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Wang S.,Yangtze University | Srivastava A.K.,National Research Center for Citrus | Wu Q.-S.,Yangtze University | Fokom R.,University of Douala
Scientia Horticulturae | Year: 2014

Key rhizosphere properties influenced by microorganism-mediated processes need to be identified for better understanding of their possible role in improving crop performance. This study monitored the changes in concentration of Bradford-reactive soil protein (BRSP), soil organic carbon (SOC) content, hyphal length, aggregate stability [fractal dimension (D), geometric mean diameter (GMD), and mean weight diameter (MWD)] and distribution of water-stable aggregate (WSA) in rhizosphere of trifoliate orange (Poncirus trifoliata L. Raf.) infected by five arbuscular mycorrhizal fungal species (Diversispora spurca, Glomus intraradices, Glomus mosseae, Glomus versiforme, and Paraglomus occultum). After four months of mycorrhizal inoculation, all the mycorrhizal plants showed higher shoot and root biomass but the increase was a function of the tested fungal species. The induced changes in rhizosphere properties were of much higher magnitude in mycorrhizal treatment than in non-mycorrhizal treatment. Mycorrhizal inoculation induced significant increases in the percentage of WSA at 1.00-2.00. mm size, fraction 1 of BRSP, SOC, and hyphal density, collectively aiding in improving the indices of soil aggregate stability, like GMD and MWD. Higher MWD and GMD conferred better soil structure in mycorrhizosphere of trifoliate orange. Correlation analysis further revealed that fraction 1 of BRSP as a new and more active glomalin may take part in stabilizing WSA but fraction 2 of BRSP as an older and more stable glomalin may contribute SOC pools. Our results suggest that mycorrhizal-mediated better soil aggregate stability might mainly be due to soil hyphal length, integrated with SOC and fraction 1 of BRSP. © 2014 Elsevier B.V.

David K.J.,National Research Center for Citrus | Ramani S.,CCS Haryana Agricultural University
Zootaxa | Year: 2011

An illustrated key and a checklist are provided for 126 species of fruit flies under 46 genera in four subfamilies namely Dacinae, Phytalmiinae, Tephritinae and Trypetinae. Among these, Acroceratitis striata (Froggatt), Rhochmopterum venustum (de Meijere) and Themara yunnana Zia are new records for India. Bactrocera yercaudiae Drew is placed as a synonymn of Bactrocera digressa Radhakrishnan. Copyright © 2011 · Magnolia Press.

Rao C.N.,National Research Center for Citrus | Shivankar V.J.,National Research Center for Citrus
Indian Journal of Agricultural Sciences | Year: 2011

Toxicity of bio-rational insecticides, viz spinosad, abamectin, novaluron, sweet flag (Acorus calamus L.), petroleum spray oil, neem (Azadirachta indica A.Juss.) oil, azadirachtin, Bacillus thuringiensis, Verticillium lecanii and dimethoate (as standard) was evaluated against the second instar nymphs of citrus psylla (Diaphorina citri Kuwayama) at NRCC, Nagpur during 2006. Based on LC 50 values, spinosad, abamectin and novaluron were 9.93, 3.29 and 2.71 times more toxic to psylla nymphs than dimethoate. Further, field appraisal of these bio-rational insecticides along with neem soap and pongamia (Pongamia glabra Vent.) soap against citrus psylla in 10-year-old acid lime (Citrus aurantifolia Swingle) cv. Pramalini conducted during ambia 2007-09 showed that abamectin @ 0.38 ml/L (90.2-92.5% reduction), followed by petroleum spray oil @ 5.9 ml/l (89.8-90.4% reduction), novaluron @ 0.55 ml/l (87.6-88.1% reduction) and spinosad @ 0.15 ml/l (65.5-72.3% reduction) were found effective against citrus psylla for a period of 15 days.

Shirgure P.S.,National Research Center for Citrus | Srivastava A.K.,National Research Center for Citrus
Indian Journal of Horticulture | Year: 2014

An experiment was conducted on 12-14 year-old bearing Nagpur mandarin (Citrus reticulata Blanco) trees to study the automatic daily irrigation scheduling as well as alternate day based on time schedule through the drip irrigation during 2007-2010. The treatments were consisted of automatic daily irrigation daily with 60 min. interval three times (I 1); automatic irrigation daily with 90 min. interval two times (I 2); automatic irrigation at alternate day with 120 min. three times (I 3); and automatic irrigation at alternate day with 180 min. two times (I 4) with six replications in randomized block design. The sustainable quality fruit production of Nagpur mandarin is possible with drip irrigation using automatic scheduling daily or on alternate days. The water use in October varied from 65.0-72.4 l/ day/ plant and during May-June it was 133.0 - 147.7 l/ day/ plant. The fruit yield was 30.91 tonnes/ ha with irrigation on alternate day 120 min. three times, followed by irrigation scheduled with 90 min. interval two times daily (30.11 tonnes/ ha). Fruit weight (154.7 g), TSS (10.22°Brix) and juice percent (40.77) was found higher with automatic irrigation at alternate day with 120 min. three times. The automatic drip irrigation scheduling was found as better substitute for manual drip irrigation operation besides enhancing the yield, fruit quality and water use efficiency in Nagpur mandarin. © 2014, Horticulture Society of India. All rights reserved.

Panigrahi P.,National Research Center for Citrus | Srivastava A.K.,National Research Center for Citrus | Huchche A.D.,National Research Center for Citrus
Agricultural Water Management | Year: 2012

The scarcity of irrigation water is one of the major causes of low productivity and decline of citrus orchards. The present study was planned with a hypothesis that the drip irrigation (DI) could save a substantial amount of water over surface irrigation, besides improving the yield of citrus plants. The experiment was conducted for 3 seasons during 2006-2009, with 'Nagpur' mandarin (Citrus reticulata Blanco) plants budded on rough lemon (Citrus Jambhiri Lush) rootstock in central India. The effects of DI and basin irrigation (BI) on soil chemical properties and crop responses were studied. DI was scheduled every-other-day at 40%, 60%, 80% and 100% of the alternate day cumulative evaporation (E cp) measured in Class-A evaporation pan. DI except irrigation at 40% E cp proved superior to BI, producing more growth and fruit yield of plants. The higher plant growth was recorded with higher regime of DI. The maximum fruit yield in DI at 80% E cp, using 29% less irrigation water resulted in 111% improvement in irrigation water productivity under this treatment over BI. The heavier fruits, with lower acidity and higher total soluble solids, were harvested in DI at 80% E cp compared with BI. The significant variation of soil water content at 0-0.2m depth under DI indicated the confinement of effective root zone of the plants in top 0.2m soil. The maximum rate of net-photosynthesis, stomatal conductance and transpiration in leafs was recorded in DI at 100% E cp. However, the plants under DI at 80% E cp exhibited the highest leaf water use efficiency. The maximum salinity build-up with highest decrease in pH was observed in 0-0.2m soil under DI, whereas the salinity development was prominent in 0.4-0.6m soil with an increase in pH under BI. The gain in available macronutrients (N, P and K) and loss of micronutrients (Fe, Mn, Cu and Zn) in soil followed the similar trend of EC. The leaf nutrient (N, P, K, Fe, Mn, Cu and Zn) analysis revealed that DI produced significantly (P<0.05) higher concentration of macronutrients in leafs than that with basin-irrigated plants. However, the effect of irrigation on micronutrients in leafs was statistically insignificant. Overall, these results reveal that the application of optimum quantity of water through DI (80% E cp) could impose desirable water stress on 'Nagpur' mandarin plants, improving their yield and fruit quality, without producing the higher vegetative growth. © 2011 Elsevier B.V.

Huang Y.-M.,Yangtze University | Srivastava A.K.,National Research Center for Citrus | Zou Y.-N.,Yangtze University | Ni Q.-D.,Yangtze University | And 2 more authors.
Frontiers in Microbiology | Year: 2014

Trifoliate orange [Poncirus trifoliata (L) Raf.] is considered highly arbuscular mycorrhizal (AM) dependent for growth responses through a series of signal transductions in form of various physiological responses. The proposed study was carried out to evaluate the effect of an AM fungus (Funneliformis mosseae) on growth, antioxidant enzyme (catalase, CAT; superoxide dismutase, SOD) activities, leaf relative water content (RWC), calmodulin (CaM), superoxide anion (O2·-), and hydrogen peroxide (H2O2) concentrations in leaves of the plants exposed to both well-watered (WW) and drought stress (DS) conditions. A 58-day of DS significantly decreased mycorrhizal colonization by 60% than WW. Compared to non-AM seedlings, AM seedlings displayed significantly higher shoot morphological properties (plant height, stem diameter, and leaf number), biomass production (shoot and root fresh weight) and leaf RWC, regardless of soil water status. AM inoculation significantly increased CaM and soluble protein concentrations and CAT activity, whereas significantly decreased O2·- and H2O2 concentration under both WW and DS conditions. The AM seedlings also exhibited significantly higher Cu/Zn-SOD and Mn-SOD activities than the non-AM seedlings under DS but not under WW, which are triggered by higher CaM levels in AM plants on the basis of correlation studies. Further, the negative correlation of Cu/Zn-SOD and Mn-SOD activities with O2·- and H2O2 concentration showed the DS-induced ROS scavenging ability of CaM mediated SODs under mycorrhization. Our results demonstrated that AM-inoculation elevated the synthesis of CaM in leaves and up-regulated activities of the antioxidant enzymes, thereby, repairing the possible oxidative damage to plants by lowering the ROS accumulation under DS condition. © 2014 Huang, Srivastava, Zou, Ni, Han and Wu.

Ladaniya M.S.,National Research Center for Citrus
Acta Horticulturae | Year: 2015

South Asian countries including India, Pakistan, Bangladesh, Nepal, Bhutan and Sri Lanka produce about 12 million tonnes of citrus fruits, contributing to roughly 12.0% of world production. Citrus is among the top three fruits in the region. With a population of 1597 million, the per capita /annum citrus fruit availability is 7.67 kg. Mandarin and sweet orange are the major citrus fruits constituting 84%, followed by acid lime, lemon and other citrus (16%). Postharvest management is mostly on conventional lines. In north-west India and Pakistan, Kinnow (King ? Willowleaf hybrid) is sorted, washed, waxed and packed in modern packing houses. Harvesting is done by clippers for Kinnow, by snapping for 'Nagpur' mandarin (Citrus reticulata Blanco) and by bamboo harvesters for 'Khasi' mandarin (Citrus reticulata Blanco). Total losses from farm to retail level in the region are 25-35% and vary with season and commodity. Acid lime losses increase with the onset of monsoon. Wooden boxes are used for mandarins. Oranges and acid limes are packed in jute bags. Bamboo containers 'doko' are used in Nepal, Bhutan and North-East Hill (NEH) region of India for 'Khasi' mandarin. Transportation of loose fruit in trucks is common. Refrigerated storage warehouses and modern packinghouses are being established. Citrus fruits are sold in supermarkets. Modified atmosphere packaging increased shelf life of mandarins up to 3 weeks. The use of evaporative cool chambers (1.5-8 tonnes capacity and very low energy consumption) extended the storage life of Nagpur mandarin, Mosambi orange (Citrus sinensis Osbeck), acid lime (Citrus aurantifolia Swingle), Kinnow and grapefruit (Citrus paradisi Macf.) up to 21, 40, 30, 60 and 77 days in respect to 10,14, 5, 14, and 27 days at ambient condition, respectively. Cellar stores are used in Nepal and Bhutan. The export of Kinnow from Pakistan is increasing. India exported nearly 55260 tonnes of citrus fruits in 2010. The value chain and postharvest overview in south Asia including postharvest research, conventional and innovative handling, storage structures, modern infrastructure and future challenges and prospects are discussed in this review paper.

Zou Y.-N.,Yangtze University | Srivastava A.K.,National Research Center for Citrus | Ni Q.-D.,Yangtze University | Wu Q.-S.,Yangtze University
Frontiers in Microbiology | Year: 2015

Arbuscular mycorrhizas possess well developed extraradical mycelium (ERM) network that enlarge the surrounding soil for better acquisition of water and nutrients, besides soil aggregation. Distinction in ERM functioning was studied under a rootbox system, which consisted of root+hyphae and root-free hyphae compartments separated by 37-μm nylon mesh with an air gap. Trifoliate orange (Poncirus trifoliata) seedlings were inoculated with Funneliformis mosseae in root+hyphae compartment, and the ERM network was established between the two compartments. The ERM network of air gap was disrupted before 8 h of the harvest (one time disruption) or multiple disruptions during seedlings acclimation. Our results showed that mycorrhizal inoculation induced a significant increase in growth (plant height, stem diameter, and leaf, stem, and root biomass) and physiological characters (leaf relative water content, leaf water potential, and transpiration rate), irrespective of ERM status. Easily-extractable glomalin-related soil protein (EE-GRSP) and total GRSP (T-GRSP) concentration and mean weight diameter (MWD, an indicator of soil aggregate stability) were significantly higher in mycorrhizosphere of root+hyphae and root-free hyphae compartments than non-mycorrhizosphere. One time disruption of ERM network did not influence plant growth and soil properties but only notably decreased leaf water. Periodical disruption of ERM network at weekly interval markedly inhibited the mycorrhizal roles on plant growth, leaf water, GRSP production, and MWD in root+hyphae and hyphae chambers. EE-GRSP was the most responsive GRSP fraction to changes in leaf water and MWD under root+hyphae and hyphae conditions. It suggests that effect of peridical disruption of ERM network was more impactful than one-time disruption of ERM network with regard to leaf water, plant growth, and aggregate stability responses, thereby, implying ERM network aided in developing the host plant metabolically more active. © 2015 Zou, Srivastava, Ni and Wu.

Ladaniya M.S.,National Research Center for Citrus
Journal of Food Science and Technology | Year: 2011

Influence of chilling temperature, intermittent warming (IW) and fungicidal wax coating was evaluated during storage of 'Nagpur- mandarins (Citrus reticulate Blanco). Fruits were light green coloured with slight colour-break at the start of storage. Waxed and non-waxed fruits were stored at 3.5 °C (constant), 2 weeks at 3.5 °C followed by IW for 1 week at 19.5 °C (cycle) and at 6.5 °C (constant), and were evaluated immediately after 30, 45, 60, 75 days and also after 1 week holding at ambient condition (24±2 °C, 60-70% RH). There was no chilling injury to fruit under IW treatment irrespective of coating. At 3.5 °C (constant) chilling injury appeared after 45 days during 1 week holding and thereafter increased at each storage interval. Wax coated fruit had lower chilling injury. Fruit under IW treatment and at 6.5 °C (constant) developed yellow-orange colour while at 3.5 °C (constant) fruit remained green during storage. Juice content, titratable acidity and ascorbic acid contents were not affected by temperature regimes and waxing while total soluble solids content was higher with IW treatment. Reducing and total sugars were higher in fruits stored at IW treatment and at 6.5 °C (constant) than at 3.5 °C (constant). Total peel phenols content were not significantly affected by waxing and temperature regimes. However, loss of phenols content was higher at 3.5 °C (constant). Phenol content decreased during storage. At 3.5 °C (constant), chlorophyll ('a-, 'b- and total) content in peel was maximum while total carotenoids were minimum with little colour development. Rapid colour development was recorded under IW and also at 1 week holding. Wax coating delayed colour development at 3.5 °C (constant). Initially carbendazim residues were higher in peel (4.0 ppm) and pulp (3.2 ppm) of waxed fruit than in non-waxed (3.2 ppm in peel and 3.1 ppm in pulp) fruit. Overall drop in residues till storage up to 75 days+ 1 week over the initial values was 80.2-85.6% in peel and 56.2-75.8% in pulp of waxed and non-waxed fruit, respectively. Respiration was lower in waxed fruit. Respiratory rate was lowest at 3.5 °C (constant) and it changed with IW. At 3.5 °C and 6.5 °C (constant), range of respiration was 4-6 mgCO2/kg/h and 7-9 mgCO2/kg/h, respectively in waxed and non-waxed fruit. Respiratory rate increased as the fruit was removed to warmer temperature. Chilling injury caused considerable rise in respiration rate of fruit. Present findings indicated that storage life of 'Nagpur- mandarin can be extended up to 75 days at 3.5 °C with IW. © Association of Food Scientists & Technologists (India) 2010.

Wu Q.-S.,Yangtze University | Srivastava A.K.,National Research Center for Citrus | Zou Y.-N.,Yangtze University
Scientia Horticulturae | Year: 2013

Citrus is one of the most widely cultivated fruit crops, whose rhizosphere inhabits a class of beneficial fungi, popularly known as arbuscular mycorrhizal fungi (AMF). Different species of AMF viz., Acaulospora, Entrophospora, Gigaspora, Glomus, Pacispora, Sclerocystis, and Scutellospora have been observed to colonize citrus roots for the formation of arbuscular mycorrhizal (AM) symbiosis, where both the symbiotic partners are mutually benefited (up to 20% of photosynthetic carbohydrates from the host plant is diverted toward the growth of AM, in the exchange of water and nutrient uptake from the fungal partner to the host plant). AM symbiosis can usually confer better plant growth, higher nutrient uptake, greater tolerance to abiotic and biotic stresses, and soil structure improvement in the host plant. Meanwhile, AM-inoculated citrus plants have shown greater tolerance to drought stress (DS). Drought stress strongly restricted both the development of non-AM-citrus and the mycorrhizal development of AM-citrus, but AM colonization produced a positive effect on plant growth and photosynthesis, even under DS. This review provides an overview of possible mechanisms involved in DS tolerance through improved water and nutrient uptake (especially P nutrition) using extraradical hyphal growth; effective spatial configuration of root system; elevated concentration of tetramine spermine; osmotic adjustment through non-structural carbohydrates, K+, Ca2+, and Mg2+, but not proline; scavenging reactive oxygen species through antioxidant enzymes and antioxidants; and glomalin-bound soil structural improvements, besides, some new exciting perspectives including water transport by mycorrhizal hyphae and molecular analysis are suggested. © 2013 Elsevier B.V.

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