Integrated weed management in wheat

摘要

Wheat crop can get infested with a number of grass and broadleaf weeds like gulli danda, jangli javi, buein, jangli palak, bathu, maina, maini, kandyali palak, button booti, bhambola etc. These weeds germinate in different flushes - along with the crop, after first irrigation, or before if there is rainfall and also after second irrigation - during the growing period of crpp. The weed plants compete with crop plants for essential nutrients and moisture resulting in lower crop yields. The extent of yield losses depends on the type of weed flora, their intensity and duration of weed competition and soil and climatic factors. Weed control is especially important early in the season when weed competition can substantially reduce crop growth and yield. The methods used for controlling weeds have been divided into two broad categories, non-chemical and chemical. Many non-chemical weed management methods are common-sense farming practices. These practices help in reducing weed populations and are of increasing importance due to consumer concerns about pesticide residues and potential environmental contamination from pesticides. Also, several weeds especially perennials, are extremely difficult to manage unless herbicides are combined with non-chemical approaches. Similarly, the herbicides alone could not provide long term control of wide range of weed flora present in a field. The aim should be to manage the weed population so it is below a level that reduces farmer's economic returns. This is possiblewith adoption of integrated weed management which includes the use of multiple weed control practices including preventive measures, cultural practices and herbicides at a particular location; these practices have been described below:Prevent the entry of new weeds and spread of existing weeds: It is possible to prevent many new weeds from being introduced onto the farm and to preventexisting weeds from producing large quantities of seed. Preventing invasive and alien weeds in fields is usually easier and less costly than controlling them after severe infestation, as it is difficult to control weeds once they are established. Some weed preventive measures include the use of clean crop seeds, the use of clean agricultural implements, and managing weeds on bunds and roads can greatly reduce the introduction of weed seeds and difficult weed species. It is even possible to selectively hand-eradicate isolated outbreaks of new weeds, effectively avoiding future infestations. Hand-roguing weeds before seed-shed could be an important practice in the state. This helps in prevention of build-up of weed seed population in the fields. Field boundaries, irrigation channels, and paths are important sources of spreading weed seeds and, therefore, these should be kept clean and free from weeds. Deep ploughing in summer exposes underground parts likes rhizomes and tubers of perennial and obnoxious weeds to scorching summer sun and kills them. Preventive measures, unfortunately, are always forgotten.