in fruits, because they have a very low transpiration rate. Therefore, it is necessary to have a constant supply of calcium for continued growth. Calcium deficiency is usually caused by low calcium availability or water stress which results in low transpiration rates. Calcium is an essential plant nutrient with many roles including participation in metabolic processes of other nutrients uptake, promotion of proper plant cell elongation, and improvement of cell wall structure – calcium is an essential part of plant cell wall. It forms calcium pectate compounds which give stability to cell walls and bind cells together. It also helps protecting the plant against heat stress - calcium improves stomata function and participates in induction of heat shock proteins. In addition, it helps protecting the plant against diseases - numerous fungi and bacteria secret enzymes which impair plant cell wall. Stronger cell walls, induced by calcium, can avoid the invasion of diseases. Considering the important roles of calcium, calcium spray increased thetraits of date fruit and decreased bunch fading percentage. As an important element in photosynthesis, , potassium regulates the opening and closing of stomata, and therefore regulates CO2 uptake. Potassium plays a major role in the regulation of water in plants (osmo-regulation). Both uptake of water through plant roots and its loss through the stomata are affected by potassium. Moreover, protein and starch synthesis in plants requires potassium, so that the enzymes responsible for starch synthesis are activated by potassium. Potassium has also an important role in the activation of many growth related enzymes in plants. Results of the analysis of the studied soil showed that available potassium content in soil was less than plant requirement. So spraying of potassium sulfate could result in the improvement of date fruit traits and reduction of bunch fading disorder. Finally, combined spray of calcium and potassium caused a significant reduction in date bunch fading percentage. Conclusion: The results of the present study indicated that spray of calcium and potassium solely improved fruit traits and bunch fading disorder, but maximum values of fruit yield components and minimum bunch fading percentage obtained from foliar spray of calcium and potassium together.
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Claims 9
Claim · model-written summary
The combined calcium nitrate and potassium sulfate treatment gave the highest wet fruit weight, fruit length and fruit diameter in date palms.
- Taxon
- date palms
Phoenix dactyliferae0 - Treatment
- combined application of calcium nitrate and potassium sulfatee1
- Outcome
- wet fruit weight, fruit length, fruit diametere1
- Direction
- higheste1
- Comparator
- controle2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sampling was performed from 3 date palms (3 bunches from each date palm were selected randomly) at the second date harvest”
e1“The highest wet fruit weight, fruit length, fruit diameter, stone weight, and stone diameter were attained in the treatment containing combined application of calcium nitrate and potassium sulfate”
e2“Furthermore, the lowest amounts of these traits were obtained in control”
Claim · model-written summary
The combined calcium nitrate and potassium sulfate treatment gave the highest stone weight and stone diameter in date palms.
- Taxon
- date palmsPhoenix dactyliferae0
- Treatment
- combined application of calcium nitrate and potassium sulfatee1
- Outcome
- stone weight, and stone diametere1
- Direction
- higheste1
- Comparator
- controle2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sampling was performed from 3 date palms (3 bunches from each date palm were selected randomly) at the second date harvest”
e1“The highest wet fruit weight, fruit length, fruit diameter, stone weight, and stone diameter were attained in the treatment containing combined application of calcium nitrate and potassium sulfate”
e2“Furthermore, the lowest amounts of these traits were obtained in control”
Claim · model-written summary
The combined calcium nitrate and potassium sulfate treatment gave the lowest percentage of date bunch fading, with a significant reduction.
- Taxon
- date palmsPhoenix dactyliferae0
- Treatment
- combined treatment of calcium nitrate and potassium sulfatee3
- Outcome
- percentage of date bunch fadinge3
- Direction
- loweste3
- Comparator
- controle3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sampling was performed from 3 date palms (3 bunches from each date palm were selected randomly) at the second date harvest”
e3“The lowest and highest percentage of date bunch fading belonged to the combined treatment of calcium nitrate and potassium sulfate, and control, respectively”
e4“Finally, combined spray of calcium and potassium caused a significant reduction in date bunch fading percentage”
Claim · model-written summary
The control gave the highest percentage of date bunch fading in date palms.
- Taxon
- date palmsPhoenix dactyliferae0
- Treatment
- controle3
- Outcome
- percentage of date bunch fadinge3
- Direction
- higheste3
- Comparator
- combined treatment of calcium nitrate and potassium sulfatee3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sampling was performed from 3 date palms (3 bunches from each date palm were selected randomly) at the second date harvest”
e3“The lowest and highest percentage of date bunch fading belonged to the combined treatment of calcium nitrate and potassium sulfate, and control, respectively”
Claim · model-written summary
Calcium and potassium spray treatments had a significant effect on wet fruit weight, fruit length and fruit diameter of date palms at the 1% level.
- Taxon
- date palmsPhoenix dactyliferae0
- Treatment
- treatmentse5
- Outcome
- wet fruit weight, fruit length, fruit diametere5
- Qualifier
- 1℅ levele5
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sampling was performed from 3 date palms (3 bunches from each date palm were selected randomly) at the second date harvest”
e5“treatments had a significant effect on wet fruit weight, fruit length, fruit diameter, stone weight, stone diameter, and bunch fading percentage at 1℅ level”
Claim · model-written summary
Calcium and potassium spray treatments had a significant effect on stone weight, stone diameter and bunch fading percentage of date palms at the 1% level.
- Taxon
- date palmsPhoenix dactyliferae0
- Treatment
- treatmentse5
- Outcome
- stone weight, stone diameter, and bunch fading percentagee5
- Qualifier
- 1℅ levele5
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sampling was performed from 3 date palms (3 bunches from each date palm were selected randomly) at the second date harvest”
e5“treatments had a significant effect on wet fruit weight, fruit length, fruit diameter, stone weight, stone diameter, and bunch fading percentage at 1℅ level”
Claim · model-written summary
Spraying calcium and potassium separately improved fruit traits and bunch fading disorder of date palms.
- Taxon
- date palmsPhoenix dactyliferae0
- Treatment
- spray of calcium and potassium solelye6
- Outcome
- fruit traits and bunch fading disordere6
- Direction
- improvede6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sampling was performed from 3 date palms (3 bunches from each date palm were selected randomly) at the second date harvest”
e6“The results of the present study indicated that spray of calcium and potassium solely improved fruit traits and bunch fading disorder”
Claim · model-written summary
The foliar spray of calcium and potassium together gave the maximum fruit yield components of date palms.
- Taxon
- date palmsPhoenix dactyliferae0
- Treatment
- foliar spray of calcium and potassium togethere7
- Outcome
- fruit yield componentse7
- Direction
- maximume7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sampling was performed from 3 date palms (3 bunches from each date palm were selected randomly) at the second date harvest”
e7“maximum values of fruit yield components and minimum bunch fading percentage obtained from foliar spray of calcium and potassium together”
Claim · model-written summary
Available potassium in the studied soil was less than the plant requirement.
- Taxon
- date palmsPhoenix dactyliferae0
- Outcome
- available potassium content in soile1
- Qualifier
- less than plant requiremente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sampling was performed from 3 date palms (3 bunches from each date palm were selected randomly) at the second date harvest”
e1“Results of the analysis of the studied soil showed that available potassium content in soil was less than plant requirement”
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