SEED AND PLANT PRODUCTION JOURNAL
Year:2014 | Volume:30-2 | Issue:3|Papers Count:7

In this study propagation of three promising genotypes of stone fruit hybrids including two genotypes of apricot and plum hybrids (Hs519 and Hs303) and one genotype of plum and almond hybrid (Hs725) were evaluated via in vitro method. Explants of apical and lateral buds of rootstocks were disinfected and placed in modified MS, WPM and Knop media with combinations of 0.6 mgl-1 BAP and 0.01 mgl-1 NAA. The results showed that modified MS medium was qualitatively the best medium for all rootstocks, thus different concentrations of plant growth regulators combinations were evaluated in the modified MS medium.0.6 mgl-1 BAP and 0.01 mgl-1 NAA was the most economical combination of plant growth regulators that produced the highest appropriate number and length of micro-cuttings. There was no significant difference between hybrids in proliferation. Hs725 and Hs519 produced micro-cuttings with a mean of 3.092 and 3.037cm, respectively. Hs519 produced callus in media with higher concentrations of NAA and BAP, and Hs725 showed vitrification in similar media. Optimal rooting number (seven) and rooting percentage (63%) were obtained in Hs725 in media culture containing 1 mgl-1 IBA. In this media culture, the highest root length of 9.33 cm was obtained in Hs725. In general, less concentrations of these plant growth regulators led to better proliferation of these promising rootstocks.

Differences between spectral reflectance can be the base of identification of crop residue rate and crop growth by remote sensing. A 2-year experiment was conducted under dryland conditions to determine the crop residue retained on soil surface in conservation and conventional tillage systems. Tillage treatments comprised of conventional tillage (MD: mouldboard plough+disk), reduced tillage (CH: chisel plough+disk), minimum till (MT: Stubble cultivator), and no-till (NT1 and NT2: with standing stubble and total residue, respectively). Remotely sensed data of crop residue and plant growth were acquired, using a handheld multispectral radiometer (350 to 2500 nm) and thermal imager (8, 000 to 14, 000 nm). Using a combination of visible and near-infrared spectra, crop residue cover indices were calculated and evaluated. Rresidues in NT1 and NT2 lowered the soil surface and wheat canopy temperature by 2.5-5.7 and 3-7oC respectively over the other treatments (MD, CH and MT). A liner negative relation between canopy temperature and wheat grain yield was found. Tillage systems were classified according to strong correlation between crop residue cover and cellulose absorption index (CAI). Conventional tillage were classified by crop residue less than 6% and CAI values below zero. Crop residue cover between 10-20% and CAI 2-4% indicated reduced tillage, and crop residue cover between 30-42% and CAI 4-5.7% found for minimum tillage. Finally No-tillage were classified by crop residue with more than 60% and CAI values between 5.8-8. Ground based hyper spectral signatures which were collected for identifying electromagnetic reflectance of crop residue can be used in calibration and validation of remote sensing imagery and its data products of airborne/space borne missions.

To evaluate the effects of different seedbed preparation methods on soil physical properties and some morphological, qualitative and quantitative characteristics of sugar beet, an experiment was performed in Motahari Research Station of Sugar Beet Seed Institute in Karaj and Ekbatan Station of Agricultural and Natural Resources Research Center in Hamedan during two cropping seasons (2007-2009) using a randomized complete block design with four replications. The experiment consisted of seven different seedbed preparation methods operated in autumn or in spring. At harvest time, the number and weight of roots, length of crown, storage roots and roots on soil surface were measured. Quality characteristics such as percentage of sugar and inpurities of roots were determined in laboratory. The results showed that different treatments of seedbed preparation in terms of bulk density and soil hardiness did not have any significant difference. Soil bulk density values increased during the growth period and also with dept from 0 to 60 cm of soil. At different growth stages with soil depth increasing, hardiness with the different processes increased and values had faster trends in the mid-season than in early season. The highest white sugar yield was 10.23 tha-1 in the treatment of autumn operation including deep ploughing, disk, leveler and cultivator tiller blade, and spring operation including disk and drive of seed rows with stacker.

The present study was conducted to investigate the terminal drought stress effect on yield and its components in oilseed rape and to identify drought tolerant genotypes with high yield potential. Thirteen oilseed rape genotypes including Karaj 1, Karaj 2, Karaj 3, Talayeh, Zarfam, Okapi, Licord, Slm046, Modena, WPN5, Opera, WPN2 and G.KH305 were evaluated under optimum and terminal drought stress conditions using a randomized complete block design with three replications at the Agricultural Research Station of Islamabad-e-Gharb in 2010-2012 cropping seasons. Combined analysis of variance showed that the effect of terminal drought stress was significant for recorded characters except oil content, the number of branches and 1000 seed weight. The mean seed yield of genotypes was decreased by 20% in response to drought stress so that seed yields in optimum and terminal drought stress conditions were 4586 kgha-1 and 3736 kgha-1, respectively. Seed yield reduction in drought stress condition was associated with reduction in seed yield components i.e. pods per plant and seed per pods. Due to favorable climatic conditions in the 2010-2011 cropping season, seed yield and it’s components were higher than those in the 2011-2012. Oilseed rape genotypes were significantly different for recorded traits except oil content. Genotype G.KH305 had the highest seed yield of 5230 and 3941 kgha-1 in optimum and drought stress conditions, respectively.

Phenolic compounds are very considerable due to their important role in plant physiology and nutrition (antioxidant role). The amount of phenolic compounds are influenced by genotype and environmental conditions. In the present research, total phenol, antioxidant activity and some phenolic compounds including chlorogenic acid, catechin and pheloredzin of three Asian pear cultivars (KS6, KS9 and KS13) were studied. Investigated cultivars were 11 years old and had been budded on seedling of European pear (Pyrus communis L.) rootstocks with a density of 5000 trees per hectare based on randomized complete block design. Results showed that all studied cultivars differed significantly for all measured phenolic compounds except for pheloredzin content. Cultivar KS6 had the highest amount of chlorogenic acid and catechin. The regression analysis of total phenol and IC50 showed a positive correlation between the amount of total phenol and IC50. The highest amount of IC50 and total phenol was observed in KS13 and KS9, respectively.

To study the effects of different irrigation regimes and the use of barley residue, zeolite and superabsorbent polymer on yield and water use efficiency of maize (SC 704) and sorghum (cv. Pegah) under minimum tillage, an experiment was conducted over two consecutive years (2012-2013) in Kerman, Iran. A randomized complete block design arranged in a factorial split was used with three replications. Irrigation regimes in two levels, normal (irrigation based on 70 mm evaporation from pan class A) and water deficit stress (irrigation based on 140 mm evaporation from pan class A) and plant species included two levels, maize and sorghum, as factorial combinations were compared in main plots. Combination treatments of zeolite, superabsorbent polymer and barley residue with 5 levels, were assigned to subplots that were as follows: I.10 tha-1 zeolite plus 4.5 t ha-1 barley residue (ZR), II. 60 kgha-1 superabsorbent polymer plus 4.5 tha-1 barley residue (SR), III.5 tha-1 zeolite plus 30 kgha-1 superabsorbent polymer plus 4.5 tha-1 barley residue (ZSR), IV. 4.5 tha-1 barley residue (R), V. Control (C). Based on the results, maize produced 62.17 and 14.03 tha-1 fresh and dry forage yield respectively, while the fresh and dry forage of sorghum were 47.6 and 9.29 tha-1 in the first cutting and 66.62 and 13.22 tha-1 in the sum of the two cuttings. In both plants water use efficiency and forage yield under water stress increased and decreased, respectively. Water use efficiency for fresh and dry forage yield of maize was 6.31 and 1.42 kgm-3 while this trait for fresh and dry forage yield of sorghum was 5.06 and 1.01 kgm-3 respectively. Application of 10 tha-1 zeolite plus 4.5 tha-1 barley residue (ZR) with production of 66.9 tha-1 fresh forage yield and 6.8 kgm-3 water use efficiency in maize and production of 72.07 tha-1 fresh forage yield and 5.44 kgm-3 water use efficiency in sorghum had the highest values than any of the other treatments. Water stress increased the forage crude protein content but zeolite decreased it. For a double cropping system in the temperate zones of Jopar in Kerman, barley residue can be recommended after maize planting under minimum tillage together with application of 10 t ha-1 zeolite and 4.5 t ha-1 barley residue.

Eight Strawberry cultivars (Paros, Queen Elisa, Pajaro, Camarosa, Gaviota, Selva, Mrak and Kurdistan as local cultivar) were evaluated to select the best cultivar based on quantitative yield production in Kurdistan province condition. An experiment was performed in a randomized complete block design with three replications during 2008- 2010 in Grizeh research station (Sanandaj). Eleven morphological and phenological charactristics, yield components and fruit yield were measured. Analysis of variance showed a significant difference (P£0.01) among cultivars for number of leaves, petiole length, leaf area, runners number, number of inflorescences, flowering period, number of fruits per plant, fruit weight, fruit size and fruit yield per plant. Means comparison showed that Queen Elisa had the highest yield with 771.5 g/plant while Gaviota had the lowest yield with 60.42 g/plant. The results also showed a high correlations between yield, inflorescence per plant (r=0.785) and fruits number per plant (r=0.789). Based on these results, cultivar Queen Elisa having high yield and good compatibility with the local cultivar Kurdistan can be a good alternative cultivar for the region.