291. Transpiration of young plants of Valencia orange in rootstock Rangpur and Swingle in two types of soil.; Transpiracao de plantas jovens de laranjeira 'Valencia' sob porta-enxerto limao 'Cravo' e citrumelo 'Swingle' em dois tipos de solo.

• Authors:
  • Tolentino, J. B.
  • Coelho, R. D.
  • Vellame, L. M.
• Source: Revista Brasileira de Fruticultura
• Volume: 34
• Issue: 1
• Year: 2012
• Summary: The total citrus area irrigated in Brazil has increased over the decades. The main cause of this increasing is due to the use of rootstocks tolerant to Citrus Sudden Death however they are less tolerant to drought than Rangpur lime. This research aims to study the influence of rootstock and soil type on transpiration of young plants of Valencia orange. The experiment was conducted in a greenhouse at the Department of Biosystems Engineering, ESALQ/USR Orange seedlings were planted in boxes of 500 L. It was determined simultaneously sweating of 20 plants through thermal dissipation probes (sap flow). It was monitored solar radiation, relative humidity and air temperature sensors were installed to 2 m tall at the center of the greenhouse. The reference evapotranspiration (ETo PM) was calculated by the standard method suggested by FAO. According to these results it is concluded that plant transpiration of Valencia oranges are influenced not only by the type of rootstock but also by leaf area growth and phenological stage, and its relationship with ETo pM is not linear in the whole range of evaporative demand of the atmosphere.

292. Influence of irrigation methods and fertilizer levels on productivity of potato ( Solanum tuberosum).

• Authors:
  • Kumar, P
  • Spehia, R. S.
  • Sharma, I. P.
  • Sharma, V
• Source: The Indian Journal of Agricultural Sciences
• Volume: 82
• Issue: 2
• Year: 2012
• Summary: A experiment was laid in split-plot design and the treatments comprised sprinkler, drip and furrow irrigation as main plot along with three doses of fertilizers, viz F 1 (NPK @ 150:150:125 kg/ha), F 2 (NPK @ 125:125:100 kg/ha) and F 3 (NPK @ 100:100:75 kg/ha) as sub-plot treatments. Results of the study indicated that irrigation methods manipulated the hydrothermal regimes of the soil comprehensively and mean maximum monthly temperature was lowered by about 1.2degreesC under sprinkler irrigation. Under drip irrigation, moisture was near to the field capacity throughout the growth period, whereas, in conventional furrow irrigation, the moisture status curve traveled from above field capacity to 50% moisture depletion conditions. The yield of tubers was appreciably higher under sprinkler and drip, compared to furrow irrigation method. F 1 and F 2 exhibited non significant differences among themselves, in respect of tuber yield, but were significantly higher than F 3. Economic analysis indicated that sprinkler irrigation and F 2 resulted in optimum benefit:cost ratio.

293. Influence of different amounts of irrigation water on salt leaching and cotton growth under drip irrigation in an arid and saline area

• Authors:
  • Liu, S.
  • Jiang, S.
  • Liu, S.
  • Hu, W.
  • Wan, S.
  • Kang, Y.
  • Wang, R.
• Source: Agricultural Water Management
• Volume: 110
• Year: 2012
• Summary: In order to evaluate the effects of different amounts of water, applied by drip irrigation, to a saline-sodic soil (surface ECe > 40 dS/m; SAR > 40), on cotton growth and soil salinity, a three-year experiment was conducted on a saline wasteland in Xinjiang Northwest China during 2008-2010. Five water treatments were used for this experiment based on the soil-water matric potential (SMP) measured 20 cm beneath a drip emitter located close to the plant: the SMP levels used to determine when to irrigate were -5 kPa (S1), -10 kPa (S2). -15 kPa (S3), -20 kPa (S4), and -25 kPa (S5). After three years, both the soil salinity (ECe) and sodicity (SAR) declined significantly in 0-120 cm depth and more reduction were achieved in 0-40 cm soil depth than in 40-80 and 80-120 cm depths. Moreover, the reductions of SAR were smaller than those of ECe. Additionally, the amount of salt removed from the 0 to 80 cm depth decreased with decreasing SMP threshold. The S1 treatment resulted in the highest lint yields in 2009 and 2010. Considering the effects of leached salts on the environment of deep soil layer and the yield of cotton, an SMP of -10 kPa can be used to trigger irrigation for cotton in the first three years for saline wasteland reclamation in Xinjiang Northwest China. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.

294. An alternative water source and combined agronomic practices for cotton irrigation in coastal saline soils

• Authors:
  • Manzur, C. L.
  • Cai, D.
  • Zhang, G.
  • Wu, H.
  • Wu, X.
  • Zheng, Y.
  • Hu, Y.
  • Zhao, Q.
  • Wang, X.
• Source: Irrigation Science
• Volume: 30
• Issue: 3
• Year: 2012
• Summary: The field experiment for cotton crop (Gossypium hirsutum L.) was conducted at the Zhongjie Farm, Huanghua city of Hebei province in the coastal salinity-affected areas in North China Plain, to determine the effects of an alternative of irrigation water sources/methods and agronomic practices on seedling emergence and yields of cotton, soil water-salt distributions, and soil pH changes during cotton growth stages. The experiment was setup using split-plot design with two water sources as main treatments (well water/desalinized sea-ice water); two irrigation methods (+PAM (Polyacrylamide)/-PAM); and four fertilization modes: check (CK), mineral fertilizer (F), mineral + organic fertilizer (FM), and mineral fertilizer + gypsum (FG). Using desalinized sea-ice water irrigation showed the same effects on top-soil salt leaching and desalinization as using well water did. There was no significant difference in seedling emergence and cotton yields between two irrigation water sources for cotton irrigation. Using PAM-treated irrigation, the 10-cm top-soil salinity significantly decreased to about 2.3-3.9 g kg(-1) from 4.6 to 8.6 g kg(-1) (PAM untreated). The PAM-treated irrigation increased seedling emergence by about 13, 29 and 36% and yields by about 50, 49, and 70%, with F, FM, and FG, respectively, as compared with CK. PAM-treated irrigation, either using well water or desalinized sea ice, especially in combination with gypsum-fertilization, shows the best practice for both seedling emergence and cotton yields. In conclusion, the desalinized sea-ice water used as an alternative water source, integrated with better agronomic practices of soil water-salt management could be acceptable for cotton irrigation in the coastal saline areas.

295. Organochlorine pesticides in soil under irrigated cotton farming systems in Vertisols of the Namoi Valley, north-western New South Wales, Australia

• Authors:
  • Hulugalle, N. R.
  • Ghadiri, H.
  • Weaver, T. B.
  • Harden, S.
• Source: Chemosphere
• Volume: 88
• Issue: 3
• Year: 2012
• Summary: Organochlorine pesticides (OCPs) such as DDT and DDE have been detected in the surface 0.2 m of Vertisols in the lower Namoi Valley of north western New South Wales, Australia even though they have not been applied to crops since 1982. However, their presence in the deeper soil horizons has not been investigated. The objective of this study was to determine if OCPs were present to a depth of 1.2 m in Vertisols under irrigated cotton farming systems in the lower Namoi Valley of New South Wales. Soil was sampled from the 0-1.2 m depths in three sites, viz. the Australian Cotton Research Institute, ACRI, near Narrabri (149 degrees 36'E, 30 degrees 12'S), and two cotton farms near Wee Waa (149 degrees 27'E, 30 degrees 13'S) and Merah North (149 degrees 18'E, 30 degrees 12'S) in northern New South Wales, Australia. The OCPs detected and their metabolites were alpha-endo-sulfan, beta-endosulfan, endosulfan sulphate, DDD, DDE, DDT and endrin. The metabolite DDE, a breakdown product of DDT, was the most persistent OCP in all depths analysed. Endosulfan sulphate was the second most persistent followed by endrin > alpha-endosulfan > beta-endosulfan > DDT and DDD. DDT was sprayed extensively in the lower Namoi Valley up to the early 1980s and may explain the persistence of DDE in the majority of soil samples. Dicofol and Dieldrin. two OCPs previously undocumented in Vertisols were also detected. The movement of OCPs into the subsoil of Vertisols may occur when irrigation or rain transports soil colloids and organic matter via preferential flow systems into the deeper layers of a soil profile. Persistence of OCPs was closely correlated to soil organic carbon concentrations. The persistence in soil of OCP's applied to cotton crops grown more than two decades ago suggests that they could enter the food chain. Their presence at depths of 1.2 m suggests that they could move into groundwater that may eventually be used for domestic and stock consumption. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.

296. Research progress on water requirements of potato.

• Authors:
  • Liu, H. Y.
  • Wu, X. K.
  • Wei, J. F.
  • Wei, D. P.
• Source: Guizhou Agricultural Sciences
• Issue: 4
• Year: 2012
• Summary: Water plays an important role in growth and development, yield and quality of potato. Water is required in large quantity for potato growth and development, but generally lack in the soil, and has to be appropriately supplied to meet the needs for its normal growth. Study the water requirements characteristics is the prerequisite and basis for rational irrigation of potato production. The water requirements characteristic of potato was summarized according to some relevant literature in this article, which included the water requirements and suitable soil moisture index for potato in growth period. Moreover, the effects of drought strees and supplementary water on physiological and biochemical reaction, growth and development, yield and quality of potato were introduced. Finally, the further research topics of water requirements in potato were also proposed.

297. The fate of fertilizer N applied to cotton in relation to irrigation methods and N dosage in arid area

• Authors:
  • Wang, J.
  • Wang, X. J.
  • Ma, T. F.
  • Wei, C. .Z.
• Source: Journal of Arid Land
• Volume: 4
• Issue: 3
• Year: 2012
• Summary: Quantitative information on the fate and efficiency of nitrogen (N) fertilizer applied to coarse textured calcareous soils in arid farming systems is scarce but, as systems intensify, is essential to support sustainable agronomic management decisions. A mesh house study was undertaken to trace the fate of N fertilizer applied to cotton (Gossypium hirsutum L. cv., Huiyuan701) growing on a reconstructed profile (0-100 cm) of a calcareous (>15% CaCO3) sandy loam soil. Two irrigation methods (drip irrigation, DI; and furrow irrigation, Fl) and four N application rates (0, 240, 360 and 480 kg/hm(2), abbreviated as N-0, N-240, N-360, and N-480, respectively) were applied. N-15-labelled urea fertilizer was applied in a split application. DI enhanced the biomass of whole plant and all parts of the plant, except for root; more fertilizer N was taken up and mostly stored in vegetative parts; N utilization efficiency (NUE) was significantly greater than in Fl. N utilization efficiency (NUE) decreased from 52.59% in N-240 to 36.44% in N-480. N residue in soil and plant N uptake increased with increased N dosage, but recovery rate decreased consistently both in DI and Fl. Plant N uptake and soil N residue were greater in DI than in FI. N residue mainly stayed within 0-40 cm depth in DI but within 40-80 cm depth in Fl. Fl showed 17.89% of N leached out, but no N leaching occurred in DI. N recovery rate in the soil-plant system was 75.82% in DI, which was markedly greater than the 55.97% in Fl. DI exhibited greater NUE, greater residual N in the soil profile and therefore greater N recovery rate than in Fl; also, N distribution in soil profile shallowed in DI, resulting in a reduced risk of N leaching compared to Fl; and enhanced shoot growth and reduced root growth in DI is beneficial for more economic yield formation. Compared to furrow irrigation, drip irrigation is an irrigation method where N movement favors the prevention of N from being lost in the plant-soil system and benefits a more efficient use of N.

298. Effects of Crop Rotation, Cultivar, and Irrigation and Nitrogen Rate on Verticillium Wilt in Cotton

• Authors:
  • Mullinix, B. G.,Jr.
  • Keeling, J. W.
  • Bordovsky, J. P.
  • Wheeler, T. A.
  • Woodward, J. E.
• Source: Plant Disease
• Volume: 96
• Issue: 7
• Year: 2012
• Summary: A field experiment was conducted under center-pivot irrigation in four wedges, with one wedge in continuous cotton (CC) and three wedges in a rotation (ROT) with 2 years cotton and 1 year in sorghum. Three irrigation rates (base = 1.0B, 1.5B, and 0.5B) were applied during 2007 to 2009 on a susceptible (ST) and partially resistant (PR) cultivar. Nitrogen applied during the season was proportional to irrigation rate. In the ROT wedges, 0.5B, 1.0B, and 1.5B irrigation and nitrogen rates averaged 1, 3, and 9% incidence of wilt, respectively. Disease incidence in the CC wedge averaged 6, 18, and 34% wilt incidence for 0.5B, 1.0B, and 1.5B irrigation and nitrogen rates. In the ROT wedges, the ST cultivar returned $143/ha more than the PR cultivars at the 0.5B irrigation and nitrogen rate whereas, at the 1.0B and 1.5B rates, the PR cultivars averaged $121 and $350/ha more than the ST cultivar. There was no significant irrigation and nitrogen or cultivar effect in the CC wedge on net value; however, trends were similar to the ROT wedge. Overall, ROT returned $285/ha more than CC, PR cultivars returned $123/ha more than the ST cultivar, and 1.0B returned $271 and $296/ha more than 0.5B and 1.5B rates, respectively. Microsclerotia density of V. dahliae averaged 2/cm(3) of soil in the ROT wedges and 23/cm(3) of soil in the CC wedge. Crop rotation, avoiding excessive irrigation, and using a partially resistant cultivar all reduced incidence of Verticillium wilt and improved net returns.

299. Intelligent micro-irrigation system based on internet of things in arid area.

• Authors:
  • He, S. R.
  • Pan, Y.
  • Jiao, X. Y.
  • Wu, Q. M.
• Source: Transactions of the Chinese Society of Agricultural Engineering
• Volume: 28
• Issue: 1
• Year: 2012
• Summary: The intelligent micro-irrigation system based on internet of things technology, an efficient way to agriculture sustainable development in arid area, can realize precision irrigation. With internet of things technique and according to the exact demands of irrigation decision-making and management, the cotton intelligent micro-irrigation system was designed and implemented. This system was applied in the cotton demonstration zone with the technology of drip irrigation under plastic film in Kuala, Xinjiang. The results indicated that the system can solve the difficulties of the layout of soil moisture monitoring points, high price of key hardware products. The intelligent micro-irrigation system cost reduced by 44.8% compared to the foreign similar products, and the system increased WUE by 22.6% compared to the traditional irrigation method.

300. XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on Citrus, Bananas and other Tropical Fruits under Subtropical Conditions, Lisbon, Portugal.

• Authors:
  • van den Bergh, I.
  • Staver, C.
  • Reinhardt, D. H.
  • Gubbuk, H.
  • Albrigo, L. G.
  • Wuensche, J. N.
• Source: ISHS Acta Horticulturae
• Issue: 928
• Year: 2012
• Summary: This proceedings contains 54 papers dealing with cultivation and production of citrus, bananas and other tropical fruits in the subtropics. Topics discussed include the effects of climate change, different substrates, thinning, girdling, heavy pruning, fertilizer application, irrigation and water stress; grafting; pollination strategies; mechanical harvesting; postharvest treatment; drying; storage; breeding; fruit drop, set and quality; growth and physiology; as well as pests, diseases and weeds.