JOURNAL OF CROP PRODUCTION AND PROCESSING
Year:2016 | Volume:6 | Issue:19|Papers Count:15

In a field experiment, the effects of foliar application of silicon (sodium silicate 6mM) on yield and yield components of wheat cultivars (Shiraz, Marvdasht, Sirvan and Chamran) and also canopy temperature depression (CTD) under water stress conditions (F.C, 60 and 40% F.C.) were investigated during 2012-2013 growing season using a split split plot as randomized complete block design with three replications. The results showed that both drought stress levels, especially 40% F.C, significantly reduced number of grains per spike, 1000 grain weight, grain yield, biological yield, harvest index and CTD of the examined wheat cultivars. The negative impact of drought stress was greater in Shiraz and Marvdasht cultivars. In contrast, foliar application of sodium silicate was associated with increased grain yield (16.11%), its components, leaf area index (20.15%) as well as CTD and this positive influence of silicon application was more pronounced under drought stress conditions. Furthermore, foliar application of silicon reduced canopy temperature and there was positive correlation between grain yield and CTD. Overall, it was concluded that foliar application of silicon under similar conditions to this experiment is potent to improve the grain yield of drought stressed wheat plants via an enhanced CTD or a reduced canopy temperature.

In this study 36 canola genotypes from seven different species including Brassica. napus, B. rapa, B. oleracea, B. juncea, B. carinata, B. nigra and B. friticulosa were evaluated under non-stressed, moderate and sever drought stress conditions during 2011-2012 in a field experiment. The relationships among different traits were assessed. Results of analysis of variance (ANOVA) indicated high variation among genotypes for most of the studied traits. Cultivar by environment interaction was significant for most of the traits, suggesting differential genotypic responses to moistures conditions. The correlation results for the three B. napus, B. rapa and B. oleracea were divided in three levels of watering regime and the coefficients were found to be species-specific but overall correlation coefficients showed that there was significant and positive correlations between grain yield and number of pods per plant and 1000 grain weight, irrespective of watering regime. Results of stepwise regression were suggestive of species and watering-specificity. Under non-stress conditions the greatest direct effect on grain yield belonged to pod length for B. napus and number of pods per plant for B. rapa and B. oleracea. Results indicated that in order to improve grain yield indirectly, breeding strategies should be specific for each Brassica species.

Melons due to domestic consumptions and high potential for export are very important in Iranian agriculture. In order to compare the agronomic characteristics of seven selected populations (Jalali, Tashkent, JaJu, Khaghani, Shadgany, Ghasri, Suski) and three hybrid varieties (Ananase, Durango, Akyla) of melon, this study was conducted for two years (2008- 2009) using a randomized complete block design field experiment with three replications. Difference between yield and yield components of populations were statistically significant. Jalali selected population and Durango hybrid, with 45810 and 13000 kg ha-1 of fruit yield produced the greatest and smallest fruit yield, respectively. Fruit weight and fruit number per plant in different populations were 0.850 to 1.900 kg, and 1.2 and 1.84 number plant-1, respectively. The highest significant correlation (0.96**) was observed between fruit weight and fruit yield. Durango hybrid, with producing 32% of the yield in first harvest, was significantly superior to other genotypes in terms of earliness index. Selected population of Tashkent and Akyla hybrid with fruit total soluble solids of 12.2 and 5.65 percent indicated the highest and lowest qualities, respectively. According to the results, Jalali selected landrace was in the first rank and Shadgany, Ghasri, Suski and Jaju were in the second place and can be considered in breeding and agronomic programs.

In order to evaluate the effect of sowing date and cultivar on accumulated heat unit, phenology and yield of maize (Zea mays L.), a two-year field study was carried out at the Agricultural Research Station of College of Agriculture, Shiraz University, Shiraz, Iran. Treatments consisted of five maize hybrids (SC704, Hido, BC677, BC666 and NS540) and five planting dates (May 15, June 1, June15, July 1, July 15) in a randomized complete block design with three replications. The results of the present study showed that the highest and lowest seed yield was obtained from Hido cultivar at June 1st planting date and NS504 cultivar at July 15th, respectively. Additionally, among the measured indices, crop heat unit (CHU), heat use efficiency (HUE) and relative thermal disparity (RTD) indices were able to estimate heat requirement of maize cultivars accurately in different sowing dates and different phenological stages. These indices provided stable trends and reasonable estimates of the thermal requirements of maize hybrids cultivated on early and delayed sowing dates and hence, they had relative superiority over the other indicators such as growing degree days (GDD), helio-thermal unit (HTU) and the pheno-thermal index (PTI). RTD and CHU had the lowest coefficients of variance which it showed that these indices have enough accuracy to estimate heat requirement of maize hybrids in different planting dates.

In order to investigate some physiological responses and grain yield of five chickpea cultivars under different levels of moisture and salinity, two experiments (i.e. a pot and a field experiment) were conducted in 2012. In the pot experiment, effects of four salt levels (i.e. control, 50, 75 and 100 mM of NaCl) on five chickpea cultivars, i.e. Arman, Azad, Hashem, ILC-482 and Noorabad were studied in a 3-replicate factorial completely random design experiment. In the field experiment, responses of the latter cultivars to four moisture regimes (i.e. no irrigation, irrigation after 75, 100 and 150 mm of evaporation) based on evaporation from a Class-A Standard Pan were evaluated in a 3-replicate split-plot randomized complete block experiment. Data obtained from the pot experiment indicated that proline accumulation, Na+ concentration and Na+/K+ were increased, but K+ concentration, relative water content and plant dry mass were decreased with increase in salt level. Since cultivar ILC-482 tended to indicate a greater proline concentration, in contrary to a smaller Na+ concentration and plant dry mass, compared to the remaining cultivars, it seemed to be more tolerant to the salinity. Data from the field experiment confirmed that delayed irrigation leads to increase in proline accumulation and decreases in leaf area index, plant dry mass and grain yield. Irrigating chickpea after 75, 100 and 150 mm evaporation resulted in 1964, 1675 and 1503 kg/ha of grain yield, leading to 114%, 84% and 64% increases in grain yield, respectively, compared to the no irrigation control. Cultivars Noorabad and Hashem produced the greatest (i.e. 1610 kg/ha) and smallest (i.e. 1361 kg/ha) grain yields, respectively. According to the findings of this one-year field study, seeding cultivar Noorabad concomitant to irrigation after 150 mm evaporation could, perhaps, lead to a substantial increase in grain yield in Noorabad region of the Lorestan Province in Iran. Though, cultivar ILC482 tended to indicate a more stable plant dry mass, when subjected to different irrigation regimes and different levels of saline water.

Harvest time, in olive, is an important key to achieve high quality and quantity of oil with a desired and balanced fatty acid (high oleic acid and low palmitic and linoleic acid) composition. Appropriate harvesting time varies in different locations depending on climatic and agronomic situations and identifying the right time for harvesting may bring about a high quality oil. Thus, the current study was carried out to determine the best harvesting time for two Iranian (Mari and Shenge) and two foreign (Kroniki and Arbequina) cultivars in the region of Tarom, Zanjan, (north of Iran). The results obtained indicated that palmitic, oleic and stearic acid contents decreased and linoleic and palmitic acid contents increased with the progress of ripening. In addition, oil percentage increased with the progress of fruit growth and development. Based on the amount of desired fatty acids, the best harvesting time for the Mari, Kroniki and Arbeqina cultivars, was 180 days after full bloom. It was revealed that the cultivar Shenge is not suitable for oil extraction, due to the low percentage of oleic acids. Therefore, Shenge could be cultivated for producing olive cans rather than olive oil and the best harvesting time for Shenge is 120 days after full bloom.

The chemical control of weeds raises serious concerns about food safety and environmental quality, which have necessitated the need for non chemical weed management techniques such as intercropping. Intercropping can suppress weeds and reduce the use of herbicides in production systems. Therefore, the objective of this work was to evaluate the effects of intercropping of faba bean and maize, as well as hand-weeding on maize grain yield and total grain yield. The experiment was carried out during growing season of 2010 as a randomized complete block design with three replications at the Agricultural Research Station, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran. Sole cropping of maize with weed control (MWF), sole cropping of maize without weed control (MWI), intercropping of 15% faba bean+maize (M+15%F), 30% faba bean+maize (M+30%F), 45% faba bean+maize (M+45%F) and sole cropping of faba bean were the experimental treatments. Weed biomass and density were affected by treatments. With increasing faba bean density in the intercropping treatments, weed biomass and density decreased significantly from 85 plants and 310 g m-2 for MWI treatment to 22 plants and 63 g m-2 for M+45%F treatment, respectively. The greatest number of seed row per ear, seed number per ear and grain and biological yields (8033 and 17933 kg ha-1, respectively) were achieved at MWF treatment and the smallest values for these attributes were revealed at MWI treatment. There was no significant difference between MWF and M+45%F treatments for total grain yield (i.e. grain yield of maize + faba bean). Sole cropping of faba bean led to the greatest yield components and grain and biological yields. With increasing faba bean density in intercropping treatments, above mentioned traits (except number of pods per plant) were increased significantly. The great values for weed control efficiency (73%) and total relative value (1.14) were achieved at M+45%F treatment. Results of this experiment indicated that additive intercropping of faba bean (especially with a high planting density) as a companion crop with maize may, potentially, lead to sufficient weed suppression concomitant to an acceptable level of grain yield.

In vitro propagation of three Iranian apricot cultivars, “Ghavami”, “RajabAli” and “Khiveei” was studied by direct micropropagation technique. To optimize sterile manipulation, shoot nods of one year-old dormant vegetative shoots and current growing vegetative shoot were cultured in WPM medium after treatment by HgCl2, citric acid, ethanol and NaClO (10, 15, 20 min). Establishment of buds was tested in the MS and WPM mediums. Proliferation of sprouting buds was evaluated in WPM medium supplemented with three concentrations of (0.5, 1 and 2 mg/l) BAP and 0.05 mg/l of IBA. A half-Strength MS medium supplemented with three concentrations (0.5, 1 and 2 mg/l) of IBA was used as a rooting medium. The greatest number of contamination-free shoots in HgCl2 0.01% and citric acid 0.07% treatments were obtained. No significant difference was found between two different mediums in terms of bud vegetative growth. The shoot number and length were significantly affected by apricot varieties and BAP concentrations. The greatest numbers of proliferated shoot were observed in Rajabali and Ghavami varieties at 1 mg/l of BAP, whereas maximum number of shoot in Khiveei cultivar was observed in 0.5 mg/l of BAP. The maximum shoot length in Rajabali and Ghavami cultivars was obtained in 2 mg/l of BAP.

The effect of drought stress and mycorrhizal symbiosis on the colonization, root and leaf phosphorous content, root and leaf phosphatase activity, root volume and area as well as shoot dry weight of a variety of hulless barley were evaluated using a completely randomized experimental design (CRD) with 3 replications. Treatments were three levels of drought stress of 30, 60 and 90% field capacity and two levels of mycorrhizal with and without inoculation. According to the results, the highest value of leaf phosphorous (1.54 mg/g) was observed at mycorrhizal symbiosis against severe drought treatment. Root phosphatase activity was highest (297.9 OD min -1 FW-1) at severe drought stress with mycorrhizal symbiosis which in comparison with mild stress in the presence of mycorrhiza showed 16.6 fold increasing. The control and non-mycorrhizal symbiosis treatments had highest root dry weight (0.091 g). The lowest root volume (0.016 cm2) observed at mycorrhizal symbiosis × severe drought treatment. Generally, Inoculation of barley seed with mycorrhiza at severe water stress could transport more phosphorous to shoot, especially leaf via inducing of leaf and root phosphatase activity. Also, in addition to supply of nutrient sources especially phosphorous for plant, mycorrhizal symbiosis could play an important role in withstanding water stress in plant via increasing of root dry weight and area.

In order to investigate the effects of temperature and radiation on rate and duration of grain filling and final grain weight in rice cultivars, a split plot experiment based on randomized complete block design with three replications was conducted at different transplanting times at the research field of University of Guilan, Rasht, Iran in 2013. Factors were: transplanting dates in main plots (5 May, 20 May and 5 June) and rice cultivars (Hashemi, Ali Kazemi, Sangejo, Khazar, Dorfak and Gouhar) in sub plots. The greatest grain weight (31.9 mg) was obtained in Gouhar at 20 May and the smallest grain weight (20.4 mg) was observed in Sangejo at 5 June transplanting dates. The longest effective filling period (32.9 days) was achieved in Gouhar at 5 May transplanting date and the shortest grain filling duration (13.9 days) was obtained in Hashemi. The greatest grain filling rate (1.62 mg day-1) was obtained in the Hashemi and the smallest rate (0.92 mg day-1) was observed in Gouhar. Significant correlations were observed between cumulative temperature and radiation with final grain weight (R = 0.689). There were significant and positive correlations between the cumulative temperature and irradiance with grain filling duration, in contrary to negative correlations with grain filling rate and grain filling period. The results of this experiment showed that the grain filling duration plays a greater role, than grain filling rate, in determination of the grain weight. It could be concluded that an early transplanting (5 May) brings about favorable temperature and radiation conditions for an appropriate grain filling period and a greater final grain weight.

Study and evaluation of genetic diversity in European pear (Pyrus communis L.) is an important task in the pear breeding programs. This research was carried out in order to evaluate morphological, physiological and pomological variations within the some of the pre-selected European pear seedling genotypes in comparison with `Shahmiveh’ as a reference cultivar. The obtained results showed significant differences within the studied pear seedling genotypes in terms of the mentioned traits. Principal coordinate analysis (PCA) indicated that the studied characters could be placed in four components, explained about 94.02% of the total variability. According to the cluster analysis, the studied genotypes were divided into three groups. A95 was found to be in the same grouping with ‘Shahmiveh’ as one of the important commercial European pear cultivars in Iran. The same grouping of A95 with `Shahmiveh’ suggests that this genotype (A95) is superior in terms of suitable vegetative growth and higher fruit quality, among the studied genotypes and in comparison to the reference cultivar. Genotype A95 indicated a better ranking, than `Shahmiveh’ as a reference cultivar, in terms of fruit taste, attractive fruit with red halo color on the skin and suitable vigor with higher productivity, leading to the conclusion that it is as a promising European pear genotype. Further research will continue in the framework of new cultivar release within the pear breeding program at TMU, Iran.

The improvement of growth and flowering of petunia as one of the most popular and cultivated bedding plants in Iran, is of significant importance. Thus, a CRD experiment with five replications was conducted at the Research Greenhouse of Shahid Bahonar University, Kerman, Iran. From 48 days after sowing, when the seedlings had 5-6 true leaves, the seedlings were sprayed with thiamine (0 and 100 mgL-1), ascorbic acid (0 and 100 mg L-1) and benzyl adenine (0 and 200 mg L-1) at 4 steps during growth and development. The results indicated that the treatment of ascorbic acid with thiamine and benzyl adenine led to 2.5 and 3.5-fold increases in the number and length of lateral shoots compared to control treatment. The greatest fresh weight was obtained with ascorbic acid with thiamine and benzyl adenine treatment which led to a 2.5-fold increase in this trait, compared to the control. The highest dry weight was achieved in benzyl adenine treatment. The greatest vase-life and flower diameter were found with ascorbic acid (100 mg L-1), thiamine (100 mg L-1) and benzyl adenine (200 mg L-1) treatments in an extent that the flower longevity and diameter were increased by 83% and 72%, respectively, in comparison to control. Furthermore, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids and reduced sugars concentrations were significantly increased by the foliar-applied compounds compared to control.

In order to evaluate the benefits of maize, pinto bean and naked pumpkin triple cropping, an experiment was carried out as a randomized complete block design with three replications at Faculty of Agricultural Science, University of Guilan, Rasht, Iran in 2012. The treatments consisted of maize, pinto bean and naked pumpkin sole cropping (100, 75 and 50% of conventional densities), maize – pinto bean and maize – pumpkin double cropping (100-100%, 75-75% and 50-50%), and maize-pinto bean-pumpkin triple cropping (100-100-100%, 75-75-75% and 50-50-50%). The highest and lowest forage fresh weights were obtained in triple cropping system with high density and sole cropping systems with low density, respectively. In double cropping systems, the maize-pumpkin out-yielded the maize-pinto bean in terms of fresh weight. The relative crowding coefficient, competitive ratio and aggressivity of maize in double cropping of maize-pinto bean and naked pumpkin in double cropping of maize-naked pumpkin were dominant. In triple cropping systems, while maize and naked pumpkin were comparable, but both of the latter crops were dominant over pinto bean. Land Equivalent Ratio (LER) for double and triple cropping was greater than one, revealing the profitability of double and triple cropping systems on sole cropping. According to the LER, the cropping systems can be ranked as follows: triple cropping > double cropping maize/pinto bean > double cropping maize/pumpkin

This experiment was conducted in order to evaluate the effect of salinity stress on some traits of two barley genotypes (Hordeum vulgare L.) at greenhouse of Department of Agronomy and Plant Breeding, Shahrekord University, Shahrekord, Iran. A factorial experiment was carried out based on randomized complete block design (RCBD) with three replications. Treatments included two barley genotypes (Afzal (salt-tolerant) and Ligne527 (salt-sensitive)) and five levels of salinity (Control, 100, 200, 300 and 400 mM NaCl). Results showed that salinity left significant effects on leaf RWC, chlorophyll a and b, sodium, potassium, magnesium, calcium and protein concentrations, sodium/potassium ratio and yield components of barley genotypes. Based on the electrophoresis pattern, protein bands were increased by increasing the salinity levels and protein bands with different molecular weight were observed in different salinity levels. It was found that high concentration of potassium ion along with low concentrations of sodium and proline in barley leaf can be used as a criterion for selection and planting this crop in saline conditions. In addition, identification and isolation of the genes encoding salt resistance proteins in barely and transferring of these genes to sensitive genotypes of crop plants can be useful for breeding and generation of tolerant varieties to salinity.

To study the effects of biological and chemical phosphorus on antioxidant enzyme activity in safflower under water deficit conditions, an experiment was conducted in 2012 at the Research Field of the Faculty of Agriculture, Shahed University, Tehran, Iran. The experimental design was a split-factorial with three replicates. The main factor was the three levels of irrigation treatment: full irrigation (irrigation up to 50% soil moisture depletion relative to field capacity), water stress in the vegetative and flowering stages (irrigation up to 75% soil moisture depletion relative to field capacity). The sub-factor was the six treatments resulting from three levels of phosphate chemical fertilizer (0, 50, and 100 kg ha-1 Triple Super Phosphate), each at two levels of Barvar-2 bio-fertilizer (with and without inoculation with Barvar-2). According to the results of our experiment, antioxidant enzyme activity is affected by high levels of chemical phosphorus when there is no inoculation with biofertilizer (Barvar 2) under water stress in the vegetative and flowering stages. The results showed that inoculation with Barvar 2 in the absence of added chemical phosphorus increases the catalase activity and soluble protein concentration under drought stress in the vegetative and flowering stages. Also, using chemical phosphorus followed by Barvar 2 led to increase in the polyphenol oxidase activity and superoxide dismutase activity under these conditions. Inoculation with Barvar 2 in the absence of added chemical phosphorus significantly decreased the amount of malondialdehyde under stress condition at the flowering stage. It was demonstrated that inoculation with a biological fertilizer (Barvar 2) followed by application of a chemical phosphorus fertilizer under drought conditions could decrease the detrimental effects of drought stress on spring safflower.