• Authors:
    • Shu, B.
    • Zhang, J. J.
    • Wang, P.
    • Xia, R. X.
  • Source: Plant, Soil and Environment
  • Volume: 58
  • Issue: 7
  • Year: 2012
  • Summary: Communities of arbuscular mycorrhizal fungi (AMF) were studied in sod culture (SC), straw mulching (NM), and herbicide treated and no-tillage (NH) citrus orchards, respectively. The highest total colonization rate (39.47%) and hyphal length density (1.15 m/g soil) were found in SC, the highest spore numbers (1024 spores/100 g soil) in NM, while the lowest ones (31.50%, 0.94 m/g soil and 719 spores/100 g soil) in NH and they varied significantly among three different types of orchards. Total 18 AMF species belonging to five families, Acaulosporaceae (four species), Claroideoglomeraceae (two species), Gigasporaceae (one species), Glomeraceae (nine species) and Pacisporaceae (two species) were identified, and Glomus aggregatum and Claroideoglomus etunicatum were the dominant species in all surveyed plots. The redundancy analysis showed that AMF community structure was influenced greatly by pH, soil management, soil organic matter (C ox) and available phosphorus (P Olsen). In SC orchards, species richness and Shannon-Wiener index of AMF were notably higher than in other treated orchards. So, it is reasonable to select SC as the best practice in citrus orchard in order to enhance AMF benefits.
  • 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.
  • Authors:
    • Ma, C. L.
    • Wang, P.
    • Guo, P.
    • Peng, H. Y.
    • Chen, L .S.
    • Yang, L. T.
  • Source: Scientia Horticulturae
  • Volume: 133
  • Year: 2012
  • Summary: 'Sour pummelo' ( Citrus grandis) seedlings were irrigated for 18 weeks with nutrient solution containing 0 (-Al) and 1.2 mM (+Al) AlCl 3.6H 2O * 0, 10 and 500 M sodium nitroprusside (SNP), a nitric oxide (NO) donor. Leaf malate content did not significantly change in response to SNP with or without aluminum (Al) except for an increase under 1.2 mM Al+10 M SNP, while leaf citrate content decreased with increasing SNP supply. Root malate content kept unchanging with or without Al except for an increase under 500 M SNP in the absence of Al, while SNP-treated roots had a higher or similar citrate content. Al decreased or did not affect malate content in roots and leaves, and citrate content in roots, but increased leaf citrate content. Al-treated roots and leaves displayed lower or similar activities of acid-metabolizing enzymes [phospho enolpyruvate carboxylase (PEPC), NAD-malate dehydrogenase (NAD-MDH), NADP-malic enzyme (NADP-ME), citrate synthase (CS), aconitase (ACO), NADP-isocitrate dehydrogenase (NADP-IDH), phospho enolpyruvate phosphatase (PEPP) and pyruvate kinase (PK)] except that they had higher or similar activities of NADP-ME and PK and Al-treated leaves had a higher or similar activity of PEPP. In conclusion, the OA metabolism in leaves and roots is differently affected by NO and Al interactions.
  • Authors:
    • Araki, T.
    • Nomiyama, R.
    • Yokota, N.
    • Setoyama, S.
    • Kagawa, H.
    • Kotegawa, R.
    • Sato, Y.
    • Ohara, M.
    • Kawano, T.
    • Yano, T.
    • Yasunaga, E.
    • Eguchi, T.
    • Kitano, M.
  • Source: Environment Control in Biology
  • Volume: 50
  • Issue: 2
  • Year: 2012
  • Summary: In order to improve temperature and water management in the greenhouse cultivation of Satsuma mandarins, short-term water and carbon balance in intact Satsuma mandarin fruits was studied by measuring fruit expansive growth, CO 2 and H 2O gas exchange, sap flux into the fruit through the phloem and xylem, and 13C partitioning. Seventy-one days after full bloom, with day/night temperature set at 28°C/23°C and under fine weather conditions, sap flux through the xylem into the fruit showed a dynamic diurnal change which was related to changes of fruit volume. In leaves, 13C partitioning decreased from 11:00 until 23:00, remaining constant thereafter, whereas in fruits, 13C partitioning increased from 11:00 until 23:00, and then remained contrast. Investigating the cumulative water balance, 19% of water output was lost by fruit transpiration, whereas 81% contributed to fruit growth. In cumulative carbon balance, 39% of carbon output was lost by fruit respiration, whereas 61% contributed to fruit growth. Quantitative analyses of physiological responses to environmental conditions, as measured in this study, are essential for establishing energy-saving temperature management strategies.
  • Authors:
    • Mulas, M.
    • Deidda, B.
    • Zurru, R.
  • Source: Acta Horticulturae
  • Issue: 928
  • Year: 2012
  • Summary: Pruning of Clementine requires a lot of time: more than 50 days of work per hectare in the traditional forms of orchard management. Because of the high cost and the lack of specialised workers, we observe a general tendency to delay the frequency of pruning in the citrus orchards. On the other hand regular pruning is of fundamental importance to have good fruit quality, to maintain health status of the orchard, and to store their regular productivity. In order to optimise the Clementine pruning technique, reduce the time of execution and maintain a good level of yield of better quality a field experiment was designed. In 1996 a commercial orchard of 'SRA 63' Clementine located in Southern East Sardinia was selected for the experiment. Plants were grafted on 'Troyer' Citrange, twenty-year-old, spaced 7*5 m, shaped to globe, over 4 m in height, and showed an excessive number of main branches (about 7-8 per tree) with a dense canopy. The entire orchard was preliminarily submitted to a gradual shape pruning during the first four years. In 2000 two main plots of 72 plants each were designed: (A) pruning every year; and (B) pruning every two years. The orchard was observed for a further period of four years for the following characters: trunk section area; canopy size, working time for pruning; pruned wood weight; fruit yield; fruit size. In both pruning applications (A and B) the canopy was more open and green than in the past, with a improvement of the plant heath status, a reduction of the number of treatments, water for irrigation and fertilizers, less working time for harvest, and with a significant better fruit size and increase of the production value.
  • Authors:
    • Klonsky, K. M.
    • Demoura, R.
    • Elkins, R. B.
    • Ingels, C. A.
    • Lanini, W. T.
    • Shackel, K. A.
  • Source: Acta Horticulturae
  • Issue: 909
  • Year: 2011
  • Summary: In 2009 and 2010, four weed control treatments (in-row mowing, landscape fabric, wood chips, and organic herbicide) and three fertilizer treatments (chicken manure at high vs. low rate and feather meal) were compared in an organic, no-till 'Bosc' pear ( Pyrus communis) orchard with solid-set sprinklers. Weed control in the landscape fabric and wood chip treatments was excellent, and multiple herbicide applications per year resulted in partial control. There were no significant yield differences among treatments, and little difference in fruit diameter or weight. There were no significant differences in trunk growth between treatments. The wood chip treatment had significantly lower stem water potential than other treatments in August 2009 only. In both years, the N content of leaves in mow+no fertilizer was significantly lower than most high-rate manure treatments, and leaf P content followed the opposite trend. Wood chips and fabric tended to have fewer vole holes than in-row mowing, and the herbicide treatment was intermediate. Assuming that landscape fabric lasts 8 years, it is only slightly more expensive per year than in-row mowing alone. An organic herbicide program is more expensive because of the herbicide cost and the many applications required. Wood chips were by far the most expensive treatment because of the cost of chips and spreading them, as well as the need to reapply every year. The use of a low rate of chicken manure was the cheapest fertilization strategy. Doubling that rate doubled the total costs, whereas the use of feather meal was about three times the cost of low-rate manure application for an equivalent amount of N.
  • Authors:
    • Keightley, K. E.
  • Source: American Journal of Enology and Viticulture
  • Volume: 62
  • Issue: 2
  • Year: 2011
  • Summary: Viticultural carbon can be used to be gauge offsets to fossil fuel carbon emissions. Carbon stored in a vineyard agro-ecosystem can be measured by traditional methods such as soil sampling, fruit harvest and pruning measurements, and the destructive harvest of the perennial woody structure (cordons, trunk, and roots). To fully characterize the dynamic nature of carbon storage in a vineyard, a regular schedule of sampling and vine removal would need to be undertaken over several decades. With the intent of eliminating the need to destructively harvest vines, a vineyard was sampled using a nondestructive terrestrial laser-scanning technique. Paired with mineral soil sampling and fruit yield, these methods provided a comprehensive spatial characterization of vineyard carbon storage. Vine perennial woody biomass was measured (n=36) and soil was sampled to a depth of 1 meter (n=24), then combined with average fruit yield and found to total 3,160 Mg organic carbon for a 32.3 hectare vineyard. Vines averaged 1.93 kg of dry biomass (0.87 kg carbon) and when combined with root biomass, constituted 2% (60 Mg) of the total perennial vineyard carbon.
  • Authors:
    • Lavee, S.
  • Source: Acta Horticulturae 888: International Symposium on Olive Irrigation and Oil Quality
  • Issue: 888
  • Year: 2011
  • Summary: The olive commodity spread in ancient times hand in hand with western civilization in the Mediterranean basin. It was till recently and in many regions still is a highly traditionally cultivated commodity. Table olives were subjected about 200 years ago to irrigation and intensification. This was unacceptable in olive cultivation for oil extraction. During the last century the economy of the olive industry declined and became questionable. A drastic increase in efficiency of the olive oil industry was obligatory for its survival. In the nineteen fifties, an approach to intensify the olive oil industry was initiated using irrigation and modern nutrition. The initial results indicated a significant increase in production without reducing oil quality. Slight changes in taste occurred occasionally due to quantitative changes of some oil constituents but oil quality was not affected. Some of these oils gained high prizes in international competitions. Some cultivars responded to irrigation better than others regarding growth, fruit yield and relative oil content. Thus, selection and breeding of responsive cultivars to intensification was initiated. Once responsive cultivars were identified and planted commercially in pioneering orchards, a revolution of the olive oil industry was initiated. An increase in both fruit and oil yield up to more than five times that in traditional orchards was achieved. This increased production and tree uniformity initiated the development of new orchard systems, advanced mechanization and oil mill technologies reducing manual labor. This attracted large scale orchard development in traditional, new and marginal regions. Basis on this development it can be concluded that the introduction of irrigation revolutionized the world's olive oil industry from a traditional barely economic one to a thriving modern economical developing industry.
  • Authors:
    • Poje, T.
  • Source: SAD, Revija za Sadjarstvo, Vinogradnistvo in Vinarstvo
  • Volume: 22
  • Issue: 1
  • Year: 2011
  • Summary: Spreading organic fertilizers in perennial plantations, such as vineyards and orchards, by mechanical means is discussed, and the different basic types of manure spreader suited to this operation are described.
  • Authors:
    • Ferraz, S.
    • Lopes, E. A.
    • Freitas, L. G.
    • Dallemole-Giaretta, R.
    • Podesta, G. S. de
    • Agnes, E. L.
  • Source: NEMATOLOGY
  • Volume: 13
  • Issue: 8
  • Year: 2011
  • Summary: The objective of this research was to evaluate the effect of the combination of Pochonia chlamydosporia var. chlamydosporia with summer and winter cover plants on the control of Meloidogyne javanica on tomato plants under glasshouse conditions. Treatment combinations were with four soil covers (pearl millet and Surinam grass in Experiment 1, oil radish and black oat in Experiment 2; plus tomato and fallow controls) and two P. chlamydosporia treatments (with or without the fungus). The antagonist was applied to nematode-infested soil when the cover crops or tomato were planted. Tomato plants were removed and the above-ground parts of the cover crops were cut, dried, and placed on the pots 60 days after planting. One tomato seedling was transplanted in each pot in a no-tillage system and cultivated for 60 days. Surinam grass, pearl millet and black oat reduced galls and eggs of M. javanica by more than 90%, without application of the fungus. However, P. chlamydosporia+Surinam grass significantly reduced by 72% the number of galls compared with cultivation of the grass in soil without the fungus. Pochonia chlamydosporia became established in soil and could be re-isolated at the end of both experiments. Colony forming units (CFU) (g soil) -1 varied from 1.0*10 5 (fallow) to 2.6*10 5 (pearl millet) and from 1.1*10 5 (fallow) to 2.3*10 5 (oil radish) for the experiments with summer soil cover crops and winter soil cover crops, respectively. The cultivation of Surinam grass, pearl millet and black oat reduced M. javanica populations, and the combination with P. chlamydosporia may favour the establishment of the fungus in the soil and enhance the control of the nematode.