الفهرس 
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Abstract
This study carried out during the two successive seasons of 2020 and 2021 on Manfalouty pomegranate trees grown at a private Orchard located at Banu Uday, Manfalout distinct, Assiut Governorate, Egypt, where the soil has a sandy loam texture.
Fifty four healthy trees, 8 years old, grown at 3.5x3.5 m apart under trip irrigation system with no visual nutrient deficiency symptoms were chosen and devoted for carrying out this experiment. The chosen trees received the same horticulture practices excepted for the tested different treatments throught the two studied seasons.
The treatments set up in randomized completely block design (RCBD) in split-plot arrangement with three replicates, two trees each. The whole and sub-plots were potassium fertilization and irrigation levels, respectively. The whole plots (A) included the effect of three potassium fertilizer different as follow:
A1- The recommended potassium fertilization via potassium sulphate only (check treatment).
A2- The recommended potassium fertilization via 60 potassium sulphate and 40% via vinasse.
A3- The recommended potassium fertilization via 40% potassium sulphate and 60% via vinasse.
Whereas, the sub-plots (B) involved the following three irrigation levels of the recommended water use (RWU) as follow:
B1- 100% of recommended water use (Control).
B2- 80% of recommended water use (RWU).
B3- 60% of recommended water use (RWU).
The following parameters were measured during the three studied seasons.
A- Vegetative growth
Four main branches almost nearly in growth and distribution in four sides of tree were selected and labeled in April for the following vegetative measurements:
1- Shoot length (cm).
2- Leaf area (cm2).
3- Leaf relative chlorophyll (SPAD).
B- Nutritional status, proline of leaves and relative water content:
Samples of fifty mature leaves were randomly selected from the spring shoots on mid-September to determine N, P and K.
C- Yield and its components:
Fruit were harvested and yield/tree (sound, splitting and sunburned fruits) was recorded. The defective fruits was separated to estimate the percentage of splitting and sun-burning fruits.
D- Fruit quality:
Samples of 10 fruits were randomly taken from each tree to estimate the fruit quality. The fruit weight, arils % and juice percentage as well as the chemical fruit quality such as total soluble solids, total acidity (expressed as g citric acid/100 ml juice), ascorbic acid (mg/100 ml juice) and reducing sugar percentage were determined. In addition, the total anthocyanin content of the peel (mg/100 gm) and juice (mg/100 ml) was calculated.
E- Water use efficiency (WUE)
Water use efficiency (WUE) was calculated as follow:
WUE = (kg)/IR (m3) which is the ratio of crop yield (Y) to the total amount of used irrigation water (IR).
The obtained results during the two studied seasons could be summarized under follow main items.
1- Effect of certain potassium fertilization and irrigation levels on vegetative growth and leaf nutrient contents:
1.1- Shoot and leaf parameters:
Concerning the effect of used different potassium sources, the results indicated that shoot length, leaf area, total leaves area/shoot and relative chlorophyll were significantly affected by various potassium fertilization sources used. Using CMS-vinasse as a source for potassium significantly increased shoot length, leaf area and relative chlorophyll as well as leaf-N, P and K content compared to using potassium sulphate (check treatment). Moreover, using 60% of potassium fertilization via CMS-vinasse gave the highest shoot and leaf traits as well as leaf-N, P and K content than using 40% via vinasse. There are no significant differences on these studied traits due to potassium fertilization via either 40 or 60% of potassium used as vinasse.
Also, the shoot and leaf traits and leaf-N, P and K percentage were significantly increased when irrigation level was 80 or 100% compared to 60% of the amount water use (WU). Raising the amount water used from 80 to 100% failed to show any significant increase in such growth traits, where using 60% significantly decreased growth traits compared to other irrigation level used.
In general, the highest value were recorded due to irrigate by 100% level (check treatment). All studied vegetative traits and leaf-N, P and K content significantly decreased when irrigation level was 60% of water use compared to use 100% of water use (WU).
The highest recorded leaf area/shoot, relative chlorophyll and leaf-N% were recorded due to use 60% of total potassium fertilization via vinasse along with irrigated by 80 or 100% water use (WU).
On other hand, the least values of leaf area/shoot and total chlorophyll were recorded on trees that irrigated by 60% of WU and amendmented via potassium sulphate only ones (check treatment) during the two studied seasons.
Moreover, no significant differences due to 40 or 60% of total potassium fertilization via CMS-vinasse combination with irrigation by 80 or 100 of out amount of water use (WU).
2- Effect of certain potassium fertilization and irrigation levels on yield components:
Concerning the effect of different potassium fertilization sources, the results indicated that yield/ tree and splitting fruit % as well as sunburn fruit and marketable fruit percentages were significantly affected by various potassium fertilization sources. Using CMS-vinasse as potassium sources significantly increased yield weight/tree and marketable fruit percentage compared to use potassium sulphate (checked treatment). On other hand, these fertilization treatments significantly decreased the fruit splitting and sunburn percentages compared to check treatment. Moreover, using the 60% of total potassium fertilization doses as CMS-vinasse gave the heaviest yield weight/tree and marketable yield % than using 40% as vinasse. On other hand, using 60% recoded the least percentage of cracking fruits and suburn compared. There are no significant differences on these studied traits due to use vinasse via either 60% or 40% total potassium fertilization doses.
Also, the yield components was significantly increased when irrigation level was 80 or 100% compared to 60% of the amount water use (WU). Raising the amount water use from 80 to 100% failed to show any significant increase in such yield, where using 60% significantly decreased yield components compared to other irrigation level used.
The yield components significantly responded to the interaction between the two studied factors. The highest values of yield/tree and marketable fruits were obtained in trees that amendmented with 60% CMS-vinasse and irrigated by either 80% or 100 of WU. On other hand, the lowest values of sunburn was recorded of trees that amendmented with 60% CMS-vinasse and irrigated by either 80 to 100% of water use (WU).
Moreover, no significant differences due to use 40 or 60% of total potassium fertilization as CMS-vinasse with irrigation by 80 or 100 of out amount of water use (WU).
3- Effect of certain potassium fertilization and irrigation levels on fruit quality:
Concerning the effect of different potassium source, the results indicated that physical and chemical fruit quality were significantly affected by various potassium fertilization sources. Using vinasse as potassium source significantly improved the physical and chemical fruit quality in terms of the fruit weight, fruit dimension and arils percentage as well as juice volume and peel anthocyanin as well as total soluble solids, V.C and juice anthocyanin compared to use potassium sulphate (check treatment). Moreover, fertilized with 60% CMS-vinasse and 40% potassium sulphate gave the highest fruit traits than 40% CMS-vinasse plus 60% potassium sulphate. There are no significant differences on these studied physical fruit traits due to replace 40 or 60% of potassium dose via CMS-vinasse as a source of potassium.
Moreover, fruit quality was significantly improved when irrigation level was 80 or 100% compared to 60% of the amount water use (WU).
Data declared that use 60% of amount water use (WU) significantly increased total soluble solids, reducing sugar and total anthocyanin in juice. On other hand, such irrigation level significantly decreased the total acidity and vitamin C contents compared to use 80 or 100 of WU.
All studied physical fruit except peel anthocyanin content significantly decreased when irrigation level was 60% of water requirement compared to use 100% of water use. Using 60% of water use significantly increased the peel anthocyanin content and total soluble solid compared to use 80% or 100% of water use.
The fruit quality significantly responded to the interaction between the two studied factors. The highest values were obtained in trees that amendmented with 60% CMS-vinasse plus 40% potassium sulphate and irrigated by either 80% or 100 of WU.
Moreover, no significant differences due to 40% CMS-vinasse as potassium source with irrigation by 80 or 100 of out amount of water use (WU).
4- Effect of certain potassium fertilization and irrigation levels on water use efficiency:
Concerning the effect of vinasse as a source of potassium, the results indicated that water use efficiency were significantly affected by various fertilization soil used. Using CMS-vinasse significantly increased water use efficiency compared to potassium sulphate (check treatment). Moreover, using the 60% CMS-vinasse gave the highest than use 40% CMS-vinasse. There are no significant differences on water use efficiency due to soil amendments via 40% or 60% CMS-vinasse as a sources of potassium.
Also, water use efficiency was significantly decreased when irrigation level was 80 or 100% compared to 60% of the amount water use (WU). Raising the amount water use from 80 to 100% significant decrease the water use efficiency, where using 60% significantly decreased highest the water use efficiency compared to other irrigation level used.
In addition, data indicated that the water use efficiency significantly responded to the interaction between the two studied factors. The highest values were obtained in trees that amendmented with 60% CMS-vinasse plus 40% potassium sulphate and irrigated by either 60 or 80% of WU.
As an overview, the results showed that the combination effects significantly increased the water use efficiency than increment of individual effected either used potassium fertilization or irrigation levels effects.
Conclusion
It could be concluded that use vinasse as a potassium fertilizers combined irrigation by 80% of amount of water use (5.90 m3/tree, 2006 m3/feddan/year) would achieve a beneficial improvement of water use efficiency. In addition, it reduce the need amount of given water and decrease the cost of production as well as was very useful in saving water consumption and reducing environmental pollution. Moreover, to be avoid rise water tables and root zone salinity.