INTRODUCTION Because of the increasing need for ecological agricultural production combined and plant raw materials for food production, the use of some branches of the industry in new research and making safe decisions to increase agricultural production is necessary (Faqenabiet al., 2009). Arid and semi- arid regions are facing a shortage of water resources, yet there is a lot of agricultural land in these regions. Extending methods that can reduce water consumption in these areas is necessary. One such method is the use of transplanting in agricultural lands for vegetable production. Transplanting is the most reliable method for better plant establishment which benefits from increased land productivity, a reduced growing season, and improved weed control (di Benedetto and Rattin, 2008). Transplanting plays an effective role in reducing the growth period, and decreasing production time on the farm can increase the efficiency of using inputs such as water and thus reduce production costs (Wien, 1997). Healthy and strong transplants are required for good plant establishment. In recent years, some new methods such as ionization, laser radiation, ultraviolet radiation, magnetic and electrical fields have been used to enhance germination rate and other plant characteristics. The effects of a magnetic field on seed germination and the growth of target plants have been investigated. Studies were performed for the first time by Savostin (1930), who observed increased grain seedlings in wheat under magnetic field conditions. After that, Murphy (1942) reported changes in seed germination caused by the effects of a magnetic field. Physical methods such as magnetic field for stimulating do not change the direction of the physiological processes controlled by the genetic systems of the plant. In other words, physical methods stimulate growth and metabolic processes without genetic manipulation (Radhakrishnan and Ranjithakumari, 2012). Therefore, the application of optimal amounts of physical methods for seeds and plants has no genetic effects on the plant and will not be transmitted to the next generation (Vasilevski, 2000). The results of some studies have indicated that MF has a positive effect on the number of flowers and yield, nutritional reserve, and water absorption of plants. Hence, magnetic therapy with proper intensities at appropriate times can be a kind of harmless environmental technology (Carbonell et al., 2004). Stimulating plants use magnetic fields as a way to replace fertilizers and supplements. Chemical and physical treatments reduce the amount of pesticides in vegetable raw materials and increase the health of the food and the environment (Vasilevski, 2003; Dhawi et al., 2009). It has been reported that a magnetic field also affects the activity of ions and the polarization of bipolar molecules in living cells (Kordas et al., 2009). The cells of the plant have a negative charge that can absorb positive charge ions. Cytochemical studies have shown that root cells exhibit a weak magnetic field to control cells and show a state of calcium saturation in all their organelles and cytoplasm (Dhawi et al., 2009). A magnetic field can increase the release of free radicals and cause stress Pak. J. Agri. Sci., Vol. 58(2), 439-446; 2021 ISSN (Print) 0552-9034, ISSN (Online) 2076-0906 DOI: 10.21162/PAKJAS/21.9505 http://www.pakjas.com.pk EFFECT OF MAGNETIC TREATMENT ON STRONG CUCUMBER ( Cucumis sativus L.) TRANSPLANT PRODUCTION Moradali Ghanbarpouri*, Ahmad Mohamadi Ghahsareh, Mitra Attaabadi 3 and Mehran Hodaji Islamic Azad University of Isfahan, Iran * Corresponding author’s e-mail: moradghanbari@gmail.com Cucumber is one of the most popular greenhouse products. Iran produces more than two million tons of this product annually, making it the third largest cucumber producer in the world after China and Turkey. Therefore, attention to maintaining its quality during harvesting is necessary. The present study was conducted to investigate the effects of the intensity and duration of a magnetic field on germination and cucumber transplant growth parameters. Experiments were conducted in a factorial arrangement in a completely randomized design with two treatments including magnetic field intensities in three levels (S1=80, S2=140, S3=240 millitesla), and magnetic field duration in four levels (T1=5, T2=10, T3=15, T4=20 minutes) with three replications. The root length, stem length, leaf area index, root weight, germination percentage, leaf chlorophyll content, and shoot dry weight were measured. The results of the analysis of variance showed that the effect of magnetic field on root length, stem length, leaf area, root weight, germination, and chlorophyll content is statistically significant. There was no significant effect on dry weight. The magnetic field intensity of 140 mT for 5- and 10-minute durations or a high intensity with low duration had more effect on plant growth compared to the blank. It is recommended that other intensities and durations of magnetic fields also be tested. Keywords: Seed germination, magnetic field intensity, magnetic field duration, chlorophyll content, cocopeat molds