JOURNAL OF CROP PRODUCTION RESEARCH (ENVIRONMENTAL STRESSES IN PLANT SCIENCES)
Year:2013 | Volume:5 | Issue:1|Papers Count:8

In order to invsetigate the effect of fertilizing methods, number of split application and nitrogen fertilizer rate on forage yield and quality of sorghum as second crop, a field experiment was conducted in research field of Tarbiat Modares University at summer 2010. Treatments were arranged as split factorial experiment based on randomized complete blocks design with four replications. Main factor was the methods of N application (M1: single side dressing, M2: Two side dressing and M3: Inside furrow) in main plots and the subplots referred to factorial of N rates (200 and 300 N kg. ha-1) and split application (S1: ½ after the sowing, ½ after the first cutting; S2: ¼ after the sowing; ¼ in 30 days after sowing; ¼ after the first cutting; ¼ in 15 days later). The results showed that in first cut, there was no significant effect on quantitative traits for all factors, but three-way interaction of factors influenced forage dry weight significantly. In such a manner M1R1S1 treatment produced the highest (32 t/ha) forage yield. From quality point of view, nitrogen rate influenced %CP and %NDF significantly. These traits plus %P were affected by M´S interaction (P³0/05). The most %CP (12.84) and %P (0.22) were obtained in M3R2S2 treatment, However M1R1S1 having %11.9 CP and % 0.206 P was arranged in the same group. In second cut nitrogen rate influenced the total forage biomass, leaf/stem ratio and stem dry weight (P³0.05). Also stem fresh weight, leaf and stem dry weight affected by nitrogen split application. Mean percentage of CP, P, and Ca in all fertilizing methods were 12.3, 0.2 and 0.64 respectively; nonetheless, inside furrow distribution of fertilizer (M3) has the lowest %NDF. Nitrogen splitting in 4 times comparing to 2 times enhanced the forage quality. Regarding forage yield in whole season, effect of fertilizing method was significant (P³0.05) just for forage dry weight. Also total fresh forage yield significantly affected by nitrogen rate split application interaction, in such a manner R2S1 produced the highest yield (48.05 t/ha). Altogether, regarding to simple method for fertilizer distribution and necessity for chemical restriction, summer cropping of forage sorghum receiving one side dressing 200 kg/ha (1.2 after sowing and 1.2 after first cut) which produced 9.15 t/ha dry forage yield is introduced as the superior treatment.

In order to evaluate for salt tolerance, 823 accessions from bread wheat collection of National Plant Gene-Bank of Iran were studied. The evaluation of genetic materials was performed under salt stress in research field of Ardekan, Yazd with soil and irrigated water salinity of 10 to 12 dsm-1 in an augmented design with three check cultivars. Grain yield of five spikes and number of tillers had the largest diversity based on coefficient of variation, 27.99 and 24.13, respectively. In principal component analysis the first seven components comprised 69.18% of the total variation. The first principal component emphasized on grain weight of five spikes, number of seeds per spike, number of spikelets per spike and number of florlets per spikelets and distinguished acessions 3528 (unknown origin from Iran), 3477 (Khorasan), 4056 (Kerman), 3532 (Markazi, 3569 (Lorestan) and 3444 (Khorasan). Cluster analysis was performed through K means method and located the accessions in five groups. In Group two, 38 accessions had higher grain yield of five spikes, 100 seed weight and number of seeds per spike than Kavir. In group five, three accession, 3228 (Khorasan), 4436 (India) and 5415 (Greece) had higher grain yield of five spikes, 100 seed weight and number of seeds per spike than Roshan and Mahooti. The total results of the research indicated high genetic diversity and possibility of selection for salt stress within bread wheat genetic resources.

Alfalfa (Medicago sativa L.) is essential forage most of the first plants domesticated forage plants to feed animals that early humans has been identified, but weed can reduce the nutritional value of the alfalfa for livestock. In order to study the effects of post-emergence herbicides Imazethapyr (Persuit) 1.5, 2 and 2.5 lit/ha Paraquat (Gramaxone), Glayphosate (Roundup), Linuron (Promethrin) and glyphosate with duplicate salts (Weedmaster) to the controlling of alfalfa weed an experiment was conducted on the basic of randomized completed block design in 2011-2012 Abadan city (Shalahy region). In this study, eight treatments and four replications were evaluated. The results showed a significant effect of herbicide treatments compared of weedy control in weed control. The results of statistical analysis in samples showed that, 30 and 10 days after spraying earned a significant effect in 1% level on the number and total dry weight of weed respectively. The results of combined analysis of alfalfa factors showed interaction between herbicide and harvest time was not significant on heigh but was significant in 1% level in dry weight and stem number of alfalfa. Findings by examining the effects of herbicides and weed dry weight were determined that paraquat herbicide is Premier, but due to crop damage in the critical period is recommended. Pursuit 1.5, 2 and 2.5 ratios than paraquat in terms of control performance in the next round in a group are recommended. In this experiment, the best yield was observed in all Persuit doses consumption and the lowes one belonged to Paraquat application.

In order to investigation the effect of Selenium foliar application on SOD, CAT, GPX antioxidant enzymes activity and degredation index (MDA) in coriander (Coriandrum sativum L.) medicinal plant under drought stress conditions an experimental was carried out in Islamic Azad University, Shahr-e-Qods Branch during 2012-2013. This experimental was carried out in a factorial design based on RCBD with three replications. Factors of experiment were drought stress in 4 levels:100% of field capacity (Control), 80% FC, 60% FC and 40% FC and second factor was selenium in the form of Selenat sodium in four concentration: Non selenium using (Control), 20 mg/L, 25 mg/L and 30 mg/L. The results showed that activity of enzymes and MDA was increased with increasing in drought stress amounts. According to the results the highest activity of SOD, CAT, GPX and MDA observed at 40% FC irrigation and 25 mg/L selenium consumption and the lowest level observed at 100% FC irrigation and without selenium foliar application.

Evaluate the effect of combined application of two herbicides; nicosulfuron+rimsulfuron and bromoxynil+MCPA for control of narrow and broadleaf weeds in corn; an experiment was carried out in Karaj at Agricultural Research Centers during 2011. The experiment was conducted in a randomized complete blocks design with two factors and four replications. The first factor was nicofulfuron+rimsulfuron dosage at four level:; 0, 125, 150 and 175 grams per hectare and the second factor was bromoxynil+MCPA at 0, 0.5, 1.0 and 1.5 liters per hectare. Additionally, a hand weeded control was added to treatments. Different factors of weed and corn including weed population reduction and dry matter reduction were evaluated 30 and 60 days after spraying. Corn height, forage yield, grain yield and yield components were measured at harvest stage. The results showed that the best combination of tank-mix of the above mentioned herbicides was 1.0 liters per hectare of bromoxynil+MCPA and 125 grams per hectare for nicosulfuron+foramsulfuron. Considering to weed control efficiency, percent of corn yield augmentation (Up to two times) and minimal environmental risk (Due to reduced herbicide), it’s was best selected treatment. These treatments had the best control of weeds and could be used for management of weed resistance to herbicides in corn fields. Because the nicosulfuron+rimsulfuron is an ALS-inhibitor herbicide, combination of two mentioned herbicides, could delayed broadleaf weed resistance to both mentioned herbicides in corn.

Purslane is a local plant in Iran that this plant can easily breed and is also highly tolerant against lack of water; it can be regarded as a hyper accumulator of heavy metals. To study the effect of Nickel and Cadmium on growth, yield and other characters of purslane (Portulaca oleracea L). An experiment was carried out as factorial in the basis completely randomized design with three replications in the field of Islamic Azad University, Shahr-e-kord branch, Iran, in the spring and summer of 2012. Treatments of this experiment included different levels of nickel (0, 20, 60, 120 mg/kg) and different levels of cadmium (0, 5, 20, 40 mg/kg). The results showed that different levels of nickel and cadmium have a significant effect on the morphological and physiological characters of purslane and after increasing in heavy metals concentration, these characters significantly decreased in comparison with the control plants. In classifying the averages of shoot and root dry matter, percentage of the extract, and Cd and Ni of soil and shoot, the highest amounts belonged to the control plants and the lowest amounts to the plants under combined treatment of nickel (120 mg/kg) and cadmium (40 mg/kg) and the single treatment of cadmium (40 mg/kg). Furthermore the toxic properties of cadmium are more than nickel and decreased most of meuasured characters. In study of phenological trend and Duncan‘s multiple range test, we saw the different groups. Perhaps heavy metals by effect on dry and fresh matter made negative influence on essential oil.

To evaluate Effect of salinity stress on mophophysiological indices of rice genotypes under hydroponic conditions in seedling growth stage, an experiment designed in randomized complete blocks design with three replications. Experimental treatment including fifteen rice cultivars, were carried out in two environmental conditions. At normal condition the Yoshida nutrient solution has been used as a control. At salinity condition Yoshida nutrient solution, has been mixed to sodium chloride (NaCl) at 8 dS/m-1. The measured traits were root and shoot length and dry weights, biomass, Na+/K+ ratio, chlorophyll content and leaf area. Significant differences among genotypes for Tolerance Index (TOL) and Sstress Tolerance Index (STI) were calculated in 8 dS.m-1 salinity level. The results of data analysis showed that there was most significant differences for salinity condition and cultivars for all traits (P<0.01). In salinity condition (8 dS/m-1) there was big and significant correlation between biomass and Na+/ K+ traits.

In order to study the effect of seed size and production region on peanut seed vigour used potassium Leachate and electrical conductivity tests. This study was performed in three peanut fields in Astaneh Ashrafieh and agronomy laboratory of Rasht branch Islamic Azad University during 2010 to 2012. Experiment was factorial with basis of randomized complete block design in 3 replications. First factor was production field of seed in 3 regions (Noghrehdeh, Amshal and Kiyashahr) and second factor was the seed size in 3 levels [Large (larger than 1 g), medium (between 0.8 and 1 g) and small (lower than 0.8 g)]. The results showed that the effect of production region, seed size and their interactions on electrical conductivity of the solution released from seeds was significant. Lowest electrical conductivity was achieved in large seeds produced in Amshal which indicates the high vigour of large seeds produced in the Amshal region. Effect of seed size on the amount of potassium released was also significant that large seeds showed lowest potassium releasing from seeds and there was the highest seedling vigour in these samples. Also, standard germination tests proved that highest seed vigour was in large seeds produced in Amshal region. Artificial neural network analysis showed that amount of calcium in the soil are greatly affecting on peanut seeds vigour. Also, other results in artificial neural network analysis showed that important variables affecting the seed vigour were the peanut electrical conductivity, seed production region, seed size and potassium Leachate, respectively.