الفهرس 
ContentsOnly 14 pages are availabe for public view
 |  | from | 185 |  |  |
| | | from | 185 | | |
Abstract
ABSTRACT: There is a paucity of information on the use of folic and humic acids as fertilizers for vegetable production. Therefore, the objective of this study was to assess the effects of two different substances; folic acid (0, 5, 10 & 20 mM) and humic acid (0, 2.5, 5 &10 mM) each applied by two modes (soaking or spraying) on growth and biological activities of spinach (Spnancia oleracea), lettuce (Lactuca sativa) and chorchorus (Chorchorus olitorius) during the vegetative stage. The obtained results cleared that: According to FA treatments, soil texture changed from clayey silty in the untreated plants into clayey loamy by soaking the seeds plants in folic acid; the WHC and porosity decreased. Although pH, and levels of Cl-, Na and Ca decreased by folic acid treatments, EC, OC, CaCO3, HCO3-, SO4, K and Mg increased. Fresh and dry weight of the test plants either decreased or increase but, water content, generally decreased by folic acid applications. At most, pigments, total carbohydrates, nitrogen, protein and phenol content increased while alkaloids decreased, in response to folic acid treatments. Treatment with folic acids decreased PPO but increased CAT and POX activity in S. oleracea; wheras in L. sativa, no change was detected in PPO activity but the activity of CAT and POX was decreased. In C. olitorius, treatment with folic, more or less have no change; or led to slight increase in the activity of PPO, CAT and POX compared to the control values. An increase in K, Ca & Mg and a decrease in Na content in the three used plants was observed in response to folic acid applications. According to HA treatments, soil texture changed from clay silty in the untreated plants into clay silty loam by soaking the seeds of the used plants in humic acid, the water holding capacity and porosity decreased. Although pH, Cl, Na and Ca decreased by humic treatments, EC, organic matter, CaCO3, HCO3, SO4, K and Mg increased, as compared to the untreated soil. Fresh and dry weight of the test plants either increase (in most cases) or decrees (in few cases) but, water percentage, generally decreased by humic applications. At most, pigments decreased in S. oleracea leaves but increased in L. sativa and C. olitorius leaves. Total carbohydrates, N, protein, phenol and alkaloids increased mostly, in response to humic treatments. Humic acids treatments decreased PPO and increased CAT and POX activity in S. oleracea but in L. sativa, humic acid increased PPO activity while the activity of CAT and POX decreased. In C. olitorius, treatment with humic, more or less have increase the activity of PPO, CAT and POX compared to the control value. An increase in K, Ca & Mg and decrease in Na content in the shoot of the three used plants was observed in response to humic applications. Foliar application of folic or humic acid (spraying) was most effective than seed pretreatment (soaking) moreover, the most response to the used treatments was in case of C. olitorius.