Evaluation of Different Internal Designs of Hydraulic Nozzles under an Accelerated Wear Test

The use of worn-out agricultural nozzles in pesticide application has a negative effect on the efficiency and cost of the application process. It also has an effect on environmental pollution due to an excessive amount of pesticide being applied when spraying with worn-out nozzles. In this paper, the resistance to wear of three different internal design hydraulic nozzles was ascertained. Changes in the flow rate and spray distribution as a result of this wear were also investigated. The wear test was done inside a closed system, and it was accelerated using an abrasive material to generate 100 h of wear. The tested nozzles were the Turbo TeeJet (TT)-twin chambered, Turbo Twinjet (TTj60)-dual outlet, and Drift Guard (DG)-pre-orifice. Wear rate, flow rate, and the virtual coefficient of variation (CVv) were measured at different wear intervals. The results showed that the TTj60 type was the most resistant to wear, followed by the TT type and DG. The latter two types showed an increase in the flow rate only in the first 45 h of wear. Virtual coefficient of variation (CVv) values were less than 10% after finishing the test (after 100 h of wear) for the three types of nozzles, which are acceptable values according to International Organization for Standardization (ISO) 16122-2, 2015.

A look forward.

This chapter focuses on different management practices in growing cotton, including the use of genetically modified varieties, pesticide application, crop rotation, spacing, irrigation, weed control, integrated pest management and organic farming.

Identification of Factors Affecting Decisions to Adopt Pesticides at Lowland Rice Farms in Indonesia

Pesticides have been widely adopted in the farming industry to control weeds, pests, and diseases in order to minimize yield losses and maintain the quality of lowland rice products; however, farmers often over-apply pesticides. This study analyzed key factors that affected the decision of lowland rice farmers in adopting pesticides and the frequency of pesticide application. A double-hurdle model was used to estimate the factors that affected the decisions of farmers to adopt pesticides and determine the frequency of pesticide application. These results demonstrate that the adoption of pesticides was high (86%) at lowland rice farms in the study area. Lowland rice farmers were found to apply pesticides an average of eight times. Gender, age, education level, access to extension, farming experience, and access to credit significantly affected the decisions of farmers to adopt pesticides in controlling weeds, pests, and diseases at lowland rice farms. The independent variable also significantly affected the frequency of pesticide application. Towards the goal, government and non-government organizations had to increase human resources through education, agricultural extension services to young farmers had to be improved. Specifically, extension material was provided on environmentally-friendly methods of controlling weeds, pests, and diseases and other alternatives to reduce the use of pesticides at lowland rice farms.

Severe disturbance overflows the stabilizing buffer of variable biotic interactions

Recent studies have uncovered that biotic interaction strength varies over time in real ecosystems intrinsically and/or responding to anthropogenic disturbances. Little is known, however, about whether such interaction variability strengthens or weakens community resistance against disturbances. Here, we examine how the change in interaction strength after pesticide application mediates disturbance impacts on a freshwater community using outdoor mesocosms. We show that the change in interaction strength buffered the disturbance impact but amplified it once the disturbance severity exceeded a certain threshold. Importantly, we also show that interactions fluctuating more temporally under no disturbances were more changeable in response to pesticide applications. Our findings suggest that a severe disturbance may have a surprise impact on a biological community amplified by their own interaction variability, but the possibility still remains that we can predict the consequences of the disturbance by measuring the interaction variability before the disturbance occurs.

Control Efficiency and Mechanism of Spinetoram Seed-Pelleting Against the Striped Flea Beetle Phyllotreta Striolata

The striped flea beetle (SFB, Phyllotreta striolata) is an important pest of the cruciferous crops in Asia. SFB is regarded as the most destructive pest of cruciferous crops in China due to the severe crop loss and frequent infestation incidents. As no SFB resistant cultivar is available at present, therefore, application of insecticides is the primary method of SFB control. On the contrary, the exploitation of chemical insecticides causes severe environmental issues and is not cost-effective. The use of a seed-pelletized coating of spinetoram effectively reduced SFB feedings on the flowering cabbage seedlings, whereas in combination with the insect-proof net, it controlled the SFB infestation throughout the cabbage growth period. The analysis of the pesticide residues in soil and different cabbage parts indicated the degradation dynamics of spinetoram. Furthermore, estimation of the half-life of spinetoram revealed that via seed-palletized application spinetoram half-life was found to be 2.82 days in soil, 4.21 days in the root, 5.77 days in the stem, and 3.57 days in the leaf, respectively. Both the lower pesticide residues and the half-life of spinetoram in soil and cabbage parts suggested it to be a promising environment and food-safe pesticide in controlling SFB. Moreover, the seed-pelletized coating ensured a sustainable release of spinetoram that can reduce the pesticide application frequency and be cost-effective and pocket-friendly for the farmers.

Weather – based crop protection stewardship at Pattambi, Kerala

Kerala, a bowl of rice is continuously facing problem of using maximum pesticide for controlling outbreak of major rice pests. Weather data, synoptic conditions have been used to predict outbreaks of certain important tropical rice pests. Weather influences on the bionomics of pests is examined the context of forecasting outbreaks. The synoptic situations as well as weather based indices are considered to forewarn the outbreaks of stem borer and leaf folder at and around Pattambi, Kerala. An attempt is made to work out optimal time of pesticide application using weather based forewarning system approach with an aim to reduce the pesticide consumption and environmental pollution.

Differential local genetic adaptation to pesticide use in organic and conventional agriculture in an aquatic non-target species

Pesticide application is an important stressor to non-target species and can profoundly affect ecosystem functioning. Debates continue on the choice of agricultural practices regarding their environmental impact, and organic farming is considered less detrimental compared to conventional practices. Nevertheless, comparative studies on the impacts of both agricultural approaches on the genetic adaptation of non-target species are lacking. We assessed to what extent organic and conventional agriculture elicit local genetic adaptation of populations of a non-target aquatic species, Daphnia magna . We tested for genetic differences in sensitivity of different D. magna populations ( n = 7), originating from ponds surrounded by conventional and organic agriculture as well as nature reserves, to pesticides used either in conventional (chlorpyrifos) or organic agriculture (deltamethrin and copper sulfate). The results indicate that D. magna populations differentially adapt to local pesticide use. Populations show increased resistance to chlorpyrifos as the percentage of conventional agriculture in the surrounding landscape increases, whereas populations from organic agriculture sites are more resistant to deltamethrin. While organic agriculture is considered less harmful for non-target species than conventional, both types of agriculture shape the evolution of pesticide resistance in non-target species in a specific manner, reflecting the differences in selection pressure.

Reducing the Nursery Pesticide Footprint with Laser-guided, Variable-rate Spray Application Technology

Nursery producers are challenged with growing a wide range of species with little to no detectable damage from insects or diseases. Growing plants that meet consumer demand for aesthetics has traditionally meant routine pesticide application using the most time-efficient method possible, an air-blast sprayer, despite its known poor pesticide application efficiency. New variable-rate spray technology allows growers to make more targeted applications and reduce off-target pesticide loss. In this study, a prototype laser-guided variable-rate sprayer was compared with a traditional air-blast sprayer. Pesticide volume, spray application characteristics, and the control of powdery mildew were evaluated over the course of two growing seasons. Spray application characteristics were assessed using water-sensitive cards (WSCs) and DepositScan software. This prototype sprayer reduced pesticide volume by an average of 54% across both years despite being tested against a low rate (<250 L⋅ha−1). In 2016, the conventional sprayer had more than double the deposit density on target WSCs among distal trees than the variable-rate sprayer; however, within proximal trees, there was no difference between the two sprayer types. In 2017, when the trees were larger, within both the distal and proximal trees, the conventional sprayer had greater deposit density on target WSCs than the variable-rate sprayer. In 2016, coverage on target WSCs was nearly 7-fold greater with the conventional treatment than with the variable-rate treatment. In 2017, when trees were larger, there was greater coverage on target WSCs in proximal trees (3.8%) compared with those in distal trees (1.0%) regardless of the sprayer type. This variable-rate spray technology provided acceptable control of powdery mildew severity on individual branches and whole trees and maintained the incidence of powdery mildew to levels comparable to that occurring among trees sprayed with a traditional air-blast sprayer. Therefore, the variable-rate spray technology has the potential to effectively control disease, dramatically reduce the pesticide footprint, and preserve natural resources such as ground and surface water, soil, and beneficial insects found within and around nurseries.