Domates Tohumlarında Pseudomonas syringae pv. tomato’ya Karşı Farklı Bor Bileşiklerinin Etkililikleri

Pseudomonas syringae pv. tomato, the bacterial agent for tomato speck disease, can cause serious epidemics with high leaf moisture, mild temperatures, and cultural practices allowing bacterial dissemination among host plants. Boron is an essential micro-nutrient for plant growth and health in agricultural production. In this study, the effectiveness of 14 different Boron compounds at 5 different doses (1, 5, 10, 20 and 40 mM) against P. s. pv. tomato at a concentration of 108 CFU ml-1 in vitro was evaluated and the most successful 4 different Boron compounds (Ammonium tetrafluoroborate, Sodium tetrafluoroborate, Zinc borate and Disodium octaborate tetrahydrate) were coated with 5 mM doses infected cv. H2274 tomato seeds to determine bacterial populations and seed emergence rates in the seeds. Among the 14 different Boron compounds used in the experiments, Disodium octaborate tetrahydrate was the most successful active ingredient 92% ratio in inhibiting P. s. pv. tomato populations in tomato seeds, while 39% success was achieved with sodium tetrafluoroborate applications. According to the results of the research, it is thought that some Boron compounds can be an economical, effective and environmentally friendly chemical in reducing P. s. pv. tomato in tomato seeds within the scope of good agricultural practices.

Borate and Quaternary Ammonia Dip Diffusion to Treat Fungal Pathogens of Metrosideros polymorpha Wood

Rapid Ohia Death is a major concern for the viability of ohia (Metrosideros polymorpha) in Hawaii and has led to restrictions on log movement. The potential for using disodium octaborate tetrahydrate (DOT) and didecyl dimethyl ammonium chloride (DDAC) dip diffusion treatments to control the two causal fungi (Ceratocystis lukuohia and Ceratocystis huliohia) was investigated. A 10 percent boric acid equivalent dip diffusion treatment killed the pathogens in 0.5-cm-thick disks obtained from 4.0- to 5.0-cm-diameter limbs of naturally colonized trees. DOT tended to diffuse more consistently in 50- to 60-cm-long bolts of small (4.0 to 9.0 cm) and large (9.1 to 17.0 cm) diameter healthy ohia compared with those bolts naturally infected by C. lukuohia. Diffusion periods longer than 6 weeks resulted in deeper penetration. Immersion (24 h) of logs (1.3 m long; 9 to 17 cm diameter) from C. lukuohia artificially inoculated trees in two forest locations in a 15 percent DOT/1 percent DDAC solution and storage for 10 weeks before evaluation resulted in incomplete elimination of the pathogen and lower boron concentrations in the inner sapwood than outer. Further investigations are needed to explore using either higher boron concentrations or longer diffusion periods to deliver fungicidal concentrations of boron deeper within the wood matrix.

Boron Sensitivity and Storage in Brassica Napus and Its Potential for Clubroot Management

Clubroot [Plasmodiophora brassica] severity in canola (Brassica napus) can be suppressed by addition of boron (B), but excess B produces phytotoxicity. However, some lines of a closely related species, B. rapa, are relatively insensitive to high levels of B. Assessment of 150 accessions of B. napus and B. rapa treated with 0, 8 and 16 kg B ha-1 as disodium octaborate tetrahydrate (trade name Solubor) identified several lines that were relatively insensitive to high levels of B. In 2015, 88 lines were planted in a clubroot-infested plot in Ontario, Canada in a replicated split-plot design, where the subplot treatments were 8 kg ha-1 of B versus a non-treated control. Boron-insensitive lines generally had slightly lower clubroot severity than sensitive lines, even in the control with no added B. Application of B reduced clubroot slightly in the most sensitive lines, but produced a large and significant reduction in severity in the most insensitive lines. Assessment of five insensitive lines under controlled conditions supported the observation that application of B substantially reduced clubroot severity in insensitive lines. Comparison of two sensitive and two insensitive lines each of B. napus and B. rapa using Boron K-edge X-ray absorption near-edge structure (XANES) spectra from a synchrotron-based soft-X-ray beamline showed that some insensitive lines were able to extract B efficiently from a soil that contained very low levels of B. The spectra of sensitive and insensitive lines differed when additional B was applied, which demonstrated that the insensitive lines stored B (and other elements such as S and P) differently than the sensitive lines. Differences in the amount and type of storage likely affect the susceptibility to clubroot, and merits further study.

Susceptibility of Environmentally Friendly Sheep Wool Insulation Panels to the Common Clothes Moth Tineola bisselliella in Laboratory Assays

In this study the resistance opposed to Tineola bisselliella larvae by a commercial sheep-wool panel incorporating borate salts was determined under laboratory conditions. The susceptibility of clothes moth larvae to different concentrations of disodium octaborate tetrahydrate (DOT) incorporated in pure wool was also determined. The commercial wool panel showed a remarkable resistance to moth attack compared with pure untreated wool, and the damage to panel samples was limited to their surface. As a result of bioassays exposing larvae to pure wool treated with DOT, a concentration dependent effect was observed, achieving a good efficacy at an application rate between 40–100 mg/mL. This study highlights the need to protect wool-based construction material with appropriate insecticidal (antifeedant or repellent) substances and supports the development of eco-sustainable solutions.