ABSTRACT Improving the effectiveness of pesticide application for controlling insects, mites, and pathogens in coffee cultivation has been a major challenge for coffee farmers, researchers, and consultants. The present study aimed to assess the deposition and distribution of a brilliant blue tracer in the coffee canopy using Jacto’s Arbus 2000 Super Export EL and Kuhn’s Twister 2000 air blast sprayers at different application speeds (5 and 7 km h-1). The experiment was conducted using a randomized block design, with a 2 × 2 factorial arrangement (two sprayer models and two application speeds), with six replicates. After spraying, leaves were collected, and the deposition of the tracer was assessed using spectrophotometry. The canopy was divided into lower, middle, and upper heights, and subdivided into external and internal crown positions. The percentage difference in spray deposition between positions was termed relative spray deposition. Spray deposition in the internal crown differed only in the upper third section between sprayers. In the external crown, the application speed affected the deposition of tracer dye for both sprayers, whereas, in the internal crown, the application speed only affected the deposition of tracer dye in the upper crown section only when using the Arbus sprayer.

ABSTRACT. Chemical control is essential for efficient pest management in coffee crops. Application technologies should safely deliver insecticides to the target whilst protecting the environment, insecticide applicators, and consumers. To achieve these goals, application volumes, hydraulic nozzles, and application techniques should be evaluated. This study assessed the biological efficiency of different spray volumes and spray nozzles used to apply insecticides to control coffee berry borer (Hypothenemus hampei) populations. We applied insecticides using a hydropneumatic sprayer with and without an electrostatic spraying system. The experiment followed a randomized block factorial design (2 × 2 + 1) and included two types of spray nozzles [a hollow cone spray nozzle (JA1) and a hollow cone spray nozzle with air induction (TVI)], two spray volumes (200 and 400 L ha-1), one additional treatment (SPE2 nozzle with a 200 system 200 L ha-1), and six replicates. We assessed the control efficiency of the different application methods by evaluating the percentage of fruits damaged 20 and 40 days after the date of application. The spray volume did not affect the biological efficiency of pest control, and the lower spray volume (200 L ha-1) was effective in the control of coffee berry borers. Application of insecticides using coarse droplets was more efficient than the application using very fine and fine droplets. The TVI hydraulic spray nozzle effectively controlled coffee berry borers at 200 and 400 L ha-1. The electrostatic application system performed similarly to the conventional system in terms of the control of the coffee berry borers, and was less efficient than the conventional system under some operational conditions.

ABSTRACT The use of remotely piloted aircrafts (RPAs) to apply plant protection products has grown a lot in agriculture worldwide. However, little research data are available regarding the efficiency and safety of this method, especially in Brazil. Thus, this review aimed to present the current scenario of scientific research involving RPAs in the application of pesticides. Several factors interfere with the quality of this type of application. Among them are height and flight speed, droplet generator elements, application rate, and spray solution properties. In general, applications have been performed between 1.0 m and 3.0 m of height and 1.0 m s-1 and 7.0 m s-1 of speed. As for the droplet generator element, there is still no clarity as to the ideal system. Efficacy studies involving RPA applications demonstrate the potential of this method in replacing applications performed mainly by using knapsack equipment in an effort to reduce occupational risks. However, it is essential to observe the advantages of RPA use, while also taking into account the risk of drift. The aerodynamic effect in the droplets, qualified personnel, appropriate formulations, regulations, and details in labels are challenges that still need to be addressed for this new technology to be successful.

ABSTRACT Coffee production faces challenges due to the susceptibility of the crop to insects. Owing to the coffee leaf miner Leucoptera coffeella, which is one of the main insect pests, the technology for the application of phytosanitary measures becomes the main challenge for coffee growers. This study aimed to evaluate the effectiveness of coffee leaf miner control using different methods of application. The study was conducted in an experimental site in the municipality of Monte Carmelo - Minas Gerais. Spray depositions in different positions of the plant canopy and the effective control of coffee leaf miner were evaluated using the following application treatments: a hydropneumatic sprayer with varying spray volumes (200 and 400 L ha-1), two hollow-cone spray nozzles with the presence and absence of agricultural adjuvant, and electrostatic application using a spray volume of 200 L ha-1 with and without spray adjuvant. The addition of an adjuvant to the spray did not influence coffee leaf miner control; in contrast, a spray volume of 200 L ha-1 combined with the application of coarse droplets was efficient in the management of insect pest. The reduction in the rate of the application using coarse droplets increased the operational capacity and reduced spray drift potential.

ABSTRACT Stenoma catenifer is considered the main pest of avocado, making impossible to commercialize the infested fruits. This study was conducted with the objective of evaluating the potential of Heterorhabditis amazonensis MC01 in the field control of avocado borer, as well as the nematode release method. Two treatments were tested, namely: release of dead Tenebrio molitor infected with the nematode and hydraulic nematode spraying; hydraulic application of chemical insecticides was used as a control. The experiment was set up in a randomized complete block design with 15 replicates. The concentration of suspension distribution was 5,500 infective juveniles per m2. At the experimental area traps with sex pheromone were installed to capture adult males. The number of borer fruits was evaluated in the two central plants of each plot, sampling 4 fruits per plant. There was a reduction in the percentage of borer fruits from 15 days of application for all control methods. After the release of nematodes, the adult population was similar to the control, and it can be inferred that, even without chemical control, there was no increase in the number of adults. Thus, H. amazonensis was considered promising under field conditions, reducing the populations of S. catenifer, in all release methods.

RESUMO Condições meteorológicas adversas, ou problemas mecânicos e redução na taxa de aplicação, podem aumentar o tempo de armazenamento da calda no tanque do pulverizador. Objetivou-se avaliar o efeito do armazenamento da calda fitossanitária na germinação de conídios de Beauveria bassiana, com e sem adjuvantes. Utilizou-se delineamento experimental inteiramente casualizado, em esquema fatorial 13 x 5, composto por treze períodos de armazenamento (0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44 e 48 h) e cinco composições para a calda de pulverização (B. bassiana, B. bassiana + Helper Neutrum, B. bassiana + TA-35, B. bassiana + Nimbus e B. bassiana + Orobor). A calda biológica contendo conídios de B. bassiana sem adjuvantes manteve-se viável para uso após seu preparo e a germinação dos conídios reduziu-se 9,2 vezes após 48 h com a adição de adjuvante.

ABSTRACT Adverse weather conditions, or mechanical problems and decrease in the application rate, may increase the storage time of the spray solution in the sprayer tank. This study aimed to assess the effect of the phytosanitary spray solution storage on the germination of Beauveria bassiana conidia, with or without agricultural adjuvants. A completely randomized design was used, in a 13 x 5 factorial scheme, consisting of thirteen storage times (0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44 and 48 h) and five compositions for the spray solution (B. bassiana, B. bassiana + Helper Neutrum, B. bassiana + TA-35, B. bassiana + Nimbus and B. bassiana + Orobor). The biological spray solution containing B. bassiana conidia and no adjuvants remained viable for use after preparation and the conidial germination decreased 9.2 times after 48 h when an adjuvant was added.

Resumen El control biológico es una alternativa al control químico, sin embargo, algunos métodos para su aplicación aún requieren ser mejorados para que atraigan la atención de los usuarios y minimizar costos. En este sentido, este trabajo se llevó a cabo para evaluar el efecto de boquillas de pulverización hidráulica sobre la viabilidad y la infectividad de nematodos entomopatógenos. El experimento tuvo un diseño de bloques completamente al azar, con 37 tratamientos, tres controles y 34 boquillas de pulverización con seis repeticiones. Para las aplicaciones, se utilizó una mesa de pulverización con una presión de 400 kPa. Durante el experimento, se asperjó una suspensión acuosa del nematodo Heterorhabditis amazonensis MC01 a una concentración de 400 juveniles infectivos (JI) ml-1. Se verificó la viabilidad de los JI después de haber sido pulverizado y su infectividad en larvas de Tenebrio molitor. Los resultados indicaron que la viabilidad de nematodos fue influenciada por las boquillas de pulverización hidráulica pero que aquellos viables, no perdieron su capacidad de infectar al insecto.

Abstract Biological control is a viable alternative to chemical control; however, some methods of releasing control agents still need to be improved in order to attract the attention of producers and to reduce costs. Therefore, this work was conducted to evaluate the effects of hydraulic spray nozzles on the viability and infectivity of entomopathogenic nematodes. The experiment was conducted using a completely randomized design with 37 treatments, of which there were three controls and 34 treatments using different spray nozzles with six repetitions. A spraying table was used for the applications. The working pressure was 400 kPa for all nozzles and the solution sprayed consisted of an aqueous suspension of the nematode Heterorhabditis amazonensis MC01 at a concentration of 400 infective juveniles (IJ) mL-1. The viability of the IJ after being sprayed, as well as the infectivity of Tenebrio molitor larvae were verified. The results indicated that nematode viability was influenced by the nozzles and the living nematodes sprayed did not lose their capacity to infect the insect.