Growth, Yield and Chemical Composition of Peas (Pisum sativum) as Affected by Potassium Levels and Different Methods of Yeast Application

Two field experiments were carried out at the Experimental farm, Faculty of Agriculture, Alexandria University during 2008 and 2009 winter seasons. The aim of the current study was to investigate the effects of potassium levels (0, 24, 48, 72 kg k2o /fed.), methods of yeast application (without, foliar and soil) on vegetative growth characters, green yield and its components and chemical constituents of green seeds of the new introduced pea cultivar “Balmoral”.  The results indicated that foliage fresh weight, foliage dry matter, no. of pods / plant, weight of pods / plant total yield (ton/ fed.),  N,  protein and K content in green seeds were significantly and positively affected by increasing potassium levels and the maximum promotion was detected at 48 kg k2 O / fed. and beyond this dose a significant reduction was detected in both growing seasons. It is clear that adding 48 kg k2O / fed. showed maximum significant increase of 32% and 16% for total yield and 18% and 19% for green seed protein more than the control in the first and second seasons, respectively.  Application of yeast extract either foliar or soil addition  showed progressive increase for plant height, vegetative  weight, number and weight of pods / plant, N%,  protein content and total yield (ton/fed.) compared to control (without adding yeast). The highest green yield obtained by soil application  of yeast extract  (1.61 and 2.08 ton / fed.) in both studied seasons. Addition of 48 kg k2o / fed combined with soil application of yeast extract gave the highest total yield / fed. 2.01 and 2.25 ton / fed.  with the highest protein content of green seeds, in both growing seasons.