By spraying weedicides, weeds are killed, but not the crop plants why?
Hint: > Weeds: The undesirable plants that grow along with the crops are called weeds. > These weeds feed on the nutrients provided to the crops and thus reduce the supply of nutrients to the crops which further decrease their growth. > The growth of these weeds needs to be limited in order to enhance the growth of the plants.
Complete answer: In order to solve this question, we need to know about weeds, and weedicides. Weeds: A valueless plant growing with the cultivated plants. Any undesirable plants grow abundantly where it is not needed. The empty area is covered by these weeds. Weedicides: They are the special chemicals which are sprayed over fields to get rid of weeds but they will not show any effect on crop plants. The most popularly used weedicides are 2, 4-D Ethyl ester, Neem extract, Glyphosate etc. By spraying weedicides, only weeds are killed but not our crop plants. This is because the chemicals used to prepare weedicides are specifically made for killing or destroying the weeds that’s why they could not harm our crop. The Right time of spraying Weedicide is after 32 - 40 days of Sowing.
Note: Weeding: It is a process of removal of weeds. So, to remove weeds, weedicides are used which essentially chemicals are made to destroy weeds. They are regularly sprayed before seeding and flowering. Weeding methods: 1. Weeds can be controlled using weedicides. 2. Tilling before sowing of crops also helps in removing weeds. 3. The manual method of removing weeds. 4. Walking the field and pulling out the weeds. 5. By mechanical method.