Iran Agricultural Research
Year:2000 | Volume:19 | Issue:1|Papers Count:8

Several treatments aimed at removing seed dormancies and to root stem cuttings of the Damask rose (Rosa damascena Mill.) were tested. The results showed that a stratification period longer than 150 d was required for the seeds of this species to remove embryo dormancy. The highest germination percentages (i.e. over 80%) were obtained with soaking seeds in 70 and 80% sulfuric acid for 10 min followed by 150-180 d of stratification. Soaking in warm water or leaching under running water were less effective than scarification with acid. The effects of scarification and stratification treatments on germination value and seedling production were also studied. Different concentrations of naphthaleneacetic acid (NAA) and indolebutyric acid (IBA) were applied on softwood (SW), semi hardwood (SHW) and hardwood (HW) cuttings to induce rooting. The SW cuttings failed to produce roots, completely. Generally, the HW cuttings had better rooting than SHW cuttings. Using 3000 mg 1-1 of either NAA or IBA, a 97% rooting percentage was obtained for HW cuttings. The effects of these growth regulators on number of roots per cutting, average root length per cutting. Root fresh and dry weight per cutting are also reported.

5×5 Latin-square experiment (21-d periods) was conducted to measure the effects of replacing of barley by sorghum grain on milk yield, milk composition, feed efficiency, dry matter intake (DMI), body weight and apparent digestibility of organic matter (OM). Five primiparous and five multiparous (n=10) lactating Holstein cows, 85±10 d in milk were given a total mixed ration of 46: 54 forage: grain ratio (DM basis). Sorghum grain substituted barley in ratios of 0: 100, 25:75, 50:50, 75:25 and 100:0 in diets 1, 2, 3, 4 and 5, respectively. The results showed significant differences (P<0.05) in many parameters in response to increasing sorghum levels. Diet 5 showed higher DMI (20.3 vs. 19.4 kg d-1), daily milk yield (25.8 vs. 24.8 kg d-1), production of 3.2 % FCM (27.4 vs. 24.7 kg d-1), milk fat (3.58 vs. 3.02%), fat yield (0.92 vs. 0.75 kg d-1), milk protein (3.0 vs. 2.7%), protein yield (0.75 vs. 0.67 kg d-1), milk lactose (4.93 vs. 4.47%) and milk solids-not-fat (8.58 vs. 8.17%), as compared with diet 1. However, feed efficiency, body weight, and apparent digestibility of organic matter were not affected by any of the treatments (P>0.05). It is concluded that substitution of sorghum grain for barley may manipulate rumen metabolism and improves milk composition.

In Iran, as in other developing countries, seed tuber is a major constraint to potato production. Thus, it is logical to consider the use of true potato seed (TPS) in Iran, as in some countries such as China. This study involved two experiments. In Experiment I, TPS-derived tubers from 12 progenies were compared to those of four cultivars. The cultivars were superior, regarding yield, number of tubers and tuber weight. However, compared to progenies, they had less uniform tubers, mainly due to more within-plant variation. Experiment II involved 5 progenies, 2 methods of elimination (eliminating small tubers or poor plants) and 2 intensities of elimination (eliminating the first 10% or 20% of small tubers, or poor plants). Eliminating the first 20% of small tubers resulted in significant 7% increase in yield per plant and improved tuber uniformity by 2%.

The percentage of oil in the seeds of four species, belonging to Compositae family, was determined. The range of fat content in the seeds studied was 16.3-43.5%. The results obtained by gas chromatographic separation showed that concentration of linoleic acid in Carthamus oxyacantha Bieb and Gundelia taurnefartii L. was 76.06 and 60.15%, respectively. The results also indicated that oleic acid (C 18:1) was the predominant fatty acid in Cynara syriaca Boiss. and Cirsium cangestum Fich & Mey with a concentration of 47.70 and 37.50, respectively. Most of the isolated fats showed a high iodine value which is comparable with those of cultivated oil seed crops. In the case of Cirsium cangesum species, palmitoleic and arachidic acids were detected. These acids were not observed in other species.

WHd relatives of common wheat (Triticum aestivum L.) and durum wheat (T. turgidum L. var durum) are valuable sources of desirable characters for improving wheat cultivars. Since the genus Aegilops L. bears a close and important relationship with durum and bread wheat, more detailed study of them should also be beneficial in understanding these polyploid wheats. In this study, seven durum wheat landraces were crossed as the female parent with 32 accessions of Aegilops belonging to five species (Ae. squarrosa, Ae. crassa, Ae. triuncialis, Ae. caudata and Ae. cylindrica). Spikes were harvested 12-15 d after pollination for embryo rescue and some spikes were left to evaluate the formation of direct amphihaploid seeds. Aegilops species had a major influence on crossability (seed set), embryo culturability and plant recovery. The highest efficiency of amphihaploid plant recovery from rescuing embryos (42.1 %) was obtained from Triticum turgidum (4x)×Ae. crass a (4x). This was followed by Triticum turgidum (4x)×Ae. crassa (6x) cross (37.8%). An efficient direct synthesis of viable amphihaploid seeds from crosses between durum wheat landraces and Ae. Crass a (4x) originating from western Iran is also reported. The high crossability together with the direct germination of F1 hybrid seeds of Ae. crassa (4x), provides new evidences concerning close phylogeny of this species and the polyploid species of wheat.

Two similar experiments were conducted at two Agricultural Experiment Stations (Bajgah and Kushkak), Shiraz University, Shiraz, I.R. Iran in 1995 to evaluate the effects of plant population and N application rates on yield and yield components of a semi dwarf hybrid of sunflower (Helianthus annuus L. c.v. Mehr) as summer planting. Both experiments were conducted as split plot arranged in a randomized complete block design with 4 replications. The seeds were drilled in sub-plots at row distances of 60 cm apart and 15, 25 and 35 cm between plants within rows. Nitrogen fertilizer was applied at 0, 23, 46, 69 and 92 kg N ha-1 as urea in main plots. Increasing plant population decreased head diameter, seed number and weight per plant and seed protein percentages at both locations. Seed and oil yields increased with increasing plant population and reached a maximum at a population of 6.66 plants m-2 (25cm between plants in row) at both locations. Head diameter, seed number and weight per plant and seed and oil yields increased with increasing N application at both locations. In general, head diameter, seed and oil yields were higher at Bajgah where favorable conditions for crop growth and seed filling prevailed. The optimum plant population and N rate were 6.66 plants m-2 and 69 kg N ha-1 for both locations.

A research project was designed to study agricultural wheat improvement project in Fars province and to find out how its technical, supportive and motivational dimensions have been used to motivate wheat producers to increase wheat production. The research project was implemented in three counties. A survey method was used to collect data. The results showed that wheat improvement project mainly focuses on offering technical assistance to wheat producers through the Rural Services Centers (RSCs). So, in terms of technical dimension, the project for wheat production encouragement is the same as the previous policies. The advantages of the wheat improvement project are its supportive and motivational dimensions. The following recommendations are suggested: provide opportunities so that wheat producers own their cultivation machineries such as seeder, furrower and tiller, accompanied by necessary education and provide more educational motivation program through radio and TV to encourage wheat producers.