Journal of Plant Production Research
Year:2009 | Volume:16 | Issue:1|Papers Count:18

Quantity-intensity (Q/I) relationships provide insight into a soil’s immediate K status. Q/I parameters of potassium and their relationships with some soil properties were investigated on 15 combined top soil samples (0-30 Cm) collected from the cultivated tobacco fields in Mazandaran. The amount of the equilibrium activity ratio for potassium (AReK) ranged from 0.0009 to 0.0313 (Cmol/l)0.5. The adsorbed K held specifically at edge /wedge shaped positions in Darabkola, Chalamardi and Ervet soils. In contrast, soils of Valaghoz and Parvarichabad held the K at planar surfaces. Labile K (-DKo) ranged from 0.007 to 1.44 with a mean value of 0.332 Cmol/kg. The lowest value found in Ervet soil and the highest one in Parvarichabad soil. However, NH4AOc-exchangeable K values were always considerably higher than DKo values. This suggests that there were over estimation by NH4AOc (1N). Therefore, DKo is a better estimate of soil labile K than exchangeable K by NH4AOc (1N) soil test. The Kx values ranged from 0.050 to 1.026 Cmol/kg and the values for PBCK varied from 11.29 to 208.60 with an average of 99.24 (Cmol/kg)/(Cmol/l)0.5. The Paja and Darabkola-baboyeh soils had the lowest and highest values for PBCK, respectively. There were significantly and positively correlations with each other among the DKo, AReK and NH4AOc-K at 1% probability level. The Q/I parameters provide useful information for understanding available K stauts of soils and can be used for K-fertilizer recommendations.

In Other to determine the effect of zinc foliar application (Zinc-Fousin 70%) in various rate (0, 0.5, 1 and 1.5 liter per hectare) and various stages of growth (V8-R3) on yield components, yield, oil and protein percentage of two soybean cultivars [(Sahar, Determinate) (Williams, Indeterminate)] in summer cultivation in 2004 at Gorgan, Golestan, Iran. The treatments were arranged in a Factorial Split Plot design based on randomized complete blocks (RCBD) with four replication. The results indicate that zinc foliar application in V8, significantly increased, number of seed per pod, seed yield and harvest index. Also one liter zinc foliar application per hectare significantly increased plant height and percent of seed protein. Cultivar Sahar was superiour than Williams for number of pod per plant, seed yield, percent of seed protein and harvest index. Also, Cultivar Williams for number of seed per pod, number of nod in main stem, plant height and percent of seed oil was superior to cultivar Sahar. positive and significant correlation was observed between seed yield with number of pod per plant, number of seed per pod, one thousand seed weight and harvest index. Among yield components, seed weight (for Williams) and pod number per plant (for Sahar) had the most correlation with seed weight.

Due to market price, rice production in Isfahan province has expanded to many locations, where there is enough fresh water for a cropping season, with no considerations on negative aspects of this practice. Organic fertilizers have been recommended as an amendment to reduce the negative impact of puddling on soil physical and chemical properties. This experiment was conducted to study the effects of cow manure on sustainability of rice yield under soil submergence and puddling practice. According to a randomized complete block design with three replications, rice were planted under six fertilizer treatments for three years. Treatments included three methods of urea applications, two levels of cow manure and a no fertilizer application as a check. Analysis of variance revealed a significant yield difference among fertilizer treatments for the first year of the experiment. Mean yield comparisons showed that highest yield was obtained when 104 kg/ha nitrogen was applied at different rice growth stages. In the second year, except for 1000-grain weight, other measured traits were significantly different among fertilizer treatments. In this year, significantly higher yield were obtained from the plots that received the highest organic manure each year (32 ton/ha). Lowest yield belonged to the check treatment. Analysis of variance for the third year,s data also indicated a significant difference among fertilizer treatments for plant dry weight, number of plants per hill, plant height and seed yield. Similar to the second year, highest value on these traits belonged to treatment with highest organic fertilizer, and the lowest to the check treatment. It may be concluded that organic manure application in rice culture could sustain a higher yield compared to chemical fertilizers, which is a common practice in Isfahan province.

In the present study resistance of tomato cultivars including Chef, Ch-Falat, Early Urbana Y and Super Strain B was evaluated against root-knot nematode with five replications and randomized complete block design (RCBD) as factorial was used. After 7 weeks dry and wet weight of root and stem, length of stem, numbers of gall and egg masses, final population and reproduction factors were evaluated. The results of experiments showed that on the number of galls and egg masses per gram of soil cv. Chef hadn't statically differences at probability 5% with Ch-Falat and Super Strain B cultivars. On the final population and reproduction factors all cultivars showed significantly differences at probability 5%. The highest amount of plant growth factors was observed in Super Strain B-0 and while the lowest amount of stem length, root and stem wet weight was belong to Early Urbana Y-2000, the minimum amount of root and stem dry weight was recorded on Early Urbana Y-0. Our observation showed that cultivars hadn't sufficient resistance against of the root knot nematode, Meloidogyne javanica.

This experiment was carried out to evaluate the effects of some widely-used pesticides in Golestan province on the growth and biological nitrogen fixation (BNF) in soybean (Glycine max (L.) Merr.). Pot experiment consisted of 10 pesticides, two pesticide application rates (recommended and twice recommended rate) and 2 soybean cultivars (a determinate and an indeterminate). A factorial arrangement at a randomized complete block design with 8 replications was used. Results showed that the effects of three factors on total dry weight (TDW), leaf dry weight (LDW), nitrogen (N%), protein (P%), total nitrogen (TN), and BNF per plant were significant (P=0.01). Pesticide kind and application rate had significant interactions on evaluated traits. Based on findings, pesticides used in this study can be divided into three groups; a) Super gallant (a post-emergence herbicide) and Admiral (an insecticide) that had no significant effects on BNF and TN even when applied in twice recommended rate, b) Basagran (post-emergence herbicide), Dursban (insecticide), Omite and Neorun (acaricides) that had no significant effect on BNF and TN when used in recommended rate, but their effects on BNF and TN were significant when applied in twice recommended rate, c) Two pre-plant herbicides (Treflan and Sonalan), a post-emergence herbicide (Fusilade) and a acari- insecticide (Novacron) that had significant effects on BNF and TN independent of application rate. These findings emphasize the importance of selected pesticide kind and application rate. Also, TDW, LDW, TN and BNF in indeterminate cultivar (Williams) was significantly more than determinate cultivar (Sahar).

Mycorrhiza is the most common symbiosis in vascular plants and it has different types. Jujube tree (Ziziphus jujuba mill) is a profitable plant, which is native to Iran and is cultivated mainly in south khorasan province. Due to the effects of mycorrhiza on vegetation and geographical spreading of plants, as well as lack of information on this type of symbiosis, the present study was carried out in order to identify of mycorrhiza symbiosis in Birjand. More over because of the positive effect of mycorrhizal symbiosis on plants yield under stressful environmental circumstances, the mycorrhizal symbiosis interactions and the age of jujube tree were studied under farm the presence of situation in factorial plans based on blocks. The findings indicated the presence of genus Glomus, particularly Glomus coronatum (Glomaceae), form vesicular-arbuscular mycorrhiza (VAM). Furthermore, considering the quantity of mycorrhiza, the results showed a meaningful and considerable difference amoung three age groups of plants: (7-10, 15-17 and 25-28). The quantity of mycorrhiza was the most in 25-28 year old trees. Therefore mycorrhizal development and application of agricultural management policies to stimulate and promote interactions of this plant, would provide a proper developmental pattern for sustainable farming of jujube tree and would be in keeping with principles of conventions on biological diversity and sustainable development.

In order to study the effect of sowing date during seed filling period on canola seed vigor, an experiment was conducted at Agriculture Research Station of Gonbad during 2005-2006. Two cultivars of canola (Hyola401 and RGS003) were sown in five sowing dates, and compared based on split plot design in 3 replications. Standard germination, seedling growth rate and electrical conductivity tests were used to evaluate seed vigor. The results showed that seed fill duration, 1000-seed weight, seed quality, and seed yield of canola were decreased with a delay in sowing date from 15 Aban. Seed vigor treats were affected by environmental conditions, such as air temperature, during seed filling period. The seed test result revealed that, in both cultivars, delaying in sowing date from 15 Aban, caused decrease in germination percentage, germination rate, uniform germination, number of normal seedling, seedling dry weight, and increase in electrical conductivity. Therefore, just canola seeds from optimum sowing date can be used to sown in the next year.

Embryogenesis is an effective method for producing a huge number of genetically modified plants with selective traits. In order to determine suitable nutritional media and organs for embryogenesis with a commercial and a native tomato cultivar, they were tested with three culture media using a factorial completely randomized design with four replications. Pieces of in-vitro cultured hypocotyls and seedling roots were transfered to B5, MS and NL media. Their embryogenesis was investigated when transfered from induction media containing auxin to the free auxin media. No embryogenesis was observed with NL, but it was greater with B5 than MS. Embryogenesis was also significantly greater with native tomato cultivar relative to commercial. one The interactions of cultivar x culture media (P<0.01) and cultivar x explants (P<0.05) were both significant. The effect of different sucrose concentrations (10, 20, 30 and 40 g/l) on somatic embryogenesis was investigated with in-vitro culture; 20 g/l showing the best response.

RecQ family members play crucial roles in DNA repair, replication and recombination. The model plant Arabidopsis thaliana contains seven RecQ homologues. We already showed that inactivation of AtRecQl4A alters plant responses to genotoxic stress. In this report, some physiological and biochemical parameters in recQl4A mutant plants were investigated under salinity treatment. Wild type and recQl4A mutant plants were grown on Murashige and Skoog agar plates containing various concentrations of NaCl arranged in a completely randomized design. When plants were treated with 100-150 mM NaCl, damage to the plants was so high that we were not able to measure physiological or biochemical parameters accurately. In 75 mM NaCl, total soluble protein in all examined plant lines declined. In response to salinity treatment, mutant seedlings exhibited less dry weight and chlorophyll content, as compared to the wild type plants. However, total soluble sugar in the mutant seedlings was higher than that in wild type plants. Similarly, the catalase activity in the mutant plants was significantly higher than that of wild type, when plants were treated with 75 mM NaCl. Interestingly, increasing of NaCl concentration form 0 to 75 mM caused a significant reduction in the polyphenol oxidase activity in the mutant plants but not in the wild type plants. These results propose that the RecQl4A gene plays crucial roles in response of Arabidopsis plants to NaCl treatment and provide new insights in understanding mechanisms underlying plant salinity tolerance.

Mismanagement of nitrogenous fertilizers has caused serious nitrate (NO3) contamination in many flood-irrigated. Low-volume irrigation practices can offer an alternative approach for controlling NO3 leaching and agricultural water use. The simultaneous application of fertilizers and irrigation water is an appropriate alternative to increase the efficiency of applied water and fertilizers. The nitrogen use efficiency of sugar beet (Beta Vulgaris L.) has been studied through the Iran but there is limited information about the response to irrigation and amount nitrogen fertilizer. The objective of this study was to investigate the effect of various irrigation and nitrogen amounts on efficiency of applied fertilizers. A field experiment with sugar beet as randomized block, split-plot design with irrigation treatments as main plots and N fertilizer rates as subplots, with three replications, was used. Four levels of the water (40, 80, 120 and 160% evaporation from surface of A class pan, treatments I1 to I4) and nitrogen fertilizer (urea) rates (N0, N1, N2, and N3, respectively 0, 90, 180 and 270 kg N ha-1 were applied. The results indicated there were significant differences (P£0.01) in root yield, sugar content, total dry matter and nitrogen use efficiency (NUE) basis of root yield, sugar and total dry matter yield between treatments Treatment I4 with 47969 kg ha-1, root yield and treatment I2 with 6855 kg ha-1, sugar content had maximum production. The result showed, root yield, sugar content and total dry matter increased with increasing applied nitrogen. Treatment I4N3 with 53621 kg ha-1 root yield, 7887 kg ha-1 sugar content and treatment I3N3 with 53075 kg ha-1 root yield, 7689 kg ha-1 sugar content had maximum yield. Nitrogen use efficiency maintained an order I4>I3>I2>I1 and F1>F2>F3. There was a decreasing pattern in NUE values with increasing fertilizer rates. The results showed that by increasing applied water, nitrogen use efficiency increased and affected by fertilizers treatments. Fertilizer use efficiency also decreased by increasing fertilizer rate. The results also demonstrated there were significant differences in all the treatment.

Due to the existence of salinity and high temperature in Khuzestan region, a factorial experiment was carried out to investigate the effect of 5 levels of salinity (0, 3, 6, 12 dS/m) and 2 levels of temperature (25oC, o) on seed germination of Celosia argentea in a Completely Randomized Design with 3 replications. ANOVA results revealed that the effect of salinity and temperature on germination percentage, germination rate and radical length were significant (P<0.01), but the interaction between salinity and temperature on germination percentage were significant (P<0.05). Mean comparison of germination percentage indicated that germination percentage decreased with increasing of salinity. Seed germination percentage decreased 20.44% from 12 dS/m to control treatment. Also, the highest and lowest radical length as 70.6 and 19.2 belonged to control and 12 dS/m, respectively. Effect of temperature on germination percentage, germination rate and radical length indicated that the highest germination percentage, germination rate and radical length were obtained in 25oC. With increasing temperature from 25oC to 35oC, seed germination percentage in 6, 9 and 12 dS/m decreased about 14%, 17.63% and 18.33%, respectively, in comparison with control treatment. Also, in all of salinities, seed germination per day decreased as 3 seeds per day.

Cereal leaf beetle (Oulema melanopus L. (is one of the major pests of cereals, particularly winter wheat, in Golestan province, northern Iran. Population density, spatial distribution and biology of this pest were studied in wheat fields of Gorgan region, during two agricultural seasons of 2006 and 2007. Emergence time and peak of the pest activity differed in different regions. In general, the first adults were emerged from hibernation sites in the mid of February and peaked in the mid of March. The maximum mean of adult beetle was estimated 15.07±0.8 per sweep net. The first oviposition was observed in the early of March and the maximum number of eggs was 17.53±1.9 per quadrate. The activity of larva population was started from the late March and reached to the peak level by the early May. The maximum counted number of larvae was 16.9±0.9 per quadrate. The Taylor’s power law and Iwao’s patchiness regression coefficients for different developmental stages of the pest were equal to 1, statistically indicating that O. melanopus populations were randomized. Also, the using of mathematical distribution models showed the adult and the larva populations dispersion dispersion were randomized during most of the growing season. However the spatial distribution of egg was not fitted with poisson model. The mean duration of incubation period, total developmental time of the larval stages and pupa in the field conditions were of 8.05±1.02, 29.23±1.03 and 12.29±1.17 days, respectively. These results can provide a reliable basis to develop proper sampling plans for estimating or classifying natural enemy populations in wheat fields of northern Iran.

Walnut kernels are dormant at maturity and therefore in order to germinate require moist-chilling or stratification, i.e. incubating imbibed seeds at cold (5ºC) for a certain period. It is assumed that reserve mobilization can not proceed in imbibed dormant seeds incubated at warm condition. In contrast to other dormant tree seeds, imbibing dormant walnut kernels showed storage protein mobilization irrespective of the temperature of incubation. However, there is no information on the nature of proteolytic processes at the protein and enzyme levels in imbibed walnut kernels. Persian walnut (Juglans regia L.) kernels were stratified at 5ºC for increasing periods up to 60 days. Thirty days stratified kernels displayed maximum germination percentage of 61% whereas only 23% of warm-incubated kernels germinated. Mobilization of total storage protein in kernels was faster under warm conditions when compared to stratification. Levels of soluble proteins remained unchanged following imbibition in both stratified and warm-incubated kernels. SDS-PAGE patterns of total proteins did not show any changes in walnut 19-23 and 32-35 kDa glutenins and 42-49 kDa vicilins under both temperature regimes. This technique however, revealed alterations in the polypeptide patterns of soluble protein fraction notably increased band intensity of 41-48 and 58 kDa in parallel with reduced band intensity of 18 kDa polypeptides. The increased levels of some polypeptides in the soluble fraction might have been resulted from the increased solubility of insoluble storage proteins, proteolysis or de novo protein synthesis, while reduced band intensity is likely to represent proteolytic processes. Using azocasein as a substrate to detect protease (s) involved in storage protein mobilization, a protease most active at pH 6.0 was found in extracts from walnut kernels. Since no significant differences were observed in measured protease activity between stratified and warm-incubated kernels, other proteases are supposed to be involved in the mobilization of walnut kernel storage proteins.