Mabood, F., Zhou, X. and Smith, D. L. 2014. Microbial signaling and plant growth promotion. Can. J. Plant Sci. 94: 1051–1063. The rhizosphere offers a complex microhabitat where root exudates provide a diverse mixture of organic compounds that are used as nutrients or signals by the soil microbial population. On the other hand, these soil microorganisms produce compounds that directly or indirectly assist in plant growth promotion. The widely recognized mechanisms of plant growth promotion are biofertilization, production of phytohormones, suppression of diseases through biocontrol, induction of disease resistance and production of volatile signal compounds. During the past few decades our understanding of the interaction between rhizobacteria and plants has expanded enormously and this has resulted in application of microbial products used as crop inoculants (as biofertilizers), for increased crop biomass and disease suppression. However, this plant–microbe interaction is affected by adverse environmenta...

Microbial signaling and plant growth promotion

SUMMARY Crop production in the northeastern North America poses unique challenges in that soils tend to be cool and wet in the spring, and there is only a brief period each summer when sufficient heat is obtained for the growth of the main crops produced in the area. This paper reviews seven areas of crop production and ecophysiology research in the context of the geo-climatic conditions of the extreme North American humid northeast. The seven areas are: (1) intercropping systems, (2) leafy reduced-stature corn, (3) intensive cereal management, (4) production of C4 grasses, (5) development of a chronic injection system for physiology research, (6) legume-to-rhizobia signals and inhibition of soybean nodulation, and (7) rhizobia-to-legume signals and crop growth. Progress has been made in each area and there is now a longer-term need to integrate some of these findings at the cropping system level.

C. Madakadze

Papers

From Chemical Ecology to Agronomy: Cropping Systems in the Humid Northeast