A cover for a tank for containing a plant protection product or a liquid fertiliser, the cover being for sealing an opening of the tank defined by an opening rim, the cover comprising: - a first cover part, - a second cover part pivotally mounted to the first cover part about a pivot axis with axial direction, between a first angular position of unblocking the cover and a second angular position of blocking the cover in which the cover is for being axially blocked to the opening rim of the tank extending about the pivot axis, - a plurality of blocking members for cooperating with the opening rim of the tank to axially block the cover relative to the tank, when the second cover part occupies the second blocking angular position, the cover being characterised in that it further comprises a latching mechanism (31, 32, 33, 41) designed to automatically latch pivoting of the second cover part, relative to the first cover part, in a pivot direction from the second blocking angular position to the first unblocking angular position, when the second cover part reaches the second blocking angular position, the latching mechanism (31, 32, 33, 41) comprising: - a latching member movably mounted to one of the first and second cover parts (12, 11) between a rest position and a restrained position in which an elastic return member returns the latching member moving towards the rest position, - a first drive member integral with the other of the first and second cover parts (11, 12), and designed on the one hand to movably drive the latching member from the rest position to the restrained position or to hold the latching member in the restrained position, when the second cover part pivots from the first unblocking angular position to the second blocking angular position, and on the other hand to release the latching member when the second cover part reaches the second blocking angular position, the latching member being further designed to abut against the other one of the first and second cover parts (11, 12), when the second cover part reaches the second blocking angular position and the latching member moves from the restrained position to the rest position under the effect of the elastic return member, so as to automatically latch pivoting of the second cover part in the pivot direction from the second blocking angular position to the first unblocking angular position. - a first cover part, - a second cover part pivotally mounted to the first cover part about a pivot axis with axial direction, between a first angular position of unblocking the cover and a second angular position of blocking the cover in which the cover is for being axially blocked to the opening rim of the tank extending about the pivot axis, - a plurality of blocking members for cooperating with the opening rim of the tank to axially block the cover relative to the tank, when the second cover part occupies the second blocking angular position, - a latching member movably mounted to one of the first and second cover parts (12, 11) between a rest position and a restrained position in which an elastic return member returns the latching member moving towards the rest position, - a first drive member integral with the other of the first and second cover parts (11, 12), and designed on the one hand to movably drive the latching member from the rest position to the restrained position or to hold the latching member in the restrained position, when the second cover part pivots from the first unblocking angular position to the second blocking angular position, and on the other hand to release the latching member when the second cover part reaches the second blocking angular position,