Determination of the insecticidal activity of the chemical preparation tranil 20% sc, received for testing against cotton bollworm on cotton crops.

Аннотация

To determine the insecticidal activity of TRANIL 20% EC against the cotton bollworm (Helicoverpa armigera Hbn), which causes significant damage to cotton crops in our country, field trials were conducted using a dosage rate of 0.2 liters per hectare. The results of the trial showed that by the 7th day, the effectiveness of the preparation reached 89.1%. Keywords: Cotton, egg, larva, polyphagous, pest, formulation, insecticide, insecticidal activity. Introduction: Uzbekistan produces approximately 3.5 million tons of raw cotton annually (ranking sixth in the world) and 1–1.2 million tons of cotton fiber. About 40% of the produced cotton fiber is exported. To increase the production and improve the quality of raw cotton in Uzbekistan, it is essential to utilize all available resources. In particular, protecting cotton crops from pests plays a crucial role in enhancing both yield and fiber quality [1]. The chemical method of protecting various agricultural crops from their primary pests is an integral part of the The American Journal of Agriculture and Biomedical 6 https://www.theamericanjournals.com/index.php/tajabe Engineering The American Journal of Agriculture and Biomedical Engineering Integrated Pest Management System (IPMS), as it From the second instar onward, larvae bore into fruiting occupies a central position in this strategy. Gradual bodies [7]. changes in Uzbekistan's climate—such as increased Biological characteristics: In spring, moth emergence precipitation and humidity in the spring, changes in the begins when the soil temperature at a 10 cm depth accumulation of effective temperatures, and the reaches 15–16 °C and the average daily air temperature redistribution of climatic parameters during autumn is 18–20 °C. Moth flight continues for over a month. The and winter-have led to significant changes in plant flight periods of different generations usually overlap diseases and the development patterns of various and may last until late October. Depending on the air insects. Notably, there has been a marked increase in temperature, adult moths live from 20 to 40 days. In fungal diseases that thrive in high-humidity autumn, pests accumulate in underdeveloped cotton environments [11]. fields, late-season maize, tomatoes, and other crops, Globally, cotton bollworms cause annual agricultural where most pupae overwinter [8]. crop losses exceeding $2 million in crops such as METHODS cotton, maize, vegetables, legumes, and others. Field trials were conducted when the infestation level of Meanwhile, control measures amount to nearly $1 cotton bollworm reached 9–10 larvae per 100 cotton million. In countries like China and India, nearly 50% of plants. The tests of the TRANIL 20% SC formulation, all insecticides are used against cotton bollworm. containing the active ingredient Chlorantraniliprole, Among the chewing pests of cotton, the cotton were carried out in the cotton field (And-36 variety) of bollworm holds a particularly significant role [12]. the “Yangi Diyor Fayzi” farm located in the Guliston Another critical reason for conducting such research is district, Sirdarya region. The treatment was applied the gradual decrease in the effectiveness of previously during the cotton budding and peak fruiting stages, recommended insecticides against target pests. This is under early morning conditions with a temperature of particularly evident in pyrethroids, where group and up to 23°C, wind speed of 1.0–1.3 m/s, and relative cross-resistance has developed in pests such as aphids, humidity of 55–60%. The working solution was applied whiteflies, and cotton bollworms [6]. Subsequently, at a rate of 300 liters per hectare using a battery- new classes of chemical compounds have gained powered sprayer (PT-16AC). popularity, including representatives of The distribution and damage caused by the pest were neonicotinoids-such as imidacloprid, acetamiprid, determined based on generally accepted methods thiamethoxam well as oxadiazines (e.g., Avaunt), [2;3;4;5]. The experiment included three variants: carbamates (e.g., Lannate), emamectins (e.g., experimental, control, and reference (standard), each Carrageenan), emamectin benzoates, and others, replicated three times. Pest population counts were which are now widely used against cotton bollworms. recorded before treatment, and on the 3rd, 7th, and The cotton bollworm was first described in the early 14th days after treatment. The effectiveness of the 19th century. Its main scientific name is Helicoverpa tested formulation was evaluated in comparison with armigera Hbn. (Hübner, 1805). Synonyms include the control variant. Field trials were conducted Chloridea obsoleta, Chloridea armigera, Helicoverpa following the methodology of Khodjaev Sh.T. (2023) [9], obsoleta, Helicoverpa barbara, Helicoverpa conferta, and biological efficacy was calculated using the formula Helicoverpa pulverosa, Helicoverpa uniformis, and developed by Püntener V. (1981) [16]. Helicoverpa rama