Maximizing Efficiency of Rock Phosphate as a Source of P-Fertilization for Faba Bean (Vicia faba L.) Plant

Abstract

A field experiment was conducted at the experimental farm of faculty of agricultural, Mansoura University, Dakahlia Governorate, Egypt during 2014 /2015 winter season to evaluate the efficiency of phosphate dissolving bacteria (PDB), sulphur (S), as well as foliar application of iron, zinc and Fe + Zn to enhance the availability of phosphorus from rock phosphate and their effects on vegetative growth parameters, chemical composition, yield and yield components of faba bean seeds cv. Giza 461. Twenty treatments were arranged according to complete randomized block design (CRBD) with three replicates; which were the sample possible combination between five treatments as soil addition (super phosphate (SP) , rock phosphate (RP), RP + phosphate dissolving bacteria (PDB) , RP + sulphur (S) and RP + PDB + S) and four spraying treatments; (1) spraying with tap water , (2) spraying with iron at the rate of Fe 300 mg/L, (3) spraying with zinc at the rate of Zn 100 mg/L, (4) spraying with solution containing 300 and 100 mg/L of Fe and Zn thus, the total number of the experimental plots were 60 plots. The results indicated that the highest values of vegetative growth (plant height , fresh and dry weight , chlorophyll a , chlorophyll b , chlorophyll a + b), yield and yield components (number of flowers. plant-1, number of pods. plant-1, fruit setting % , weight of pods. plant-1, 100-seeds weight and seed yield) of faba bean plant as well as nitrogen , phosphorus , potassium and protein contents in faba bean seeds were significantly increased for the plants treated with rock phosphate + PDB + S + (Fe + Zn) as compared to those obtained from the treatment of rock phosphate in single form except Fe content in faba bean seeds, the highest values were recorded when faba bean plants were treated with rock phosphate + PDB + S + Fe, but had no significant effect on K content. Faba bean seeds decreased significantly in their content of Zn as a result of the applied treatments. So, the lowest Zn content in faba bean seeds were recorded from (RP + PDB + S + Fe + Zn) compared with (RP + Zn) because of the dilution caused by growth response of P values which is known as P induced Zn deficiency. Generally, under the conditions of the present study, it can be concluded that adding RP mixed with PDB + S under sprayed of Fe 300 mg/L + Zn 100 mg/L may be the recommended treatment for enhancing the productivity of faba bean crop.