الفهرس 
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Abstract
This investigation was conducted during two successive seasons of 2008 and 2009 on two cultivars of Vitis vinifera L. i.e. Thompson seedless and Ruby seedless grown at the experimental vineyard plant Pathology Department, Faculty of Agriculture, Assiut University, Egypt, where the soil is clay and well drained. The vines trained in traditional double cordon with three wires and pruned during the second week of January. The chosen vines were of normal growth, uniform in vigor and were divided into two groups to carry out two experiments.
First experiment:
This experiment involved the following three factors:
- The first factor (A) was the application of micronutrients either via foliage (A1) or soil dressing (A2) compared to untreated one (A3).
- The second factor (B) involved two treatments from potassium fertilization
- B1. Application of the recommended rate of K (100 g K2O/vine/year) via mineral source (200 g potassium sulphate 50% K2O).
B2- Using potassiumag K-biofertilizer (75 g/vine)
The third factor included the following five treatments from mineral, slow release, bio-forms and organic of N
C1- Application of the recommended rate (R.R.) of N (80 g N/vine) in fast mineral release source (240 g ammonium nitrate 33.5% N/vine).
C2- Application of 80% of (R.R.) via slow release-N fertilizer (160 g Enciaben 40% N/vine).
C3- Application of 60% of (R.R.) via slow release-N fertilizer (120 g Enciaben 40% N/vine).
C4- Application of 30% of (R.R.) via organic manure (8 kg FYM) plus 30% bio-forms (60 g Rizhobactrin)/vine.
C5- Application of 10% of (R.R.) via fast mineral (24 kg ammonium nitrate) plus 25% of (R.R) via organic (6.7 kg FYM) and 25% bio-forms (50 g Rizhobactrin)/vine.
Thirty treatments were involved in this experiment, each treatment was replicated four times, one vine per each. The experiment was set up in a split split plot arrangement of completely randomized block design with four replicates, one vine per each. Micronutrients application represented the main plots while, the potassium and nitrogen fertilizer treatments occupied the sub-plots and sub sub-plots, respectively. Therefore, 120 healthy vines with no visual nutrient deficiency symptoms were chosen and devoted to achieve this experiment.
Farmyard manure (FYM) was added in the first week of January. Ammonium nitrate (33.5%) as a mineral N source was applied at three times: growth start, after berry set and at 45 days later.
Fertilizers were mixed with 30 cm surface layer of the soil under the vines foliage and about 0.75 m around the vine trunk. The biofertilizer and slow release were mixed with surface layer of the soil at first bloom. Potassium sulphate application was applied in two equal patches after berry set and after one month later, whereas, potassiumag as bio-K was added once at growth start. Cotangin as micronutrient was added as soil dressing at growth start, while, citrin as micronutrient spraying was applied at two times after berry set and one month later. Calcium superphosphate (15.5% P2O5) was added twice the first with organic manure and second after berry set.
The following parameters were determined to evaluate the effects of different fertilization treatments on growth, nutrient status, yield and berry quality.
1 – Some vegetative growth parameters.
2 – Leaf nutritional status.
3 – Yield and yield components.
4 - Cluster and berry characteristics.
The obtained results could be summarized as follows:
1- Effect of certain fertilization treatments on vegetative growth
1.1- Effects on main shoot growth:
Main shoot growth aspects such shoot length and thickness and laterals numbers were significantly increased by micronutrients application compared to unapplication ones.
Shoot growth parameters i.e. shoot length and thickness and laterals number per shoot insignificantly affected by various sources of potassium fertilization.
All combinations of micronutrients either spraying or soil application significantly increased the shoot length, thickness and laterals number per shoot. Since the potassium fertilization had no effect on shoot growth parameters, therefore the significantly increased in shoot growth episode due to the influence of micronutrient applications.
Growth parameters i.e. shoot length and thickness and laterals number per shoot were significantly affected by application of slow release, organic and biofertilization compared with using the recommended dose of nitrogen (RDN) via fast release-N source alone. Application of the RD via either bio plus organic (C4) or three forms (C5) significantly decreased the shoot length compared to using fast release-N source only (C1). Moreover, no significant effect due to fertilization via either 80% slow release (C2) or 63% slow release (C3). Raising slow release-N from 60% (C3) to 80% (C2) failed to show any measurable increase in shoot length.
All combinations of micronutrient application (A1 & A2), potassiomag (B2) and nitrogen fertilization sources (C) were significantly increased the length and thickness shoots and laterals number per shoot. All combination with either fast release-N (C1) or 80% slow release-N (C2) gave the highest shoot length compared to other combination.
All combination with three fertilization form (C5) gave the thickest shoot and highest laterals number per shoot compared to other combinations.
1.2- Effect of pruning wood weight and wood ripening percentage:
The pruning wood weight and wood ripening percentage were significantly affected by various sources of micronutrients. Using cetrien as vine foliage spraying or cotangin as soil dressing were significantly increased the pruning wood weight and wood ripening percentage compared to untreated ones (control).
Using potassiomag as bio-K led to a significant increase in wood ripening percentage compared to fertilize by potassium sulphate (control).
Pruning wood weight and wood ripening percentage were significantly increased to response of slow release-N, organic and biofertilization compared to fertilize with RDN via fast release-N source alone (C1). Increasing slow release-N from 60 (C3) to 80% (C2) of RDN caused an insignificantly increased on these traits. The maximum value of such traits were found in vines fertilized with three fertilization form (C5) followed by 30% organic form plus 30% bioform (C4) and slow release-N either 60% (C3) or 80% (C2) during the two studied seasons.
Combined of cotangin, as micronutrients soil dressing with potassiomag as bio-K fertilizer (A2B2) gave the highest pruning wood weight.
All combination with either C4 or C5 were most effective increasing the pruning wood weight and wood ripening coefficient compared to other combinations.
So, it could be concluded from the obtained results that fertilizing by either slow release or three forms (fast, organic and bio) accompanied with bio-K and micronutrient were effective in improving the vine vigour.
1.3. Leaf characters:
Using micronutrient either vine foliage (A1) or soil dressing (A2) significantly increased the number of leaves per shoot and leaf area compared with control (A1). The highest leaves number and biggest leaf area were obtained due to micronutrient soil dressing (A2).
Using potassiomag as bio-K improved the leaves number and significantly increased the leaf area compared to fertilizing by potassium sulphate (B1).
Fertilized with slow release (C2 or C3), organic plus biofertilizers (C4) or three forms (inorganic, organic plus, bioform, C5) signficiantly increased the number of leaves per shoot and leaf area compared with using fast release-N source only (C1). No significant differences were found between using 80% or 60% slow release. The highest number and area of leaves were recorded on vines that fertilized by three forms of fertilization (C5).
Leaves number leaf area significantly increased to the interaction between micronutrients application (A) and potassium fertilization sources (B).
All combinations especially with C3 and C5 were very effective in increasing the leaves number and leaf area. The highest leaves number and leaf area were detected on vine treated by A2B2C5 during two studied seasons.
2- Effect of certain fertilization treatments on leaf nutrient content:
Micronutrient either as vine foliage spraying or soil dressing was associated with significant increase in the percentage of N in leaves compared to untreated one (A3). Furthermore, using catongin as micronutrients soil application (A2) resulted in a more announced in leaf nitrogen content compared to the increase obtained from cetrien as micronutrient spraying (A1). whereas, such treatment unsignificantly improved the percentage of P and K compared to control (A3).
Using potassiomag as bio-K significantly increased the percentage of N, P and K in the leaves compared to potassium sulphate fertilization (check treatments).
Using the RD via either slow release (C2, C3), organic plus bio-form (C4) or three fertilizer forms (C5) significantly increased the contents of N, P and K in leaves compared to using fast release-N source only (C1). Moreover, no significant differences due to fertilize with either C2 or C3, as well as C4 or C5. Using three fertilizer forms (C5) gave the highest values of these nutrients compared to other fertilizer application.
All combinations of micronutrients application (A1 & A2), potassiomag (B2) and nitrogen fertilization sources (C) were significantly increased the percentages of N, P and K in leaves. All combination with either 80% slow release-N (C2), organic plus bio-forms (C4) or three fertilizer forms (C5) gave the highest values of N, P & K leaf contents compared to other combination.
3- Effect of certain fertilization treatments on wood total carbohydrate and nitrogen percentage and C/N ratio:
Micronutrient either as vine foliage spraying or soil dressing was associated with significant increase in the percentage of carbohydrates and nitrogen in wood, hence the C/N ratio was significantly increased compared to untreated one.
Using potassiomag as bio-K significantly increased the percentage of carbohydrates nitrogen and C/N ratio on woods compared to potassium sulphate fertilization (check treatments).
Fertilizing the Thompson seedless grapevines with slow release-N and fast mineral plus organic and bio forms highly significant increased the total carbohydrates of wood compared to use the fast release-N only. whereas, such fertilization treatments slight significantly increased the nitrogen percentage of wood. Hence, the C/N ratio was significantly increased comparing to fast release N only (check treatment).
Using three fertilizer forms gave the highest values of these nutrients compared to other fertilizer application.
Contents of wood significantly responded to interaction between micronutrients and potassium application. Most combination of micronutrients either spraying or soil dressing significantly increased the percentages of carbohydrates, nitrogen and C/N ratio in wood.
All combinations of micronutrients application, potassiomag and nitrogen fertilization sources were significantly increased the percentages of carbohydrates, N and C/N ratio in wood. All combination with either 80% slow release-N, organic plus bio-forms or three fertilizer forms gave the highest values of wood carbohydrates, nitrogen and C/N ratio compared to other combination.
All combinations with three fertilization form (C5) gave the highest N% and C/N ratio in wood compared to other combinations.
4- Effect of certain fertilization treatments on yield:
Micronutrients either spraying (A1) or soil application (A2) were significantly increased the clusters number per vine in second studied seasons, as well as yield/vine in both studied seasons compared to untreated ones (A3).
Cotangin as micronutrients soil application was more effective in increasing the yield/vine compared to citrin as micronutrients spraying.
Using potassiomag significantly increased the clusters number per vine in the second studied season, as well as the yield per vine in both studied seasons compared to fertilize with potassium sulphate (B1).
The using fertilization with either slow release-N, two or three fertilization forms significantly increased the clusters number and yield/vine compared to application of N as 100% fast mineral fertilizers.
The maximum yield was recorded in vines received N as three fertilization (C5). Application of N as 100% fast mineral gave the minimum values of clusters number and yield/vine.
This is a good evidence for the importance of using slow release and organic and bio-fertilization forms plus mineral-N source to increase the efficiency of fertilization and to control the release of nutrients to vines than to produce the high yield.
Yield components significantly increased to interaction between micronutrients application (A) and potassium fertilization sources (B). In this respect combined micronutrients soil application with bio-K fertilizer (A2B2) gave the highest clusters number and heaviest yield.
All combinations, especially with organic plus bio-form (C4) and three fertilization forms (C5) were very effective in increasing the clusters number and yield/vine. The highest clusters number and yield/vine were detected on vines treated by A2B2C5 during two studied seasons.
So, it can be concluded that either slow release, organic plus bio or three forms of fertilizers singly or in accompanied micronutrient plus bio-K fertilizer was more effective increasing the yield of the Thompson seedless grapevines.
5- Effect of certain fertilization treatments on cluster characters:
Using micronutrient either vine foliage or soil dressing significantly increased the weight and length of cluster compared with control. The heaviest cluster and longest one were obtained due to micronutrient soil dressing.
whereas, the number of berries per cluster unsignificantly affected as response to using the micronutrient application. Hence, the compactness coefficient of cluster was significantly decreased compared to unapplication ones.
Using potassiumag as bio-K significantly increased the weight and length of cluster compared to fertilizing by potassium sulphate. whereas, the number of berries per cluster was unsignificantly effected as response to potassiumag application. Therefore, the compactness coefficient of cluster was significantly decreased due to using potassiumag as bio-K.
Fertilization with slow release, organic plus biofertilizers or three forms (inorganic, organic plus, bioform, significantly increased the weight and length of cluster and number of berries per cluster compared with using fast release-N source only. Fertilized with slow release unsignificantly effected on cluster length, hence significantly increased the compactness coefficient of cluster compared to use the fast release-N source only. whereas, organic plus bio-fertilizer or three forms significantly decreased the compactness coefficient of cluster compared to using either slow release or fast release-N. The heaviest, longest and highest number of berries per cluster were recorded on vines that fertilized by three forms of fertilization.
All combinations especially with three forms of fertilizers were more effective in improving the cluster traits than combination with fast release fertilizers. The heaviest, longest and berries of clusters highest were detected on vine treated by A2B2C5 during two studied seasons.
All combination with three fertilization forms was more effective in decreasing the compactness coefficient of clusters than combination with fast release only.
So, it can be concluded that either slow release, organic plus bio or three forms of fertilizes singly or in accompanied micronutrient plus bio-K fertilizer was more effective in improving the cluster traits of the Thompson seedless grapes.
6- Effect of certain fertilization treatments on berry quality:
6.1- Physical properties of berries:
Micronutrients either spraying or soil application were significantly increased the berry weight compared to untreated ones.
Using potassiomag significantly increased the berry weight compared to fertilize with potassium sulphate.
The using fertilization with either slow release-N, two or three fertilization forms significantly increased the berry weight compared to application of N as 100% fast mineral fertilizers. The maximum berry weight recorded in vines received N as three fertilization. Application of N as 100% fast mineral gave the minimum values of berry weight.
Combined micronutrients soil application with bio-K fertilizer gave the heaviest 25 berries weight (37.94 & 37.87 g) compared to other combination during the two studied seasons. On the other hand, the least 25 berries weight was (31.39 & 31.69 g) recorded on vines the untreated micronutrient combined with potassium sulphate (check treatment).
So, it can be concluded that micronutrients accompanied with bio-K application was more effective in improving the berry weight compared to either micronutrient or bio-K application only.
All combinations, especially with organic plus bio-form and three fertilization forms were very effective in increasing the berry weight. The heaviest berry was detected on vines treated by A2B2C5 during two studied seasons. whereas, the least berry weight were recorded on vines that check treatment.
So, it can be concluded that either slow release, organic plus bio or three forms of fertilizers singly or in accompanied micronutrient plus bio-K fertilizer was more effective increasing the berry weight of Thompson seedless grapes.
6.2- Chemical constituents of juice:
Micronutrients either spraying or soil application were significantly improved the berry quality compared to untreated ones. Cotangin as micronutrients soil application was more effective than to ascorbien as micronutrients spraying. Using potassiomag as bio-K significantly improved the berry quality compared to using potassium doses via fast release source (potassium sulphae). In addition, fertilization with either slow release-N, two form (organic & bio) or three forms (organic and bio plus fast release-N) had improved the berry quality.
Micronutrients accompanied with bio-K application was more effective in improving the berry chemical properties compared to either micronutrient or bio-K application only.
All combinations, especially with organic plus bio-form (C4) and three fertilization forms (C5) were very effective in improving these chemical traits. The highest these chemical properties were detected on vines that treated by A2B2C4 and A2B2C5 in the first and second studied seasons, respectively. whereas, the least berry chemical properties was recorded on vines that check treatment (A3B1C1).
So, it can be concluded that either slow release, organic plus bio or three forms of fertilizers singly or in accompanied micronutrient plus bio-K fertilizer was more effective improving the chemical constituents of Thompson seedless grapes.
Second experiment
This experiment aimed to study the effect of berry thinning and pinching on yield and cluster and berry traits of Thompson and Ruby seedless grapevines. Twenty-four vines from each cultivar were chosen according to their similarity in growth vigour and uniform as possible and devoted for achieving this experiment. The chosen vines for two cultivars were divided into five different thinning pinching, defoliation treatments including the control. The experiment was arranged in complete randomized block design with four replications per treatment one vine each. Thus the treatments were as follow:
1- Thinning by cutting back about 25% from the apical clusters portion.
2- Thinning by alternatively removing about 25% from cluster branches (latrals).
3- Removing about 25% of shoot length (pinching 25% of shoot top).
4- Four basal leaves removal of fruiting shoot at veraison phase.
5- Pinching 25% of shoot top plus removing.
6- Control (untreated vines).
Thinning treatments were performed after berry set using special shears. whereas, pinching and leaves removal were performed at two weeks of berry set and at verasion phase, respectively.
At harvest date, when soluble solids contents (SSC%) attained (16-18%) and color development in 80% Ruby seedless berries. Three clusters were taken at random from the yield of each vine to determine the following characters.
Average weight of cluster (g), cluster length (cm), and berries number of cluster, as well as, cluster compactness coefficient.
In addition, berry quality in terms of berry weight SSC, total acidity and reducing sugars %.
The obtained results could be summarized as follow:
Berry thinning by removing either 25% of cluster apical (T1) or 25% of shoulders (T2) significantly decreased the berries number per cluster and consequently unsignificantly decreased the cluster weight and yield/vine.
Contrarly, either shoot toping (T3) or defoliation (T4) each alone or together (T5) gave no clear affect on number of berries per cluster, while significantly increased the cluster weight and yield/vine except (T4) compared to untreated ones.
Furthermore, all treatments except berry thinning by removing 25% of cluster apical (T1) failed to show any significant effect on cluster length compared to untreated one (control), whereas (T1) significantly decreased the cluster length comparable to other treatments during two studied seasons.
berry thinning as any method and shoot tip either alone or combined plus leaves removal significantly improved the Ruby and Thompson seedless grapes quality in terms of berry weight, soluble solid contents, reducing sugars and SCC/acidity ratio and decreasing titratable acidity %.
Conclusion:
On the light of the previous results, it could be concluded for carrying out nitrogen fertilization on one of these forms
- Using slow release-N (Enciabene) at 60-80% of RDN.
- Using 30% organic plus 30% bioform, or
- Using three fertilization forms (10% mineral plus 25% organic + 25% bioform).
- Using potassiomag as bio-K fertilization.
- Using cotangin as micronutrients soil application.
So, it can be concluded that either slow release, organic plsu bio or three forms of fertilizers singly or in accompanied micronutrient cotangin) plus bio-K fertilizer were more effective in improving the vine nutritional status, yield and berry quality. In addition, minimized the production costs and environments pollution which could be occurred by excess chemical fertilizers.
Berries thinning must be done by alternatively removing about 25% from cluster branches (laterals). In addition, pinching the shoot tips after berry set along four basal leaves removal at veraison phase to improve the clusters and berries attributes of Ruby and Thompson seedless grapes.
These advantages will eventually enable growers to obtain high yield with good cluster and berry attributes of Thompson seedless and Ruby seedless. Furthermore, using slow release, organic and bioforms enhanced and preserved the soil fertility, as well as reduced the added fertilizer requirement amount, thus the growers enable to produce organic grapes.