Phytochemical analysis and fungicide potential of Pouteria ramiflora against Lasiodiplodia theobromae

<div><p>ABSTRACT The use of plant extracts can be an alternative to reduce the use of pesticides, to control diseases and pests that affect agricultural production. The aim of this study was the chemical characterization of the extract and fractions of Pouteria ramiflora leaves and to determine its fungistatic potential on Lasiodiplodia theobromae. The ethanolic extract of dried and crushed leaves was obtained by maceration. Part of this extract was sequentially partitioned and the following fractions were obtained: hexane, dichloromethane, chloroform, ethyl acetate, n-butyl, and hydromethanol for subsequent bioassay, and qualitative and quantitative phytochemical analysis. Experimental development comprises of adding a L. theobromae mycelial disk (5 mm), obtained from pure colonies, in the middle of Petri dishes with PDA culture growth (potato-dextrose-agar) plus the aforementioned substances in different concentrations (800; 1,200; 1,600; 2,000, and 2,400 µg/mL), and a control treatment (PDA). The plates were incubated in B.O.D. (25±2°C), and the assessment was performed by measuring the diameter of the colonies until it reaches the edge of the board. The experimental design was completely randomized with five replications, and the treatments were constituted of a factorial of seven extracts/fractions and six concentrations. For the Mycelial Growth Rate Index (MGRI) obtained, the analysis of variance was performed, and when significant, the regression analysis was performed. All extract/fractions decreased MGRI of L. theobromae, as the concentrations were increased. The best MGRI reduction occurred in n-butanolic fraction, and the efficiency of this fraction may be related to the presence of flavonoids and anthraquinones. The extract and fractions of P. ramiflora, a tree from the Cerrado biome in Mato Grosso do Sul, was effective in the control of L. theobromae, which can be used as a control option in organic farming or in integrated management systems.</p></div

Cashew nut shell liquid and formulation: toxicity during the germination of lettuce, tomato seeds and coffee senna and seedling formation

<div><p>ABSTRACT. Cashew (Anacardium occidentale) nut shell liquid (CNSL) has been successfully used in trials as an Aedes aegypti larvicide, but little is known about its environmental effects. In this study, the potential effects of CNSL and a CNSL-based phyto-product formulation on the germination and growth of Lactuca sativa (lettuce), Lycopersicon esculentum (tomato) and Senna obtusifolia (coffee senna) were assessed. The pH of CNSL and the formulation were 6.4 and 6.8, respectively; the electrical conductivities were 2.89 μS cm-1 (CNSL) and 2.21 μS cm-1 (formulation), respectively, and both contained anacardic acid (53.2%) and degradation products. In bioassays for germination and growth, CNSL (25, 50, 100, 150, and 200 mg mL-1), the formulation (100 mg mL-1) and the control were used in a completely randomized design. The results demonstrated the chemical effects of CNSL, which negatively affected the germination and vigor of lettuce and tomato and the vigor of coffee senna; for growth, it negatively influenced both the root and aerial parts of lettuce and tomato, but only the roots of coffee senna. The formulation had negative effects on the vigor of coffee senna and the growth of tomato and lettuce seedlings (roots and aerial parts). The results indicate the phytotoxicity of CNSL and the formulation for the plant species tested.</p></div