Natural products in plant protection

Abstract

Natural products can be used to control pests and diseases in crops. These products include anorganic compounds, but aiso a variety of plant extracts. In the beginning of this century active microbial extracts were discovered as well. Synthetic crop protection chemicals were developed from about 1940 onwards and sustained progress in modero agriculture. The first generation chemicals have aspecific modes of toxic action and are in many instances deleterious to the environment. The second generation chemicals have specific modes of action and meet modero environmental requirements. A disadvantage of these chemicals is the potency of target organisms to acquire resistance. This condition urged agrochemical industry to develop chemicals with new modes of action. Such chemicals can be developed by using natural bioactive products as leads in synthesis programmes.This paper decribes the progress that was made in the development of natural bioactive compounds in pest and disease control.

Current Status of Botanical Pesticides for Crop Protection

“…After World War II, the agrochemical industry with discoveries of the major classes of synthetic pesticides (organochlorines, organophosphates and carbamates) provided agriculture with a vast array of crop protection chemicals such as fungicides, insecticides, nematicides, and herbicides (Jespers and De Waard, 1993). Crop growers have mainly used such synthetic agrochemicals to control plant diseases.…”

Purificação do flavonóide trans-tilirosídeo do extrato metanólico das folhas de Gochnatia barrosii Cabrera (asteraceae) e avaliação da sua atividade nematicida

“…Uma das possíveis alternativas para contornar tais problemas consiste no emprego de produtos naturais, que têm sido fontes de compostos para o manejo de pragas e doenças (Jespers & Waard, 1993;Isman, 2000;Oliveira et al, 2007a;Oliveira et al, 2008;Amaral et al, 2009). Dentre tais produtos podem ser citados os de origem vegetal (Roel et al, 2000), nos quais são encontradas diversas classes de substâncias com efeito fitonematicida (Datta & Saxena, 2001;San Martin & Magunacelaya, 2005;Pastor de Abram & Zelada Mariluz, 2006;Oliveira et al, 2007b;Begum et al, 2008;Thoden et al, 2009) e, dentre elas, os flavonóides (Begum et al, 2000;Wuyts et al, 2006;El Allagui et al, 2007;Jones et al, 2007;Adekunle & Aderogba, 2008;Shakil et al, 2008).…”

Screening extracts of Achyranthes japonica and Rumex crispus for activity against various plant pathogenic fungi and control of powdery mildew

“…Many studies have focused on integrated control of powdery mildew fungi, with the aim of reducing the input of fungicides 2, 3, 16, 20, 21. Various alternative control measures, such as the application of mineral salts, oils, plant extracts and biocontrol agents, in combination or as a replacement for fungicides have been developed 22–25. Milsana, a plant extract of R sachalinensis that induces mildew resistance in plants, effectively protected cucumber plants against powdery mildew 2, 3.…”