JOURNAL OF CROP PRODUCTION RESEARCH (ENVIRONMENTAL STRESSES IN PLANT SCIENCES)
Year:2013 | Volume:5 | Issue:3|Papers Count:9

Arsenic is one of the toxic heavy metals in contaminated crop environments. Arsenic stress leads to ROS damages in plants. Sodium nitroprusside inhibit the production of reactive oxygen species and protect plants against ROS damages. In this research the effects of Arsenic contamination and sodium nitroprusside foliar sprays was examined on the quantitative characteristics in bitter squash plants. The experimental design was as factorial in the basis of completely randomized block desighn with 3 replications, sodium nitroprusside in 3 levels; 0, 50 and 100 mM and arsenic contamination in four levels 0, 30, 60 and 90 mg. kg-1. The experiment was conducted in 2011 at the Zabol university greenhouse. Heavy metal stress reduced number of fruits per plant, seed weight, seed yield, fruit size, fruit weight and chlorophyll fluorescence. Application of 100 mM sodium nitroprusside had the greatest number of fruits per plant, seed weight, seed yield, fruit weight, fruit diameter and chlorophyll fluorescence. This results sugestes that sodium nitroprusside can relieve arsenic toxicity on fruit yield, seed weight, fruit fresh weight and fluorescence.

In order to study the relationships among agro-morphological traits under drought stress and screen the tolerant accessions, 1024 populations form accessions from bread wheat collection of National Plant Gene Bank of Iran were evaluated in research field of Yazd in an augmented design. Most of the studied populations died of the stress severity and only 35 accessions (3.42%) survived which agro-morphological traits of them were measured. Stepwise regression was performed for grain weight of five spikes as dependent variable, and three traits including number of grains per spike,100 grain weight and spike density entered in the model indicating their importance in variation of the dependent variable. The results of principal component analysis showed that the first five components justified 73.75% of the variation. The accessions were distinguished by biplot of the first two principal components. Four accessions including 2406 (Unknown origin), 400 (Unknown origin), 3947 (Khorasan) and 1488 (Tehran) had larger grain weight of five spikes, 100 grain weight and number of grains per spike than other accessions and the check cultivars. The superior tolerant accessions identified in this research could be suggested to be utilized in breeding programs for drought tolerance.

In order to study Phenology evaluation and yield comparison of twenty five sunflower genotypes under environmental conditions of Shahroud Region, a fieldexperiment was carried out in Agricultural Research Center of Semnan province (Shahroud) during 2009 growing season. This research was carried out in the form of simple 5´5 latis design with two replications. In this experiment, 25 treatments including 24 new hybrid producted from different cross between CMS (Cytoplasmic Male Sterilitiy) and RN (Restore of Fertility) were compared along with hybrid cultivar Azargol (Control). In this research, morphological traits of sunflower were analyzed such as plant height, stem diameterand, capitul diameter also other characters as biomass (Plant dry weight), seed yield, harvest index, 1000 grain weight and grain quality including oil and protein percentage and yield. The results indicated a significant effect of genotype on the majority of studied traits in 1% probability level. In the present research, hybrid RN-126×CMS-31.2 had the highest capitul diameter (19.12 cm) and seed yield equal to 4391.1 kg/ha. Azargol hybrid (Control) which is plantable recommended for all determined regions for sunflower cropping, produced 4255.18 kg/ha grain yield and was set in one statistical group with bartar hybrid. Achievement of the maximum oil yield (1928.31 kg/ha) of RN-125×CMS-31.2 hybrid can be attributed to predominancy of this genotype, in traits of harvest index (35.17%) and 1000 seed weight (75.12 g) among sunflower hybrids. Azargol hybrid had 1720.33 kg/ha oil yield and indicated 12% decreasment in comparison to bartar hybrid.

Due to study the effect of nitrogen and manure fertilizer application on yield and yield components of calendula (Calendula officinalis L.) under water deficit stress conditions, An experiment was conducted at Research Field of Islamic Azad University, Takestan branch in 2010. Field experiment was carried out as a split plot design based on completely randomized block design with 4 replications. Three levels of stress as irrigation intervals after 40, 80 and 120 mm water evaporation from class A evaporation pan arranged as main factor and fertilizers consumption 90 kg/ha nitrogen, 75% nitrogen and 10 ton/ha manure fertilizers, 50% nitrogen and 20 ton/ha manure fertilizers, 25% nitrogen and 30 ton/ha manure fertilizers and 40 ton/ha manure fertilizer considered as sub factor. The results indicated that water deficit stress had significant effect on capitulum diameter, seed per capitulum, number of capitulum/m2, seed yield and harvest index. The highest capitulum diameter, seed per capitulum, number of capitulum/m2, seed yield and harvest index gained in irrigation after 40 mm evaporation from pan class A. Nitrogen and manure fertilizer had significant effect on number of capitulum/m2, seed yield and harvest index. The highest harvest index (16.43%) conducted in 40 ton/ha manure fertilizer. Irrigation, nitrogen and manure fertilizers triple interaction effects were significant on number of capitulum/m2, 100 grain weight and seed yield. The highest flower yield took place in irrigation after 40 mm evaporation from class A pan and 40 ton/ha manure fertilizer consumption. It seems that after increasing in drought stress, manure fertilizer was more effective than mineral one.

To study the effect of planting pattern and plant density on yield of Iranian oxtonyue, a factorial experiment was done based on completely randomized block design with three replications during 2009-2012 at the Eshkevarat region in Guilan province. Planting patterns factor in two levels (Square and rectangular) and the plant density factor in four levels (2, 4, 6 and 8 plant/m2) were applied. The results showed that the effect of year was significant for all studied characters, which generally in years after planting with increasing in plants age, from the second year onwards, the number of flowering stems and flower number decreased. The overall effect of planting pattern on dry weight of flowers per plant, weight of dried flowers per area unit and number of flowers in m2 was significant. Effect of plant density on the weight of dried flowers per plant, dried flowers weight per area unit, number of flowering stems, number of flowers per area unit, number of flowers in inflorescence and flowers number were significant. The interaction effects of both factors for dry flower weight per area unit, number of flowers per plant, number of flowers per inflorescence and flower length were significant. The maximum amounts of dried flowers per area unit gained in square planting methods and 6 plants/m2 density (96.45 g/m2). The highest number of flowers per area unit (4532.3) was obtained in square planting method. Most number of flowering stem per area unit (792.89) and number of flowers per area unit (5044.3) by 8 and 6 plants density were obtained respectively. The highest number of flowers in inflorescence (104.56) and flowers length (4.82 cm) observed in square planting and 2 plants/m2.

To study the Effect of Cu and Mn micronutrients foliar application on quantitative and qualitative yield of thyme (Thymus vulgaris L.) a research was performed in Shahrekord as factorial based on completely randomized block design with 3 replications under farm conditions during spring and summer 2012. The used factors in this research included copper and manganese in 3 levels (0, 200 and 400 ppm) as solution spraying. Before flowering, shoots harvested and dried in oven. Essence percentage and thymol and carvacrol were measured by clevenger and GC respectively. The results showed that amoung Cu and Mn treatments on experimental traits, Cu 4/1000 and Mn 2/1000 had significantly increasing effect on root length, but in more situations, Cu 2/1000 and Mn 2/1000 treatment was the best treatment in themost of characters. Also there was significant correlation between essence percentage and dry and fresh weight of shoot.

Sunflower (Helianthus annus L.) is the most important oilseed crop in Iran. This study evaluated the effects of soil application levels of zinc on sunflower yield and yield components under drought stress conditions. This experiment was conducted as split plot design based randomized complete block design at Sabzevar Agricultural Research Station in 2010-2011. Experimental factors were: Irrigation regimes in three levels (50, 100 and 150 mm evaporation from class A pan) as main plots and four fertilizer treatments of Zn (Control, 30 kg/ha, 60 kg/ha, 90 kg/ha) as subplots. The results showed that, irrigation interval did not show significant effect on plant height and oil percent. Head diameter, seed number per head, seed weight, biological and seed yield was affected by irrigation interval. The results indicated that, increasing irrigation intervals decreased head diameter, seed number per head, seed weight, biological yield and seed yield significantly. The maximum amounts of these traits were obtained in 50 mm irrigation interval. 90 Kg/ha Zn application had the maximum value for all characteristics that did not have significant difference with 60 kg/ha Zn application. Increased Zn levels were reduced the effects of drought in sunflower. Drought stress effects wre decreased in higher Zn levels consumption. Although increasing irrigation intervals were decreased yield and yield components but this reduction was less than control for treatments that received Zn. Overall, In both stress and non stress conditions, 60 Kg/ha Zn application as zinc sulfate was recommended in order to achieve acceptable yield in sunflower.

In order to evaluate the effect of different nitrogen amounts and rows spacing on morphological and medicinal attributes of purple coneflower (Echinacea purpurea L.), an experiment was carried out in Isfahan Agriculture Research Center. The experiment was as split plot based on completely randomized block design with three replications. N fertilizer levels including 0, 75, 150 and 225 kg/ha considered as main factor and different rows spacing 15, 30 and 45 cm lacated in sub factors. Analysis of variance showed that the effect of different nitrogen levels on seed yield per plant, root dry yield, root fresh weight, shoot fresh weight, number of leaves, number of flowering branches, flowering branch length, plant height and flower height was significant. Number of flowers per plant, plant height, leaf number, shoot dry and fresh weight, root dry and fresh weight, flower height, leaf area, seed weight and seed yield per plant were raised with increasing nitrogen fertilizer up to 225 kg/ha. The experimental results showed that also the number of flowers per plant, number of branches, plant height, flower height, number of leaf, shoot fresh and dry weight, root fresh and dry weight, leaf length, leaf area and seed weight were maximum in 45 cm row spacing. Clorogenic acid amounts in shoot were variable between 3.56% (Control+15 cm rows spacing) and 4.84% (150 kg/ha nitrogen+30 cm rows spacing).