Showing 12 results for Citrus
Mahmood Alichi, Ali Asghar Ahmadi,
Volume 3, Issue 1 (4-1999)
Abstract
The effectiveness of Buprofezin (40% SC) and Pyriproxifen (10% EC) on the mortality of nymphal stages and fecundity of cottony cushion scale was investigated under glasshouse conditions. The LC50 of IGRs was also determined for the first nymphal stage. Two applications were conducted at intervals of 1 day prior to introduction of crawlers and 42 days after infestation. The results indicated that Buprofezin was superior to Pyriproxifen in suppressing the growth and development of crawlers. The mortality of first instars was determined 28 days after the first application. Although the total mortality of second instars due to Pyriproxifen was higher than that by Buprofezin, but the cummulative mortality of 1000 ppm treatment was estimated to be 100% in both experiments after 42 days. The effect of Buprofezin on incomplete molting of nymphs and its ovicidal activity showed a decreasing rate in third instar nymphs survival and fecundity of cottony cushion scale in relation to different concentrations of the IGRs, but it never reached 100%. Meanwhile the 1000 ppm concentration of Pyriproxifen in the same treatments brought about complete mortality to third instar nymphs and inhibited adult and egg formation due to imbalanced juvenile hormone activity. However in 1 ppm concentration of Pyriproxifen, a noticeable increase in fecundity of cottony cushion scale was observed.
A. Hassanli, A. Sepaskhah,
Volume 4, Issue 2 (7-2000)
Abstract
In this study, seven citrus gardens in different parts of Darab were chosen to evaluate the drip irrigation systems. The evaluation process was based on the Merriam and Keller’s model (1978). Besides the evaluation of drip irrigation systems, the water requirement of citrus was estimated using four models including Blany-Criddle modified by FAO, Hargrive-Samani, Pan Evaporation and Solomon-Kodama model. On the basis of the results obtained by Hargrive-Samani with 1296 mm annual water requirements, a comparison was made between irrigation with existing systems and irrigation under favorable and desired conditions.
The results from field measurements indicate a considerable reduction in the emitter discharges. The low pressure and emitter clogging could be two major reasons for the problem. Low pressure at head control, topography, head losses and also using no filter(s) or unefficient filters are the main reasons for the reduction. In some gardens, overirrigation even up to 2.5 times of water requirement was practiced by using extra emitters and increased irrigation times. Overirrigation causes considerable water losses through deep percolation and in reased overwetting area.
Field measurements indicated a good emission uniformity (EU) for the fields with overirrigation. EU in chosen fields varied from 40 to 91%, AELQ varied from 31 to 82% (poor to good) and PELQ varied from 36 to 82%. This study showed that most farmers are not familiar with plant water requirements. The fields with efficient filtration due to using extra emitters per plant are mainly overirrigated. But fields without any filter of unefficient filters are not irrigated sufficiently. The very high manufacturing variation coefficient of IEM emitters (Cv=0.22), which are widely used in Darab, causes a design emission uniformity of 55%.
J. Keramat, G. H. Kabir, B. Ghanaati,
Volume 6, Issue 4 (1-2003)
Abstract
Citrus juice and concentrate are among the major industrial products in Iran. Large quantities of citrus peels with considerable amounts of pectin are also produced. Pectin could be extracted from the peels to be used as a gelling agent in some food products. Unfortunately, all pectin used in the food industry is imported. This study was carried out to find the best conditions of pectin extraction from orange peels. Samples of orange peels were collected from a concentrated orange juice factory. Pectin was extracted by sulfuric, nitric and hydrochloric acids. Certain qualitative and quantitative tests, such as yield of extraction and cost of extraction were determined. Also, food safety aspects as a result of using the above acids were considered. Hydrochloric acid was found to be the most suitable acid. In the second part of the research, the effects of temperature (85 and 90˚C), time (40, 50 and 60 minutes) and pH (1.6, 1.8 and 2.0) on the yield of extraction, purity, gelling ability, percentage of methoxylation and degree of esterification of the extracted pectins were measured. Statistical analysis of the results showed that the best conditions for the extraction of pectin include a pH level of 1.6, a temperature of 90˚C and a period of 50 minutes.
S. M. Taghavi, M. Ziaee,
Volume 7, Issue 1 (4-2003)
Abstract
In order to compare Pseudomonas syringae pv. syringae (Pss) isolates from cereals, citrus, stone fruits and weeds by phenotypic characteristics, serological properties and pathogenicity, samples were taken during 1998-1999 in Fars Province, Karaj, Fereidan, Aligudarz and Shahrekord regions. From 350 fluorescent isolates, 47 were negative with respect to oxidase, potato soft rot and arginine dihydrolase tests but positive in hypersensitive reaction (HR) on tobacco, pelargonium, or both. In complementary biochemical tests, these isolates were identified as Pss. Based on LOPAT (levan, oxidase, potato soft rot, arginine dihydrolase and HR on tobacco leaves) tests, the isolates were divided into two groups, but based on the results of GATTa tests alone, isolates were divided into nine groups. Isolates from different hosts showed differences in lipolysis, syringomycin production, ice nucleation activity, lecithinase, pathogenicity, serology and protein profiles.
E. Gharizadeh, B. Hatami, H. Seyedoleslami,
Volume 8, Issue 2 (7-2004)
Abstract
The coccinellid Cryptolaemus montrouzieri Muls. is an oligophagous predator that is used to control mealy bugs in the orchards and greenhouses. Citrus soft scale, Pulvinaria aurantii, as an active pest on citrus plants in North of Iran is also attacked by this predator. This research was conducted to study biological characteristics of C. montrouzieri on citrus soft scale and mealy bug, Planococcus citri. Initially, Cryptolaemus eggs were collected from colonies of two preys and reared in laboratory (14 L: 10 D, 25±1˚C, and RH 70 ±5%). The incubation period of eggs, 1st, 2nd, 3rd and, 4th larval instars, and total larval, prepupal, and pupal stages were studied on two preys. The developmental stages on two preys were not significantly different, except for the 4th larval instar at 1% and total larval stages at 5%. The sex ratio of male to female on two preys were not significantly different at 1% and was 1:1. Except for pre-oviposition period, other parameters including female longevity, average number of eggs laid per day, average total number of eggs laid per female and percentage of hatching were significantly different at 1% on the two preys. The average feeding of total larval period on eggs of mealy bug and citrus soft scale were 5715 and 7694, respectively that, the difference was significant at 1%. The results showed that some of the biological characteristics of Cryptolaemus on two preys were significantly different. Since the predator feeding on the eggs of citrus soft scale was higher than the mealy bug, it seems that this beneficial insect could be used for biological control of the citrus soft scale.
J A. Aboutalebi, E. Tafazoli, B. Kholdebarin, N. Karimian,
Volume 9, Issue 4 (1-2006)
Abstract
The Effect of various NaCl levels on the shoot content of trace elements, in the seedlings of five citrus species namely: Bakraei (Citrus reteculata X C. limetta), Volkamer lemon(C. volkameriana), Sour orange(C. aurantium), Sweet lime (C. limetta) and Mexican lime(C. aurantifolia), were studied in a glasshouse, by a randomized complete block design with factorial arrangement and four replications. One-year old seedlings of each species were grown in the pots, containing native soil (pH=8.2) and irrigated with water supplemented with 0(control), 20, 40 and 60 mM NaCl. At the end of experiment, the amount of Fe, Zn, Mn, Cu, Cl and B in shoots were determined. The amount of trace elements varied among the species even in the control plants (no salt). Salinity had different effects on the shoot content of trace elements. Salinity reduced Fe content in the shoot of all species except in Bakraii and sweet lime and increased the amount of Zn in the shoot of all species except in Bakraii. The Mn content was reduced in the all species but increased in sour orange. Salinity reduced the amount of Cu in the shoot of volkamerina but had no effect in the other species. The amount of Cl increased in the shoot of all species with salinity. Boron content in the shoot of all species except in sour orange, increased with low salinity level but decreased with increased salinity levels. However in sour orange, salinity in the all levels decreased the amount of B in the shoot of seedlings.
M. Esfandiari, M. S. Mossadegh, R. Eslamizadeh,
Volume 10, Issue 4 (1-2007)
Abstract
The cottony Cushion Scale, Icerya purchasi Mask., is a polyphagous, cosmopolitan and destructive pest that infests more than 200 plant species apart from citrus. Laboratory studies were carried out on the orange at three temperatures, 17±1, 27±1 and 40±1°C 65±5% RH and 14:10 (L:D). The duration of nymphal stages, female longevity and the life cycle at 17±1°C were 85.8±3.83, 74.9±3.53 and 173.6±7.63 days and at 27±1°C were 62.6±4.40, 72.6±4.59 and 144.1±9.26 days, respectively. The duration of pupal stage and the life cycle of male at 27±1°C were 16.1±0.78 and 59.4±1.30 days, respectively. Field studies on the pest were conducted from July 2003 to September 2004 at Sharafabad region of Dezful. At 10-days intervals, five randomly selected orange trees in a citrus orchards (3ha) were sampled by taking 75 twigs, 15cm in length, at random. Number of eggs, nymphal stages and adults were recorded. From these observations I. purchasi had three generations in a year that were recorded as spring, summer and autumn-winter generation for I. purchasi. The autumn-winter generation developed in 6 months. I. purchasi overwinters as different developmental stages on different host plants with the 2nd nymphal stage was more abundant. Apart from different citrus cultivars, altogether 41 species of 22 different families of plants were recorded as the host plants of this scale in Khuzestan province.
A. Aboutalebi, E. Tafazoly, B. Kholdebarin, N. Karimian,
Volume 11, Issue 1 (4-2007)
Abstract
This study was conducted to evaluate the effect of salinity on concentration of potassium (K), sodium (Na) and chloride (Cl) ions, in sweet lime budded on five citrus rootstocks, including Bakraii (mandarin x sweet lime), Volcameriana, Sour orange, Sweet lime and Mexican lime in a glasshouse, using a randomized completely design with factorial arrangement and four replications. Rootstocks had great effect on the concentration of ions in scion. Concentration and distribution of ions were significantly different in control and other treatments. Salinity increased Na and Cl ions in shoots and roots, but the rate of increase varied among rootstocks and treatments. Lowest concentration of Na and Cl ions were in shoot of scion on Volkameriana. Under salinity stress, K concentration increased in shoots of scion on Sour orange and Bakraei and decreased it on other rootstocks. Salinity increased K concentration in roots of all rootstocks except for Mexican lime.
K. Nazem, Y. Rozbehan, S.a. Shodjaosadati,
Volume 12, Issue 43 (4-2008)
Abstract
The nutritive values of lemon and orange pulps treated with Neurospora sitophila fungus were assessed by chemical composition, in vitro digestibility, in situ (dry matter and nitrogen) degradation methods. The obtained data from the untreated and treated pulps with fungi were compared using t-test. Mean values of the chemical analysis for crude protein, ash, organic mater, NDF and ADF for untreated lemon pulp were 6.3, 6.2, 93.8, 21.3 and 17.9 for treated lemon pulp 25.1, 10.6, 89.4, 12.7 and 6.8 for untreated orange pulp 6.8, 6.5, 94.5, 26.1 and 20.3 and for treated orange pulp 23.2, 8.1, 91.9, 18.5 and 15, respectively. In all cases, a significant difference (P<0.01) between untreated pulp and treated pulp of lemon and orange was observed. Digestibility coefficient of DM, OM and DOMD of untreated lemon pulp were 79.3, 80.5 and 75.5 treated lemon pulp were 91.4, 93.5 and 83.5 untreated orange pulp were 81.5, 82.8 and 78.2% and treated orange pulp were 91.2, 94.5 and 86.9%, respectively. The digestibility coefficient for the treated pulps (lemon and orange) was significantly (P<0.01) higher than those untreated. The percentages of DM degradability of pulps in nylon bag after 48 hours of incubation with the out-flow rate of 0.05 were as follows: 66.3 for untreated lemon 75.2 for treated lemon 68.7 for untreated orange and 75.5 for treated orange. The DM degradability for the treated pulps (lemon and orange) was significantly (P<0.01) higher than those untreated. The effective degradability of protein after 48 hours of incubation in nylon bag with the out-flow rate of 0.05 was as follows: 12.1 for untreated lemon 73.7 for treated lemon 14.8 for untreated orange and 77.8 for treated orange. The effective degradability of protein for the treated pulps (lemon and orange) was significantly (P<0.01) higher than those untreated. In conclusion, treating citrus pulps with Neurospora sitophila increased the concentration of CP, digestibility coefficients and protein degradability.
G. Khodakaramian, J. Swings,
Volume 12, Issue 45 (10-2008)
Abstract
Protein electrophoretic pattern similarity among 21 strains of Xanthomonas axonopodis pv. citri isolated from Hormozgan and Kerman provinces together with the representatives of reference strains of X.a. pv. citri and X. a. pv. aurantifoli and 246 strains of the other Xanthomonas spp. including : X. a. pv. citri, X. a. pv. glycins, X. a. pv. manihotis, X. c. pv. campestris, X. a. pv. phaseoli, X. cassavae, X. vesicatoria, X. c. pv. euphorbia, X. c. pv. arracaciae, X.c. pv. malvacearum, X. a. pv. clitoriae, X. a. pv. citrumelo, X. a. pv. aurantifolii, X. a. pv. alfalfae, X. cucurbitae, X.c.pv. dieffenbachiae, X. vasicola. pv. holcicola, X. melonis, X. hortorum. pv. pelargonii, X. a. pv. poinsettiicola, X. arboricola pv. pruni, X. c. pv. raphani, X. a. pv. ricini, X. a. pv. vasculorum, X. a. pv. vignicola, X. c. pv. armoraciae, X. c. pv. barbareae and X. c. pv. Carotae was compared and analyzed via Gel Compare version 4.2 software. Results indicated 86% of mean similarity among the strains tested. The highest similarity was 100% for strains isolated from Hormozgan and Kerman provinces and X. a. pv. citri LMG 9176 and X. a. pv. citri LMG 9654. The lowest similarity was 84.90% for these strains and X. c. pv. euphorbia LMG 7402 and X. a. pv. ricini LMG 7444. The 100% of protein pattern similarity among the strains isolated from Hormozgan and Kerman provinces and the reference strains from pathotype A (X. a. pv. citri LMG 9176 and X. a. pv. citri LMG 9654) was supported by host range and pathogenicity patterns of these strains obtained from our previous study.
M.s Tadaion, Gh Moafpourian,
Volume 13, Issue 47 (4-2009)
Abstract
In arid and semi arid regions with high boron content in irrigation water, boron toxicity is a considerable problem. Critical levels of boron in irrigation water variy between 1 and 10 mg/l for sensitive and resistant plants, respectively. In southern parts of Iran especially large citrus production region as Jahrom and Giroft cities, high boron content in irrigation water at toxic levels in most of the region has been the restricting factor for citrus yield increase and for citrus trees exposed to intensive deficiency of potassium and micronutrients like iron, zinc and magnesium. In this experiment, the separate effects of citrus rootstocks including Macrophylla (Citrus macrophylla Wester), Volkamer lemon (Citrus volkameriana), Sour orange (citrus aurantium), Sour lime (Citrus aurantifolia Swing) and their combination with ‘Valencia’ orange, ‘Washington navel’ orange, ‘Jahrom local’ orange, red pulp orange (‘Moro’) as scions on boron uptake were studied. The experiment was conducted as factorial arranged in randomized complete block design with 5 replications and 2 trees per plot in Jahrom Agricultural Research Station for 4 years. According to experimental results, the highest level of boron uptake belonged to ‘Volkamer’ lemon and the lowest to ‘Macrophylla’ rootstocks. Although, Sour orange rootstock had the medium level of boron uptake, but the leaf boron concentration of grafted cultivars on it was clearly very high. In comparison with other rootstocks, interaction between ‘Macrophylla’ rootstock and ‘Valencia’ orange, ‘Washington navel’ orange and red pulp orange (Moro), except ‘Jahrom’ local orange as scions, caused a significant decrease to leaf boron concentration.
V. Shahrokh, H. Khademi, H. Shariatmadari,
Volume 23, Issue 2 (9-2019)
Abstract
Despite the great importance of potassium applied as a fertilizer in the orange orchards, no information is currently available regarding the rate of potassium release from rhizosphere and the bulk soils of such trees. The objectives of this study were to investigate the weathering of micaceous minerals and their non-exchangeable K release and also, to examine the status of different forms of K in the rhizosphere and bulk soils of orange orchards with different ages in Darab, Fars Province. Samples were, accordingly, taken from the rhizosphere and bulk soils of orange orchards with the ages of 5, 10 and 20 years; also, virgin soils (control) were obtained from three soil depths including 0–30, 30–60, and 60–100 cm. Water soluble, exchangeable and nonexchangeable K, and the clay mineralogy of the soils were determined. The results demonstrated that the concentration of soluble and exchangeable K in the cultivated soils was less than that in the control soil and that the concentration of nonexchangeable K in the soils of 20-year-old orchards was less, than that in other soils. Soluble and exchangeable K values decreased with depth in all soils. Clay mineralogy investigation also showed that the quantity of illite decreased and that of smectite and illite-smectite increased as the age of orange trees was raised. With increasing the age of orange trees and root development, more potassium could be taken up from soil and more changes occurred in the soil minerals. In order to avoid a very high decline in the reserved K in the soils under orange trees, particularly in the orchards with older trees, K fertilization has to be taken more seriously based on the soil testing results.
