Standard Sprayer Research Articles

Effect of Orange and Cinnamon Oil on the Occurrence and Harmfulness of Thrips tabaci Lind on Onion – Preliminary Results

Abstract The aim of the present research work was to investigate the effect of orange and cinnamon oil on the occurrence and harmfulness of Thrips tabaci Lind on onion. In 2014, the nonchemical treatment was made with Prev-B2 (the concentration of 0.4%), which contains: 4.2% of orange oil, 2.1% of boron and product Canol 70% p/p exstract of Cinnamomum zeylanicum. In 2015, only Prev-B2 product was used. The standard sprayer was used and the treatments were done: twice in 2014 and three times in 2015. The thrips were collected directly from the leaves, using standard sweeping nets. The plants were examined to find the leave damages caused by feeding thrips. In 2014, Thrips tabaci was recorded from 11 June to 19 August, whereas in 2015 from 24 June to 4 August. Over two years of observations, the highest number of thrips was collected from onion growing on control plots (not treated with any preparation). Also, the mean percentage of areas damaged on the onion leaves was significantly higher on control plots than on plots treated with cinnamon oil in 2014 and orange oil in 2015.

Comparative performance of recycling tunnel and conventional sprayers using standard and drift-mitigating nozzles in dwarf apple orchards

The use of tunnel sprayers should be encouraged because they can potentially reduce pesticide input and drift in orchards. They could also allow smaller plot size in multifactorial trials in which fully randomized or randomized block designs are recommended. However, the effectiveness of plant protection products applied with tunnel sprayers cannot be reliably assessed without a thorough investigation into spray distribution in tree canopies. A set of three experiments was undertaken in an apple orchard to compare a new type of recycling tunnel sprayer with a standard axial fan sprayer, both of them fitted with either conventional hydraulic hollow cone nozzles (ATR) or drift-mitigating air induction cone nozzles (TVI). Its performance was assessed in terms of 1) spray deposit and coverage in the canopy, 2) sedimentation drift (spray drift to the ground) and 3) collection and recycling rate of the liquid sprayed in the tunnel. Artificial targets composed of cellulose papers and water-sensitive papers were used to evaluate the spray deposit and coverage at similar target positions for each treatment. A fluorescent dye was used as the spray tracer. The study showed that, when using the ATR nozzles, the spray deposit, at each sampling point in the tree canopy, produced by the tunnel sprayer was not significantly different from that produced by the standard sprayer. The spray deposited on the top of the trees when using the TVI nozzles, however, was significantly less than with the standard sprayer. At the same spray deposit level, the spray cover on the canopy, estimated by image analysis, was relatively better with the standard sprayer than with the tunnel sprayer. At the same spray deposit level, the TVI nozzles resulted in significantly poorer spray cover of the canopy than the ATR nozzles. At low wind speeds, the sedimentation drift varied on average from 5.8 to 9.1% of the total sprayer output, irrespective of the type of sprayer or nozzle. The overall mean of the sedimentation drift was not significantly different for the two types of sprayers. The recovery system, which included a continuous recycling process in the tunnel sprayer, led to average savings of 28 and 32% of the applied spray mixtures for the ATR and TVI nozzles, respectively. The tunnel sprayer might therefore be suitable for small-scale apple orchards when fitted with traditional ATR nozzles rather than with air-induced TVI nozzles.

Field Evaluations of Concentrated Spray Applications of Microencapsulated Sex Pheromone for Codling Moth (Lepidoptera: Tortricidae)

The application of a microencapsulated (MEC) sex pheromone formulation (Checkmate CM-F) for codling moth, Cydia pomonella (L.), in low volume, concentrated sprays was evaluated in a series of small plot and grower trials in apple, Malus domestica Borkhausen, and pear, Pyrus communis L. Preliminary tests found that MEC sprays applied at 172-207 kilopascals in 12-23 liters/ha deposited the highest density of microcapsules per leaf. The addition of a latex sicker did not increase the deposition of microcapsules. Small plot tests in 2004 compared the effectiveness of two low-volume sprayers against a standard high-volume spray (926 liters/ha) applied at 1,379 kilopascals. Moth catches and fruit injury were significantly lower in plots treated with the low-volume sprays compared with plots treated with the standard sprayer. These results suggest that concentrating the MEC formulation increases the deposition of microcapsules and improves its effectiveness. Larger trials were conducted with a low-volume sprayer in 4-ha plots within commercial apple (2005-2006) and pear orchards (2005) paired with similar plots treated with hand-applied pheromone dispensers. Levels of fruit injury were not significantly different between pheromone treatments in any of the three tests. Moth catches, however, were significantly higher in the MEC- versus the dispenser-treated apple plots in 2005. No difference was found in the fruit injury levels in MEC-treated apple orchards in 2005 caused by irrigation method, but moth catches were significantly higher in overhead versus undertree orchards. The advantages and current limitations of using MEC sex pheromone sprays to supplement current grower's management strategies for codling moth is discussed.

Influence of Spray Application Parameters on Deposition in an Asparagus Crop

A commercial air-assisted sprayer was tested in asparagus crop using a water-soluble food dye as a tracer. The machine had been modified by lowering the nozzles and the air outlets by 20 cm, in order to match more close by the geometry of the asparagus crop canopies and to improve deposition at the base of the stems. Several tests were performed to investigate how deposition was affected by various treatments, including: the number, position and size of the nozzles; the spray volume rate; the presence or absence of air assistance; the spray output angle, relative to the travel direction; and the forward speed. The most uniform deposition was obtained with: four nozzles per side (the lowest at a height of 46 cm from the ground), directed horizontally; an air flow rate of 6·1 m3/s; and a forward speed of 1·69 m/s. This adjustment was eventually compared with the standard sprayer setting, showing that total deposition on the canopy could be increased from 48·4 to 65·6% of the dose applied, without substantially increasing spray losses to the ground.

Air-assisted spraying of arable crops, in relation to deposition, drift and pesticide performance

Field experiments comparing spray deposition, spray drift and the biological efficacy of one herbicide and a number of fungicides in several crops treated by hydraulic nozzle sprayers and a novel air-assisted sprayer (Degania) are reported. Air-assisted sprays using fine-spray hollow-cone nozzles spaced at 25 cm were compared with coarser sprays applied at similar or greater volumes from standard hydraulic pressure nozzles. The quantity of spray deposited on different crop types was generally similar from both methods of application, but the uniformity of droplet distribution from the air-assisted system was usually superior. The air-assisted sprayer generally produced more drift than the standard sprayer. All spray methods generally produced similar biological results at full and half pesticide dose rates. A Brussels sprouts crop normally considered as being difficult to spray showed some biological benefits from air-assisted spraying.