Effect of Foliar Spray with Active Yeast Extract on Morphological , Anatomical and Yield Characteristics of Kidney Bean ( Phaseolus vulgaris L . )

Field experiments were performed at the Agricultural Experiments and Researches Station, Faculty of Agriculture, Cairo University, Giza, Egypt during the two summer growing seasons of 2009 and 2010 to study the effect of foliar application with active yeast extract (AYE) at various concentrations of 25, 50, 100 and 150 ml/L on morphological, anatomical and yield characters as well as on seed quality of Kidney bean 'Giza 6'. Results revealed that foliar application with active yeast extract at the relatively low used concentration of 25 ml/L showed no significant effect on all studied morphological characters of vegetative growth, yield of green pods/plant, seed yield per plant and its related characters as well as on seed quality of Kidney bean 'Giza 6' in both studied seasons. On the other hand, foliar application with the relatively median used concentration of 50 ml AYE/L as well as with the relatively high used concentrations of 100 and 150 ml AYE/L induced significant promotive effects on all investigated morphological characters (plant height, number of branches/plant, number of leaves/plant, total leaf area/plant and shoot dry weight/plant), yield of green pods/plant, number of pods/plant, number of seeds/plant, seed yield/plant and the percentage of crude protein in seeds of Kidney bean 'Giza 6' in both studied seasons and the maximum promotion was detected at 100 ml AYE/L. It is clear that sprayed Kidney bean plants with active yeast extract at concentration of 100 ml /L showed maximum significant increase of 22.5 and 25.2% for yield of green pods/plant, 34.0 and 36.6% for yield of seeds/plant and 14.7 and 8.6% for seed protein more than the control in the first and second season; respectively. As to the effect of foliar application with the most effective concentration of active yeast extract (100 ml/L) on anatomical structure of vegetative growth of Kidney bean 'Giza 6', it could be stated that such treatment increased stem diameter due mainly to the increase in the thickness of epidermis, cortex, phloem tissue, xylem tissue and parenchymatous area of the pith more than those of the control although a slight reduction in diameter of hollow pith less than the control was observed. Likewise, such treatment increased thickness of both midvein and lamina of leaflet blades of Kidney bean 'Giza 6'. The increase in lamina thickness was accompanied with increments in thickness of palisade and spongy tissues. Also, the main vascular bundle of the midvein was increased in size as a result of spraying active yeast extract.