الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 121 |  |  |
| | | from | 121 | | |
Abstract
The Egyptian Government is eager to increase the production of strategic crops e.g., potato, especially that grown on degraded soils to face the escalating population increase. It is known the importance of organic fertilization for potato tubers; however, there is no consensus among the researchers in the plant nutrition field on the best organic source that should be used, where the opinions differ in this regard. Also, it is known the vital role of potassium (K) in sizing agents for potato tubers but there is no consensus on the best potassium source that should be used. So, this research work is executed aiming to assess the effect of soil addition of different organic sources before planting i.e., ChM, plant residues compost and FYM as main plots and K fertilization under fertigation system via different K sources [potassium nitrate (46.0 % K2O), potassium silicate (K2SiO3, 60.0 %K), potassium citrate (K3C6H5O7, 45.0 % K2O), potassium sulphate (K2SO4, 48.0 % K2O)] as sub main plots on performance growth, tubers quality and productivity of potato ̎Cv Spuntaʺ plant grown on a sandy loam soil located in the North Nile Delta of Egypt during the growing season of 2022. The highest values of plant height (cm), fresh and dry weights (g plant-1) and chlorophyll content (SPAD, value) were observed in the potato plants treated with the ChM amendment. Following closely were the plants treated with plant residues compost, and finally, the values were comparatively lower in the potato plants treated with FYM. The potato plants fertilized with potassium silicate possessed the maximum values of plant height (cm), fresh and dry weights (g plant-1), chlorophyll content (SPAD, value), N, P and K (%) at period of 80 days from planting in comparison with that fertilized with other studied K sources. Also, it is worthy to observable the potassium nitrate form came in the second-order followed by potassium citrate, while the potassium sulphate form came in the last order.When the best treatments for each factor were combined, the potato plants exhibited the highest values for all the parameters mentioned above, representing optimal growth performance and favorable leaf chemical composition. On the other hand, when fewer treatments were combined for each factor, the potato plants showed the lowest values for these parameters.The potato plant treated with ChM had the maximum values of the average weight of one tuber, No. of tuber plant-1, total tubers yield (Mg h-1), T. carbohydrates (%), T. sugars (%), DM (%), TDS (%), protein (%) and V C (mg 100g-1) then plant treated with PRC and lately that treated with FYM. The potassium silicate form was superior treatment for all studied tuber physical characteristics (average weight of one tuber, No. of tuber plant-1 ) and total tubers yield (Mg h-1) as well as all studied quality parameters i.e., T. carbohydrates (%), T. sugars (%), DM (%), TDS (%), protein (%) and V. C (mg 100g-1). Potassium nitrate form came in the second order followed by potassium citrate then potassium sulphate form, respectively.The highest values of all studied yield and quality parameters were recorded when potato plants were treated with the combined treatment of ChM amendment x potassium silicate form. While the lowest ones were recorded when potato plants were treated with FYM amendment and simultaneously were fertilized with potassium sulphate form.The mean values of available nutrients (N, P, K, mg kg-1) of the studied sandy loam soil after harvest of potato plants pronouncedly increase compared to that before sowing. Also, post-harvest soil analyses elucidated that soil available N, P, K (mg kg-1) pronouncedly differed owing to studied organic and potassium sources. The soil amended by FYM had the highest values of available N, P, and K (mg kg-1) followed by that fertilized by plant compost, whilst the sandy loam soil amended by ChM possessed the lowest one. As well as the soil treated with potassium sulphate had the highest values of available N, P, and K (mg kg-1) followed by that treated with potassium citrate then that treated with potassium nitrate, whilst the sandy loam soil treated with potassium silicate possessed the lowest one. The highest net return of L.E 55800 fed-1 was obtained from the plants treated with ChM and simultaneously potassium silicate.Based on the obtained findings, it is evident that the combined treatment of ChM (organic source) and potassium silicate (K source) resulted in the highest performance growth, tuber quality, and productivity for the potato cultivar ”Cv Spunta” under sandy loam soil conditions in the North Nile Delta of Egypt. The use of organic sources before planting, such as ChM and plant residue compost, showed superior results compared to FYM (organic source). Among the K sources tested potassium silicate exhibited the most favorable effects on potato growth and yield, followed by potassium nitrate, potassium citrate, and potassium sulphate.