This Investigation was carried out during the two Fall (Nili) seasons of
1998/1999 and 199912000 on potato OJ. Oiamontat Baramoon Experimental Fann,
Oakahlia Govemorate, Egypt, to study the influence of Microbein as biofertilizer and
four different rates of nitrogenous and phosphorous as I'IIinaIaI fertilizers, Le., 25 % N
+ 25 % PzOs, 50 % N + 50 % P~s, 75 % N +-75 '" Ms. and 100 % N + 100 % PzOs
of the recommended dose of N+P (180 kg •• +- 75 Ita P-~.) aa well as their
interactions on growth. tuber yield and contoenbr 01 NPK ift fOnage and tubers as well
as starch and Ni&rate content in tubers. R.esufts shoMld that treating potaID seed tubers with Mlcrobein before
planting. increased sIgnificantly pfants stand (%) In the first season, vegetative
growth. i.e., plant height, foliage fresh welghVplant (In the first season), number of
main stemslplant (in the second season), foliage dry weight ('Yo), and yield
panlmet8rs I.e., total tuber yield (tonlfed.). number of tubers/plant, tuber average
weighf (g). tuber dry matter (%), NP content in foliage, N (in the second season), Pin
the Mo aeasons), K (in the first season) in tubers and starch content in tubers as
compared to the untreated seed tubers. On the other hand, nitrate concentration
(ppm) was not significantly affected In both seasons. Increasing nitrogen and phosphorus rates up to 75 % N + 75 % PZ05 of the
recommended dose/fed., increased significantly in foliage dry weight (%), yield
parameters and starch content In tubers In the two seasons, while plant stand (%),
p'lant. heiQht, foliage fresh weight (In first season). number of main stems/plant (In the
~ ~,IMPKin foliage and tubers as well as nitrate concentration. increased
by incre.i-"~) r,atasu~to. the recommended full doses (100. ~ N + 1Qm%.~.
in two seaSQIIL Th& i~ between Mraobein and (N.... PlQa) rates shawad: alao
significant effedai CDI1; 101lag80 diy welPt.. yield pai'8lTletetS •. M content in foil •••. 1"< bcJIII1
seasons and K content!lrTJoIiag_e in the saand season. Generally, tr.e..'"t!i'cg: ,..,.potato tulbers will Microbein (biofertillzer) af rafe of
10.67 kg/ton before pJantilllii iil1 aUdition lD 75 II£. N + 75 % P20~ed.) of the
recommended doses gave· ~ •• mum, ~Id and quality of tubers. Moreover,
treating s~e~ ti.iwrs with Microt)101~ ~ ptantlng will IIV. about 25 % of the
requ;~d amo~nts of NP fertilizerlfed, pariic~:!~: In the 4~Y'Y loa~ soil and
consequent wi.l decrease the total cost of production per It# •.•• -!n .addltlon to ~e
environmental pollution with the high rates of chemical fertiliul'l wiii iilsc pt;
decreased.