IMPROVING GROWTH, YIELD AND NUTRIENT UPTAKE OF FABA BEAN (Viciafaba L.) BY INOCULATION WITH MYCORRHIZAY AND FOLIAR APPLICTION OF COBALT UNDER SALINE IRRIGATION WATER ON A CALCAREOUS SOIL.

A field experiment was conducted during 2012/2013 and 2013/2014 winter growing seasons to evaluate the effect of mycorrhiza inoculation and foliar application of cobalt on growth,  yield and nutrient uptake  and quality of  faba bean ( variety Giza 643 ). The experiment was carried out under drip irrigation system on calcareous soil at the experimental farm El-Arish Agricultural Research Station, ARC, Egypt. The adopted treatments were arranged in a split plot design with four replicates, in which mycorrhiza treatments were allocated in the main plots, while five levels of cobalt e.g. 0, 5, 10, 15 and 20 ppm were foliar - sprayed  on faba bean seedlings in the form of cobalt sulfate( CoSO₄, 7H₂O) were arranged in the sub plots.
The results showed that mycorrhiza inoculation significantly affected chlorophyll contents, growth characters i.e. plant height and branches N^oplant^-1 and yield attributes e. g, pods N^o plant^-1and seed weight plant^-1 and seed yield as well as macronutrients (N, P and K)  and micronutrients (Co and Fe) contents in straw and seeds. The highest figures of the abovementioned traits were attained due to inoculation the faba bean seeds with mycorrhiza fungi in 1^st and 2^nd seasons.
Spraying the plant with cobalt at 10-ppm exhibited the highest figures of the abovementioned traits in 1^st and 2^nd seasons, comparable with the other tested concentrations.
Cobalt at 10 ppm as interacted with mycorrhiza inoculation enhanced chlorophyll, growth parameters, yield, status of N, P, K and Fe in shoots and seeds except iron, which was decreased particularly without mycorrhiza inoculation. Generally, the obtained results showed that increasing cobalt concentration above 10 ppm had an adverse effect on all parameters recorded.