• Authors:
    • Fernández-Trujillo, J. P.
    • Provencio, A. B.
    • Martínez-López, J.A.
    • Pérez-Reverte, R.
    • Pérez-Pastor, A.
    • Domingo, R.
    • Robles, J. M.
    • Pagán, E.
  • Source: Acta Horticulturae
  • Issue: 892
  • Year: 2011
  • Summary: The quality of 'Fortune' mandarin fruit ( Citrus clementine Hort. Ex. Tanaka * C. reticulate Blanco) subjected to four different drip irrigation treatments was studied at harvest and after a subsequent storage period of 50 days at 5degreesC plus a shelf-life period of 8 days at 20degreesC. Irrigation treatments consisted of a control (CTL) irrigated at 130% of crop evapotranspiration (ETc) throughout the season, and three regulated deficit irrigation (RDI) regimes. These treatments were irrigated as a CTL except during the non critical periods, when different percentage of the control were applied: 50% during stage I and beginning of stage II in RDI 1 and RDI 2 treatments, and 80 and 200% during stage III in RDI 1 and RDI 2, respectively. RDI 3 was irrigated at 50% of RDI 1 during the water deficit periods. The electrical conductivity of the irrigation water averaged 4.23 dS m -1. RDI treatments promoted a water stress integral, derived from stem water potential at midday values, of 56, 46 and 114 MPa day for RDI 1, RDI 2 and RDI 3, respectively. Fruit at harvest from RDI1 and RDI 3 treatments showed around 15% higher total soluble solids and 11 and 19% higher levels of titratable acidity, respectively than CTL (13.8degreesBrix and 20.3 g L -1 citric acid). RDI fruits showed about 5-10% lower values of extractable juice than control. The storage period reduced fruit titratable acidity compared with harvest levels. Weight loss in control fruit reached 1.4 or 2.3% w/w at the end of cold storage or shelf-life, respectively, while in RDI treatments were reduced by 0.2-0.4% w/w. Overall, the effect of water stress on fruit quality were more pronounced at harvest than after the postharvest treatments. Under water scarcity conditions RDI1 showed acceptable fruit quality at harvest and increased storability of mandarin fruit, saving considerable amounts of water.
  • Authors:
    • Srivastava, A. K.
    • Panigrahi, P.
  • Source: Indian Journal of Soil Conservation
  • Volume: 39
  • Issue: 2
  • Year: 2011
  • Summary: A field experiment was conducted during 2006-08 to assess the response of deficit irrigation (DI) in 16 year old drip-irrigated Nagpur mandarin ( Citrus reticulata) trees budded on Rough lemon ( Citrus jambhiri L.) root stock at Nagpur, Maharashtra. The DI regimes imposed were at 30, 50, and 70% of Full irrigation (FI) and compared with FI (control). The annual increase in vegetative growth parameters (tree height and canopy volume) of trees under FI was found to be superior over DI treatments. The soil moisture status measured at 30 cm, 45 cm and 60 cm depths showed that the mean monthly soil moisture content was significantly affected at 30 cm depth, with highest magnitude (27.6-30.7%, v/v) under FI. Leaf nutrients (N, P, K, Fe, Mn, Cu, and Zn) analysis indicates that FI registered the maximum leaf N, K, and Fe, followed by 70% FI. The highest fruit yield (14.10 t ha -1) recorded under FI was at par with DI at 70% FI (13.35 t ha -1). More number and smaller size of fruits were recorded in FI as compared to DI at 70% FI. However, DI at 70% FI produced 36% higher water productivity with superior quality fruits (more fruit weight, higher TSS and lower acidity) over FI.
  • Authors:
    • Srivastava, A. K.
    • Panigrahi, P.
  • Source: Journal of Agricultural Engineering
  • Volume: 48
  • Issue: 3
  • Year: 2011
  • Summary: A field experiment was conducted during 2006-2008 to optimize the combined use of irrigation and fertilizers through drip irrigation for bearing Nagpur mandarin ( Citrus reticulate Blanco) plants at Nagpur, Maharashtra, India. The irrigation at 50% (I 1), 75% (I 2), and 100% (I 3) of daily class-A pan evaporation rate (Ep) along with 25% (F 1), 50% (F 2) and 75% (F 3) of recommended dose of fertilizers (RDF: 600 g N+100 g P 2O 5+200 g K 2O) were applied through drip emitters to 12 year old mandarin plants. For comparison, band placement of fertilizer (BPF) at 100% RDF under basin irrigation (BI) was taken as control. All the irrigation and fertilizer treatments (except I 1F 1) imposed through drip system produced higher plant growth and fruit yield, with better quality fruits over BI with BPF. The highest fruit yield (16.03 t.ha -1) with superior quality fruits (41.8% juice content, 10.2degreesBrix TSS and 0.82% acidity) was recorded under I 2F 3. Leaf nutrients (N, P, K, Fe, Cu, Zn and Mn) analysis indicated that I 2F 3 registered significantly higher leaf-N (2.15%) and K (1.87%), whereas I 3F 3 produced higher P (0.11%) and Fe (113.99 ppm) as compared with BI with BPF (1.98% N, 0.081% P, 1.64% K, and 93.52 ppm Fe). The study demonstrated that the application of optimum quantity of water and fertilizers (I 2F 3) through drip irrigation saved 50% and 25% of water and fertilizers, respectively, besides producing 60% higher fruit yield with better quality fruits over BI with BPF.
  • Authors:
    • Singh, A. K.
    • Srivastav, M.
    • Dubey, A. K.
    • Patel, S. K.
    • Dahuja, A.
    • Pandey, R. N.
  • Source: The Journal of Horticultural Science & Biotechnology
  • Volume: 86
  • Issue: 2
  • Year: 2011
  • Summary: Seven-month-old, uniform-sized seedlings of five citrus rootstocks [sour orange ( Citrus aurantiam), Attani-2 ( C. rugulosa), Troyer citrange ( C. sinensis * Poncirus trifoliata), billikhichlli ( C. reshni), and RLC-6 ( C. jambhiri)] were irrigated to 70% of field capacity with water containing 0, 50, 100, or 200 mM NaCl for 180 d. Growth, in terms of plant heights and the numbers of leaves, decreased with increasing levels of salinity in all five rootstocks. The decrease in plant height was greatest in the salt-susceptible Troyer citrange and billikhichlli at higher levels of salinity. However, in the salt-tolerant sour orange and Attani-2, NaCl caused only a slight decrease in plant height. Defoliation was maximum in the salt-susceptible Troyer citrange and billikhichlli. The maximum increases in superoxide dismutase (SOD) and peroxidase (POD) activities were found in the salt-susceptible Troyer citrange at higher levels of salinity. Leaf proline contents increased most in Attani-2, sour orange, and RLC-6 at higher levels of salinity. The concentration of Na + ions in leaf tissues increased to a maximum in Attani-2; while, in root tissues, RLC-6 and Troyer had the highest Na + ion contents. The maximum increase in leaf Cl-ion levels occurred in Troyer citrange, and the minimum was in RLC-6, at 200 mM NaCl. These data suggest that higher levels of proline accumulation and leaf abscission could be used as indicators for screening citrus rootstocks for resistance to NaCl stress. Sour orange and Attani-2 were able to exclude Cl-ions, whereas Troyer citrange appeared to exclude Na + ions at lower levels of NaCl. Further studies are required to observe the translocation of harmful and beneficial mineral elements to scion cultivars grafted onto sour orange and Attani-2 and grown under NaCl stress. Overall, salt-tolerance increased in the following order: Troyer
  • Authors:
    • Lei, T.
    • Cao, L.
    • Liu, S.
    • Wang, X. S.
    • Jiang, C. L.
    • Chun, C. P.
    • Peng, L. Z.
    • Ling, L.
  • Source: ACTA HORTICULTURAE SINICA
  • Volume: 38
  • Issue: 1
  • Year: 2011
  • Summary: A field experiment was conducted during 2002-2007 to evaluate effects of various drip fertigation frequencies (4 times/year, 10 times/year, 16 times/year) on tree growth, fruit yield and quality of Trovita sweet orange ( Citrus sinensis Osbeck) on 'Carrizo' citrange [ Poncirus trifoliata (L.) Raf.] * [ Citrus sinensis Osbeck] rootstock (planted in 2001) in calcareous purple soil in Zhongxian County of Chongqing. The control trees were fertilized (10 times/year) by broadcast application. The results showed that tree trunk circumference, tree height and canopy diameter did not show significant response to fertigation frequency; And no significant difference existed between fertigation treatments and control for tree growth. However, fertigation treatments showed significant effects on increasing fruit yield with 29.4%-36.5% more accumulative yield than the control, but high fertigation frequency did not increase fruit yield. No significant effects was observed for fertigation on fruit quality. It is recommended that citrus growing in calcareous purple soil should be drip fertigated 4 times a year.
  • Authors:
    • Pires, L. F.
    • Nova, N. A. V.
    • Pereira, A. B.
    • Alfaro, A. T.
  • Source: Revista Brasileira de Meteorologia
  • Volume: 26
  • Issue: 2
  • Year: 2011
  • Summary: The uptake of water from the roots of crops comes to being a physiological response of the plant to the water loss process through its stomata. Getting to know the daily transpiration rates throughout the phenological cycle allows for the application of the ideal amount of irrigation water at the right moment to maximize production with environmental protection. Since transpiration direct measurements at the field, mainly for trees in general, are to be of operational difficulty and relatively high cost we came up with a methodology that allows one to calculate the daily transpiration rates of apple trees and citrus orchards from variables of both the physical environment and the crop. The input data of the proposed model are air temperature, air relative humidity, photoperiod duration, and leaf area. Estimated transpiration rates based on the water potential gradient between the air and leaf approach were comparable in apple trees and citrus orchards. Sap flow daily values were obtained by means of the heat balance method at Bordeaux, France, and Piracicaba, SP, Brazil. All the coefficients of determination of the regression equations obtained herein were higher than 0.93. This allows one to calculate the amount of irrigation water to be applied throughout the crop growing seasons with a high precision as a function of meteorological data and crop covering density at the sites in the study.
  • Authors:
    • Stoffella, P. J.
    • He, Z. L.
    • Pereira, B. F. F.
    • Melfi, A. J.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 12
  • Year: 2011
  • Summary: The effects of irrigation with reclaimed wastewater (RWW) were compared with well water (WW) on citrus ( Citrus paradisi Macfad. * Citrus aurantium L.) nutrition. The deviation from the optimum percentage (DOP) index of macro- and micro-nutrients were used to evaluate the nutritional status: optimal (DOP=0), deficiency (DOP0). After 11 years of RWW irrigation the influence on nutrient concentration in plants decreased in the order: B > Zn > Mn=Ca > Cu > Mg > P > K. Reclaimed wastewater irritation positively affected citrus nutrition as it rendered the concentration of macro-nutrients, i.e. P, Ca, and K. closer to their optimum levels (SigmaDOP macro=7). However micro-nutrients tended to be excessive in plants (SigmaDOP micro=753) due to imbalanced supply of these elements in the RWW, particularly, for B and Cu. Citrus groves with long-term RWW irrigation may exercised caution in monitoring concentrations of B and Cu to avoid plant toxicity and soil quality degradation.
  • Authors:
    • Villar, H. L.
    • Sakai, E.
    • Bodine Junior, D.
    • Pires, R. C. de M.
    • Silva, T. J. A. da
    • Arruda, F. B.
  • Source: Engenharia Agrícola
  • Volume: 31
  • Issue: 6
  • Year: 2011
  • Summary: The aim of this study was to evaluate the effect of different microirrigation designs on root system distribution in wet bulb region, orange orchard yield and quality of orange fruits. The experiment was installed as random blocks with five treatments and four replicates in an orchard of 'Pera' orange trees grafted on 'Cleopatra' mandarin rootstock. The treatments consisted of: one drip line (T1), two drip lines (T2), four drip lines (T3) per planting row, microsprinkler irrigation (T4) and without irrigation (T5). Irrigation treatments favored yield and degreesBrix. The treatment with a single drip line (T1) showed the greatest quantity of roots in relation to the treatments T2 and T3.
  • Authors:
    • Pompeu Junior, J.
    • Blumer, S.
  • Source: Pesquisa Agropecuária Brasileira
  • Volume: 46
  • Issue: 1
  • Year: 2011
  • Summary: The objective of this work was to evaluate the size, fruit yield and canopy production efficiency of 'Valencia' sweet orange trees, budded onto citrumelos, 'Rangpur' lime and citremon rootstocks, cultivated without irrigation. Eleven rootstocks were visually assessed for symptoms of tristeza, citrus blight and bud-union-ring incompatibility with the scion. The 'Swingle' and W-2 citrumelos induced larger and more productive trees with the same productive efficiency as the ones on 'Rangpur' lime rootstock. The F.80.6, F.80.5, F.80.3 and F.80.18 citrumelos induced plants with height and canopy diameter smaller than 2 m. The citrumelos and the 'Rangpur' lime are tolerant to tristeza and blight, and are compatible with the 'Valencia' sweet orange. Citremon is susceptible to tristeza.
  • Authors:
    • Manmohan, J. R.
    • Singh, J.
    • Kaul, M. K.
    • Bhatnagar, P.
    • Chauhan, P. S.
  • Source: The Indian Forester
  • Volume: 137
  • Issue: 12
  • Year: 2011
  • Summary: Comparative effects of drip and micro sprinkler systems under kinnow+kinnow and kinnow+poplar silvi-horti system were studied under sub tropical climate. Drip system of irrigation was found promising in maintaining better growth of kinnow plants. Kinnow+Poplar system of plantation was found superior over kinnow+kinnow system of plantation under drip irrigation system. Under this system (kinnow+poplar) of plantation, values of plant height at 70% ETC were 2.55 m, canopy volume 23.51 m 3, rootstock girth 11.13 cm, scion girth 10.76 cm, and leaf area were 16.07 cm 2. Of course, values for all these traits were higher at 100% ETc under kinnow+kinnow system of plantation over kinnow+poplar system of plantation under drip system but these were at par with each other. Irrigation of kinnow orchards at 100% ETc was found better irrespective of the systems of irrigation.