Crop Allelopathy and Its Role in Ecological Agriculture

Abstract

A number of crops exhibit allelopathic interactions that play a significant role in the complex environment of agroecosystems. Several studies have shown that allelopathic crops reduce growth, development and yield of other crops growing simultaneously or subsequently in the fields. Another aspect of interest regarding crop allelopathy is that allelochemicals may exhibit inhibitory effect on the same crop which is commonly called as crop autotoxicity. It is predominantly common in fields where sole cropping under reduced or no-tillage system is practiced. Though any crop part can be allelopathic, including even the pollens, but decomposing crop residues exhibit more influence on other plants. Furthermore, the extent of allelopathy by a crop plant varies with age, part and type of cultivar being used. Nowadays allelopathic crops are being used as an important tool in managing weeds and harmful pests under sustainable pest management programs. In this context several cover/smother and green manure crops with allelopathic

Plant: soil interactions in temperate multi-cropping production systems

“…Belowground competitive processes by which weedy plants may be outcompeted have frequently been reported in cereal-legume intercrops, and include the rapid exhaustion of existing resources (light, water and nutrients) and niches (Hauggaard-Nielsen et al 2001b;Singh et al 2003;Poggio 2005;Zarea et al 2009). In addition, allelopathic traits of certain crops have the potential to inhibit the growth of weeds (Batish et al 2001).…”

“…The list contains cultivars of common leguminous, graminaceous and brassica crop species, and species such as rye (Batish et al 2001;Fujii 2001;Bhowmik and Inderjit 2003;Singh et al 2003) and nearly 80 tree species (Rizvi et al 1999). Lemerle et al (2001) studied the effects of several wheat varieties on perennial ryegrass (Lolium perenne) and found that negative effects on the weed were partly due to environmental conditions but also due to genotype, and individual weed inhibiting traits.…”

Adverse Effects of Allelopathy from Legume Crops and Its Possible Avoidance

“…In such a condition suitable succeeding crop with a crop rotation has good control over it. It can limit the soil autotoxicity due to all allelopathy to a greater extend [57]. Assaduzzaman et al [58] investigated sixty seven cultivars of 42 vegetable crop species from 14 families through seedling growth bioassay using replanting soil for succeeding crops of V. faba L., P. sativum L. and P. vulgaris L. replanting soil to suggest their possible succeeding crops.…”

Prospect of bioactive molecules from Jatropha curcas to improve soil and microbial quality for sustainable agriculture

“…In general, the chemical substances potentially involved in allelopathy are liberated from plants by leaching of foliage by rain, abscission and litter fall, volatilization and root exudation. Crop allelopathy may be useful to minimize problems affecting agricultural production such as environmental pollution, unsafe products, human health concerns, depletion of crop diversity, soil sickness and reduction of crop productivity (Batish et al, 2001). Presence of various toxic chemicals in different parts of J. curcas indicates possible allelopathic nature.…”