نشریه زراعت دیم ایران
سال چهارم شماره 2 (پاییز و زمستان 1394)

Planting date and plant density are effective factors for optimum yield. Hence, an experiment was conducted to determining the best planting date and plant density of advanced genotypes of bread wheat in dryland conditions. The experiment was conducted in factorial based on randomized complete block design with four replications in Sararood research station (Kermanshah) during three cropping seasons 2006-2009. The treatments were planting date with 2 levels (before and after effective rainfall), plant density with 3 levels (250,400 and 550 seed/m2) and 4 bread wheat genotypes (Ww33G/Vee"S"//Mrn/4/HD2172/Bloudan, Rizhaw, Awhadi and Sardari). The results showed that under intense drought stress, the effects of plant density, and planting date and their interactions with genotypes were significant on grain yield and its components. Planting before effective rainfall is recommended in Kermanshah along with 250-400 seed/m2. According to mean yield, Rizhav variety had better performance than Sardari especially under severe drought conditions.

Sainfoin is a forage legume that can be cultivated in irrigated and rainfed areas. This study was conducted to study genetic diversity in agro-morpho phonological traits of Onobrychis germplasms for exploiting in sainfoin breeding programs. A total of 159 accessions belong to 20 species, naturally distributed in the country, were planted in field. Nineteen agro-morpho phonological traits were characterized in these materials over 2 years. There was high degree of diversity in the studied traits. Species were divided into 4 clusters based on cluster analysis. In this analysis, those species with similar agronomic traits revealed in the same cluster. In factor analysis, the first factor was affected by forage quantitative and qualitative traits, whereas generative characters had the most effect on the second factor. Produced bi-plot in factor analysis confirmed cluster analysis results. Based on theses analysis, wild species of O. pulchell Schrenk., O. hohenackeriana C.A.Mey, O. subnitens Bornm., O. chorassanica Bungeand O. schahuensis Bornm wereproposed as suitable species for forage production.

In order to evaluate drought tolerance and genetic variation in barley genotypes based on morpho-physiological traits and molecular markers, an experiment carried out in split plot based on randomized complete block design (RCBD) in three replications. Main factor was the different levels of irrigation included continuous irrigation as control, 2/3 and 1/3 continuous irrigation and secondary factor included 18 barley genotypes. Analysis of variance showed considerable variation among genotypes for the measured traits. Also, the Genotype×Stress interaction had significant effect on grain number per spike, protein content, proline content, carotenoid content, chlorophyll a, b and yield. In ISSR markers analysis 9 primers used that were totally produced 61 bands, where 50 bands were polymorphic. The mean PIC and MI indices were obtained for all primers were 0.46 and 2.6, respectively. High value of these indices showed high performance of certain primers for synchronized analysis of more bands. At current study, primer 2 with PIC index of 0.57 was the best primer for evaluation of genetic variation amon the studied barley genotypes. At well watered level (control), the highest significant correlations found between markers and morphological traits related to P5L5 and the highest correlation among markers and physiological traits were related to P16L2 markers. At 2/3 well watered condition the highest significant correlations between markers and morphological were related to P5L5 and P9L5, and also among marker and physiological traits belonged to P13L4 and P5L5 markers. According to cluster analysis, the genotypes were classified into four clusters. The first clusters included three genotypes Licivi, Sahand and FA1-2. Also, the genotypes F-GRB-84-11,F-GRB-85-5,PALLIDUM48//NORDIC…¡.GLORIA-BAR/COPAL//.., Dasht and Sahra were located in second cluster and third cluster containing genotypes CHAMICO/TOCTE// CONGONA (a), CHAMICO/TOCTE//CONGONA(d) CONGONA/BORR and the other genotypes were located in the fourth cluster. Overall of indices and studied traits, it seems that among the studied genotypes the genotypes STIPA/PETUNIA//KOLLA/BBSC (a) and CHAMICO/TOCETE//CONGONA (a) for irrigated areas and the Sahand genotype for rainfed areas are suitable genotypes.

Simultaneous drought stress and zinc (Zn) deficiency can affect plant responses to water scarcity and limit wheat production in rainfed areas of Iran. Zinc-deficient plants have low water use efficiency and they cannot control well osmotic pressure to cope with water stress. In this study, the effects of Zn application and drought stress were investigated on grain yield of 10 wheat varieties (6 bread wheats and 4 durum wheats) grown in a Zn-deficient calcareous soil over 2 cropping seasons under rainfed conditions. Plants were treated with (: 10 kg Zn/ha, as ZnSO4.7H2O) and without Zn (-Zn) in RCBD with 3 replications. Zinc fertilization could enhance biomass, harvest index and grain weight of genotypes that resulted in 9% and 7% grain yield increase on average in the first and second years, respectively. Increases in yield varied among genotypes from 1% to 19%; and durum genotypes showed higher rising. Accordingly, there was variability in Zn efficiency of genotypes (ratio of grain yield under Zn deficiency compared to that under Zn fertilization). The correlation between Zn-efficiency and yield increase of genotypes was positive (r=0.72); however, durum wheat genotypes generally showed low level of Zn efficiency that resulted in lower yield under Zn deficiency especially under drought conditions in the first year. The results presented here demonstrate the existence of variation in Zn efficiency among bread and durum genotypes, and suggest the possibility of breeding for higher yield and Zn efficiency in Zn-deficient soil under rainfed condition. Moreover, Zn application would increase bread and especially durum wheat’s productivity in cold drylands.

In order to increase yield and nitrogen fertilizer use efficiency in autumn application of fertilizer for rainfed wheat through nitrification inhibitor DMPP, a field experiment was conducted in RCB design in 2014-2015. The treatments were five bread wheat genotypes (with different ∆ value) and nitrogen (control no N, 60 kgN/ha 15N ammonium sulphate and 15N ammonium sulphate with DMPP). The results showed that use of DMPA could delay conversion of ammonium to nitrate for 42 days. DMPP had greatest impact on nitrogen derived from fertilizer and had little effect on nitrogen derived from soil. It seems ammonium ions fixed by exchangeable sites of soil reduce effectiveness of DMPP in the soil. Application of DMPP could increase yield and nitrogen fertilizer use efficiency by 1516 kg/ha and 12.2%, respectively. The interesting point in this regard was complete absorption of ammonium ions in the genotype G5 (Zergan 6) compared with other genotypes. It seems that preferential absorption of ammonium by genotype G5 (with lower Δ index) caused toxicity effects. Thus, a small reduction of nitrogen fertilizer use efficiency (6.5%) appeared. Therefore use of DMPP in fast growing genotypes with ammonium preferential absorption ability (like G5) should be performed with caution.

Introduction of suitable forage crops for drylands is possible through identification and effective selection of superior genotypes between and within local landraces. 25 local vetch landraces from Vicia villosa, V. panonica and V. sativa were evaluated using simple lattice by accounting for spatial variability to select suitable genotypes for autumn planting in Maragheh research station. Results showed that lattice design with correlated errors along rows and columns, the lattice design and the randomized complete block design with first order auto-correlated errors along rows were the best models and most effective in accounting for spatial variability in forage yield, plant height and days to flowering, respectively. There was not any evidence for fixed trend in this experiment. Based on the selected models, the best linear unbiased estimates for all genotypes were calculated and the superior genotypes were selected based on related standard errors. It was concluded that the criterion used was based on maximum information of the data, so the inferences drawn from the best model for each trait would give the most realistic assessment of the genotypes.

In order to evaluate the possibility of autumn/winter planting of new oilseed sunflower genotypes under rainfed conditions of Gonbad, an experiment was conducted at the agricultural research station of Gonbad over 2 years (2008-2010). A split-plot design arranged in RCBD with four replications was used. Four planting dates (starting from 1st December with 15 day intervals) and 6 sunflower genotypes (SHF81-90, Farrokh, Favorit, Azargol, CMSG5*R-43, CMSG6*R-43) were the levels of main and sub-plots, respectively. The studied traits were stem and head diameter, plant height, growth period, 1000-seed weight, grain yield, oil content and oil yield. The effect of genotype was significant on all traits studied except oil content. Hybrids CMSG6*R-43 and SHF81-90 had the highest (1.889 t/ha) and lowest (1.385 t/ha) seed yields, respectively. Thousand-seed weight and growth period decreased while plant height increased with a delay in planting. The studied traits responded differently to planting dates in two years. Although seed yield was significantly affected by planting dates, only in the second year, two-year mean of the seed yield indicated the superiority of the second planting date. To obtain higher seed and oil yield under rainfed conditions of Golestan province in years with lower rainfall, we recommend sowing of late maturing hybrids i.e CMSG5*R-43 and Azargol in autumn. In years with suitable rainfall, we might suggest sowing of OP cultivar Favorit because of its lower production cost and higher net income.

Study on effects of nitrogen starter and spray fertilizer application differences on chickpea genotype and varieties was carried out. In order to do this study, experiments were carried out with 12 treatments including factor A chickpea a1 = ILC482, a2 = Azad, a3 = Arman and factor B is methods and levels of nitrogen fertilizer rates b1 = without of N fertilizer, b2 = 20 kg/ha N at the planting time as a starter, b3 = 2% and b4 = 4%, N spraying at the flowering time with factorial randomized complete block design (RCBD) with three replications from 1391 to 1393.The results showed that checkpea genotypes and varieties were significantly different at nitrogen application methods and rates. Genotype ILC482 had heights (1191 kg/ha) and Arman had lowest grain grain yield (994 kg/ha) at nitrogen methods and rates. žžChickpea genotypes and varieties indicated that genotype ILC482 with 77 kg/ha, Azad variety with 165 kg/ha and Arman variety with 159 kg/ha increase differently chickpea yields at 20 kg/ha N application. N starter application of 20 kg /ha increased grain yields of check pea genotype and varieties compared to No nitrogen application. Arman variety with 2% spraying N fertilizer produced higher grain yield compare to other nitrogen treatments . It can be concluded that chickpea genotype and variety produced grain yields differently at different methods of nitrogen applications. ILC482 and Azad by nitrogen starter application and Arman by spray N application can increase chickpea grain yield differently.