Response of chickpea grown on ando-soil to vesicular-arbuscular mycorrhizal infection in relation to the level of phosphorus application

Abstract

Chickpea (Cicer arietinum L.), one of the important grain legumes in the semi-arid and arid tropics, appears to exhibit a low response to P application even when the content in available P in soil is low.

In order to analyze the cause of the low response of chickpea to P application, the growth and nutrient uptake of the plant were examined in relation to the infection of indigenous vesicular-arbuscular (VA) mycorrhizal fungi, using a sterilized sub-soil sample of an Ando-soil to which different levels of P had been applied in pot condition. Small amounts of surface soil from the field, and spores of Gigaspora gregaria collected from the same soil were used as the inoculum.

Correlation between VA mycorrhizal infection and shoot growth and P % in shoots was significantly positive when P was applied at a level below 200 mg/800 g dry soil (<around 8 ppm by Bray II-P), but negative when 2,000 mg P was supplied. As compared with maize (Zea mays L.), chickpea seemed to have a more efficient relationship with VA mycorrhizal fungi.

VA mycorrhizal infection significantly reduced the defoliation of chickpea at the earlier stage of flowering, irrespective of the infection level and P % in shoots. VA mycorrhizal infection may also promote the photosynthetic activity at the pod filling stage of chickpea, presumably due to the continuous uptake of P from soil.

Key Words:

• chickpea
• response to P application
• VA mycorrhizae
• Ando-soil.