20.—(1) Subject to sub-paragraph (2) below, a farmer shall not apply herbicide to the set-aside land concerned unless–
(a)it is of a type which either–
(i)is absorbed into a plant primarily through the leaves and stem, or
(ii)has been approved under regulation 5 of the Control of Pesticides Regulations 1986(1) or under regulation 5, 7, 8 or 11 of the Plant Protection Products Regulations 1995(2) and its application is not outside the coverage of the uses for which it has been approved, and
(b)such application, if undertaken on guaranteed set-aside land or prior to 15th April in the current scheme year on any other form of set-aside land–
(i)is not likely significantly to damage green cover on the land,
(ii)is made prior to replacing green cover on the land in accordance with paragraph 15 above,
(iii)is undertaken using herbicide applied either as a spot treatment or with a wick applicator, or
(iv)is undertaken in order to create a bare fallow strip as permitted by paragraph 8(2) above, or to keep such a strip bare.
(2) The Minister shall on application from a farmer exempt him from the restriction imposed by sub-paragraph (1) above so as to permit him to apply any herbicides to set-aside land in order to create a bare fallow strip permitted by paragraph 8(2) above or keep such a strip bare, where the Minister is satisfied that the application of herbicides in accordance with sub-paragraph (1)(b)(iv) above has not been effective to prevent the growth of vegetation on that strip.