• Authors:
    • Amiri, N. A.
    • Kangarshahi, A. A.
    • Namdari, M.
  • Source: AFRICAN JOURNAL OF AGRICULTURAL RESEARCH
  • Volume: 6
  • Issue: 11
  • Year: 2011
  • Summary: In this study, the citrus (orange and mandarin) production in Mazandaran province of Iran and the energy equivalences of input used in this production are investigated. Data in this study was obtained from 110 citrus orchards by a face to face questionnaire method. The results revealed that mandarin production had more energy intensive compared to orange. The major energy inputs in orange and mandarin production were diesel fuel (27 and 24%), chemical fertilizers (22 and 23%) and irrigation water (21 and 23%), respectively. The results showed that 62375.18 MJ ha -1 energy were consumed by orange orchards and 77501.17 MJ ha -1 by mandarin orchards. Energy use efficiency, energy productivity, specific energy, and net energy gain were calculated. The energy use efficiency for orange and mandarin were 0.99 and 0.77, respectively. In average, the non-renewable form of energy input was 67.14% of the total energy input used in citrus production compared to 33.07% for the renewable form. Optimal consumptions of diesel fuel, chemical fertilizers and other major inputs would be useful techniques for decreasing energy consumption in citrus production.
  • Authors:
    • Rodriguez-Moran, M.
    • Garcia-Olmos, B.
    • Andujar, S.
    • Navarro, J. M.
    • Perez-Tornero, O.
    • Morte, A.
  • Source: Acta Horticulturae
  • Issue: 922
  • Year: 2011
  • Summary: Arbuscular mycorrhizal (AM) symbiosis is thought to increase host resistance to salinity stress, a characteristic that could be interesting in areas where the scarcity of irrigation waters forces growers to use low-quality irrigation water. To test this hypothesis seedlings of the rootstocks Mandarin Cleopatra ( Citrus reshni Hort. ex Tan.), Sour orange ( Citrus aurantium (L.)) and Alemow ( Citrus macrophylla Wester) were grown in a growth chamber and inoculated with a mixture of two AM fungi ( Glomus intraradices and Glomus mosseae) (IP), or left non-inoculated (NIP). From forty-five days after fungal inoculation onwards plants were irrigated with nutrient solution containing 50 mM NaCl and, three months after inoculation, the growth, mineral nutrition and physiological response were analysed. AM fungi significantly increased all plant growth parameters studied, especially in the Cleopatra and Alemow rootstocks. In general, plant growth parameters were higher in salinized IP plants than in non-salinized NIP plants, demonstrating that AM colonization compensates for the growth limitations imposed by saline conditions. The water content was higher in IP plants of Cleopatra and Alemow but not in the Sour orange seedlings. Under saline conditions NIP Alemow plants had a strongly-decreased water content, while the water content of IP Alemow plants was similar to that of non-salinised plants. In all three rootstocks, NIP plants showed a greater degree of salt-induced foliar damage and chlorosis than IP plants. Although IP plants were not fertilised with phosphorus in the experiment, they had significantly higher levels of this nutrient in roots, stems and leaves than NIP plants both in salinised and control plants. The beneficial effect of mycorrhization appears to be unrelated with protection against the uptake of excess of Na + or Cl - by the plant. Our findings confirm that AM fungi can alter host responses to salinity stress, improving the P nutrition and diminishing chlorosis and salt damage.
  • Authors:
    • Bhandary, N. P.
    • Koike, Y.
    • Nishimura, F.
    • Tsuno, H.
  • Source: Journal of Water and Environment Technology
  • Volume: 9
  • Issue: 2
  • Year: 2011
  • Summary: Matsuyama region, located in Shikoku Island, Japan faces the Seto Inland Sea on the west, where the annual rainfall is relatively less than in the other areas in Japan. In such favorable condition, the cultivation of citrus fruits is popular, and there are a large number of small reservoirs for irrigation purposes. The citrus groves are distributed in hilly areas surrounding the paddy fields and residential areas so there are higher chances for the nearby water environment to get affected by leachate from the groves. This paper investigates the water quality characteristics of the leachate from the groves, and studies the changes of the leachate quality near the collecting reservoirs. It was found that the grove soils are highly acidic and the leachate contains metals and nutrients in high concentration. On the other hand, the water quality of the leachate changed after it flowed into the reservoirs, and the concentrations became lower. It is understood that chemical and biological reactions help remove the contaminants in the reservoir, and from the standpoint of self-purification, reservoirs play an important role. This paper also discusses the kinetics of the self-purification and the quantitative estimation based on the experimental results.
  • Authors:
    • Sheffield, K. J.
    • Abuzar, M.
    • Whitfield, D. M.
    • O'Connell, M. G.
    • McClymont, L.
    • McAllister, A. T.
  • Source: Acta Horticulturae
  • Issue: 889
  • Year: 2011
  • Summary: SEBAL-METRIC estimates of evapotranspiration (ET) were derived from Landsat-5 imagery of Sunraysia Irrigation Region of Victoria, Australia. Paired estimates of ET and vegetation cover, NDVI, were derived from an image taken mid-season on 5 January 2009. NDVI and ET were attributed to land use based on data provided by SunRISE21 Inc. Relationships between ET, scaled by field measured reference tall crop evapotranspiration, ET r, and NDVI for the dominant almond, citrus and grape crops showed that the evaporation ratio (ET/ET r) was strongly related to NDVI. These findings suggest that SEBAL-METRIC satellite remote sensing approaches offer an affordable and robust method for the deviation of NDVI-based block-customised estimates of crop coefficient (K c) for almond, citrus and grape crops.
  • Authors:
    • Al-Mohammadi, F.
    • Al-Zu'bi, Y.
  • Source: Journal of Agricultural Science and Technology
  • Volume: 13
  • Issue: 2
  • Year: 2011
  • Summary: This research was conducted under greenhouse conditions to evaluate the optimum combination of irrigation and fertilizer levels to attain the best yield and quality of tomato crop. The experiment was conducted by using a split-plot design with three replicates. Irrigation levels were applied to the main plots and fertilizer levels to the sub-plots. For each experimental unit, the irrigation levels were W1=8 mm/day, W2=7 mm/day, W3=6 mm/day, and W4=5 mm/day. Fertilizers treatments varied during the growing season. For the period after transplanting till flowering, the treatments consisted of weekly applications of F1=(N1, P1, K1, respectively, 9.8, 6.13, 7.35 g/plot), F2=(N2, P1, K1, respectively,14.7, 6.13, 7.35 g/plot), F3=(N2, P2, K1, respectively, 14.7, 9.19, 7.35 g/plot), and F4=(N2, P2, K2, respectively, 14.7, 9.19, 11.0 g/plot). Fertilizer levels were increased as the plants developed during the growing season. Plant height and the number of flowers per tomato plant were measured during the growing season and at harvesting time. Random samples of tomato leaves and fruits were taken from each experimental plot to determine the percentage of dry matter, total nitrogen, phosphorus, and potassium contents of fruits and leaves. Total yield during harvesting period and average fruit weight were also measured. Results indicated that irrigation and fertilizer levels had significant effects on the number of flowers per plant and W1F2 combination was significantly the most effective treatment compared to the other treatments. Plant height was not affected significantly by any treatment. The total yield significantly increased in W3F1 treatment. Average fruit weight was significantly higher in W2F3 as compared to the other treatments. The percentage of dry matter was significantly affected by the treatment W3F3 in both leaves and fruits. Total leaf contests of nitrogen, phosphorus, and potassium significantly increased in W2F4 treatment. Total nitrogen content in tomato fruits did not show any significant difference among different treatments, whereas fruit phosphorus and potassium contents significantly increased in W2F3 and W4F4 treatments.
  • Authors:
    • Blanke, M. M.
  • Source: Acta Horticulturae
  • Issue: 916
  • Year: 2011
  • Summary: Technological innovations appear under-utilised in many fruit tree crops, whereas viticulture, citriculture and vegetable crops have largely automated planting, pruning, thinning and harvesting and integrated GPS and/or GIS in their cultivation practises. As a consequence of the trend from pedestrian to tall orchards, innovation and technology is required to overcome shading, particularly in the lower part of the tree canopy. Types, properties and prices are presented of reflective ground covers (textile, aluminium and paper) as well as organic alternatives (lime, straw) as well as titanium dioxide and bio-degradable white line marker paint with additives. To combat sunburn, kaolin, carnauba-wax and other products are available, which can be combined with evaporative cooling. Mechanisation includes new machinery for mechanical thinning, pruning and harvesting to save labour. An autonomous prime mover (APM) is being developed for camera systems for assessment of flowering intensity, alternate bearing, fruit set, June drop, leaf nutrient status, pest and disease control and yield estimation/prediction. The two approaches for better light utilisation in row systems include reducing the spacing of every row from the current 14 feet (4.3 m) to 10-12 feet (3.0 to 2.6 m) or maintaining the spacing of a centre row at 14 feet (4.3 m) or ease of access, but narrower row spacing either side to less than 10 feet (3.0 m) The OTR (over the tree rows) developed by Washington State University and two commercial European multi-row sprayers are presented and new harvesting techniques with pre-sorting in the orchard.
  • Authors:
    • Fourie, J.
    • Joubert, M.
    • Freitag, K.
  • Source: SA Fruit Journal
  • Volume: 10
  • Issue: 1
  • Year: 2011
  • Summary: Five soil management practices applied in a micro-sprinkler irrigated 'Pink Lady' (Cripps Pink/M7) orchard established on a loam soil near Grabouw were evaluated from October 2003 to March 2010. Dry matter production by the cover crops at the end of September was higher under integrated soil management (IP) than under organic soil management (Organic) during 2004, 2007 and 2008, with the same trend being observed during 2005, 2006, and 2009. Cover crops in the IP and Organic treatments suppressed the winter growing weeds significantly over all seasons compared to treatments in which no cover crop was sown and weeds were slashed during the growing season of the trees (Weeds (IP) and Weeds (Organic) treatments). Except for September 2004, a similar result was achieved where a full surface straw mulch was packed out annually during October, followed by hand weeding during the growing season of the trees (Straw Mulch (Organic) treatment). Summer growing weeds were controlled effectively by the Cover Crop (IP) and Straw Mulch (Organic) treatments. Weeds (IP) and Weeds (Organic) caused broad leaf weeds to disappear and perennial grasses to dominate the weed spectrum. Although not as drastic, a similar trend developed in the Cover Crop (Organic) treatment. In contrast, annual weed species became dominant where Cover Crop (IP) was applied. All soil cultivation practices caused changes in the weed spectrum, with species dominance shifting with time. This aspect of weed control should be studied more extensively in future.
  • Authors:
    • Garland, G. M.
    • Suddick, E.
    • Burger, M.
    • Horwath, W. R.
    • Six, J.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 144
  • Issue: 1
  • Year: 2011
  • Summary: Knowing underlying practices for current greenhouse gas (GHG) emissions is a necessary precursor for developing best management practices aimed at reducing N2O emissions. The effect of no-till management on nitrous oxide (N2O), a potent greenhouse gas, remains largely unclear, especially in perennial agroecosystems. The objective of this study was to compare direct N2O emissions associated with management events in a cover-cropped Mediterranean vineyard under conventional tillage (CT) versus no-till (NT) practices. This study took place in a wine grape vineyard over one full growing season, with a focus on the seven to ten days following vineyard floor management and precipitation events. Cumulative N2O emissions in the NT system were greater under both the vine and the tractor row compared to CT, with 0.15 ± 0.026 kg N2O–N ha−1 growing season−1 emitted from the CT vine compared to 0.22 ± 0.032 kg N2O–N ha−1 growing season−1 emitted from the NT vine and 0.13 ± 0.048 kg N2O–N ha−1growing season−1 emitted from the CT row compared to 0.19 ± 0.019 kg N2O–N ha−1 growing season−1 from the NT row. Yet these variations were not significant, indicating no differences in seasonal N2O emissions following conversion from CT to NT compared to long-term CT management. Individual management events such as fertilization and cover cropping, however, had a major impact on seasonal emissions, indicating that management events play a critical role in N2O emission patterns.
  • Authors:
    • Ortega-Farias, S.
    • Selles, G.
  • Source: ISHS Acta Horticulturae
  • Issue: 889
  • Year: 2011
  • Summary: These proceedings contain 79 papers on irrigation systems for horticultural crops. Specific topics covered include the following: improvement of water use for agriculture at catchment level under drought conditions; impact of climatic change on irrigated fruit tree production; effects of the irrigation regime and partial root zone drying on grape cv. Vermentino in Sardinia, Italy; effects of canopy exposure changes on plant water status in grape cv. Syrah; water use by drip-irrigated early-season peach trees; soil water content variations as water stress indicator in peach trees; reduction in the number of fruits in peach (T204) due to postharvest deficit irrigation; effects of irrigation management and N fertilizer on the yield and quality of apple cv. Gala; canopy temperature as an indicator of water status in citrus trees; effects of root anatomy on sap flow rate in avocado trees; influence of rootstock on the response of avocado cv. Hass to flooding stress; methods of selection for drought tolerance in potato; and drip irrigation for the establishment of strawberry transplants in southern California.
  • Authors:
    • Rypowski, K.
    • Cortes, M.
    • Osorio, A.
    • Burgos, M.
  • Source: Acta Horticulturae
  • Issue: 889
  • Year: 2011
  • Summary: Six tests were done to evaluate the application of irrigation rates in Limari River Valley (3036′ South Latitude 7112′ West Longitude and 218 m of altitude) in avocado and mandarin tree orchards during two agricultural seasons. Assessments were made in volumes of water applied, discharge of the drippers and irrigation frequency used. Also, the water stored in the soil profile was monitored by moisture direct sampling with drill, performed deeply and transversely to the drip lines and plantation rows. In the cases studied it was possible to appreciate a wide variety of situations regarding water stored in the profile. In the vast majority of cases, excess water conditions were found, both in the root zone and below it. In very few cases, the moisture in the root zone of trees reached levels close to permanent wilting percentage (PWP). This would reflect poor efficiency in the implementation and management of irrigation water through drip irrigation, regardless of the uniformity coefficient (UC) of drippers. This situation becomes much more problematic in those soils which present high percentages of clay; creating low aeration conditions for root development. It is also possible to observe an important deviation from moisture profiles to the lower or steeper sectors of the plantation system; generating drier soil or less humid conditions in higher zones, with a big impact on root development. When calculating the relation between the water stored in the root zone versus the total water available in the profile, results between 44 and 73% were obtained, values that reflect inefficient irrigation conditions. These results were corroborated by the high variation coefficients (VC) in the moisture content in the profile, with values higher than 19.00% and with maximum value equal to 43.64% VC.