Response of tuber yield and chemical composition of potato CV. Nicola 10
some growth substances GAJ ( 200 ppm), methionine (100 ppm) and Pix ( 300 ppm)
under complementary fertilizer between farmyard manure (FYM) and inorganic was
st.udied during the two growing seasons 2001 and 2002 in El-Salhia, Sharkia
Governorate . The results indicated that spraying of Pix increased whereas GAJ
decreased tuber yield I plant and feddan. The highesl values of specific gravity and
dry matter COlo) resulted from GAJ and Pix respectively . Spraying GA3 gave the highest N. P and K contents in the tuber, Application of the three growth substances
increased Fe content especially Pix treatment. Potato plants fertilized with 50% FYM + 50% NPK produced the highest
number of tubers I plant , luber yield J plant, tuber yield J fed and tuber diameter as
well as starch % while. the heaviest tuber weight resulted from 100% NPK. The
highest value of N% resulted from application of 25% FYM + 75% NPK , P and Fe
contents were increased by increasing FYM level. Opposite trend was observed with
K content. Conceming the interaction between growth substances and fertilizer. the
results indicated that farmyard manure treatments were more effective on tuber yield I
fed than the growth substances. The interaction between 50% FYM + 50% NPK arid
Pix increased slgnificanUy tuber yield I plant, tuber yield I fed and tuber diameter as
well as Fe content compared to control (100% NPK with spraying water ). The
highest values of tuber weight and dry matter % were obtained with control. GAJ
combined with 50"04, FYM + 500k NPK gave the highest specific gravity but, it gave the
lowest dry matter % and T5S% . The combination of the growth substances with 50% FYM + 50%. NPK increased starch % as compared with 100% NPK. 25% FYM + 75%
NPK with spraying water recorded the highest free amino acids and proteins contents
. GAl combined with fertilizer treatments had an effect on increasing Nand P % ,