Oils as adhesives for seed inoculation and their influence on the survival of Rhizobium spp. and Bradyrhizobium spp. on inoculated seeds

Abstract

Mineral oil, peanut oil and soybean oil were compared with water and gum arabic for their suitability as adhesives for seed inoculation with peat inoculants. Inoculated seeds were stored at 4, 28 and 34°C, and sampled after 1, 3 and 9 days to determine the survival of rhizobia. Germination and nodulation tests were performed on the inoculated seeds. Results showed that oils were suitable adhesives for peat inoculants. Although the oils initially bound less inoculant to the seed, the number of surviving rhizobia was similar to that obtained by the gum arabic treatment after storage at 28 and 34°C for 3 and 9 days. An interesting finding of this experiment was that peanut and soybean oils were superior to gum arabic in supporting significantly higher numbers of chickpea rhizobia at 34°C. Inoculated seeds tested for germination and nodulation showed no adverse effects from the oil treatments. Oils hold good potential as adhesives for seed application in inoculation technology.

Formulations for delivering Trichoderma atroviridae spores as seed coatings, effects of temperature and relative humidity on storage stability

“…Trichoderma atroviridae spores were added to the oil‐coated seeds at 0·5% (10 10 spores g −1 ), and shaken for 30 s. Spore‐coated seeds were dried on filter paper in laminar flow for 2·5 h at 20°C (Hoben et al . ). Formulation 3: A slurry was prepared of 7 : 5 : 15 w/w, starch (waxy maize) : sugar alcohol (mannitol) : T. atroviride spore suspension (10 8 ml −1 ). Seeds were coated with slurry at 23% w/w and dried in the laminar flow at 20°C for 12 h (Watt and Walker ). Formulation 4: 2% methylcellulose slurry was prepared with T. atroviride spore suspension (10 8 spores ml −1 ).…”

“…400 ml air was trapped with the seeds and oil and shaken for 1 min so that the seeds were uniformly coated with the oil. Trichoderma atroviridae spores were added to the oil-coated seeds at 0Á5% (10 10 spores g À1 ), and shaken for 30 s. Spore-coated seeds were dried on filter paper in laminar flow for 2Á5 h at 20°C (Hoben et al 1991). Formulation 3: A slurry was prepared of 7 : 5 : 15 w/ w, starch (waxy maize) : sugar alcohol (mannitol) : T. atroviride spore suspension (10 8 ml À1 ).…”

Role of Plant Growth-Promoting Rhizobacteria and Their Formulation in Biocontrol of Plant Diseases

“…Polysaccharides such as gums, carboxymethyl cellulose, and polyalcohol derivatives are frequently used to alter the fl uid properties of liquid formulations (Paau 1988 ). Materials used in liquid formulations are synthetic medium, sludge, baker's yeast, effl uents, paneer-whey, and vegetable oil (Kremer and Peterson 1982 ;Hoben et al 1991 ;Vendan and Thangaraju 2006 ;Pandey and Maheshawari 2007 ;Rebah et al 2007 ;Albareda et al 2008 ). In an experiment conducted with Rhizobium inoculants, liquid inoculant was found equally effective in comparison to the solid carrier-based inoculants (Gupta 2005 ).…”

Abiotic and Biotic Limitations to Nodulation by Leguminous Cover Crops in South Texas

“…Obviously, an inoculation method this precise would not be feasible in the field. That said, any alternative method for farm-scale inoculation that increases rhizobial adherence to seeds such as adhesive additives (gum arabic, methyl cellulose, or vegetable oil) would improve the possibility of successful infection and nodulation and thus nutrient management [47,48]. Although outside the scope of this investigation, agronomic practices are as critical as biological and ecological factors in the task of maximizing N fixation efficiency by cover crops on South Texas farms.…”