BENEFIT, COST, AND PHOSPHORUS USE EFFICIENCY OF MYCORRHIZAL FIELD-GROWN GARLIC AT DIFFERENT SOIL PHOSPHORUS LEVELS

ABSTRACT

A field experiment was conducted to determine the effects of arbuscular mycorrhizal fungi (AMF) and soil phosphorus (P) on bulb yield, benefit and cost analysis, and P use efficiency in garlic (Allium sativum L.). Treatments included application of the AMF Glomus mosseae inoculum to the planting furrows after treatment with different levels of P (0, 20, 40, and 60 kg P ha⁻¹). Garlic cloves were planted in furrows within a day after treatments were imposed. AMF-inoculated plants had higher fresh bulb yields than plants in uninoculated plots regardless of P level. The enhancement in fresh bulb yield due to AMF-inoculation was highest in plots fertilized with 20 kg ha⁻¹. The AMF-inoculated plants had less P use efficiency than uninoculated plants. Bulb yield differences between AMF-inoculated and uninoculated plants were considered the benefit derived by plants from AMF-root associations. Bulb yield differences between AMF-inoculated and uninoculated plants with similar P concentrations were considered the costs paid by plants for AMF-root associations. Values of benefit and cost analysis for AMF-root associations were highest when soil P was lowest and decreased with increasing P application. Benefit and cost analysis may be helpful in evaluating host plants to optimize efficiencies of AMF symbiosis under field conditions.

ACKNOWLEDGMENTS

The financial support by the Deanship of Scientific Research, Jordan University of Science and Technology, is greatly appreciated. The help from Mr. Ahmad Al-Karaki is greatly acknowledged.