Two field experiments were carried out at EI- Bramoon Agricultural Farm of EI-
Mansoura Horticultural Research Station, during the summer seasons of 2002 and
2003. The study aimed at investigating the effects of some micronutrients; a mixture
of ln, Fe and Mn, each at 100 ppm; bio-phosphate fertilizers, VAM fungus and
Phosphorein, and mineral phosphate fertilizer at 0, 30~4 and 60 kg P20slfed., on
sweet potato growth, yield and its components, as wei s tuber root Characteristics.
Results showed that foliar application of micronutrt nts significantly improved
vegetative growth parameters, except number of branches/plant, yield/plant,
marketable and total yield/fed., as well as decreasing non-marketable yield/fed.
Micronutrients also increased average weight and diameter of tuber roots, but did
not affect tuber root shape (length/diameter).
Increasing the supplied phosphate fertilizer level to 45 or 60 kg P205/fey!
significantly improved vegetative growth parameters, yield/plant and marketable
yield/fed., significantly decreased non-marketable yield, and increased average
weight, diameter and length of tuber roots, but did not affect tuber root shape.
The addition of bio-phosphorus fertilizers (Phosphorein or mycorrihza)
resulted in significant increases in vegetative growth, total marketable yield and its "-
components. Bio-phosphorus fertilizers also increased tuber root weight, diameter
and length, but did not affect their shape.
Positive interactions among micronutrients, mineral P-rates and bio-
phosphorus fertilizers on studied characters were detected.