Question

Which of the following is not a herbicide? (a) Sodium chlorate (b) Sodium arsenite (c) Polyphosphate (d) Triazines

Short answer

The correct answer is (c) Polyphosphate.

Step-by-step solution

- Identify Known Herbicides

First, identify which of the options are known herbicides. Sodium chlorate and Sodium arsenite are both known to be used as herbicides.

- Research Triazines

Triazines are also a well-known class of herbicides that interfere with photosynthesis in plants.

- Examine Polyphosphate

Polyphosphates are not used as herbicides. Instead, they are typically used in detergents, water treatment, and as food additives.

- Verify the Answer

Since Polyphosphate is not used for killing weeds or plants, it is not a herbicide.

Key concepts

Herbicides

Herbicides are chemicals used to control or kill unwanted plants, such as weeds. They play a crucial role in agriculture, helping farmers protect their crops from being overtaken by these unwanted plants. Herbicides can be classified into various categories, depending on their chemical composition and mode of action.
Some common classes of herbicides include:

• Selective herbicides: These target specific plant species while leaving others unharmed.
• Non-selective herbicides: These kill all plants they come in contact with.
• Contact herbicides: These only affect the parts of the plant they touch.
• Systemic herbicides: These are absorbed by plants and transported to various parts, having more widespread effects.

Understanding the type and function of herbicides can significantly enhance efficiency in agriculture and gardening. Always follow proper guidelines and safety measures when using these chemicals.

Sodium Chlorate

Sodium chlorate is a commonly used herbicide. It is effective for controlling a broad spectrum of plants, including both weeds and woody plants. Sodium chlorate kills plants by interfering with their ability to photosynthesize, which eventually causes them to die.

Sodium chlorate has different applications:

• Non-selective weed control: It kills virtually any plant it comes in contact with, making it useful for areas where complete vegetation removal is needed, like sidewalks and industrial sites.
• Soil sterilization: It is sometimes used in soil to prevent any plant growth for an extended period.

Despite its effectiveness, sodium chlorate can be hazardous and must be handled with care. Always follow the recommended guidelines and safety instructions when using this chemical.

Polyphosphate

Polyphosphates are not herbicides; instead, they are chemicals used in a variety of non-agricultural applications. Polyphosphates are chains of phosphate units and are utilized for their ability to bind to other substances.

Common uses of polyphosphates include:

• Water treatment: They help prevent scale formation and corrosion in pipes.
• Food industry: Polyphosphates act as stabilizers in many processed foods.
• Detergents: They enhance cleaning effectiveness by softening water and helping to dislodge dirt particles.

Given these uses, it's clear that polyphosphates serve essential roles in many industries, but they are not used for controlling or killing plants.

Triazines

Triazines are a well-known class of herbicides commonly used to control a wide range of weeds in agricultural settings. These chemicals work by inhibiting photosynthesis in plants, which effectively starves them and causes their death.

Triazines are used in different ways:

• Pre-emergence herbicides: Applied to the soil to prevent the growth of weeds by attacking weed seeds as they germinate.
• Post-emergence herbicides: Applied directly to weeds that have already started growing, causing their eventual death.

Some common triazines include atrazine and simazine. These chemicals are highly effective but must be used with caution to prevent environmental contamination and resistance development in weed populations.