Manual method includes handweeding and use of hand tools. Mechanical method, on the other hand,includes the application of mechanized interrow cultivation and other mechanical method.
Handweeding and the use of hand tools- Examples of hand tools are hoes and sickles
Hand weeding is most useful on annual weeds and certain perennial weeds that usually do not regenerate from underground parts. It is a practical method of removing weeds within rows and hills where a cultivating implement cannot be used, but requires more labor than other direct weed control methods.
Handweeding of young weeds at the two-leaf to three-leaf growth stages is extremely difficult. Therefore, handweeding is generally delayed until weeds are large enough to be grasped easily. The method requires adequate soil moisture to ensure that weeds can be easily pulled. After weeding, the weeds usually have to be removed from the field to stop them from regenerating when left sitting in the field water.
For mechanical weed control, straight row planting is essential. Example of tillage implements are rotary weeder and lithao.
Weed control by tillage is achieved by:
Mechanical weeding is another direct method of weed control. For all mechanical methods, straight-row planting is essential.
Mechanized inter-row cultivation has the advantage that it aerates the soil, which often seems to help crop growth. However, mechanical weeding may be less effective than hand weeding because weeds within the crop rows are not removed. Competition from those weeds that survive can be harmful.
The challenges for mechanical weeding are that it requires row planted crops and it is very difficult if the soil surface is dry or if the soil sets hard.