الفهرس 
Introduction
Importance of nitrogen and potassium fertilizationOnly 14 pages are availabe for public view
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Abstract
This study carried out during three consecutive seasons of 2010, 2011 and 2012 on two cultivars of Vitis vinifera L., namely Thompson and Flame Seedless. All grapevines were 12-year-old spaced at 1.5x3 m, grown at the Experimental Vineyard, Plant Pathology Department, Faculty of Agriculture, Assiut University, Egypt, where the soil is clay and will drained.
The vines were trained in traditional double cordon with three wires. They were pruned during the end of December and left total bud load 60 and 36 buds per Thompson and Flame Seedless vines, respectively.
The experiment involved two factors (A and B). The first factor (A) included the effect of bio, organic and inorganic fertilization. Six treatments were included in this factor as follows:
1- Application of the recommended dose of nitrogen (RDN), 80 g/vine in mineral (N) source (control).
2- Application of RDN via bioforms 200 ml yeast/vine as soil dressing.
3- Application of RDN via organic-N filter mud cake (FMC) at 4 kg/vine.
4- Application of 70% of RDN via bioforms 140 ml yeast/vine as soil dressing.
5- Application of 70% of RDN via organic-N (FMC) at 2.8 kg/vine.
6- Application of 35% via organic (1.4 kg FMC)/plus 35% via bioforms, (70 ml yeast)/vine.
The second factor (B) involved three treatment from potassium fertilization.
1- Application of feldspare 700 g/vine, as soil dressing.
2- Spraying vinasse (2.02% K2O) 350 ml/L/vine.
3- Potassium sulphate (48-52% K2O), 200 g/vine, as soil dressing.
Seventy two healthy vines with no visual nutrient deficiency symptoms were chosen and devoted for achieving the experiment. The chosen vines were divided into 18 different treatments with four replicates one vine per each. The experiment was set up in a split-plot complete randomized block design with four replication per treatment, one vines each.
Filter mud cake (FMC) was added as an organic fertilizer in the first week of January. Ammonium nitrate (33.30% N) as a mineral N source was application at three times: growth start, immediately after berry set and at two month late in July. Yeast strain Saccharomyces erigans was isolated from composite sample of the clay soil of ”Assiut experiment farm” planted with grape and pomegranate and added once at growth start.
Potassium sulphate was divided into two equal batches after berry set and the second at one month later. In addition, vinasse spraying was used three times, first was used after berry set the second was applied three weeks later, followed by the third application two weeks later.
Feldspare was provided by Al-Ahram Co. for mining and natural fertilizers. Feldspare was added as a slow release K in the first week of January.
All the experimental vines received the regular horticultural practices that carried out in vineyard except those dealing with the present treatment.
The following parameters were determined to evaluate the effects of different fertilization treatments on growth and fruiting.
1- Some vegetative growth parameters.
2- Leaf nutritional status.
3- Yield.
4- Cluster and berry characteristics.
The obtained results could be summarized as follows:
1- Effect of different sources of nitrogen and potassium fertilizers in vegetative growth:
1.1. Effect on shoot growth:
Growth parameter i.e. the length of shoot and internode and shoot thickness were significantly affected by application of organic and bio-fertilization compared with using the recommended dose of nitrogen (RDN) via mineral form only. Application of the RDN via either organic or bio form significantly decreased the length of the shoot and internode compared to using mineral-N only (check treatment). No significant effect due fertilization via either bio, organic-form or either bio plus organic form. The maximum shoot length and internode length were detected on the vines that fertilized with mineral-N. Whereas, the minimum values were recorded on the vines that fertilized with combination of 35% of RDN bio and 35% organic-N.
In contrarily, all fertilization treatments significantly increased the shoot thickness compared to application of RDN via mineral source (check treatment). No significant differences were found due to fertilization via either bio or organic as well as combined application of fertilizers as 35% via bio plus 35% out of RN via organic form.
The maximum values of shoot thickness were recorded due to fertilize either by bio-form or combined application of bio plus organic form.
A significantly increase of Thompson Seedless and Flame Seedless shoot growth due to use either feldspar as slow release-K or vinasse spraying compared to vine shoots, that fertilized by potassium sulphate (check treatment).
All combinations of nitrogen fertilizer with either feldspar or vinasse significantly increased the shoot growth traits compared to all combinations of different nitrogen sources with potassium sulphate. The maximum values of shoot length and internode length were recorded on the vines that with 100% mineral-N companied sprayed by vinasse.
On the other hand, the maximum values of shoot thickness were recorded on the vines that fertilized with bio-N companied with vinasse or feldspar. Whereas, the minimum values were detected on vines that fertilized with RDN using 100% mineral of nitrogen and potassium sulphate.
Therefore, it could be concluded that the two cultivars were nearly similar in their response to such fertilization treatments, but Flame Seedless cultivar was better in its response than Thompson Seedless cultivar.
1.2. Effect on pruning wood weight and wood ripening percentage:
Pruning wood weight and wood ripening percentage significantly increased by using the recommended dose of nitrogen (RND) via either the bio or organic fertilizers, whatever, at 100% or 70% out of RDN compared to use the mineral-N fertilizer (check treatment). The maximum values of pruning wood weight and wood ripening percentage of Thompson Seedless and Flame Seedless cultivars were recorded on 100% organic and combined application of fertilizers as 35% via bio plus 35% out of RDN via organic form, respectively. No significant differences were found due to fertilization via either bio- or organic at 100% or 70%, as well as combined application of fertilizers as 35% via bio plus 35% out of RDN via organic form.
Pruning wood weight and wood maturity percentage were significantly affected by various sources of potassium fertilization. Using either feldspar as slow release-K or vinasse spraying significantly increased such growth traits compared to fertilize by potassium sulphate (check treatment). The highest of these growth traits were obtained due to vinasse spraying.
All combinations of either bio or organic-N, as well as feldspar or vinasse significantly pruning wood weight and wood ripening coefficient compared to use mineral form (check treatment). The maximum values of pruning wood weight and wood ripening coefficient were recorded on 100% organic or 35% bio plus 35% organic N companied sprayed by vinasse, respectively. Whereas, the minimum values were detected on vines that fertilized with RDN using 100% mineral and potassium sulphate (check treatment).
So, it can be concluded that using bio or organic-N singly or together accompanied with vinasse or feldspar as a source of potassium were more effective in improving the vine vigour compare to either using bio as well as organic-N or vinasse, as well as feldspar only.
1.3. Effect of leaf characters:
All nitrogen application significantly increased the number of leaves per shoot and leaf area compared with the check treatment. The highest leaves number and biggest leaf area were obtained due to fertilized with combined bio plus organic form and organic form, respectively. No significant differences of leaves number due to all studied fertilization treatments. Whereas, the leaf area significantly decreased due to fertilize via either bio or organic-N form at 70% out of RDN compared to organic-N form at 100% of RDN.
Using either feldspar or vinasse spraying significantly increased the leaves number and leaf area on Thompson Seedless and Flame Seedless vines compared to fertilize by potassium sulphate. The highest values of leaf traits were obtained due to vinasse spraying. No significant differences of leaves number, but there are a significant increase of leaf area due to vinasse spraying compared to feldspar.
Moreover, all nitrogen fertilizer combinations with either feldspar or vinase, as well as all potassium fertilizer combinations with bio or organic-N form were more effective in increasing the leaf traits than combination with either potassium sulphate or mineral N fertilizers, respectively.
These findings could be due to the important role of bio and organic-N, as well as slow release-K on increasing the coefficient fertilization using induce an improving the soil fertility and plant growth and vigour.
So, it can be concluded that using either organic or bio-fertilization alone or together, single or in accompanied feldspar or vinasse were more effective in improving the growth and vigour of Thompson Seedless and Flame Seedless grapevines.
1.4. Effect on leaf nutrient content:
Using RDN via either the bio or organic fertilizers, as well as 35% bio plus 35% organic form significantly increased the contents of N, P and K in leaves of the two studied cultivars compared to use the mineral fertilizer. Using either organic-form or combined 35% bio plus 35% organic form gave the highest values of N and K, respectively compared to other fertilizer application. Moreover, no significant differences due to fertilize with either N2, N3 or N6, as well as N4 or N5 for contents of N and K in leaves. Furthermore, using yeast as a bio fertilizer alone or combined with organic-N resulted in more announced and highly significant increment in leaf phosphorus content compared to other fertilization applications.
Using either feldspar as slow release-K or vinasse spraying significantly increased the contents of N, P and K in leaves of Thompson Seedless and Flame Seedless vines compared to fertilize by potassium sulphate (mineral-K). Vinasse spraying gave the highest leaf contents of N, P and K compared to other potassium fertilization treatments.
All combination either bio organic or bio-plus organic with feldspar or vinasse significantly increased percentage of N, P and K in leaves compared to check treatment. All combinations of organic-N or bio plus organic with vinasse spraying gave the highest values and were most effective in increasing the leaf contents of N, P and K.
2- Effect of different sources of nitrogen and potassium fertilizers on yield components:
Application of RDN either organic or bio form significantly increased the number of cluster and yield/vine compared to 100% RDN via mineral. No significant effect due fertilization via either bio. Organic form or either bio plus organic form on the cluster numbers. The highest number of cluster and heaviest yield/vine were detected on vines fertilized with the recommended dose of RDN using 100% of organic-N, whereas the least one recorded on vines fertilized with RDN via mineral.
Significantly increase of number of cluster and yield/vine of Thompson Seedless and Flame Seedless grapevines due to use either feldspar as slow release-K or vinasse spraying compared to the fertilized by potassium sulphate. No significant effect of cluster number/vine in two studied cultivars due fertilization via either feldspar or vines spraying, whereas, the yield/vine significantly increased due to feldspar application compared to vinasse spraying.
All combination of either bio or organic N as well as feldspar or vinasse significantly increased number of cluster and yield/vine (kg) companied to use mineral form (check treatment). The maximum values of number of cluster and yield/vine (kg) were recorded on 100% organic compared sprayed by vinasse or using feldspar, respectively. Whereas, the minimum values were detected on vines that fertilized with RDN using 100% mineral and potassium sulphate (check treatment).
Moreover, all combination either bio or organic singly or together plus feldspar or vinasse was more effective in increasing the yield components than combined of mineral-N plus mineral-K (potassium sulphate).
So, it can be concluded that using bio or organic-N singly or together accompanied with vinasse or feldspar as a source of potassium fertilization were more effective in improving the number of cluster and yield compare to using bio or organic-N as well as vinasse or feldspar only.
3- Effect of different sources of nitrogen and potassium fertilizers on cluster characteristics:
Fertilized with organic and bio-fertilization significantly increased the weight and length of cluster and number of berries per cluster compared with using mineral-N source only. Contrarly, such fertilization treatments significantly decreased the compactness coefficient of clusters. The heaviest and highest number of berries, longest and least compactness coefficient of cluster were recorded on vines that fertilized by N as organic and 35% organic plus 35% bio form, respectively. Application of N via mineral-N only gave the minimum values of weight, berries number and length of clusters and highest compactness coefficient.
Using feldspar as slow release-K or vinasse spraying significantly increased the weight and length of cluster compared to fertilize by potassium sulphate. Whereas, the number of berries per cluster was unsignificantly effected as response to feldspar or vinase. Therefore, the compactness coefficient of cluster was significantly decrease due to use vinasse.
All combination of either bio or organic-N as well as feldspar or vinasse significantly increased the weight, berries number and length of cluster and significantly decreased the compactness coefficient of cluster compared to use mineral (check treatment). The heaviest clusters were detected on the vines that received organic-N combined with feldspar, whereas, the highest berries number and longest cluster and least compactness coefficient recorded in the vines that fertilized by organic plus bio combined with vinasse. Whereas, the minimum of weight, berries number and length and highest compactness coefficient values were detected on vines that fertilized with RDN using 100% mineral and potassium sulphate.
Moreover, all combination either bio or organic singly or in combined plus feldspar or vinasse was ore effective in improving the cluster traits compared to all combinations of mineral-N plus mineral-K (potassium sulphate).
4- Effect of different sources of nitrogen and potassium fertilization on berry characteristics:
4.1. Physical properties of berries (berry weight):
Application of RDN either organic or bio form significantly increased the berry weight compared to 100% RDN via mineral. No significant differences due fertilization via either bio, organic or bio plus organic form. The heaviest berry was detected on vines fertilized with the recommended dose of RDN using 100% of organic, whereas the least one recorded on vines fertilized with RDN via mineral.
The berry weight was significantly increased due to use either feldspar as a slow release-K or vinasse spraying compared to the fertilized by potassium sulphate. No significant differences due fertilization via either feldspar as or vinasse spraying. The heaviest berry weight was recorded on vines that fertilized by feldspar, whereas the lightest one was recorded on vines fertilized by potassium sulphate (check treatment).
All combination of either bio or organic-N as well as feldspar or vinasse significantly increased the berry weight compared to use mineral form (check treatment). The heaviest berry was recorded on 100% organic companied using feldspar. Whereas, the lightest berry was detected on vines that fertilized with RDN using 100% mineral and potassium sulpahte (check treatment).
Moreover, all combinations either bio, organic singly or together plus feldspar or vinasse were more effective in increasing the berry weight than companied of mineral-N plus mineral-K (check treatment).
Such treatments are very important in grapes production since the increase in berry and size is the most important target than total yield due to the increase in berry weight and size induce an increase in packable yield.
4.2. Chemical constituents of berry juice:
Application of RDN either organic, bio or two form (bio plus organic) significantly increased soluble solid and reducing sugar contents and reduced the titratable acidity, hence increased total soluble solid/acid ratio compared to application of RDN via 100% mineral fertilizer. The highest values of these chemical quality parameters recorded in vines received N as 35% organic plus 35% bio form, whereas, application of N as 100% mineral gave the minimum values of these chemical parameters.
Using feldspar as slow release-K or vinasse spraying significantly increased reducing sugar contents, soluble solid and reduced the titratable acidity, hence increased total soluble solid/acid ratio compared to fertilize with potassium sulphate. No significant effected due fertilization via either feldspar or vinasse. The highest values of these chemical quality parameters recorded in vines that fertilized by feldspar, whereas the least one was recorded on vines that fertilized with mineral-K (check treatment).
All combination of either bio or organic N as well as feldspar or vinasse significantly increased reducing sugar contents and total soluble solids and reduced titratable acidity, hence increased total soluble solid/acid ratio compared to use mineral form (check treatment). The highest values of these chemical quality parameters recorded on vines that received 35% organic plus 35% bio combined with feldspar K1. Whereas the minimum values were detected on vines that fertilized with RDN using 100% mineral and potassium sulphate.
Moreover, all combination either bio or organic singly or together plus feldspar or vinasse was more effective in improving the berry quality compared to combined of mineral-N plus mineral-K.
Conclusion
On the light of previous results, it could be concluded that fertilizing by either organic, bio-form or two forms (bio plus organic) accompanied with feldspar or vinasse as a source of potassium fertilization enhancing growth and nutritional status as well as increased the yield and improved the fruit quality of Thompson Seedless and Flame Seedless grapevines. In addition, they improved the soil fertility and minimized the production cost and the environments pollution which could be occurred by excess of chemical fertilizers used. Moreover, they help to maintain and preserve soil and water resources for future generation.