JOURNAL OF CROP PRODUCTION RESEARCH (ENVIRONMENTAL STRESSES IN PLANT SCIENCES)
Year:2015 | Volume:7 | Issue:2|Papers Count:6

NACL stress is one of the reduction reasons of the medicinal plants and crop yield. Hormonal factors like as gibberellin (As a plant growth regulators), can play different physiological and biochemical effects on plants under salt stress. In present research, the effects of different sodium chloride (NaCl) concentration (0, 30, 60, 90 and 120 mM) and gibberellin (0 and 100 mg L-1) were studied on some morphological traits, photosynthetic pigments content, and proline in savory plant ( Satureja hortensis L.). Experimental design was Randomized Complete Blocks (RCB) with 4 replications. The results demonstrated that different levels of salinity significantly decreased both dry and fresh weight of root and shoot. Reduction trend of dry and fresh weight were done more moderate with application of 100 gibberellin. This response showed that gibberelin could relief negative effects of NaCl on biomass productions under salt stress and gibberellin application caused improvement of growth. With increasing the levels of salinity, chlorophylls a and b reduced considerably in compared to control and concentration of this traits at NaCl × gibberellin interaction significantly decreased in comparison with individual salty treatment. Also anthocyanin content in individual salty treatment increased significantly compare with individual gibberellin treatment and NaCl × gibberellin interaction. The results showed that proline concentration increased considerably in NaCl × gibberelin interaction in comparison with control treatment and the highest concentration of proline was observed in 90 Mm NaCl and gibberellin consumption.

In order to investigate the relationship among the traits and identification of tolerant germplasm to salinity stress, a total of 88 accessions of durum wheat collection of National Plant Gene Bank of Iran were evaluated. The studied accessions along with three cultivars of Kavir, Roshan and Mahooti as tolerant controls were planted under salinity stress and normal conditions in Ardekan region of Yazd and Karaj, respectively. Agro-morphological traits were evaluated according to the international descriptor. The results of descriptive statistics showed that the relating values decreased under stress compared to normal condition for all the evaluated traits. Mean value of 100 grain weight for 14 accessions was larger than that of check cultivars. A total of 26 accessions were located in region A of superior germplasm. Based on the coefficient of correlation among stress tolerance indices, STI, GMP and MP were identified as the best indices to select salinity tolerant durum wheat germplasm. The studied accessions were separated in seven groups through K means cluster analysis. The total results of the current research indicated valuable potential and tolerance to salinity stress in durum wheat accessions of National Plant Gene Bank of Iran.

One of the most important methods in integrated weed management to reduce the amount of herbicides is nutrient management. In order to study nitrogen split application pattern and Nicosulfuron dosages, an experiment was conducted as split plot based on randomized complete block design with 3 replication in the research field of natural resources Sabzevar in 2011-2012. Experimental factors were nitrogen splitting patterns (75% as sowing +25% as top dressing, 50% as sowing +%50 as top dressing and 25% as sowing +75% as top dressing) as main factor and herbicide amounts (Control, Recommended, Recommended + 25% and Recommended - 25%) as sub plot. Amount of applied nitrogen was 225 kg as urea and herbicide dose was 1.5 lit. ha-1 (80 g ai ha-1). The results showed that biological yield, economic yield, number of rows in cob and seed per rows affected by nitrogen split application and 25% at sowing+75% as top dressing was the best treatment compared to others. Although, increasing 25% herbicide dose increased yield and yield component of corn but hadn’t significant difference with recommended dose. Generally, the results showed that the nitrogen application as 25% at sowing and 75% at top dressed and recommended dose of herbicide is the most appropriate attendance to obtain maximum yield.

In order to evaluate the effect of plant density on some agronomic traits of new grain corn hybrids compared to KSC704, a factorial experiment in a randomized complete blocks design with three replications done at the agricultural Research Station of Gorgan in the summer of 2014. Scrutiny factories in this experiment involved of 4 hybrid in the named of KSC703, KSC704, KSC705, KSC706, and plant density in three level of 55000, 65000 and 75000 plants per hectare. In order to achieve the desired density, plants spacing were considered 24, 20 and 17 Cm respectively on each row. Also, some traits affected the plant yield measured that were included maize length, the one thousand grains weight, Plant height, corn yield, grain yield, the number of grain rows per ear, the number of grains per ear and total yield. Analysis of variance showed that effect of hybrid and plant density on yield and its components were significant (One thousand grain weight, grain yield, corn yield, corn length, Plant height and total yield). With the increasing plant density, plant height increased and one thousand grain weight, grain yield, corn yield, the length of corn and total yield decreased. The density of hybrid KSC703 compared to other varieties allocated most corn length, plant height, one thousand grain weight, total yield, corn yield and grain yield. According to the findings, 55000 plants per hectare, in order to achieve corn grain in studied varieties was appropriate and justifiable.

Distribution of plants per unit area is one of the most consistent factors in order to increase yield. This research was conducted in the summer of 2013 cropping season in Izeh, North-west of Khuzestan province to determine the best cultivar and the most appropriate of density to achieve the highest yield. The research was conducted as factorial based on randomized complete blocks design with three replications. The first factor consisted of three rows spacing (10, 15, 20 cm) and the second one was three cultivars of Mungbean (Pakistani MN92, Gohar and local). The interaction effects of treatments showed that the highest yield (1430.2 kg/ha) obtained from Pakistani cultivar in density of 13.3 plants/m2. The lowest grain yield (496.57 kg/ha) belonged to local cultivar with density of 10 plants/m2. Although the individual plant yield in density of 10 plants/m2 was more than 13.3 plants/m2, but enhancement of individual plant yield couldn’t commencement of reductions of the number of plants/m2. The results of yield components (Pods per plant, number of seeds per pod and 1000 seed weight) showed that there is significant difference between density and cultivars. Therefore, the selection of plant density (13.3 plants/m2), according to Mungbean cultivars (Pakistani NM92) under similar conditions can be appropriate.

This study was conducted to evaluate the effect of different doses of cadmium and superabsorbent polymers on the uptake and growth of cucumber plant. The research was conducted as factorial based on completely randomized design with 4 replications. The first factor superabsorbent polymers in 2 levels (Non application and application) and the second factor cadmium cosuntration in 4 levels (0, 30, 60 and 90 mg/kg of dried soil) were considered. The results showed that with increasing cadmium concentrations in the soil, its concentration in roots, shoots, leaves, fruits and fruit skin approved and root and shoot dry weight and chlorophylls content reduced. Accumulation of cadmium in cucumber fruit peel was more than the fruits. Superabsorbent polymers increased cadmium accumulation in roots, shoots, leaves, fruits and bark of the fruits and decreased total dry weight of the plant. So the superabsorbent polymers by increasing the cadmium uptake and its accumulation in organs, decreased plant height, root and total dry weight and fruit weight. Bioaccumulation factor (BCF) was affected by superabsorbent polymers. Application of superabsorbent polymers increased BCF. With increasing of cadmium concentration the BCF amount was changed from zero up to 0.25.