Showing 4 results for Chemical Control
B. Bahraini-Nejad, M.r. Khajehpour,
Volume 3, Issue 3 (10-1999)
Abstract
Combining herbicides for controlling broadleaf weeds and grasses in wheat farms has not been studied under Isfahan environmental conditions. Thus, this experiment was conducted in 1995-96 at the Agricultural Research Station, Isfahan University of Technology, in order to investigate the issue. In this study, 2,4-D+MCPA (U46 Combi Fluid 6), bromoxynil, metribuzin, diclofop-methyl and tralkoxydim and their combinations in 11 treatments plus weed-free and weedy checks were evaluated using a randomized complete block design with 4 replications. Goldbachia laevigata and Avena fatua were the dominant weeds. Cirsium arvense and Convolvulus arvensis were of less importance. Efficacy of bromoxynil on annual broadleaf weeds was higher than 2,4-D+MCPA, while 2,4-D+MCPA was more effective on perennial broadleaf weeds. Diclofop-methyl and combination of bromoxynil with tralkoxydim were the most effective on A. fatua, while differences between treatments containing diclofop-methyl or tralkoxydim on decreasing A. fatua numbers were non-significant. The most and the least visual damages to wheat plants were caused by metribuzin and bromoxynil, respectively. Wheat yield was not significantly affected by treatments. However, the highest yield was obtained by tralkoxydim + bromoxynil treatment, which produced the lowest total dry weight of weeds at terminal spikelet and heading stages of wheat. The results obtained here indicate that combination of bromoxynil with tralkoxydim might be the best treatment for the control of all annual weeds under conditions similar to this experiment. But if perennial broadleaf weeds and wild oat are dominant in the field, combination of 2,4-D+MCPAwith diclofop-methyl might be preferred.
A. Jozyan, R. Ebadi,
Volume 5, Issue 4 (1-2002)
Abstract
In order to study the efficacy of Sunn pests' parasitoid flies, four overwintering sites of Sunn pest in Isfahan, including mountains of Kolahghazy, Panjeh, Jozdan and Sacepid were selected and from each site four different elevations were designated as sampling sites. During 1997, at least 6 and, in 1998, three samples were taken at each sampling site. In spring 1998, four wheat and barley fields were selected from Mahyar, Zeyar, Shahinshahr and Lavark regions and from each field eight samples were taken. In order to observe the larvae of parasitoids and to determine their efficiency, 100 Sunn pests were dissected from each sampling unit of aestivation, overwintering, wheat and barley fields.
The parasitism of prevalent species (Phasia subcoleoptrata L.) in spring 1998 was 15.39% for the 1st generation and 1.5% in 1997 and 3.5% in 1998 for the second generation of the pest. All other parasitoid species parasitized less than 1% of the pest population. In some regions, such as Lavark and Zeyar, chemical application against nymphs of Sunn pest were accomplished in spring 1998 at the peak of adult activity of parasitoids' 2nd generation. This application had negative effects on the population of parasitoids but in Shahinshahr where chemical application was accomplished at pupal stage of parasitoid, it did not have any direct adverse effects on the population of dominant parasitoid.
J. Shakarami, E. Bazgir, M. Feizian,
Volume 10, Issue 3 (10-2006)
Abstract
To search for reproducible and environment-friendly antifungal agents, essential oils of five plant species including Myrtus communis, Mentha aquatica, Vitex agnus-castus, Thymus daenensis and Artemisia aucheri were studied for their inhibition effects on the mycelial growth of plant pathogenic fungi including Fusarium oxysporum, Pythium ultimum, Rhizoctonia solani and Gaeumannomyces graminis. The experiment was conducted using a completely randomized design of factorial experiment including three essential oil concentrations and three replications at 25±2 ºC on PDA. Results revealed that R. solani with 48.83 and P.ultimum with 89.62% mean of mycelial growth inhibition were the most resistant and the most susceptible fungi to the essential oils, respectively. The essential oil of M. aquatica and T. daenensis with 93.70 and 92.74% mean of mycelial growth inhibition showed the most inhibition effect and V. agnus-castus with 33.88% was the least mycelial growth inhibitor. The essential oil of M. aquatica and T. daenensis at 20 µl/petri plate (9 cm. in diameter) completely inhibited the mycelial growth of the tested fungi. Considering the high antifungal effect, and low human and environmental hazard of essential oils, it seems that the essential oils may be used for the control of plant pathogenic fungi, or at least they may be adopted as a model for the synthesis of new antifungal agents.
V Zabihollahi, F Maighany, M Baghestany, M Mirhady,
Volume 13, Issue 47 (4-2009)
Abstract
To study the goosegrass (Eleusine indica (L.) Gaertn.) in tall fescue (Festuca arundinacea Schreb.), an experiment in 15-year old turf was conducted during 2006 in Tehran in Sheikh Fazlollah highway using randomized complete block design with 4 replications in 1*1 m2 plots. Treatments were diclofop methyl at 2.5 and 3 Lha-1, fenoxaprop-p-ethyl at 0.8 and 1 Lha-1, clodinafop propargyl at 0.6 and 0.8 Lha-1, tralkoxydim at 1 and 1.2 Lha-1, sulfosulfuron at 27 and 35 gha-1 and untreated control. All treatments were repeated 3 times during the growing period of goosegrass. The results showed that after the last spraying, diclofop methyl at 2.5 and 3 Lha-1, fenoxaprop-p-ethyl at 0.8 and 1 Lha-1, clodinafop propargyl at 0.6 and 0.8 Lha-1 decreased goosegrass's biomass up to 81, 83.64, 81.26, 78.58, 80.27 and 81.26 percent, respectively and goosegrass's density up to 82.5, 83.13, 79.38, 79.38, 78.75 and 80.63 percent, respectively, without significant differences. Treatment after 2 times of spraying controlled goosegrass more than 80 percent. Tralkoxydim and sulfosulfuron decreased goosegrass' biomas and density about 70 and 60 percent, respectively. One week after the last spraying, diclofop methyl, fenoxaprop-p-ethyl and clodinafop propargyl treatments did not decrease tall fescue's biomass without significant differences with untreated control. Turf biomass was decreased by tralkoxydim at 1 and 1.2 Lha-1 and sulfosulfuron at 27 and 35 gha-1, by 37.54, 36.79, 40.48 and 48.55 percent, respectively. Herbicide treatments made visual rating by 49.38, 48.75, 48.75 and 50.63 percent, respectively. Overall, diclofop methyl at 2.5 Lha-1, fenoxaprop-p-ethyl at 0.8 Lha-1 and clodinafop propargyl at 0.6 Lha-1 can be recommended for goosegrass control in tall fescue because of insignificant differences between both their doses, bio-environmental problems, costs, and no damage to tall fescue.
