Weed Identification Book

Dr. V. S. G. R. NAIDU

Preface

Man has selected his food crops from the many thousand plant species that exist for their nutritional and flavor characteristic rather than through their ability to compete. Growing of crops, as part of agriculture for centuries, has changed the natural vegetation. Weeds grow on soil along with crop plants. But this growth of weed is not desirable in the monoculture system. These undesired plants deplete the nutrients, water and space allotted for the intended crop, and finally cause huge reduction in crop yield. Weeds, in crop field, reduce input efficiency, interfere with agricultural operations, impair quality and act as alternate hosts for several insect pests and diseases. Some weeds release toxic substance which affects the crop growth. The obvious effect of these traits is the hike in cost of cultivation by several folds. Along with this, weeds affect and interfere in the management of all the terrestrial and aquatic resources. They endanger the native biodiversity by choking and deliberate takeover of the native plants. The animals which depend on this native biodiversity for their survival are also getting affected. On the other hand, as part of the primary producers within farming systems, weeds also considered as important components of the agroecosystem. Reductions in abundances of weeds which act as hosts may affect associated insects and other taxa which are beneficial. Thus, weeds have a role within agroecosystems in supporting biodiversity more generally. Weeds play important role as resource in pharmaceuticals and animal nutrition.
Weed biology relates to the plant attributes such as morphology, seed dormancy and germination, physiology of growth, competitive ability and reproductive biology. Knowledge of weed biology is essential for development of both economically and environmentally acceptableweed management systems. It is also essential to understand and predict how weed species, populations and biotypes evolve in response to the selection pressure primarily due to agricultural and related practices. Weed identification is the first step in understanding their biology. Knowing the weeds that are competing with the desirable crops is important to understand how to manage their populations. It is said that identification is half way to control. The first step in effective weed management is the accurate identification which in turn will help in a basic understanding of the weeds’ life cycle. Correct identification can be an important step in making sure that new weeds can be eradicated before they become established. The types of weeds can also tell about the field and its management, and also the best form of direct control. Proper weed identification can help in selecting right herbicide to control a particular weed.

Identification is important also with be taken if the identified plant is not a troublesome weed and also helps in protecting the weeds of economic importance and conserving the biodiversity. Being able to identify the weeds is important as it helps in determining the expected level of the problem as weeds vary in the extent to which they can reduce the yield and quality or to the extent to which they are beneficial. Weed identification may form the first step in balancing the needs for weed control with the requirements for biodiversity and more sustainable production methods. An effort has been made to brought out this publication entitled “Hand book on Weed Identification” to help in identifying the weeds easily. I hope this publication would be of great help to scientists, researchers, quarantine officials, academicians and students.
I thank ICAR for giving me the opportunity to serve in this position. The financial support by the Department of Agriculture and Cooperation, Ministry of Agriculture, under National Weed Surveillance project is duly acknowledged. The encouragement by the present and former Directors, scientist colleagues, and technical and other staff members of DWSR is worth to recognize. The support from PIs of the AICRP-WC centres and Area Coordinators of the NIWS is unforgettable. The technical support by Mr. Sandeep Dhagat, Mr. Virendra Kumar Kamalvanshi and Mr. V.K.S. Meshram in shaping up this publication is acknowledged.
March, 2012 Dr. V. S. G. R. NAIDU

Citation : Naidu, V.S.G.R. 2012, Hand Book on Weed Identification Directorate of Weed Science Research, Jabalpur, India Pp 354.

COPYRIGHT © 2012 INDIAN COUNCIL OF AGRICULTURAL RESEARCH