Response of Cotton plants to Phosphatic and
Zinc Fertilization Accompanied with Arbuscular Mycorrhizae Inoculation as a
Biological Control of Cotton Seedling-Damping-off
[75]
Elwan1, I.M.; Hoda Z. Mohamed2 and
Samya E.H. Omran3
ABSTRACT
This work has been
carried out at the Cotton Disease Department, Plant Pathology Research
Institute, Agricultural Research Center at Giza, under out-door conditions, and
in a private field in Fayoum Governorate in season of 2000 using certified seeds
of Egyptian cotton (Gossypium barbadense L.) cultivar Giza 80, to study
the response of cotton plants to phosphatic and zinc fertilization accompained
with a-mycorhizae inoculation. Application of arbuscular mycorrhizae along with
phosphatic and zinc fertilization in pot experiment using natural field soil and
soil infested with R. solani, significantly reduced the disease incidence
of cotton seedlings. However, it significantly increased the survival of plants
and gave the heaviest dry weights of shoots and roots, compared to
non-mycorrhizal application, in either infested soil or natural field soil. The
highest percent of mycorrhizae-root colonization was found in the plants grown
in infested soil at low P-level. Mycorrhizal plants had a higher content of
total chlorophyll and total carbohydrates than non-mycorrhizal plants in either
infested or natural field soil. In infested soil, zinc treatment increased
K-concentration, regardless of mycorrhizal inoculation at two P-levels. The same
trend was observed with P concentration. Mycorrhizal inoculation decreased Fe,
Mn, Zn and Cu contents in shoot of cotton plantsgrown in natural field soils. On
the other hand, mycorrhizal inoculation increased thier concentrations in shoots
of cotton plants grown on infested soils, regardless of P and Zn levels. Under
field conditions, obtained data show that application of arbuscular mycorrhizal
fungi (AMF) with previous treatments led to a significant reduction in
damping-off and increased the survival of plants, along with significant
influence on seed index, seed cotton yield and lint cotton yield, no significant
differences were imposed, however, on boll weight and lint percentage.