Recently, there has been a resurgence of interest in bioorganic fertilizers as part of sustainable agricultural practices to alleviate drawbacks of intensive farming practices. N 2 -fixing and P-solubilizing bacteria are important in plant nutrition increasing N and P uptake by the plants, and playing a significant role as plant growth-promoting rhizobacteria in the biofertilization of crops. A study was conducted in order to investigate the effects of two N 2 -fixing (OSU-140 and OSU-142) and a strain of P-solubilizing bacteria (M-13) in single, dual and three strains combinations on sugar beet and barley yields under field conditions in 2001 and 2002. The treatments included: (1) Control (no inoculation and fertilizer), (2) NP. N and NP plots were fertilized with 120 kg N ha −1 and 120 kg N ha −1 + 90 kg P ha − for sugar beet and 80 kg N ha −1 and 80 kg N ha −1 + 60 kg P ha −1 for barley. The experiments were conducted in a randomized block design with five replicates. All inoculations and fertilizer applications significantly increased leaf, root and sugar yield of sugar beet and grain and biomass yields of barley over the control. Single inoculations with N 2 -fixing bacteria increased sugar beet root and barley yields by 5.6-11.0% depending on the species while P-solubilizing bacteria alone gave yield increases by 5.5-7.5% compared to control. Dual inoculation and mixture of three bacteria gave increases by 7.7-12.7% over control as compared with 20.7-25.9% yield increases by NP application. Mixture of all three strains, dual inoculation of N 2 -fixing OSU-142 and P-solubilizing M-13, and/or dual inoculation N 2 -fixing bacteria significantly increased root and sugar yields of sugar beet, compared with single inoculations with OSU-140 or M-13. Dual inoculation of N 2 -fixing Bacillus OSU-140 and OSU-142, and/or mixed inoculations with three bacteria significantly increased grain yield of barley compared with single inoculations of OSU-142 and M-13. In contrast with other combinations, dual inoculation of N 2 -fixing OSU-140 and P-solubilizing M-13 did not always significantly increase leaf, root and sugar yield of sugar beet, grain and biomass yield of barley compared to single applications both with N 2 -fixing bacteria. The beneficial effects of the bacteria on plant growth varied significantly depending on environmental conditions, bacterial strains, and plant and soil conditions.

No abstract

SummaryDifferences in seed vigour of zero‐ and high‐tannin faba beans were investigated using 25 seed lots of 12 cultivars following earlier reports of poor emergence in the zero‐tannin types. Field emergence ranged from 54–96% indicating differences in seed vigour between cultivars all having high laboratory germination (>91%). Seed from zero‐tannin accessions with poor emergence had a higher incidence of testa and cotyledon cracking, a smaller percentage of hard seeds, more rapid water uptake, a lower percentage of vital staining of cotyledons and a greater leaching of solutes than high‐tannin types. Nevertheless, variation in these characteristics existed between cultivars and lines of both types. Seeds with more cracks in the seed coat and fewer hard seeds imbibed water more rapidly and consequently showed lower levels of vital staining and more cracks in the abaxial surface of the cotyledons. Slower imbibition in polyethylene glycol lessened the incidence of these deleterious characteristics and may provide a practical resolution to the problem of poor field emergence in zero‐tannin lines of faba bean with low seed vigour.

No abstract