Natural pesticides for pest control in agricultural crops: an alternative and eco-friendly method

Biological pesticides are pesticides derived from natural materials such as bacteria, plants, and minerals that are applied to crops to kill pests. Biopesticides are targeted, inexpensive, eco-friendly, sustainable, leave no trace, and are not associated with the production of greenhouse gases. It contributes significantly to the agricultural bio-economy's sustainability. The advantages to the ecosystem provided by many significant biological resources justify the incorporation of biopesticides in Integrated Pest Management (IPM) programs. Through advancements in research and development, the use of biopesticides has significantly reduced environmental contamination. The development of biopesticides promotes agricultural modernization and will surely result in a gradual phase-out of chemical pesticides. Although synthetic pesticides have positive effects on crop yield and productivity, they also have some negative impacts on soil biodiversity, animals, aquatic life, and humans. In general, synthetic pesticides make the soil brittle, decrease soil respiration, and reduce the activity of some soil microorganisms, such as earthworms. Pesticide buildup in bodies of water can spread from aquatic life to animals including people, as their biomagnification can cause fatal diseases like cancer, kidney disease, rashes on the skin, diabetes, etc. Biopesticides, on the other hand, have surfaced and have proven to be quite beneficial in the management of pests and are safe for the environment and hence have emerged as very useful in the control of pests with a lot of merits.  The present review provides a broad perspective on the different kinds of pesticides. We analyzed suitable and environmentally friendly ways to improve the acceptance and industrial application of microbial herbicides, phytopesticides, and nano biopesticides for plant nutrition, crop protection/yield, animal/human health promotion, as well as their potential integration into the integrated pest management system

Based on a Markov Model

This paper considers the problem of assessing the reliability of a software system that can be decomposed into a finite number of modules. It uses a Markovian model for the transfer of control between modules in order to develop the system reliability expression in terms of the module reliabilities. An operational test procedure is considered in which only the individual modules are tested and the system is considered acceptable if, and only if, no failures are observed. The minimum number of tests required of each module is determined such that the probability of accepting a system whose reliability falls below a specified value R0 is less than a specified small fraction β. This sample size determination problem is formulated as a two-stage mathematical program and an algorithm is developed for solving this problem. Two examples from the literature are considered to demonstrate the procedure

(Senior Member, IIE) Associate Professor of Industrial Engineering

Since mathematical models based on component reliabilities are frequently used for prediction of system reliability, it stands to reason that cost-effective inferences on the reliability of a system could be made on the basis of tests of its constituent components. Prior research in the area of system-based component testing has for the most part addressed the development of plans that test only the components. From a practitioner's point of view, this is an issue of concern since system failures are often caused by imperfect interfaces and other causes that are not directly attributable to component failures. The exclusion of system tests may thus be unappealing. This paper addresses the development of test plans that explicitly consider the possibility of interface failures. The paper analyzes a series system to determine when testing should be performed on the system alone, on the components only, and on both, depending on test costs and interface reliabilities. Optimum test plans a..

Minimum Cost Test Plans for a Series System with Imperfect Interfaces

In order to draw cost-effective inferences on the reliability of a system one approach is to design test plans that only test the components of the system. However, such an approach is inappropriate when the component failures are not independent or when interfaces between components cause system failures. In such instances one must plan on testing the system as well as its components and a natural question of interest is the relative extent to which the system and the components should be tested. This paper analyzes such a situation for a series system and determines the optimal plan for allocating the total testing effort between component and system tests. It also illustrates the use of mathematical programming techniques for obtaining test plans that guarantee conventional statistical properties. Running Title: Optimum Test Plans Key Words: Reliability, Mathematical Programming, Series System, Test Plans AMS Subject Classification: 62 Statistics, 90 Economics, operations research..