Biochemical Estimations of Tetranychus urticae Koch Infested Marigold Leaves in Summer and Winter Seasons under Screen House and Field Conditions

Background: African marigolds an important medicinal and ornamental plant is grown throughout the world. The two spotted red spider mite, Tetranychus urticae is one of the most destructive pests of the crop. Methods: Estimation of various minerals and stress measures of T. urticae infested and non infested leaves was performed in two seasons namely summer and winter under both screen house and field conditions. ANOVA was analysed under two factorial Completely Randomized Design. Mite population per leaf was correlated with each biochemical measures and statistical significance of data was analyzed. Result: Significantly lower nitrogen, phosphorous and potassium content was recorded in infested (2.01, 0.307, 1.509% dry weight) leaves as compared to uninfested leaves (2.93, 0.387, 1.874% dry weight) respectively. Summer season reported higher per cent loss in mineral content as compared to the winter season. The content of total phenol and proline was significantly more in infested leaves (18.75 mg/g, 57.07 µ/100 g) as compared to the uninfested leaves (11.42 mg/g and 47.50 µ/100 g). The per cent increase of phenol and proline ranged from (43.90 and 20.81%) in summer and (42.90 and 17.45%) in winter, respectively.

Acaricidal activity of nishinda (Vitex negundo) leaf and garlic (Allium sativum) bulb extract against red spider mite, Oligonychus coffeae (Acari: Tetranychidae) in tea plantations of Darjeeling hill, West Bengal, India

The red spider mite, Oligonychus coffeae (Nietner) serves as a serious threat to the Darjeeling tea plantations affecting the quality of the leaves. Various plant extracts are currently being researched as an alternative to the chemical pesticides to control the red spider mites. In the present study, the leaves of Vitex negundo L. and the bulb of Allium sativum L. were analyzed for their acaricidal activity on the larval, nymphal and adult stages of the mite. Both the extracts were found to have potent activity against red spider mites and may prove to be potential acaricides in future.

Effects of Clonostachys rosea f. catenula Inoculum on the Composting of Cabbage Wastes and the Endophytic Activities of the Composted Material on Tomatoes and Red Spider Mite Infestation

Globally, fungal inocula are being explored as agents for the optimization of composting processes. This research primarily evaluates the effects of inoculating organic vegetable heaps with the entomopathogenic fungus Clonostachys rosea f. catenula (Hypocreales) on the biophysicochemical properties of the end-product of composting. Six heaps of fresh cabbage (Brassica oleracea var. capitata) waste were inoculated with C. rosea f. catenula conidia and another six were not exposed to the fungus. The composted materials from the fungus- and control-treated heaps were subsequently used as a medium to cultivate tomatoes (Solanum lycopersicum). The biophysicochemical characteristics of the composted materials were also assessed after composting. In addition, the protective effect of the fungal inoculum against red spider mite (Tetranychus urticae) infestations in the tomatoes was evaluated through the determination of conidial colonization of the plant tissue and the number of plants infested by the insect. Furthermore, phytotoxicity tests were carried out post experiment. There were few significant variations (p < 0.05) in heap temperature or moisture level between treatments based on the weekly data. We found no significant differences in the levels of compost macronutrient and micronutrient constituents. Remarkably, the composted materials, when incorporated into a growth medium from fungus-treated heaps, induced a 100% endophytic tissue colonization in cultivated tomato plants. While fewer red spider mite infestations were observed in tomato plants grown in composted materials from fungus-treated heaps, the difference was not significant (χ2 = 0.96 and p = 0.32). The fungal treatment yielded composted materials that significantly (p < 0.05) enhanced tomato seed germination, and based on the phytotoxicity test, the composted samples from the heaps exposed to the C. rosea f. catenula inoculum were not toxic to tomato seeds and seedlings. In conclusion, this study showed that C. rosea f. catenula improved the quality of composted materials in terms of fungal endophytism and seed germination.

Bioacaricidal Potential of Moringa oleifera Ethanol Extract for Tetranychus merganser Boudreaux (Acari: Tetranychidae) Control

The Tetranychidae family includes mites causing severe damage to agricultural fields. The red spider mite, Tetranychus merganser Boudreaux (Acari: Tetranychidae), causes severe damage to several plant species grown as cash crops. Current red spider mite control depends mainly on chemical insecticides. There is a need for alternate control measures that are environmentally friendlier than chemical pesticides. The aim of the study was to assess the effects of Moringa oleifera leaf ethanolic extract at different concentrations (0.1, 0.5, 1, 5, 10, 15, and 20% (v/v)) against T. merganser females. Such effects can serve as a basis to include this compound in integrated pest management programs for the control of red spider mites. Mites treated with 20% (v/v) killed 86.67%, 13.70%, and 96.30% at 24, 48, and 72 h, respectively, as compared to the control treatment. Oviposition, egg hatching, and the damage caused by red spider mites were all reduced at high concentrations. Moringa oleifera leaf ethanolic extract can be used as a powerful bioacaricide for the control of T. merganser.

The most important diseases and pests of beans and green beans and the possibility of their control

The production of beans and green beans in our country takes place in relatively small areas, and it is additionally reduced by the presence of various harmful agents (pests and diseases). Economically significant diseases of beans and green beans are gray rot (Botrytis cinerea), white rot (Sclerotinia sclerotiorum), seedling rot, and seedling blight (Pythium sp.), Fusarium wilt (Fusarium oxysporumf. sp. phaseoli), bean rust (Uromyces phaseoli), anthracnose (Colletotrichum lindemuthianum), gray leaf spot (Mycosphaerella pinodes), brown leaf spot or bacterial blight (Xanthomonas campestris pv. phaseoli), and bean mosaic virus. Five plant protection products (PPPs) based on four active substances have been registered in our country for the control of pathogens in beans and green beans. Signifi cant pests of beans and green beans in our country are black aphid (Aphis fabae), thrips (Kakothrips robustus), plant aphids (family Aphididae), cotton bollworm (Helicoverpa armigera), as well as red spider mite and Atlantic (strawberry) spider mite (Tetranichus urticae and Tetranichus turkestani). Eight PPPs, based on seven active substances, have been registered for the control of pests in the crop of beans and green beans. This paper aimed to present the registered PPPs in the Republic of Serbia for the control of the most economically important pathogens and pests of beans and green beans, classified according to the mode of action.