Mn recovered from the total plant biomass may have been caused by partial immobilization of soluble Mn by oxidizing bacteria, which is a common phenomenon in aerated nutrient solutions ( Bromfield, 1978 ). The bacteria develop rapidly as pH increases
. Microbial biostimulants include plant growth-promoting bacteria (PGPB) and beneficial fungi ( Du Jardin, 2015 ). Common genera of PGPB include Bacillus , Pseudomonas , and Azospirillum ( Ruzzi and Aroca, 2015 ), with Bacillus being one of the most
, Glomeromycotan fungus, and Trichoderma sp. within the lily continuous cropping showed a downward trend. Glomeromycota (AMF) and Trichoderma sp. are plant-beneficial bacteria that can improve plant resistance ( Kubicek et al., 2001 ; Whipps, 2004 ). The
, 2017 ). Finally, the use of soil microorganisms (bacteria or fungus) as biostimulants for increasing the nutrient and water-use efficiency of horticultural crops has also been successfully tested ( Acikgoz et al., 2016 ; López-Bucio, et al., 2015
bacteria can also inoculate fruit prior, during, or after harvest. Insect injuries in combination with high moisture in the plant canopies can lead to fruit decay in the field. If the plant canopies contain free moisture from rainfall, dew, or guttation at
box, and shipped within 24 h to a soil testing laboratory (Earthfort, Corvallis, OR) for microbial assessment. Active bacteria and fungi were determined using the procedure of Ingham and Klein (1984 ); soil samples were stained with fluorescein
tryptic soy agar (Difco Laboratory, Detroit, MI), yeast and molds on potato dextrose agar (Difco Laboratory) with chloramphenicol (200 mg·L −1 ), and lactic acid bacteria (LAB) on Lactobacilli Man-Rogosa-Sharpe agar (Difco Laboratory). APC and yeast and
Abstract
Seedlings of six tomato (Lycopersicon esculentum Mill.) cultivars were evaluated for differences in ice-nucleation activity. Freezing temperatures of tissues were not significantly affected by cultivar. Greenhouse-grown seedlings, 0.3- to 34-g fresh weight, of ‘Beefsteak’, ‘Pixie’, ‘Supersteak’, ‘Red Cherry’, ‘Big Boy’, and ‘Supersonic’, with and without natural infestations of ice-nucleation active (INA) bacteria, had an overall mean freezing temperature of −5.9°C. Plants without detectable INA bacteria exhibited mean freezing temperatures ranging from −6.1° to −6.9°, while seedlings with INA bacteria froze from −4.7° to −5.7°. Plant mass and presence of INA bacteria significantly affected plant freezing temperatures. Innate differences in frost avoidance capability among the tomato cultivars examined were not apparent.
Benlate 50 DF has been implicated in causing long term damage to leatherleaf ferns. Damage to leatherleaf fern including frond distortion, discoloration and growth suppression continues to occur even after two or more years following last Benlate application. Electron micrographs of affected plants roots indicate a loss of root hairs and a proliferation of associated soil bacteria on the root surface compared to healthy plants. Plants with history of continued Benlate application have extensive bacterial colonies embedded on the root surface, but these colonies were not parasitic. Lcatherleaf fern plants which only had their rhizomes dipped in Benlate at planting lacked the embedded colonies, but were extensively covered with bacteria. Bioassays of bacteria taken from the rhizoplane and rhizosphere of the these leatherleaf ferns showed that these bacteria have the ability to produce growth regulators and/or toxins which may be detrimental to plant growth when absorbed through the root. Consequently, Benlate may be influencing fern growth indirectly by modifying bacteria composition of the growing media to favor proliferation of deleterious, non-parasitic bacteria.
spore germination ( Mmbaga et al., 2016 ). In addition, the applications of the two bacteria by root drenching suppressed powdery mildew similarly to foliage sprays and suggested that the BCAs may also cause induced systemic resistance (ISR), which may