Showing 24 results for Hatami
B. Hatami, J. Khajehali, M. R. Sabzalian,
Volume 12, Issue 45 (fall 2008)
Abstract
Safflower having oil with high unsaturated fatty acids is a very valuable plant. However the sensitivity of safflower to some pests as safflower fly (Acanthiophilus helianthi), particularly in drought stress conditions has limited its production. In order to evaluate the effect of drought stress on population density and damage of important safflower pests, especially safflower fly, an experiment was conducted in the field using 5 irrigation treatments including 50, 70, 90, 110 and 130 mm evaporation from class A pan in a randomized complete block design with three replications. The local safflower variety used in this study was Isfahan land variety, Kooseh. In each irrigation regime, the half of one plot was locally sprayed by Chlorpyrifos in 2ml per liter of water to be compared with non-sprayed part. During 8 weeks of sampling, population of aphids, Uroleucon carthami, leafhopper, Empoasca decipiens and safflower fly, A. helianthi and also percentage of damaged heads by safflower fly were measured. The results showed that in non-sprayed conditions, the highest safflower fly (2.38 flies per net) and aphid population (165.57 aphids per plant) was observed at 130 mm evaporation regime. Drought stress also decreased (30.23 %) safflower seed yield. Severe drought stress together with non-spaying may increase safflower pests population particularly safflower fly and reduce seed yield. However low level of drought stress (70 mm evaporation from class A pan) may decrease relative number of insects and save irrigation water. Drought stress also decrease the population of leafhopper. In this study, 70 mm evaporation regime was the optimum irrigation treatment regarding lower aphid and fly damage (15.86% damaged heads in non-sprayed condition) and higher safflower seed yield (1687.5 kg/ha in sprayed condition).
M. Mehrparvar, M. Mobli, B. Hatami,
Volume 12, Issue 45 (fall 2008)
Abstract
Rose is one of the most important ornamental shrubs of the world because of its durability, long period of flowering, different cultivars and its beauty. The rose aphid, Macrosiphum rosae is the most important pest of the rose which causes significant economic damage annually. In order to compare four rose cultivars including Black Magic, Caramba, Noa and Good Life, and a wild rose, Nastaran, infested with rose aphid, a split-plot in time experiment was arranged in randomized complete block design layout with three replications, in Isfahan (Iran) from February 2004 to March 2005. The infestation levels of roses with the rose aphid and its seasonal fluctuations were determined by weekly sampling. Analysis of data showed that there are significant differences (P<0.01) between cultivars. Noa (with pink flowers) has the highest infestation of rose aphid (with average 23.12 ± 0.036 aphids) and Caramba (with yellow flowers) has the lowest infestation (with average 6.46 ± 0.036 aphids). The wild rose, Nastaran, showed low infestation (with average 8.76 ± 0.036) as well. Different sampling times also showed significant differences (P<0.01). There was a significant interaction (P<0.01) between cultivars and sampling date, such that reactions of cultivars to aphid (nymphs, adults and total) were not similar in different sampling dates. Seasonal fluctuations of the rose aphid showed two peaks in a year, in May and December. Activity of the rose aphid in spring which coincides with rapid growth and tenderness of rose foliage causes severe fading and inhibiting of floral opening.
H. Hatami, A. Karimi, A. Fotovat, H. Khademi,
Volume 18, Issue 69 (fall 2014)
Abstract
Organic acids play an important role in improving the bioavailability of soil nutrients. The objectives of this study were to determine the effect of oxalic acid on the release of soluble, exchangeable and non-exchangeable forms of K from micaceous minerals and potassium feldspars, and also to investigate the trend of K release by time. A laboratory study was carried out using a completely randomized design with two replicates. Biotite, phlogopite, muscovite, Zanjan and Yazd K-feldspars (< 50 μm size) were treated with 0, 10 and 100 mM of oxalic acid solutions for a period of 5 hours and 20, 60 and 90 days. The amount of K was determined by flame photometer. The results indicated that most amount of soluble, exchangeable and no-exchangeable K was released by 100 mM of oxalic acid. The maximum soluble K (0.86 gKg-1) was released from phlogopite, and the maximum exchangeable and non-exchangeable K (1.5 and 29.6 gKg-1, respectively) were released from biotite. Muscovite with 0.19, 0.34 and 1.41 gKg-1 of soluble, exchangeable and non-exchangeable K, respectively, had the lowest release of K among the studied minerals. The kinetics K release from minerals consisted of two phases. The first phase was relatively rapid and then it had a slow rate until the end of the experiment. Given that the applied concentration of organic acid was high, potassium release during the experiment period did not reach the steady state. Therefore, a longer period of release experiment is suggested.
J. Khajehali, M. Kohansal, B. Hatami, M. Mobli,
Volume 22, Issue 2 (Summer 2018)
Abstract
The grape leafhopper, Arboridia kermanshah Dlabola (Hemiptera, Cicadellidae), is an economically important pest of most vineyards in Isfahan. The effects of two irrigation regimes [normal (100 liter/ tree/ week) and minimum (100 liter/ tree/two weeks)] seasonal population changes and the damage of A. Kermanshah as well as the percentage of leafhopper egg parasitism by Anagrus atomus were studied on five grape cultivars including Shahani, White Rishbaba, Askari, Black Rishbaba and White Yaghoti; this was done in a completely randomized blockdesign with split plots in three replications at Isfahan University of Technology in the 2005-2006 period. Adults and nymphs were assessed by weekly sampling using a vacuum insect collector (D-VAC). Non-parasitized and parasitized eggs were counted weekly by clipping three leaves from different strata of vine canopy as a sample unit, in each plot. The results showed that the leafhopper population density, damage percentage and egg parasitism in both years of study in the normal irrigation plots were higher than those with the minimum irrigation. The maximum density of adults and nymphs was observed in June and early July on the White Yaghoti. The highest egg density and parasitism were recorded in June and October-November, respectively, on black Rish-baba in the normal irrigation. The highest damage was on the white Yaghoti in August and September, and the lowest damage was on Askari and Shahani, both in the normal irrigation regime.
