Pesticides and Pest Control

Mycotoxin is a toxic secondary metabolite produced by organisms of fungi.

Statement 1 is wrong because alachlor is a herbicide used to control the growth of broadleaf weeds and grasses in corn and many other crops. Statement 2 is correct because it mixes well with other herbicides. It is used mainly to control annual grasses and broadleaf weeds in corn (maize), soybeans and peanuts. Statement 3 is correct. Alachlor is slightly toxic because, when it is exposed to levels above the maximum contaminant level (MCL), there occurs slight skin and eye irritation and at lifetime exposure to levels above the MCL, it causes potential damage to liver, kidney, spleen, lining of nose and eyelids.

The advantages of using biopesticides:

Agrobacterium radiobacter is an effective, commercially applied, biological control agent for the prevention of crown gall disease caused by many virulent strains of Agrobacterium tumefaciens and Agrobacterium rhizogenes. Trichoderma harzianum is an effective biocontrol agent against several fungal soil borne plant pathogens.

DDT (Dichlorodiphenyltrichloroethane) is a synthetic organochlorine insecticide used to control mosquitoes and agricultural pests. It is not a herbicide (kills weeds), fungicide (kills fungi), or rodenticide (kills rodents).

Pesticides are chemical substances primarily used to destroy or control insects that damage crops. While they can affect other organisms, their primary agricultural use is insect pest management. The word is derived from 'pest' - mainly insects that harm agricultural produce. Herbicides (for weeds) and fungicides (for fungi) are different categories.

DDT (Dichlorodiphenyltrichloroethane) is a synthetic insecticide that was widely used to control mosquitoes and other disease-carrying insects. It works by disrupting sodium ion transport in nerve cells, leading to paralysis and death. Herbicides kill weeds, fungicides kill fungi, and rodenticides kill rodents. DDT's use is now restricted due to environmental concerns.

Freon (chlorofluorocarbons) is not a pesticide; it is a refrigerant and propellant that was phased out due to ozone layer damage. BHC (benzene hexachloride), Malathion, and DDT are all organochlorine or organophosphate pesticides used in agriculture and public health.

Seeds are treated with fungicides to avoid seed-borne diseases. So, this is the correct answer.

Weedicides are used to kill weeds.

A general purpose tree fruit spray, available under a variety of trade names, is effective for control of many of the common diseases and insect pests of apple. This mixture usually contains captan as the fungicide component and methoxychlor and malathion or carbaryl as the insecticide component. Other alternative to control of fungal diseases are-

1. coppers (fixed)- early season control of scab and fire blight;
2. fenarimol- control of scab, mildew, and rust;
3. ferbam- some control of scab, rust, black rot, and the summer diseases; causes undesirable black residue when used late in season;
4. maneb, mancozeb- control of rust, scab, fruit rots, and summer diseases;
5. myclobutanil- control of scab, powdery mildew and cedar-apple rust;
6. sulfur- for control of mildew; some control of scab, summer diseases, and fruit rots; can be phytotoxic to some cultivars and may cause fruit russetting and/or yield reduction when sprayed after bloom;
7. thiram- some control of scab, rust, and summer diseases;
8. thiophanate-methyl- control of scab, fruit rots, and summer diseases;
9. triadimefon- very good control of powdery mildew and rust.

NPV (Nuclear Polyhedrosis Virus) is a biopesticide - a virus that specifically infects and kills insect pests, particularly lepidopteran larvae like caterpillars. It's used in organic farming as an environmentally friendly pest control method. NPV is not itself a pest, but a control agent; it's more specific than 'bio control agent' which is a broader category.

Endosulfan is an off-patent organochlorine insecticide and acaricide. Because of its threats to human health and the environment, a global ban on the manufacture and use of endosulfan was negotiated under the Stockholm Convention in April 2011.

Insecticide is a chemical substance specifically designed to kill insects. The suffix '-icide' means killing. Pyrethrum is a natural insecticide, germination is seed sprouting, and larvacide kills larvae specifically.

All the given characteristics are found in Bacillus thuringiensis; so this is a wrong answer.