الفهرس 
Materials and MethodsOnly 14 pages are availabe for public view
 |  | from | 193 |  |  |
| | | from | 193 | | |
Abstract
Two field experiments were conducted during the two successive winter seasons of 2007/2008 and 2008/2009 at the EL-Maniel village, Dakahlia Governorate to study the effect of effective microorganisms, biostimulants, and potassium levels as well as their combinations on the growth, yield and its nutritional values of potato tuber as well as some related physiological and anatomical characters. The most important results achieved are summarized as follows: • Addition of potassium fertilizer rates significantly increased potato growth characteristics (shoot length, shoot fresh and dry weights, branches number per plant, leaf number per plant, leaf area per plant), photosynthetic pigments concentration (chlorophyll A, chlorophyll b, total chlorophyll and total carotenoids), total carbohydrates concentration, ion percentage (nitrogen, phosphorous and potassium), potato yield (tuber yield per plant and tuber yield per feddan) and tuber quality (total soluble solid, total acidity, specific gravity, cruid protein, ascorbic acid, phenol, soluble sugars, starch, nitrogen, phosphorous and potassium) in both growing seasons. Potassium fertilizer gave the highest values for all mentioned characteristics except for potassium percentage in both shoot and tuber the highest value was obtained due to addition 80 kg K2O/fed in both growing seasons. Anatomically, the addition of potassium fertilizer rates from 20 (control) to 80 Kg K2O/fed increased all leaflet anatomical characteristics represented as leaflet thickness in the midrib region, thickness of leaf blade, palisade parenchyma thickness, spongy parenchyma thickness, epidermis thickness, main vascular bundle dimension, thickness of xylem tissue and thickness of phloem tissue. Moreover, addition of potassium fertilizer rates from 20 (control) to 80 Kg K2O/fed increased stem and pith diameter, collenchyma thickness, chlorenchymatous layers thickness, length and width of vascular bundle, as well as the thickness of phloem and xylem. • Inoculation with effective microorganisms significantly increased potato shoot growth characteristics, photosynthetic pigments concentration, total carbohydrates concentration, ion percentage, and potato yield and tuber quality. Anatomically, inoculation of potato plants with EM increased all leaflet anatomical characters as well as the diameter of stem, number of parenchymatous layer, length and width of vascular bundle, and the thickness of external phloem and xylem, meanwhile decreased the diameter of pith, and the thickness of epidermis, collenchyma layers, and, internal phloem tissue. • Foliar spraying with both biostimulants, in particular, seaweed extract, in most cases increased potato shoot growth characteristics, photosynthetic pigments concentration, total carbohydrates concentration, ion percentage, potato yield and tuber quality in both growing seasons. Anatomically, foliar application of both biostimulants, in particular, seaweed extract increased all leaflet anatomical characters, as well as in most cases, all studied anatomical characteristics of potato stem, where its application increased the diameter of stem, pith and thickness of collenchyma layers, and xylem tissue as well as the length and width of large vascular bundle beside the thickness of external phloem. On the other hand, the thickness of internal phloem tissue was decreased. • Application of either seaweed extract or humic acid with or without an addition of effective microorganisms under all potassium levels in most cases did not-significantly increased potato shoot growth characteristics, photosynthetic pigments concentration, total carbohydrates concentration, ion percentage, and potato yield and tuber quality in both seasons compared with untreated one. In most cases, the highest value was obtained under the treatment of addition 40 kg K2O/fed with addition of effective microorganisms and spraying plants with 500 mg/l seaweed extract. Anatomically, in most cases, all interactions increased all anatomical characteristics of potato stem. The highest values for thickness of epidermis, collenchyma and external phloem as well as stem diameter were obtained due to inoculated potato plants with effective microorganisma and foliar spraying with seaweed extract under moderate potassium fertilizer rate (40 kg K2O/fed). Meanwhile, foliar spraying with seaweed extract without effective microorganisms inoculation under 40 kg K2O/fed gave the highest diameter of pith. The data also indicated that the highest values of large vascular bundle width and thickness of xylem tissue were obtained due to foliar application of humic acid in the absence of effective microorganisms inoculation under 80 kg K2O/fed. On the other hand, foliar application of either humic acid or seaweed extract under 40 kg K2O/fed without inoculation with effective microorganisms gave the highest values of length of large vascular bundle and thickness of internal phloem tissue. Regarding the thickness of parenchyma tissue, the data in the same table and figure proved that the highest thickness of chlorenchymatous tissue could be attained after foliar application of humic acid less than 40 kg K/fed with effective microorganism’s inoculation. Moreover, all interactions, in most cases, increased all anatomical characteristics of potato leaflet. Economically, addition of potassium fertilizers rates, inoculated potato plants with effective microorganisms and foliar application of biostimulants as well as their interactions increased the economical consideration relative to that control represented as total cost, total income, net income and investment rate. • It could be pointed out that potato plants can give good growth and high quality yield and high net income by addition of 40 kg K2O/fed at two equal doses to be added before the first irrigation and before the second irrigation, and inoculated with effective microorganisms before the first irrigation and spraying 500 mg/l seaweed extract at 60 and 75 days from planting.