RESPONSE OF SOME SUGAR BEET VARIETIES TO THE INTEGRATED SOIL AND FOLIAR APPLICATION OF POTASSIUM IN SALINE SOIL

Abstract

Two field experiments were carried out at Gelbana district, Sahl El-Tina(longitudes 32o 20' and 32o 33' E and latitudes 30o 57' and 31o 04' N), North SinaiGovernorate during the two seasons of 2011/2012 and 2012/2013 to study theeffect of the combined application of potassium fertilizer on some chemicalcompositions, growth, yield and quality of sugar beet under saline soil. Thiswork included eighteen treatments represent the combinations among threemulti-germ sugar beet varieties viz. Gloria, Toro and Desperez poly N and six Kcombinations, which were:1) The check treatment (without K application).2) 3 cm3 l-1 as potassium silicate as foliar application,3) 24 kg K2O fed-1 as potassium sulphate as soil application.4) 48 kg K2O fed-1 as potassium sulphate as soil application.5) 24 kg K2O fed-1 as potassium sulphate + 3 cm3 l-1 potassium silicate.6) 48 kg K2O fed-1 as potassium sulphate + 3 cm3 l-1 potassium silicate.A split plot design was used with three replications in both seasons, the mainplots were assigned to K-fertilization treatments, while sugar beet varieties were sownrandomly in the sub plots. The obtained results pointed out the following.The applied potassium treatments either soil or foliar application alleviatedthe adverse effect of soil salinity and significantly increased chlorophyll a, b andcarotenoides, root length, diameter and fresh weight/plant, sucrose%, sugarextracted%, quality index as well as root and recoverable sugar yields/fed andreduced Na root content, while increased K/Na ratio in root in comparison to thecontrol, in both seasons.The application of K-fertilizer at 24 and/or 48 kg K2O fed-1 as soil sidedressing of K-sulphate, along with the foliar application of K-silicate at 3 cm3 l-1 weremore effective and significantly increased root yield (ton fed-1) by (8.19 and 10.24%), and sugar yield by (8.83 and 13.85%) compared to the soil single application inthe 1st season and the 2nd one was the same trend. Supplying sugar beets by 48 kgK2O fed-1 as form of K-sulphate, given as soil application, combined with foliarapplication of 3 cm3 l-1, as K-silicate, significantly increased quality index andsucrose% and reduced impurity index in both seasons compared to the soil singleapplication.Gloria variety showed the superiority over the other tested ones and recordedthe highest values of chlorophyll a, b, proline, the thickest and heaviest roots/plant,root and recoverable sugar yields/fed., sucrose%, sugar extraction% in both seasonsand K/Na ratio in the 2nd one. Fertilizing Gloria sugar beet variety with 48 kg K2Ofed-1 as K-sulphate added to the soil integrated with 3 cm3 l-1 of K-silicate sprayed onbeet foliage can be recommended to get the highest root yield/fed and sucrose% andthe lowest content of sodium in juice in Sahl El-Tina, North Sinai.