Wheat (Triticum aestivum L.) is an important cereal crop and staple food of many countries including Pakistan. It is widely planted in both irrigated and rainfed areas all over the world. What is a high-calorie food due to its higher nutrient contents, and has an important role to ensure food security in current climate change patterns of the world?
Aphids are important pests of different crops, which cause severe yield losses worldwide by damaging the crops. Cereal crops are also damaged by aphids which are alarming, especially in the case of wheat crops. Aphids stay for a limited time in the field, but these have the ability to multiply rapidly and damage the whole crop within a few days. These are the most destructive sucking pests of agricultural and horticultural crops, with recorded 4000 species, infesting over 250 host plants.
In Pakistan wheat yield adversely affected by aphids, as they cause severe damage by sucking the cell sap of the plant. Its population is dramatically increasing and estimated to a 50% reduction in grain weight per year.
It is estimated that 35-40% of yield losses are caused directly by sucking cell sap by aphids, while indirectly 20-80% yield losses are reported by transmitting fungal and viral infections. Sap sucking reduces the plant vitality and leaves wilts, plant shows a silky appearance and turns pale. Wheat foliage gets sooty fungi growth due to aphid exuding honeydew secreted by the aphid.
Control of aphid in wheat.
Aphid in wheat can be controlled conventionally as well as non conventionally.
The conventional method to control aphids.
There are several insecticides that are used in cultivated crops for controlling sucking pests. These insecticides have the potential to destroy harmful insects like aphids, but unfortunately, uncontrolled use of these chemicals has outstripped their beneficial effects. By using Nonselective pesticides, the non-targeted organisms are also killed along with the targeted pests. In addition to this, some pests also develop resistance to pesticides with the passage of time.
Neonicotinoids this class of pesticide distinguish them from currently available pesticide classes in their systemic nature. These have relatively smaller molecules and are highly water-soluble, when uptake occurs in plants to these compounds, their metabolites circulate primarily via the xylem to plant tissues they give a longer period of protection against a number of sap-feeding insects like aphids.
Dinotefuran, acts as an agonist of insect nicotinic acetylcholine receptors, by binding in a mode that varies from other neonicotinoid insecticides. Its mode of action is to destroy the nervous system of the insect. It has low toxicity, high efficiency, and a wide range of control of leafhoppers, aphids and whiteflies, and it is also safe for human beings and animals.
Pymetrozine insecticide is a new chemistry of class which is known as the pyridine azomethines. It is most effective against sap-sucking insect for the different crops in the field. It has systemic action and its selectivity is good, especially effective against sucking insects for example aphids. When injected or ingested, it prevents aphids from eating by preventing stylet penetration into plant tissues, resulting in the insect’s death due to starvation.
Matrine, it is a natural plant agent derived from the wild medical plant Sophora Flavescens. It dispenses its function mainly by direct contact. When the pests get in touch with this insecticide, their nervous system paralyzed immediately, then body protein is denatured and finally death occurs. It is highly efficient, broad-spectrum and has no residual effect, hence also protect the environment.
Aphid control by seed dressing
Imidacloprid, lambda-cyhalothrin, thiamethoxam can be used as a seed treatment in wheat for controlling aphid attack.
Non-conventional methods to control aphid in wheat.
- Always select certified varieties only that are suitable for the growing area. For this purpose, one can contact his local agronomist or seed supplier for more details.
- Sowing of the wheat crop should be done in November, Not after that.
- Intercropping should be done of wheat with canola. Use one canal canola after every 400 feet of wheat.
- the field with nitrogenous fertilizer should be avoided.
- Scouting should be done weekly so that the pest is recognized early in its attack.
Anjum Naeem1, Haroon Zaman Khan2 , Asif Iqbal3, Muhammad Ashfaq Wahid4 and Muhammad Farrukh Saleem5
