EFFECT OF FOLIAR SPRAY WITH IAA AND/OR KINETIN ON PHYSIO-CHEMICAL PROPERTIES AND YIELDS OF SUGAR BEET PLANTS

Two field experiments were conducted at Sakha Agricultural Research Station, Kafr-EL-Sheikh Govemorate during the two successive seasons 2002 - 2003 and 2003 - 2004 to investigate the effect of soil K-fertilizer at 100 and 50 % of the recommended rate (24 kg K20/fed), foliar application with growth regulators (IAA and/or Kinetin) at levels of 104 and 104 Molar and their combination on some physiochemical properties and yields of sugar beet plants. The results indicate the following: 1- Decreasing K-rate from 24 to 12 kg K20/fed led to obvious reduction in root diameter and length, fresh and dry weights of root and top, leaf area and yields of roots, tops and sugar. Decreasing the K-rate also decreased the chemical properties namely: individual sugars, invertase activity and mineral elementals composition. Meantime, root impurities (K and ()- amino N) and some technological parameters, i.e. sugar lost in molasses (WI), extractable sugar (Ex s) and alkalinity coefficient (AC) showed the same trend. On the contrary, decreasing the K-rate only increased juice purity and Na % in the juice. 2- Growth regulators (IAA or KO affected positively most of above traits except invertase activity and juice purity. This effect was increased with the increase in their concentrations. 3- K- fertilizer combined with MA or 1G gave the same trend as that of the tested growth regulators when used alone. 4- Foliar sprays with MA alone or combined with K-fertilizer was more effective than 1G treatments. Based on, the above results It could be recommended to use K-fertilizer at 12 kg K20/fed combined with MA at 104 to improve juice quality of sugar beet root and reduce environmental pollution.