Arslan Masood Peerzada

Cyperus rotundus L.: Traditional uses, phytochemistry, and pharmacological activities.

ETHNO-PHARMACOLOGICAL RELEVANCE Cyperus rotundus L. (Cyperaceae) is a medicinal herb traditionally used to treat various clinical conditions at home such as diarrhea, diabetes, pyresis, inflammation, malaria, and stomach and bowel disorders. Currently, it is one of the most widespread, problematic, and economically damaging agronomic weeds, growing wildly in various tropical and subtropical regions of the world. The present paper summarizes the available information that will aid in future medicine preparation by identifying active ingredients and their mode of action for a specific therapeutic activity using the latest technologies. MATERIAL AND METHOD This review article is based on the information available on the phytochemical, toxicological, and pharmacological studies on and traditional uses of C. rotundus. The present paper covers the literature available particularly from 2000 to 2015 online (Google Scholar, PubMed, ScienceDirect, Scopus, SpringerLink, and Web of Science) and in books on phytochemistry, ethnopharmacology, and botany of this plant. RESULTS Phytochemical and pharmacological studies revealed the significance of C. rotundus as an antiandrogenic, antibacterial, anticancerous, anticonvulsant, antidiabetic, antidiarrheal, antigenotoxic, anti-inflammatory, antilipidemic, antimalarial, antimutagenic, antiobesity, antioxidant, anti-uropathogenic, hepatoprotective, cardioprotective, neuroprotective, and nootropic agent. This is the most investigated plant worldwide due to the higher concentration of active ingredients in the form of essential oils, phenolic acids, ascorbic acids, and flavonoids in the tuber and rhizomes. Unfortunately, this significant plant species has not been assessed under improved cultivation conditions with the aim of conservation in natural habitats and high quality. CONCLUSION Reports can be found on the ehtnobotanical use of C. rotundus in atherosclerosis, aging, apoptosis, cancer, cystitis, epilepsy, hirsutism, nociception, prostatitis, and genotoxicity disorders. The phytochemical and pharmacological activities of C. rotundus have supported its traditional as well as prospective uses as a valuable Ayurvedic plant. Previous researches focuses on the phytochemistry, biological properties and clinical application of rhizomes and tubers of C. rotundus. However, such studies on the other parts of this medicinally important plant are still quest to be investigate. Furthermore, future study should aim at confirming the clinical activities and safety of this plant before being used for the development of new therapeutic agent in human subjects.

Eco-biology, impact, and management of Sorghum halepense (L.) Pers.

Sorghum halepense (L.) Pers. is ranked among the worst and extensively disseminated weed species. It is emerging as a potential menace for agroecosystems in 53 different countries across the world. This weed is adapted to warmer regions and is native to Mediterranean areas of Africa, Asia, and Europe. In the mid-1900s, cultivation of this weed species as a potential forage crop resulted in its escape from crop fields and invasion of agricultural and natural areas, but in some European countries, it has been introduced deliberately (e.g., as contamination of seeds and soil). S. halepense interferes with economically important agronomic and horticultural crops and cause 57–88% yield losses. Herbicide tolerance, diverse propagation mechanisms, rapid development, and strong competitiveness are key attributes in its invasion. Conventional management approaches are limited in their scope to control this weed due to its rapid vegetative growth and increasing herbicidal tolerance. Integration of chemical methods with cultural or mechanical approaches is important for restricting its future spread to non-infested areas. This review provides insights into the invasion mechanisms of S. halepense, which will help in its management. A better understanding of ecobiological aspects, survival mechanisms, and genetic variabilities of S. halepense, within a wide range of environmental conditions, will assist in designing more effective management strategies for this serious invasive weed. Collaborative research between the various countries impacted by this weed will assist in developing efficient, sustainable, and economical approaches to restrict its invasion in new areas.

Germination Ecology of Cenchrus biflorus Roxb.: Effects of Environmental Factors on Seed Germination

ABSTRACT Better understanding related to germination and seedling emergence of plant species assists in predicting the potential distribution and provides insight for efficient management. Cenchrus biflorus Roxb. has been considered as potential forage species in arid environment due to its high nutritive values, prolific seed production, and tolerance to extreme temperature and prolonged drought conditions. A series of laboratory and greenhouse assays were conducted to determine the effect of different environmental factors, such as temperature, light, pH, salinity, osmotic potential, and seed burial depth on the germination and seedling emergence of C. biflorus. The maximum germination (95%) was recorded at 35°C/25°C, followed by 40°C/30°C; however, minimum germination was observed at 45°C/35°C (17.5%). Light significantly promoted the germination with maximum percentage (97.5%) when seeds were exposed to altering light and dark conditions (12/12 h). The osmotic potential for the 50% inhibition of C. biflorus germination was -0.4 MPa, although some seed germinated at -0.8 MPa (12.5%). Germination decreased from 97.5% to 12.5% as salinity stress increased from 0 mM to 200 mM sodium chloride (NaCl) with no germination >200 mM. Seed germination was significantly affected by pH levels and was between 27.5% and 92.5% at 5–8 pH, respectively. No seedling emerged when seeds were placed on the soil surface; maximum seedling emergence (90%) at 2-cm burial depth and emergence decreased considerably as seeding depth increased above 2 cm. Its tolerance to drought and salinity make C. biflorus a potential candidate to be used as an alternative source during periods of forage scarcity under harsh climatic conditions, and it could possibly be used for rangeland rehabilitation purposes in arid environments.

Thermal Weed Control: History, Mechanisms, and Impacts

Abstract In the recent years, there has been a revival in the development and improvement of thermal weed control to deliver heat for weed management. Thermal weed control techniques are based on foliar contact mechanisms in which temperatures of approximately 100°C are applied for the duration of few seconds, resulting in intracellular water expansion and cell membrane rupture. Nowadays, several heat machines are being developed in many countries, which can be used to deliver heat for controlling weeds. Several biological and technical factors, including the weed type and their stage, soil properties, and energy consumption of the system, influence the practicability of these thermal weed control options. In this chapter, the impact of heat energy on the plant and soil/microbes and methods for the application of heat to control weeds, their mechanism, and merits or demerits has been discussed.

Biology and management of Avena fatua and Avena ludoviciana : two noxious weed species of agro-ecosystems

Avena fatua and Avena ludoviciana are closely related grass weed species infesting a large number of crops around the world. These species are widely distributed in diverse agro-ecosystems from temperate to sub-tropical regions due to their unique seed traits, successful germination ecology, high competitive ability, and allelopathic potential. A. fatua is more widespread, adaptable, and problematic than A. ludoviciana. Both these species infest major winter and spring crops, including wheat, oat, barley, canola, maize, alfalfa, and sunflower, causing up to 70% yield losses depending on crop species and weed density. Chemical control has been challenged by large-scale herbicide resistance evolution in these weed species. A. fatua is the most widespread herbicide-resistant weed in the world, infesting about 5 million hectares in 13 countries. The use of alternative herbicides with different modes of action has proved effective. Several cultural practices, including diverse crop rotations, cover crops, improved crop competition (using competitive cultivars, high seed rates, narrow row spacing, altered crop geometry), and allelopathic suppression, have shown promise for controlling A. fatua and A. ludoviciana. The integrated use of these cultural methods can reduce the herbicide dose required, and lower dependency on herbicides to control these grasses. Moreover, integrated management may successfully control herbicide-resistant populations of these weed species. The use of integrated approaches based on the knowledge of biology and ecology of A. fatua and A. ludoviciana may help to manage them sustainably in the future.

Biology, agricultural impact, and management of Cyperus rotundus L.: the world's most tenacious weed

Purple nutsedge (Cyperus rotundus L.), a troublesome weed, is economically damaging weed, which is widely naturalized in the tropical and subtropical regions of the world. This weed has been reported to cause 20–90% yield losses in various agronomic and horticultural crops across the world. Perennial nature, genetic diversity, ability to tolerate adverse climatic conditions, high rate of reproduction, ease-of-dispersion, strong competitive abilities, and allelopathic potential assist this weed to thrive in a range of agro-climatic regions. Routine cultural approaches, including crop rotation, crop choice, and mechanical cultivation, are ineffective in achieving season-long management of C. rotundus. Pre-emergent and post-emergent herbicides, as well as myco-herbicides, can control its growth but fail to limit the regenerative capacity and tuber viability of C. rotundus in the long term. Integration of herbicides with tillage operations during summer fallows would be a reliable option to desiccate the tubers and rhizomes of C. rotundus. Furthermore, preventive measures as well as complete destruction of nascent foci would be helpful in preventing future spread of this weed. This review will help researchers and scientists in understanding the reproductive biology and future threats of C. rotundus, leading towards the development of improved control methodologies. The information presented in this article will also enable researchers and growers to address the prevailing gaps in the eco-biology of this weed for the long-term control of C. rotundus in economically important field crops.