A. Hosseini, M. Hosseini, M. Goldani, J. Karimi, H. Madadi,
Volume 17, Issue 6 (11-2015)
Abstract
Reducing nitrogen status of floriculture plants is an effective tactic in pest management by decreasing host plant quality. Life table parameters and population growth rate of Aphis craccivora(Hemiptera: Aphidiae), as well as cosmetic and qualitative parameters losses associated with aphid infestation were evaluated in relation to N fertilization levels on Gomphrena globosa, under greenhouse condition. Four N fertilization levels (0, 30, 60, and 100% of recommended 2 kg m-3) were used. The results indicated that aphid’s intrinsic rate of natural increase on plants fertilized with 100% of the recommended N level was the highest. Abundance and population growth rate of aphid also positively correlated with N fertilization levels. The interactive effect of aphid population and N fertility significantly affected growth parameters of the plants. In the absence of aphid, plant yield improved linearly with increasing N levels. However, aphid population highly decreased shoot to root ratio and the number of flowers in plants fertilized with 100% of the recommended N level. According to our findings, fine-tuning fertility to reduce A. craccivora population is a steadfast tactic to produce marketable globe amaranth ornamental plant.
S. Mirzamohammadi, M. Hosseini, J. Karimi, H. Sadeghi, T. Darvish Mojeni,
Volume 21, Issue 3 (5-2019)
Abstract
Ant-aphid mutualism may increase or decrease plant yield. This depends on the relative cost of damage by ant-tended aphids versus the relative benefit of ant suppression of other (non-aphid) herbivores and associated yield losses. To evaluate the effect of mutualism between cotton aphid, Aphis gossypii, and brown ant, Lasius brunneus, on the productivity of cotton plant, a field experiment was conducted in the presence or absence of ants in the Cotton Research Center of Golestan province (Iran), in 2014. During the two-month test, the numbers of A. gossypii and visiting ants L. brunneus as well as Coccinella septempunctata and Helicoverpa armigera on each plant were counted in four-day intervals and, finally, the yield of cotton plants was measured. Ant presence significantly increased the abundance of cotton aphid, whereas the ant with suppression in presence of C. septempunctata and H. armigera significantly reduced their abundance. Regardless of the increase in the abundance of A. gossypii, cotton plant yields significantly increased in the presence of L. brunneus. This could be due to the effect of ant presence and the reduction of H. armigera abundance and the associated yield losses on cotton plant. In general, the results of the current study showed that indirect benefits of ant-aphid mutualism influence cotton plants by suppression of H. armigera damage. Since this pest causes serious damage on cotton plant, increasing attention to the role of ant predation is economically useful.
