• Authors:
    • Kahrizi, D.
    • Dehaghi, M.
    • Heidari, S.
    • Mofrad, A.
    • Azizi, K.
  • Source: African Journal of Biotechnology
  • Volume: 10
  • Issue: 1
  • Year: 2011
  • Summary: In order to investigate the effect of intercropping and sole cropping of barley and narbon vetch with weed control and interference conditions on their qualitative and quantitative traits, this experiment was conducted with 5 levels of intercropping (seed contribution): sole cropping of narbon vetch, 75:25 (narbon vetch : barley), 50:50, 25:75 and sole cropping of barley. Two levels of weed control and weed interference in row replacement series system in the form of factorial was designed with Randomized Complete Blocked Design (RCBD) in 3 replications in the College of Agriculture, Lorestan University, from 2006-2007. Results showed that the interaction of weed and the contribution of complementary components of intercropping has significant effect on crude protein (CP) and neutral detergent fibers (NDF) content in barley. Maximum CP and NDF were related to sole cropping of barley (infected by weeds), and maximum CP with minimum NDF were related to (narbon vetch: barley) 75:25 treatment, so that 31% of CP decreased in sole cropping of barley (infected by weeds) when compared with 75:25 combination. NDF percentage in sole cropping increased to 16.6%, therefore 25:75 (narbon vetch: barley) combination was better than the others. So, in order to get proper percentage of protein and digestibility of forage for livestock, 75:25 (infected by weeds) combination is better, especially the combination of 25:75 (infected by weeds), due to its high protein content. The highest and lowest dry forage production of barley were related to its sole cropping (a control which is equal to 3.75 t/ha) and 75:25 barley (infected by weeds that are equal to 1.59 t/ha), respectively.
  • Authors:
    • Darbandi, M.
    • Asadi, S.
    • Hokmalipour, S.
    • Sharifi, R.
    • Barmaki, M.
    • Darabad, G.
  • Source: World Applied Sciences Journal
  • Volume: 15
  • Issue: 2
  • Year: 2011
  • Summary: In order to study the phenology and competition of potato and safflower, as compared to those of the pure cropping, a study was carried out using factorial experiment with completely randomized block design, with three replications. This study was done in experiment field of University of Mohaghegh Ardabili in 2010. The investigated treatments included potato pure cropping in the fixed density of 6 plants pre m 2, safflower pure cropping with the densities of 6, 12 and 18 plants per m 2 and the intercropping of potato (6 plants pre m 2 density) with safflower in the densities of 6, 12 and 18 plants per m 2. The analysis of variance in phenology stages of pure culture and mixed with potatoes showed that all treatments were significant differences. Comparison mean the stages of phenology of safflower intercropping with potatoes showed that two stage emergence and stem elongation earlier seen in plant grown intercropping 18 plant in per. Mixed safflower plants and potatoes compared to other treatments. Delay was seen the phenology stages of flowering and handle the product because the longer vegetative phase and later getting into the reproductive stage, in terms of lime. Safflower competition mean the stage phenology of safflower effected density of potato showed that pure cultures of safflower compared with intercropping earlier spend of emergence, the stem elongation and head visible, flowering and seed ripening. Coefficient of relative congestion in all treatments on potatoes is greater than one, this study shows advantage competitive potatoes compared to safflower. Similarly, the smaller of these indexes suggest weak competition in safflower as compared to potatoes. Amount of relative yield total of potatoes and safflower in all treatments intercropping was smaller than the one. It shows that both components mixed to compete for use limited recourses.
  • Authors:
    • Asadi, S.
    • Hokmalipour, S.
    • Sharifi, R.
    • Barmaki, M.
    • Kandi, M.
    • Darabad, G.
  • Source: Australian Journal of Basic and Applied Sciences
  • Volume: 5
  • Issue: 11
  • Year: 2011
  • Summary: In order to investigate the yield and yield components of mixed cropping of potato and safflower, as compared to those of the pure cropping, a study was carried out using factorial experiment with completely randomized block design and with three replications. This study was done in experiment field of University of Mohagheg Ardabili in the solar year 2010. The investigated treatments included potato pure cropping in the fixed density of 6 plants pre m 2, safflower pure cropping with the densities of 6, 12 and 18 plants per m 2, and the intercropping of potato (6 plants pre m 2 density) with safflower in the densities of 6,12 and 18 plants per m 2. The variance analysis of potato traits in both the intercropping and pure cropping indicated that, except from the number of stems pre m 2, other studied traits; including the number of tubes per plant, the tube weight per plant and the tube yield statistically differed meaningfully with each other. Moreover the results showed that all the studied traits including the number of receptacles pre plant, the number of seeds per receptacle, seed weight in the receptacle and seed yield, in terms of statistic figures differed with each other noticeably. In order to assess the efficiency of the intercropping, the indexes of LER and RVT were utilized. These indices proved that, almost in all cases, the intercropping is superior to the pure cropping. In this study the highest rates of LER and RVT (1/35 and 1/32 respectively), concerned the intercropping of safflower and potato with densities of 12 plants per m 2 and 6 plants per m 2 respectively.
  • Authors:
    • Sanchez Chopa, C.
    • Descamps, L.
  • Source: Chilean Journal of Agricultural Research
  • Volume: 71
  • Issue: 3
  • Year: 2011
  • Summary: The bird cherry-oat aphid Rhopalosiphum padi L. (Homoptera: Aphididae) is one of the main pests in a number of crops in the semiarid Pampas of Argentina. In the present study, the effect of different host plants, including Triticum aestivum L., * Triticosecale Wittm., Hordeum vulgare L., Hordeum distichum L., Avena sativa L., and Secale cereale L. on biological parameters of R. padi L. was studied in the laboratory at 241°C, 6510% RH and a 14:10 photoperiod. Longevity, intrinsic rate of natural increase (r m), net reproductive rate (R 0), mean generation time (T), doubling time (DT), and finite rate of increase (lambda) of the bird cherry-oat aphid on the different cereal crops were estimated. Differences in fertility life table parameters of R. padi among host plants were analyzed using pseudo-values, which were produced by Jackknife re-sampling. Results indicated that beer barley might be the most suitable food for R. padi due to greater adult longevity (20.88 d), higher fecundity (41 nymphs female -1), higher intrinsic rate of natural increase (0.309 females female -1 d -1), lower doubling time (2.24), and lower nymphal mortality (22.2%). Therefore, it can be concluded from the present study that R. padi prefers beer barley for fast and healthy development over other cereal crops.
  • Authors:
    • Ahmadi, A.
    • Maafi, Z.
    • Hajihassani, A.
    • Taji, M.
  • Source: International Journal of Agriculture and Biology
  • Volume: 13
  • Issue: 4
  • Year: 2011
  • Summary: Cereal cyst nematodes are one of the most important soil-borne pathogens of cereals throughout the world. This group of nematodes is considered the most economically damaging pathogens of wheat and barley in Iran. In the present study, a series experiments were conducted during 2007-2010 to determine the distribution and population density of cereal cyst nematodes and to examine the biology of Heterodera latipons in the winter wheat cv. Sardari in a microplot under rain-fed conditions over two successive years in Markazi province in central Iran. Results of field survey showed that 40% of the fields were infested with at least one species of either Heterodera filipjevi or H. latipons. H. filipjevi was most prevalent in Farmahin, Tafresh and Khomein, with H. latipons being found in Khomein and Zarandieh regions. Female nematodes were also observed in Bromus tectarum, Hordeum disticum and Secale cereale, which are new host records for H. filipjevi. Also, H. filipjevi and H. latipons were found in combination with root and crown rot fungi, Bipolaris sorokiniana, Fusarium culmorum, F. solani and Gaeumannomyces graminis, in some fields. Results of the biology study showed that H. latipons developed only one generation in each wheat growing season and its developmental stages are closely related to the climate conditions and the host plant growth. Immature females were first evident on roots in the third week of March to early April, with soil temperatures of 11.8-13.3degreesC. The mature females containing eggs with embryo were observed in third week of April until early May, when the soil temperature was 14.2-15.3degreesC. H. latipons completed its life-cycle in about 145-150 days in wheat.
  • Authors:
    • Ward, G.
    • Jacobs, J.
  • Source: Animal Production Science
  • Volume: 51
  • Issue: 12
  • Year: 2011
  • Summary: Limitations to the current perennial ryegrass-based pasture system on dryland dairy farms in southern Australia has led to research into alternatives that can produce either additional DM, out of season feed or can improve nutritive characteristics. The use of winter annual crops followed by a summer crop have the potential to achieve these goals but often result in considerable periods where new crops are establishing and feed is not available for consumption. Companion cropping offers an option to overcome these limitations. The experiment reported in this paper examines the DM yields, nutritive characteristics and mineral content of companion cropping wheat or triticale at different sowing rates into an existing chicory monoculture over a 2-year period. We hypothesised that oversowing cereal crops in autumn into an existing stand of chicory would result in improvements in nutritive characteristics at ensiling, without adversely affecting DM yield or subsequent chicory DM yields following harvesting, thus negating the need to sow a new summer forage crop each year. Total DM yields for the chicory and cereal monocultures were similar over the experimental period, while DM yields for all triticale mixtures were higher than the chicory only treatment. Chicory produced lower DM yields for silage but higher DM yields at most grazing events. The crude protein and estimated metabolisable energy content of the chicory only treatment was higher than the cereal monocultures and all triticale/chicory mixtures at both silage harvests with wheat/chicory mixes being intermediate. The proportion of chicory in the mixed swards declined over the course of the experiment. The use of chicory with cereals resulted in no adverse effects on total DM yields, some improvements in nutritive characteristics and mineral content and a more continuous supply of DM compared with double cropping with annual species in winter and summer. This experiment has highlighted the potential of oversowing cereal forages into an existing chicory sward to contribute to DM production on dairy farms in southern Australia. Such forage mixes can provide flexibility into forage systems through the provision of forage for grazing in early winter, the production of high DM yield silage harvests and then subsequent feed supply over summer and early autumn.
  • Authors:
    • Liu, Y.
    • Ma, L.
    • Li, X.
  • Source: Acta Phytophylacica Sinica
  • Volume: 38
  • Issue: 3
  • Year: 2011
  • Summary: In order to fully understand the regular pattern of the population dynamics of Lithocolletis ringoniella Matsumura in the apple production region of the Loess Plateau, the distribution pattern and the ecological niche index were determined and the clustering analysis was conducted to describe the dynamic change of L. ringoniella population. The results showed that the leaf insect spot caused by L. ringoniella was visible in June; the number of the insect increased in July, with the damage symptom severe in August; and the quantity of the population number was in surge in September and October. The relative abundance of the temporal sequence was in a strong rising trend since August. Population distribution in the crown was uniform in early July and aggregative after that. The spatial distribution among the vertical positions of the tree crown showed significant difference, population number following the order of lower > middle > upper parts, whereas distribution among horizontal directions had no significant difference. The general distribution within the crown appeared in cluster, with individuals attractive to each other. The ecological niche occupation of this pest in vertical and horizontal directions as well as in temporal sequences are 0.179, 0.371 and 0.594, respectively. The resource utilization rate in the lower part of the crown reached 53.73% and almost nothing utilized in the upper part, indicating a more horizontal expansion potential. Viewing from the four directions, the maximum utilization of resources was in the north and east, up to 27.90% and 21.66% respectively. The ecological niche overlap index of L. ringoniella with hawthorn spider mite in vertical and horizontal directions reached 92.65 and 64.95, respectively, in addition to temporal sequence to be 66.36, indicating that hawthorn spider mite is the most intense space-temporal competitor for the limited resources of apple's crown leaves. The dominance degree index of L. ringoniella in the young apple orchard in different intercropping patterns increased over time since August and largest increase happened in the middle of August. The highest dominance degree index was found in soybean-apple intercropping pattern and the lowest index with sweet potato-apple intercropping pattern. The index fluctuated in the orchard with weeds unwell-managed.
  • Authors:
    • Olson, B. L.
    • Schlegel, A. J.
    • Holman, J. D.
    • Maxwell, S. R.
  • Source: Crop Management
  • Issue: June
  • Year: 2011
  • Summary: A common crop rotation in the west-central Great Plains is no-till winter wheat-corn-fallow. Because most of the corn produced is herbicide-tolerant, volunteer corn in fallow is not controlled with glyphosate. This study evaluated the impact of volunteer corn on soil moisture storage in fallow and the succeeding winter wheat crop across three locations in western Kansas from 2008 to 2010. Volunteer corn reduced available soil water at wheat planting in 8 out of 9 site years. On average, available soil water was reduced by 1 inch for each 2,500 volunteer corn plants per acre. Volunteer corn water use reduced wheat tillers in half of the site years. Similarly, volunteer corn reduced wheat yields in half of the site years, and yields fell 1 bu/acre for every 500 volunteer corn plants per acre. When wheat yields were above 70 bu/acre or below 35 bu/acre, other factors affected wheat yield more than the preceding volunteer corn population or available soil water at wheat planting.
  • Authors:
    • Lenssen, A. W.
    • Sainju, U. M.
    • Jabro, J. D.
    • Evans, R. G.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 42
  • Issue: 18
  • Year: 2011
  • Summary: We evaluated the effect of no tillage (NT) and conventional tillage (CT) on soil penetration resistance (PR), bulk density (BD), gravimetric moisture content (MC), and saturated hydraulic conductivity (Ks) during the fallow phase of a spring wheat-fallow rotation. The study was conducted on two soils mapped as Williams loam at the Froid and Sidney sites. Soil measurements were made on 19 May, 23 June, and 4 August 2005 at the Froid site and on 6 June and 8 July 2005 at the Sidney site. Tillage had no effect on either soil properties except on the PR at Sidney. However, soil PR, MC, and BD varied significantly with depth regardless of tillage and location. Further, soil PR and MC varied with the date of sampling at both locations, and PR generally increased with decreased MC at all soil depths. Soil Ks was slightly influenced by tillage at both locations.
  • Authors:
    • Mengel, D. B.
    • Olson, B. L.
    • Martin, K. L.
    • Diaz, D. A. R.
    • Liesch, A. M.
    • Roozeboom, K. L.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 6
  • Year: 2011
  • Summary: Soybean [ Glycine max (L.) Merr.] production has increased by more than 55,000 ha in the last 25 yr in the western third of Kansas, a region with soils that can be prone to Fe chlorosis. The objective of this study was to evaluate the relative effectiveness of varietal selection, seed-applied Fe fertilizer, and foliar Fe application to reduce the incidence of Fe chlorosis under irrigated soybean production. Seven locations with a history of Fe deficiency in soybeans were selected. The study consisted of a factorial design with three foliar treatments (two chelated Fe fertilizer forms and no foliar), two seed-applied Fe fertilizer treatments (with and without chelated Fe fertilizer), and two different varieties (a nontolerant and tolerant commercial variety). Plant population, chlorophyll meter (CM) readings (V3 and V6 growth stage), plant height at maturity, and grain yield were measured. Foliar Fe application did not affect any plant parameter except for CM reading and grain yield at one location. However, the use of seed-applied chelated Fe fertilizer significantly increased CM readings at the V3 and V6 growth stages, plant height at maturity, and grain yield across all locations. Given soil conditions conducive to the development of severe iron chlorosis, seed-applied chelated Fe fertilizer increased yields by approximately 55% for both varieties. Chlorosis quantified as CM readings at V3 to V6 growth stage may not be correlated to the yield potential of a variety in all environments. This suggests that producers should choose the best varieties primarily based on yield potential if supplemental seed-applied Fe fertilizer will be used.