Phytotoxic Effects of Catnip (Nepeta meyeri Benth.) on Early Growth Stages Development and Infection Potential of Field Dodder (Cuscuta campestris Yunck)

Abstract

Dodder (Cuscuta campestris Yunck.) is one of the most devastating parasitic plants, which reduces quantity and quality of crops. The inhibitory effect of catnip (Nepeta meyeri Benth.) extracts on germination and some seedling characteristics of the C. campestris were investigated in three phases in a laboratory and greenhouse. Aqueous extracts from different organs of N. meyeri were used in bioassays. The N. meyeri extracts reduced germination percent, root and shoot growth, and dry weight of C. campestris seedlings. Moreover, results showed an inhibitory effect of the N. meyeri extracts on the activity of alpha-amylase, protease, and beta-1,3-glucanase enzymes in C. campestris germinating seeds. Under greenhouse conditions, C. campestris seeds were planted with 30-day-old alfalfa plants and irrigated with N. meyeri extracts. The application of extracts from different organs of N. meyeri reduced emergence percent and length of stem and hampered C. campestris attachment to alfalfa. N. meyeri extracts also inhibited the activity of antioxidant enzymes and increased the accumulation of hydrogen peroxide and the malondialdehyde in C. campestris seedlings. The strongest inhibitory effects were observed from flower, leaf, and stem extracts of N. meyeri, respectively. However, after C. campestris attachment to alfalfa plants, treatment by N. meyeri extracts did not exhibit any effect on infestation efficiency and C. campestris growth traits. According to these findings, N. meyeri extract, especially from flower and leaf, may be recommended as a potent bio-control agent to control germination and early stage development of C. campestris.

Impact of Selected Plant Extracts on Winter Wheat (Triticum aestivum L.) Seedlings: Growth, Plant Health Status and Soil Activity

“…Plant extracts rich in bioactive compounds constitute one of the most promising groups of botanical biopesticides. Their antimicrobial activity has been repeatedly confirmed, and furthermore, their ability to induce defense reactions and even systemic resistance has been demonstrated [35,36,64,65]. The present work complements the existing literature on the effects of plant-derived extracts on plants as well as on soil microbiomes.…”

“…Preparations based on plant extracts constitute a new generation of products and are an environmentally friendly complement to widely applied chemicals. The native environment serves as a source of numerous valuable compounds that can and should be utilized to protect plants from indigenous pests [2,7,17,18,35,36].…”

“…These results confirmed the findings of Suteu et al [37], who emphasized the low toxicity of plant extracts even against non-target microorganisms. The safety of the application of plant extracts is also due to their biodegradable nature, as well as the desirable interactions of individual components in terms of plant health, especially with regard to extract mixtures [35,36]. Current literature reports varying effects of plant extracts on plant dry and fresh weight.…”

Is the Phytotoxic Effect of Digestive Fluid of Nepenthes x ventrata on Tomato Related to Reactive Oxygen Species?

“…Extracts from the leaves and flowers of catnip ( Nepeta meyeri Benth.) decreased α-amylase, ß-1,3 glucanase and protease activities in seeds of field dodder ( Cuscuta campestris Yunck) [ 33 ]. Allelochemicals could disrupt the action of phytohormones in germinating seeds.…”