Spraying deposits using different nozzles and application volumes for pest management of cotton at reproductive stage

Abstract

With the growing need for greater operational capacity, information about the effect of application volume and spray nozzles on the quality of pesticide application are essential to obtain greater efficiency in pest management in cotton crops. This study aimed to assess the effect of the spraying volume and nozzles on the deposition of spray solution on cotton crops at the reproductive stage. The treatments of the first experiment correspond to the 55, 67, 140 and 194 L ha-1 volumes obtained by variation of the displacement speed using the XR11004 flat fan nozzle. In the second assay the treatments corresponded to the applications of MGA9004 (hollow cone), XR11004 (flat fan), AIXR11004 (air induction flat fan) and CVIA04 (air induction hollow cone) nozzles with 120 L ha-1. An artificial brilliant blue food dye (FD&C 1) was used as a tracer (2.5 g L-1) to determine the deposited volumes on the leaves of the upper, middle and lower third of cotton plants. The results showed that increase in the application volume contributed to obtain the larger deposits in the upper third of the cotton crop during its reproductive phase, especially up to 140 L ha-1, but did not exhibit a significant increase of the deposition in the middle and lower thirds of the plants. The MGA9004, XR11004 and AIXR11004 nozzles provided the largest deposits in the three plant sectors. The flat fan nozzles resulted in greater uniformity of deposits in the upper and middle thirds of the plants.

Ethological aspects of Helicoverpa armigera in the reproductive phase of cotton

“…When a caterpillar moves, the possibility of finding food with higher nutritional quality, encountering natural enemies (JOHNSON; ZALUCKI, 2005), or being hit by insecticide drops increases. According to CAVALIERI et al (2015) andCOSTA et al (2019), failure to reach the biological target is one of the factors which influences the efficiency of the insecticide applied in the reproductive phase of a crop. Therefore, identifying the time of day preferred by caterpillars to perform these behaviors is important when thinking about the ideal time to reach the target (caterpillar) via spraying.…”

“…It is known that the efficiency of applying phytosanitary products during the reproductive phase of a crop is affected by factors such as droplet size, spray volume, uniformity in spraying distribution, weather conditions, or even the failure to reach the biological target (CAVALIERI et al, 2015;COSTA et al, 2019). Thus, knowing the habits of a pest is essential so that control strategies are designed and achieve satisfactory results.…”

The Effect of Spraying with Micronutrients using Different Types of Nozzles on the Growth and Yield of Corn (Zea mays L.)

“…What Discovered [13]. The size, number, and percentage of droplet coverage on maize leaves achieved with this nozzle increased nutrient absorption and vegetative growth rates as a result of the speed of absorption and penetration through leaf tissue and stomata, and as a result increased the stem diameter [14]. Table 3.…”