Plant extracts as potential control agents of Black Sigatoka in banana

Aqueous extracts of Cinnamomum zeylanicum, Capsicum annuum and Azadirachta indica were tested for efficacy for management of Pseudocercospora fijiensis in banana (Musa spp.) when applied as foliar sprays. Extracts of C. annuum and A.indica demonstrated fungicidal effects in vitro, without showing phytotoxic effects. The two extracts protected tissue culture banana plantlets of cultivar Musakala to a similar degree as the traditional fungicide difenoconazole. Extracts of A. indica and C. annuum (0.3 g/ml) reduced Black Sigatoka severity by 69.3% and 65.6%, respectively, and were thus comparable to the fungicide difenoconazole (72.7%). Soil drenching of the extracts did not significantly reduce Black Sigatoka severity. In planta effects of the extracts mainly consisted of delayed symptom appearance and reduced lesion number. Symptom development was dependent on extract concentration and days between extract application and inoculation. Effect of the tested extracts on height of plants and new leaves was not significant. Collectively, our data suggest that A. indica and C. annuum have interesting and unique properties as plant protection agents against Pseudocercospora fijiensis, but further research is needed to investigate their efficacy

Controlled Radical Polymerization of Vinyl Acetate Mediated by a Bis(imino)pyridine Vanadium Complex

Source type: Prin

Chlorobis{2-[(di­methylamino)methyl]phenyl-C1,N}(pyridine)vanadium(III)

The octahedral coordination of the tervalent bis-aryl vanadium complex [VCl(C5H5N)(C9H12N)(2)] is completed by one pyridine and one Cl ligand with a V-Cl distance of 2.395 (2) Angstrom

A Dichromium(II) BiS(eta(8)-pentalene) double-sandwich complex with a spin equilibrium: Synthetic, structural, magnetic, and theoretical studies

The new bis(pentalene) complex Cr-2(eta(5):eta(5)-C8H4 (1,4-Si1Pr3))(2) has been synthesized and characterized; it is found to exhibit paramagnetism at room temperature, and solid-state magnetic studies show that the dimer is best modeled as containing a pair of antiferromagnetically interacting S = 1/2 centers with the separation between the singlet ground state and triplet excited state being 2.23 kJ mol(-1). Structural data show a Cr-Cr distance of 2.2514(15) angstrom, consistent with a strong metal-metal interaction. The bonding has been further investigated by density functional, hybrid, and CASPT2 methods. The metal-metal interaction is best described by a double bond with each metal having an 18-electron count. Theory predicts the singlet and triplet states to lie close in energy but puts the triplet state at a slightly lower energy than the singlet. The energy difference predicted by CASPT2 is closest to the experimental value