فصلنامه پژوهش های تولید گیاهی
سال بیستم شماره 4 (زمستان 1392)

this study was conducted to find allometric relationships between green leaf area and green leaf dry weight, vegetative dry weight and plant height in faba bean. To this, a randomized complete block design as split plot-factorial experiment with four replications was carried out at the research field of Gorgan University of Agricultural Sciences and Natural Resources during 2010-2011 growing season. inter-row spacing (30, 45 and 60 cm) and factorial of sowing date (15 Nov. and 24 Dec 2011) and cultivar (Barakat and French) were placed in main-and sub-plots as main plots, respectively. Plant samplings were carried out during growing season with 15 days intervals up to end of the effective leaf formation. At each sampling, leaf area, leaf dry weight, above ground vegetative dry weight and plant height were measured. To describe the relationships between leaf area and the above mentioned vegetative characteristics, different equations were evaluated and a power equation (Y=aXb) was choosed due to a better fit to the date, finally. Relationships obtained for faba bean cultivars, inter-row spacings and planting dates were consistent and only the relationship between leaf area and dry weight of vegetative components was affected by planting date. Hence, two separate equations were estimated for each of tow sowing dated. Since the relationship between leaf area. Y. and green leaf dry weight, X, (Y=176.7X0.935) has a higher determination coefficient and a smaller root mean square error than the plant height, using it can be proposed in the simulation models and quick estimation of green leat area of faba bean, especially when accurate measuring device for measuring leaf area are not available.

In order to investigate the effect of urban sewage and nitrogen fertilizer levels on yield quantity and quality forage of sweet corn, an experiment was carried out as split plot in randomized complete blocks design with three replications in Yasouj Research Field Station at 2009. The main factor consisted of irrigation in five levels: common irrigation water without urban sewage in entire growing season (I1), the first half of plant growing season irrigation with urban sewage and continues growing season whith common irrigation water (I2), inverse of treatment I2 (I3), alternate irrigation with common irrigation water and urban sewage (I4), urban sewage in entire growing season (I5), and the sub factor was including nitrogen fertilizer in three levels (N0=0, N80=80 and N160=160 kg N ha-1) The effects of irrigation treatment, nitrogen fertilizer levels and interaction of irrigation treatments and nitrogen fertilizer levels were significant on fresh forage yield. The highest fresh forage yield was obtained in I4N80 treatment equal 2897 gr m-2 and Minimum fresh forage yield in I1N0 treatment equal 1863 gr m-2. The results show that application of urban sewage led to reduced nitrogen fertilizer consumption in production forage sweet corn. Also effect of irrigation treatments was significant on protein content and ash forage sweet corn. According to results of means comparison, maximum and minimum of crud protein content was obtained in irrigation levels I5 and I1 equal 13.6 and 5.9 percent respectively, and also, maximum and minimum of ash forage in irrigation levels I5 and in I1 equal 16.2 and 12.5 percent, respectively. The effect of nitrogen fertilizer levels was significant on crud fiber content. Maximum and minimum crud fiber content was obtained in N0 and N160 levels, equal 36.1 and 33.9 percent, respectively.

Remote sensing is one of the techniques recently used for the purpose of monitoring and predicting crop yield. The objective of this study was predicting wheat yield in Mashhad during 2009 and 2010 by Landsat (TM) and (ETM+) images with ground based data. For this purpose, three images dated 6, 14 and 22 Jun 2009 and 8 and 24 May and 9 Jun 2010 were analysed and vegetation indices were computed. Field data included wheat growth stage, yield and geographical position. Results showed that the best relation between yield and indices were obtained in 14 Jun 2009 and 14 May 2010. These dates coincided with milky and maturity stages of wheat. Cumulative indices estimated yield prediction more precisely than others indices. Red band had the highest correlation (r2=0.76) with yield among the other band. Through the other indices, PD311 and PD312 had the best correlation with the yield. Correlation between NDVI and yield was not significant. The best correlation with the yield was obtained by applying the multi linear regression method (r2=0.83).

In order to study of yield and qualitative characteristics of potato (Aola variety), an experiment was conducted in Mashhad conditions under irrigation regims and different levels of potassium fertilizer. This experiment was based on randomized copmpletely blocks with split plot design with three replications in Khorasan Razavi Agricultural and Natural Resource Research Center in 2010. Three levels of water regimes were including: irrigation after 70, 100 and 130 mm evaporation from class-A pan and potassium level had five levels: 0, 62.5, 125, 187.5 and 250 kg ha-1. Water regimes arranged as main plots and potassium placed in sub plots. Deficit irrigation decreased yield and sturch content of potato tubers and increased tuber protein. The smallest tuber size and tuber second growth were in 130 mm evaporation from class-A pan. In this research, application of potassium fertilizer was increased tubers yield, size and sturch and tubers phosphour and potassium concentrations and decreased number of marketable potato tubers. Uusing 250 kg ha-1 K2O increased tuber yield, sturch, phosphour and potassium about 31.5%, 14.26% 2.78% and 3.85% respectively. The highest sturch was in 70 mm evaporation from class-A pan with 250 kg ha-1 K2O and also the highest tuber protein was in 100 mm evaporation from class-A pan with 187.5 kg ha-1 potassium level.

Marigold (Calendula officinalis L.) is one of the oldest medicinal plants which had been used for the pharmaceutical industries. In order to evaluate the effects of different plant densities and nitrogen levels on growth, yield and qualitative characteristics of marigold flower, a field experiment was conducted as split plot based on a randomized complete blocks design with four replications at the Agricultural Research Station, Azad University of Torbat-e-Jam, during growing season of 2008-2009. Main and sub plots included four nitrogen levels (zero, 30, 60 and 90 kg.ha-1) and three plant densities (25, 50 and 75 plants.m-2), respectively. Nitrogen (as Urea) was used at 4-6 leaves and flowering stages of marigold as topping dress. Plant height, shoot and root dry weights, seed yield, flower yield, biological yield, harvest index (based on the flower yield), essential oil content and flower extract contents of marigold were studied. The results showed that the simple effects of nitrogen and plant densities were significant (P≥0.01) on plant height, shoot and root dry weights, seed, flower and biological yields, harvest index and essential oil and extract contents of marigold. By increasing nitrogen level from zero to 60 kg.ha-1, enhanced flower dry weight and essential oil content due to increasing in vegetative growth and photosynthesis up to 100% and by increasing nitrogen level up to 90 kg.ha-1, these traits declined 33 and 52%, respectively. Whereas, by increasing plant density from 25 to 50 plants.m-2, increased flower yield and essential oil content up to 23 and 29% and by increasing in nitrogen level up to 75 plants.m-2, these trait decreased 20 and 44%, respectively. Thus, in order to achieve suitable quantitative and qualitative yields of marigold can be considered as appropriate levels of nitrogen fertilizer and crop density as these agronomic approaches.

In order to evaluate the response of quantitative and qualitative characteristics of the isabgol (Plantago ovata Frosk.) medicinal plant to separate and combined a application of urea and biofertilizer an experiment was conducted in randomized complete blocks design at the Research Farm of Shahrekord University in 2011. The experimental treatments consisted of control (non-urea and biological fertilizers), U: 88 kg urea/ha, Az: Azotobacter, My + Az: Mycorrhiza + Azotobacter, Az+50% U: Azotobacter + 44 kg urea/ha, My + U: Mycorrhiza + 88 kg urea/ha, My + Az +50% U: Mycorrhiza + Azotobacter + 44 kg urea/ha. The results indicated that the seed yield under separate application of Azotobacter was less than separate application of urea; however the mucilage yield was similar to urea. The combination of Azotobacter with urea and/or Mycorrhiza did not change in seed and mucilage yield in compared to urea. The maximum of seed and mucilage yield (931 and 166 kg/ha, respectively) were recorded with using Mycorrhiza + 88 kg urea/ha. However, amended fertilizer had no significant effect on swelling factor and the percentage of isabgol mucilage. In conclusion, the combined use of Mycorrhiza in oculant and urea leads to increase (54%) in yield, which can be verified potential of Mycorrhiza application for isabgol production under field conditions.

In order to determine the resistance levels and the most suitable potato genotypes to the early blight, an experiment was conducted in a completely randomized factorial design with three replications, in National Plant Gene Bank of Iran during 2007-2008. Factors included pathogenic fungus, A. tenuissima and A. alternata and six potato genotypes, Picasso, Marfona, Delta, Agria, Cosmos and Armida. Analysis of variance, in vitro and greenhouse evaluation showed that there were significant between pathogen, genotype and their interactions. In vitro evaluation, symptoms appeared after the second day and continued until the sixth day. Based on area under the disease progress curve for pathogenic A. alternata, Cosmos genotype had a lower level of Agria (susceptible control), while Picasso and Marfona with Delta (resistant control) were resistant patients.With the pathogenic A. tenuissima, Cosmos was sensitive, and only Picasso was resistant patient.The method greenhouse, symptoms began on the third day and it lasted until the twentieth day. In this evaluation, using both fungal isolates, Cosmos was sensitive level and Picasso was resistant level. In vitro and greenhouse assessment, Armida not show any signs of disease, it may be referred to as a genotype-immune disease, after field testing. Since, the results of the assessment of resistance was generally similar in both in vitro and greenhouse conditions, it can be argued that this study is validated by classifying genotypes to resistant and susceptible.

Today special attention is paid to the microbial quality of medicinal plants. One of the operations in order to maintain the quality of plants is drying which may also affect the quantity and quality of the essential oil. In order to evaluate drying process effect in Peppermint, an experiment was conducted in randomized complete blocks design with 4 treatments and 3 replications. The treatments included: 1- Cotrol, 2- Shade drying, 3- Oven drying at 45 oC, 4- Microwave drying at 450 W power. Samples were analyzed for their drying rate, essential oil content and microbial load (mesophilic aerobic bacteria, total coliforms, yeasts and moulds and E. coli) according to the standard guideline. Results indicated that the treatments significantly affected on all traits (P<0.01). Accordingly the fastest method was using the microwave. The maximum essential oil content was obtained from the shade dried samples (3.7% V/W) and the minimum one was obtained from the microwave dried samples (0.23% V/W). Microbial contamination in mesophilic aerobic bacteria and yeasts and moulds was at the lowest level in microwave dried samples (4.47 log CFU/g and 3.42 log CFU/g, respectively); and total coliforms contamination was the lowest in samples which were dried in shade (3.36 log CFU/g). The maximum microbial contamination was observed in fresh samples. The existence of E. coli was not proved in any of the treatments. According to these results we can conclude that drying in microwave oven could reduce microbial load under standard levels, however it reduced essential oil content; whereas oil content could be maintained in higher levels in shade method, but this methods could not decrease microbial load.

Evaluating the efficiency of some physiological indices for recognizing water deficit effects, selecting water deficit tolerant fall rapeseed genotypes and also evaluation of drought effects on seed and oil yields and its components were the main goals of this study. The experiment was conducted as factorial based on a randomized complete blocks design with three replications in East Azarbaijan Research Center for Agriculture and Natural Resources during 2010-2011. The experimental factors were irrigation with three levels including: non-stressed (irrigation at 30-35% available soil water depletion), water deficit stress during rosette stage in fall and seed filling stage (irrigation at 70-75% available soil water depletion) and genotype including six genotypes: Karaj 1, Karaj 3, Opera, Okapi, Licord and Modena. The results indicat that water deficit during rosette stage at fall increased leaf temperature and decreased relative water content and stomatal conductance significantly, but effects of drought on seed yield and its components were not significant. Whereas water deficit during seed filling stage, significantly increased leaf temperature and decreased leaf relative water content, stomatal conductance, plant height, yield components except seeds per silique and finally seed and oil yields. Between seed yield with silique per plant significant and positive correlation was seen. It seems that drought stress decreased seed yield mainly by decreasing silique per plant. Indices of leaf temperature, leaf relative water content and stomatal conductance indicated significant correlations with seed yield and therefore can be used for recognizing the effects of drought on rapeseed. The cultivars Okapi and Licord with 4670 and 4518 Kg/ha seed and 1861 and 1758 Kg/ha oil yield, indicated higher performances in cold climate of Tabriz region respectively.

Linum album L. contains pharmaceutical composition podophyllotoxin (PTOX) which is currently being used as a precursor to semi-synthetic anticancer drugs etoposide, teniposide and etopophos. Cell culture is an important source for the production of PTOX. Several strategies, including treatment with elicitors have shown for enhanced production of secondary metabolites in cell culture system as well as elicitor concentration, the time of application and type of medium culture. These factors affect signal transduction pathways, leading to changes in gen expression and the production of metabolites as defense responses against stress. In a time course study, the effect of 100 μM methyl jasmonate on accumulation of PTOX was studied after 1, 6, 12, 24, 48 and 72 h in cell culture system. According to the results, cell growth was not changed by treatments. Podophyllotoxin production was enhanced and received to 0.32 mg/g dry weight after 48 h. To understand the functional of methyl jasmonate on biosynthesis of PTOX was determined phenyl alanine ammonia lyase (PAL) activity. This activity promoted 6 h after the addition of methyl jasmonate to the cell suspension culture. The enhancement of PTOX correspond the PAL activity increment.

Salicylic acid is a phytohormone with phenolic nature which has been proved its role in increasing plant resistance to biotic and abiotic stress in several studies. This study was performed in order to investigation of interaction between 0, 0.5 and 1.5 mM concentrations of salicylic acid, as a seed pretreatment and different levels of drought stress (100, 75, 50 and 25 percent of field capacity) on the proline and soluble carbohydrates accumulation and the catalase and peroxidase activity in Nitraria shoberi. Data analysed after 21 days of drought stress exerting on 45-old days seedlings showed that the carbohydrate content increased significantly about 50% and proline as much as 123% in moderate stress by high concentration of SA. But with the increase in water stress levels, was reduced the rate of this effects, insofar as the severe drought, SA could not to make a significant positive difference with the control samples. These results might be due to activation of metabolic consumption of these substances to form new cell constituents, as a mechanism to stimulate growth and or triggering other mechanisms of resistance by SA and no need to overproduction of this the substance. On the other hand SA causes 66% inhibition in the catalase activity and 50% stimulation in peroxidase activity. This event can lead to an increase of H2O2, which it involved in resistant as a signal molecule and also used for peroxidase activity as a precursor of lignin production and development of resistance in drought condition.

In order to investigate the effects of humic acid on three tomato varieties, a field experiment was conducted as a split-plot design experiment based on randomized complete blocks design (RCBD) with 3 replications in Ahmad Abad, of (Mashhad), Khorasan Razavi, during 2009-2010. Two factorial combinations were four levels of humic acid (0, 1, 1.5 and 2 kg.ha-1) and three tomato varieties (Super CH, Estern, Super Chief). According to the results, all characteristics (except fruit pH) were significantly different (P<0.01). The level of 1.5 kg.ha-1 humic acid led to the highest increasing in fruit and leaf dry weight, final yield and Brix index in comparison with control. The effect of different humic acid levels and three tomato varieties interactions on most of characters, except Brix index and fruit dry weight, was significant (P<0.05). The highest yield (65.67 t.ha-1) and fruit dry weight (133 g) belonged to Super Chief variety in 1.5 kg.ha-1 humic acid level. Also, the highest Brix index was obtained in Super CH variety and 1.5 kg.ha-1 humic acid level.