ABSTRACT
Weed Response Visual assessment of weed response is based on such effects as weed k i l l , weed
growth, weed population, injury to weeds, etc. by a particular treatment. This is done scoring each major weed, using the scales of 0-10, 1-9, 0-5, or 1-5. Of these, the most widely used and simpler rating scale is 0-10, where 0 represents no effect (no weed control) and 10 corresponds to complete effect (complete weed control) as given in Table 19.2. These scores may be converted later to percentage numbers. (0-10 being equal to 0-100.)
Table 19.2. Qualitative description of treatment effects on weeds and crop in the visuals croping scale of 0 to 10
It is not always possible to find uniform infestation of all target weeds in all the plots. Some plots may not have the weed species present in the other plots and vice versa. In such a situation, one should carefully t ry to determine whether or not this is the effect of treatment. To eliminate this possibility, the experiment should have one unweeded or weed-free control treatment for every 5 or 6 treatments.
