فصلنامه اکوفیزیولوژی گیاهان زراعی
پیاپی 27 (پاییز 1392)

To study the effect of the best planting date of rapeseed cultivars on seed yield¡ a split plot experiment was conducted in randomized compete block design with four replications at Agricultural and Natural Resources Research Center of Ilam province¡ Iran of 2005. Planting dates (September 5th¡ October 1st¡ October 15th and November 1st) were assigned to main plot and cultivars (Talaye¡ Rijent×Kobrah and Okapi) to sub plots. The results of the analysis variance of data showed that planting date¡ cultivars and their interaction effect were significant on under study traits at 1% level probability. The highest seed yield (3622 kg.ha-1) was obtained from September 5th and the lowest (3075 kg.ha-1) from October 1st planting dates. The highest number of seed per pod (61.55 seed)¡ 1000-seed weight (3.477 g) and number of pod on main stem (64.75 pods) were observed in September 5th planting date. Zarfam cultivar had the highest seed yield¡ number seeds of per pod¡ 1000-seed weight and number of pods on main stem in comparison to other cultivars. Talaye had the highest days to flowering and plant height than other cultivars. Among planting dates¡ September 5th had lowest days to flowering and it was also evaluated as to be better than other planting dates. Therefore¡ September 5th planting date can be the results of this study recommended to Zarfam cultivar in this region.

To create genetic variations in potato during four years of study (2007-11) and use than in breeding programs, some 105 hybrids were selected from cresses of Agria, Savalan, Boren, Kennebek and Ceaser cultivars as hybrids parents, and planted in augmented design at the Agricultural and Natural Resources Research Station of Ardabil during 2010-2011. The marketable tuber yields produced by the parents and hybrids were 42-52 t.ha-1 and 10.4-138.8 t.ha-1, respectively. The marketable tuber yields of hybrids exhibited 23.81% over dominance, 52.38% incomplete dominance, 13.33% reduction dominance and 10.48% interval dominance. Almost 24% of all hybrids selected produced higher marketable tuber yield than their parents. Heterosis for marketable tuber yield was found to be 58%. Based on the traits considered like marketable tuber yield, tuber uniformity, shallow eye depth, short stolon and yellow flesh and skin color, heterosis and dominancedegrees some 28 hybrids were selected. Among hybrids selected, 14 belonged to ♂Ceaser × ♀Savalan cross (021, 022, 023, 025, 026, 049, 057, 081, 087, 088, 095, 098, 0104 and 0105), four to ♂Savalan × ♀Agria cross (0500, 0502, 0503 0508), five to ♂Ceaser × ♀Agria cross (0611, 0613, 0616, 0618 and 0623) with early to mid-early maturity group, one to ♂Boren × ♀Savalan cross (0205), two to ♂Savalan × ♀Ceaser cross (0300 and 0303) and two to ♂Ceaser × ♀Kennebek cross (0401 and 0403) with mid-late maturity group.

A factorial split experiment using randomized complete block design with four replications was performed at Agricultural Farm Experimental Station of Ilam province (Iran) during growing season of 20007-2008. The treatments consisted of 3 levels water deficit (usual, irrigation each 5 days, three days later and six days later than usual irrigation) and 2 levels of phosphate biofertilizer (without and using of biofertilezer) and 3 levels of chemical fertilizer (0, 45 and 90 P2O5 kg/ha of triple superphosphate). In addition, 100 kg/ha of K2O before planting and 400 kg/ha of CH4N2O at 3 times, one-third at planting, one third at stem elongation and the rest at inflorescence stage were applied. 13 kg/ha of biofertilezer banded of planting time, 3-5cm besides seeds on the planting rows. Results showed that application of biofertilezer and 45 kg/ha of chemical × irrigation interaction on traits like plant height, height of ear from ground, seed number/ear, rows per ear, 1000 kernel weight, seed yield and protein content were significant and resulted in highest yield (9840 kg/ha) as compared to the other fertilizer and irrigation treatment.

To investigate association of some morphophysiological characteristics with seed yield and its components of oilseed rape varieties, a research was carried out at East Azerbaijan Agriculture and Natural Resources Research Center in 2005-2006. Experimental design was randomized complete block with four replications. Varieties under study showed significant differences in leaf area and leaf number per plant (typeI, II and total), leaf dry weight per plant, specific leaf weight, leaf temperature, seed oil percent, seed and oil yields. The results indicated that high yielding varieties possessed higher levels of leaf area (type II). SLMO46, Sunday, ARC-2, Opera and Ebonite had the higher seed yields than other varieties respectively. Sunday, Ebonit, SLM046, ARC-2 and Opera produced higher and Okapi, Sinatra, Regent×Cob, Geronima and Olpro lower oil yields. In this research, a positive and significant correlations were observed between seed yield with oil yield, leaf area type II, total leaf area, leaf dry weight, while a negative and significant correlation between seed oil and seed yield were seen. Correlations of oil yield with seed oil, seed yield, leaf dry weight and leaf area (typeI, II and total) were positive and significant. It seems that leaf area, especially larger leaves with longer petiole (type II), had important role in seed and oil yields. It can be concluded that replicating the experiment, would possibly result in recommending adaptable and high yielding oilseed rape varieties for cold climates of the country.

To evaluate the effect of foliar application of copper on yield and yield components of four barley cultivar a factorial experiments with two factors was conducted in randomized complete block design with three replications in 2011 - 2012. The first factor was four barley cultivars (Fisasih, Yousof, Reyhan and Cb17) and the second factor consisted of foliar application of copper chelate in three levels (non, one time at booting stage and two times at both booting and heading stages). Results showed that there were differences among number of fertile tillers, number of seed per spike and seed weight of cultivars. Although yields of cultivars did not differ significantly, one or two times of foliar applications of copper increased biological and seed yield. Seed yield increased mainly as a result of increase in thousand seed weight, number of fertile tillers per unit area and the number of seeds per spike. Mean while harvest index was not affected by foliar application. In general, it seems due to essential of elemental copper on plant physiology, particularly in a copper sensitive plant like barley application of copper-containing compounds may enhance plant growth.

To study the effect ofphysical seed priming techniques on seed germination, growth and yield of a wheat cultivar (Triticum aestivum, cv. Falat), an experiment was conducted. Factors under study were ultrasonic intensity of 3 W.cm-2, laser wave of length of 6328 Å, magnetic field with intensity of 0.6 T, gamma and beta radiations both with intensity of 2 mc for 5 and 10 min and a control. Results indicated that effect of laser and magnetic field for 5 min was effective on duration germination as compared to other treatments. Seedling treated by magnetic field for 5 min resulted in greater vigor than ultrasonic and beta radiations. Seed weights, under magnetic field and gamma radiation treatments for 5 and 10 min were heavier (55.6 g) than other treatments. Seeds that treated with magnetic field for 5 min produced 21.5% more yield as compared to the control. Laser (for 5 min) along with gamma and magnetic field (for 5 and 10 min) radiations could produce yield up to 588 g.m-2. Seed yield in control plot was 71 g lower than those treated with laser for 5 min, gamma and magnetic field for 5-10 min radiations.

To study the effects of foliar applications of salicylic acid under cutting off irrigation at BBCH and phenological growth stages of plants and their interaction on chlorophyll a, b, carotenoid concentrations and chlorophyll fluorescence of sesame varieties (Sesamum indicum) a split factorial experiment based on a randomized complete block design with 3 replications was conducted at Shahrood (Semnan province of Iran) during growing season of 2011-2012. Main factor was three irrigation levels (full irrigation as control, cutting off irrigation at 69 BBCH (at 90% flowering stage), and cutting off irrigation at BBCH79 (at full growth of pods). Sub plots were three cultivars of sesame (Biarjomand native, Dashtestan 2, Darab 1) and two levels of the foliar applications salicylic acid (0, and 0.6 mM). The results of variance analysis showed that drought stress due to cutting of the irrigation at 90% flowering and full growth of pods reduced content of chlorophyll a, carotenoid and chlorophyll fluorescence significantly. Foliar application also reduced chlorophyll b and chlorophyll fluorescence (Fv, Fm) significantly. Experimental results indicated that highest concentrations of chlorophyll a and carotenoid 0.629 and 0.265 mg/g.Fw respectively produced by plants when irrigation was cutted off at BBCH 69 and the highest concentration of Fv/Fm (0.656) in control treatment. Based on the results obtained the maximum chlorophyll b content belonged to Darab (0.423 mg/g.Fw) and the lowest (0.364 mg/g.Fw) to Biarjomand native.

To study the yield and growth indices of potato under different potassium levels an experiment was conducted in Agricultural and Natural Resource Research Center, Khorasan Razavi province, Iran during 2010. Potassium levels 0, 90, 180 and 270 kg K2O per hectare were included. In the experiment the tuber yields were 18.90, 21.59, 22.26 and 24.94 t/ha in 0, 90, 180 and 270 kg K2O per hectare, respectively. Potassium increased total dry matter (TuDM), root dry matter (RDM), stem dry matter (SDM), leaf dry matter (LDM), tuber dry matter (TDM), crop growth rate (CGR), leaf area index (LAI), leaf area duration (LAD), and net assimilation rate (NAR).The maximum TDM (835 g.m2) was obtained in 270 kg K2O per hectare and lowest TDM (778 g.m2) was taken in 0 kg K2O per hectare. The maximum RDM, SDM, LDM and TDM were in 1600 GDD, 1800 GDD, 1500 GDD and 2300 GDD, respectively. The maximum RDM, SDM, LDM and TDM obtained in 270 kg K2O per hectare and were 26.1, 324.86, 171 and 500 g.m2, respectively. The maximum LAD (309.37 m2.GDD-1) was obtained in 270 kg K2O per hectare in 1600 GDD. In the general potassium increased all of the growth indices in potato.

To investigate the effects of different levels of seed priming on germination indices and nutrient absorption at early growth stages of sweet corn (Golden Kernel Hybrid) a factorial experiment based on completely randomized design was conducted with three replications in 2011. The experiment consists of 6 levels of primings (seeds without priming, priming with tap water, priming with distilled water, priming with sodium chloride, potassium chloride, and hydrous calcium chloride) and five levels of salinity (zero, 4, 8, 12 and 16 ds/m sodium chloride). The characteristics studied were germination percentage, germination rate, root and shoot length, fresh weight and dry weight of seedling, root to shoot ratio and determination of sodium, chloride, calcium, and potassium concentration in different parts of seedlings (stems, roots and seed). The results indicated that increasing salinity stress levels decreased all parameters measured. Priming seeds with hydrated calcium chloride responded to significantly to salinity stress better than other treatments. Results also showed that increasing concentration of sodium chloride salt, increased absorption rate of sodium but concentration of calcium and potassium were reduced. Because application of hydrous calcium chloride stimulates cell in using calcium under salinity conditions it leads to improved seedling growth parameters. To achieve a more accurate results slicing interaction effect of seed priming×salinity levels was performed. Hydrous calcium chloride treatments improved all traits under study except sodium and potassium concentration. This represents a better performance of seeds germination under salinity stress when seeds primed with hydrous calcium chloride.