• Authors:
    • Tello-Marquina, J. C.
    • Gómez-Vázquez, J.
    • Santos-Hernández, M.
    • Pérez-Vargas, M.
    • Palmero, D.
    • de Cara, M.
  • Source: Acta Horticulturae
  • Issue: 914
  • Year: 2011
  • Summary: Cherry tomato crops were introduced in the late 1990s in the continental areas of southeast Spain. These fields had been previously cultivated with dry land crops as grapevine, olive, and cereal. After two years of cultivation, different soil-borne diseases widely appeared. The main disease observed was the root rot caused by Phytophthora parasitica, killing the plants during harvest period, concurring with the maximum demand of water from plants. The importance of the mycosis in the area together with the lack of control were the aim to first search for the inoculum sources, and then study the preservation of this oomycete in the infested soils for a long period time. Regarding the inoculum sources, no Phytophthora was found in seeds or seedlings from commercial nurseries sampled from the studied area, but the pathogen was isolated from the irrigation pools. Phytophthora parasitica was also isolated from the soils of the home gardens within the surrounded area, and even from the wheels of the tractors used in these fields. About the preservation study, a total of 92 samples from 42 different fields naturally infested with P. parasitica were analysed. All samples have been kept under laboratory conditions in sealed plastic bags. Only 20.58% of all samples preserved the oomycete for 4 years (48 months), and 18.18% for 5 years (57 months). These results can explain the rapid dissemination of the disease and its difficult control in the area.
  • Authors:
    • Souza, R. F. de
    • Medeiros, M. A. de
    • Marouelli, W. A.
    • Resende, F. V.
  • Source: Horticultura Brasileira
  • Volume: 29
  • Issue: 3
  • Year: 2011
  • Summary: The efficient use of water and the environmental diversity are crucial to the balance and sustainability of the organic production system of tomatoes. The present study aimed to evaluate the organic production of tomato cultivated as a single crop and in consortium with coriander, under sprinkler and drip irrigation. The experiment was carried out at an organic production area on the Federal District of Brazil. The experimental design was randomized blocks with treatments arranged in a 2*2 factorial (two irrigation systems * two cropping schemes). No significant interaction between the both factors occurred, and there was no significant effect of the cropping scheme over the evaluated variables. Although the crop cycle has been reduced when tomato was drip irrigated, the fruit yield was not affected by the irrigation systems. The larger reduction in the stand of plants observed under sprinkler irrigation has been compensated by an increase in the number of fruits per plant, without a change on the fruit mass. The smaller volume of soil explored by the tomato roots associated with the higher incidence of South American tomato pinworm ( Tuta absoluta) and mainly powdery mildew ( Leveillula taurica) may have limited the yield of drip irrigated tomato. The fruit decay rate on sprinkle irrigated plants was twice the rate found on the drip irrigated system.
  • Authors:
    • Nonnecke, G. R.
    • Portz, D. N.
  • Source: HortScience
  • Volume: 46
  • Issue: 10
  • Year: 2011
  • Summary: Yield of strawberry grown continuously on the same site often declines over time as a result of proliferation of weed seeds and pathogenic organisms in the soil. Plots were established and maintained in seven different cover crops and as continuous strawberry or continuous tillage for 10 years (1996 to 2005) in a site that was previously in strawberry production for 10 years (1986 to 1995). Cover crops included blackeyed Susan (Rudbeckia hirta L.), sorghum Sudangrass [Sorghum bicolor (L.) Moench], marigold (Tagetes credo L.), big bluestem (Andropogon gerardii Vitman), perennial ryegrass (Lolium permute L.), switchgrass (Panicum virgatum L.), and Indiangrass [Sorghastrum nutans (L.) Nash]. Treatments were ended in 2005 and plots were planted with 'Honeoye' strawberry in a matted row. Effectiveness of soil pretreatments in reducing weed populations and enhancing strawberry production was evaluated for four growing seasons by quantifying weed growth by type and biomass and strawberry plant density and yield. The results indicate that matted-row strawberry production plots that were either in continuous tillage or established in S. bicolor, P. virgatum, or A. gerardii before planting strawberry had lower weed biomass and greater strawberry plant establishment and yield than plots established in L. permute or R. hirta or that had supported continuous strawberry production.
  • Authors:
    • Thakare, S. S.
    • Shende, N. V.
  • Source: The Asian economic review: journal of the Indian Institute of Economics
  • Volume: 53
  • Issue: 3
  • Year: 2011
  • Summary: In this study an attempt has been made to study the structural changes in cost of cultivation of selected crops in Vidarbha. The study is based on estimates of cost of cultivation of four selected crops viz. Cotton, Soybean, Sorghum and Paddy of Vidarbha region of Maharashtra. The study used cross sectional cum time series data of Vidarbha region for selected crops for ten years from 1999-00 to 2008-09. The total cost of cultivation of cotton, soybean, sorghum and paddy has been depicting an increase by 1.82,1.86, 1.17 and 1.42 times during the period of study respectively. It was revealed that the share of operational cost to total change in cost of cultivation has been almost same for cotton, soybean and paddy crops indicating that the operational cost and fixed cost increased over time in a commensurate manner for these crops except sorghum crop. For all selected crops, the cost of cultivation has increased at a faster rate as compared to increase in prices of their output. The study also revealed that, during 1999-00, the return over cost A was highest for paddy crop followed by sorghum and cotton and lowest for soybean. The return over cost C was highest for paddy followed by sorghum but the return over cost C for soybean and cotton found negative. There for paddy crop had comparative economic advantage as compared to other selected crops of Vidarbha in 1999-00. During 2008-09, return over cost A was highest for cotton crop followed by paddy, soybean and sorghum. The return over cost C was highest for cotton followed by soybean and paddy crop. There for cotton crop had comparative economic advantage among the selected crops of Vidarbha in 2008-09. Cotton and paddy are the important crops of Vidarbha. These crops are more profitable as compared to other crops of Vidarbha, but now the area under cotton was replaced by soybean due to high cost of cultivation of cotton. Hence cotton area is likely to dominate day by day.
  • Authors:
    • Xu, W. L.
    • Feng, Y. Z.
    • Jang, Y. L.
    • Rao, X. J.
    • Wang, Z. G.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 48
  • Issue: 12
  • Year: 2011
  • Summary: Objective: The purpose of this project is to study the effects of different irrigation models of jujube-cotton intercropping in ecological areas on the temperature and humidity and determine the ecological result of different irrigation models to the environment in order to provide some scientific basis for optimum water-saving irrigation model for jujube-cotton intercropping. Method: Three EL-USB automatic measuring system of temperature and humidity was established in the different positions in treatment 1 - jujube garden, treatment 2 - double water pipes in one line, treatment 3 - spray, treatment 4 - ditch irrigation, treatment 5 - cotton, EL-USB automatic measuring system of temperature and humidity of different distances from tree row to be monitored for 3 days in a row. Result: Effects of east-to-west jujube row on micro-ecological areas temperature are: the south of Jujube > the north of Jujube > Jujube row, and humidity: jujube row > The north of Jujube > The south of jujube; There was a negative linear correlation between humidity and temperature. Effects of different irrigation models on micro-ecological areas temperature of Jujube-cotton intercropping are: treatment 5 > treatment 1 > treatment 4 > treatment 3 > treatment 2, and humidity: treatment 2 > treatment 3 > treatment 4 > treatment 1 > treatment 5. Conclusion: Results showed that the crown shading of a east-to-west jujube row affected micro-ecological area temperature and humidity differently with different directions from tree row. Generally, temperature is the south of Jujube > the north of jujube > jujube row. There was a negative linear correlation between humidity and temperature. The temperature of jujube-cotton intercropping is lower than that of the single cotton model, but the humidity is higher. The treatment of spray and the treatment of double water pipes influence temperature and humidity greatly, which was advantageous to increase the jujube fruit setting rate.
  • Authors:
    • Zuo, Y. M.
    • Zhang, F. S.
  • Source: Plant and Soil
  • Volume: 339
  • Issue: 1/2
  • Year: 2011
  • Summary: Plants and humans cannot easily acquire iron from their nutrient sources although it is abundant in nature. Thus, iron deficiency is one of the major limiting factors affecting crop yields, food quality and human nutrition. Therefore, approaches need to be developed to increase Fe uptake by roots, transfer to edible plant portions and absorption by humans from plant food sources. Integrated strategies for soil and crop management are attractive not only for improving growing conditions for crops but also for exploiting a plant's potential for Fe mobilization and utilization. Recent research progress in soil and crop management has provided the means to resolve complex plant Fe nutritional problems through manipulating the rhizosphere (e.g., rhizosphere fertilization and water regulation), and crop management (includes managing cropping systems and screening for Fe efficient species and varieties). Some simple and effective soil management practices, termed 'rhizosphere fertilization' (such as root feeding and bag fertilization) have been developed and widely used by local farmers in China to improve the Fe nutrition of fruit plants. Production practices for rice cultivation are shifting from paddy-rice to aerobic rice to make more efficient use of irrigation water. This shift has brought about increases in Fe deficiency in rice, a new challenge depressing iron availability in rice and reducing Fe supplies to humans. Current crop management strategies addressing Fe deficiency include Fe foliar application, trunk injection, plant breeding for enriched Fe crop species and varieties, and selection of cropping systems. Managing cropping systems, such as intercropping strategies may have numerous advantages in terms of increasing Fe availability to plants. Studies of intercropping systems on peanut/maize, wheat/chickpea and guava/sorghum or -maize increased Fe content of crops and their seed, which suggests that a reasonable intercropping system of iron-efficient species could prevent or mitigate Fe deficiency in Fe-inefficient plants. This review provides a comprehensive comparison of the strategies that have been developed to address Fe deficiency and discusses the most recent advance in soil and crop management to improve the Fe nutrition of crops. These proofs of concept studies will serve as the basis for future Fe research and for integrated and optimized management strategies to alleviate Fe deficiency in farmers' fields.
  • Authors:
    • Finetto, G. A.
  • Source: Acta Horticulturae
  • Issue: 890
  • Year: 2011
  • Summary: Afghanistan can be considered the country of the pomegranate fruit because of the excellent quality of the cultivars that thrive there. Afghanistan is a land for 48 leading world cultivars of pomegranate commonly growing in Kandahar, Kapisa, Samangan, Farha, Nenroz and Balkh Provinces. Kandahar Province has historically, widely been known as main production area for its high quality and productivity. Other pomegranate orchards are located along the Arghandab River. Pomegranate ranks 5th after grapes, almond, apricot and apple. The area has decreased from 5667 ha (1996) to 2500 ha (2003). The average yields are in the range of about 8600 kg/ha in Dand district to more than 19000 kg/ha in Arghandab district. Although one estimate says the total production is around 24,000 Mt, a rational estimation is around 15-20,000 Mt, due to the poor production in some areas. Production in the Kandahar Province is approximately 10,000 metric tons; and the main cultivar is 'Kandahari'. Smaller volumes are produced elsewhere in Afghanistan. Elevation is the main restriction in production, with 'Bedana' produced in Nangarhar at or above 1000 m elevation. 'Kandahari' is produced at elevations from 550 m to below 1000 m. Up to now no collection of local cultivars has been carried out by the fruit tree projects funded by international organisations (EC, World Bank, FAO, USAID, DFID, ICARDA, etc.). To meet the high demand of the world market, Afghanistan must increase production levels and improve productivity through better husbandry of pomegranate orchards. In Afghanistan few are commercial orchards, commonly the farmers grow this fruit species in small plots with intercropping, due to very exiguous dimensions of farms (average 0.8 ha per household), dire needs of staple food for their families and an instable political situation. In spite of the good local cultivars few cultural practices such as irrigation, fertilisation, pruning, etc. are applied often in an unsteady way. Due to the health benefits of the fruit (anti-oxidant) several traders in Afghanistan have started to receive orders for pomegranate from outside their traditional markets in the Sub-Continent. So, locally the market for pomegranate does not compare with other more common fruits because the demand is growing rapidly. Pomegranate commercialisation has a typical supply chain that involves the following major players: Grower, Pre-harvest Contractor, Pakistani Importer/Financier, Packaging Company. From harvest to market, wooden baskets (typically 3 sizes, but without uniform size/weight), made of flexible pomegranate tree branches (1st or 2nd year shoots) are used. For export mostly wooden crates are used. Pomegranate is an ideal fresh fruit for Afghanistan to export as they come in a tough outer rind and have good storage properties. So, pomegranate should be considered as one of the most promising crops for support but refrigeration, postharvest handling and promotion should all be applied to this crop.
  • Authors:
    • Fernandez, G. E.
    • Schroeder-Moreno, M. S.
    • Garland, B. C.
    • Creamer, N. G.
  • Source: HortScience
  • Volume: 46
  • Issue: 7
  • Year: 2011
  • Summary: The effects of eight summer cover crop treatments combined with two arbuscular mycorrhizal (AM) fungal inoculants on strawberry growth and yields were examined in a 2-year field experiment. Cover crop treatments included 1) sudangrass [Sorghum bicolor (L.) Moench cv. Piper]: 2) pearl millet [Pennisetum glaucum (L.) R.Br. CV. 102 M Hybrid!: 3) soybean [Glycine max (L.) Merrill cv. Laredo]: 4) velvetbean [Mucuna deeringiana (Bort) Merr. cv. Georgia Bush]: 5) sudangrass/velvetbean combination; 6) pearl millet/soybean combination; 7) a non-mycorrhizal host consisting of rape (Brassica napus L. var. napus cv. Dwarf Essex) and buckwheat (Fagopyrum esculentum Moench) in Year 1 and Year 2, respectively; and 8) no cover crop control. Strawberry tips were inoculated with either a native mixture of several AM fungal species or a single species sold commercially, Glomus intraradices. Cover crop treatments were assessed for their aboveground biomass and nutrient uptake as well as their impacts on weed abundance and diversity, soil nutrients, and parasitic nematode populations. Cover crop and AM treatments were assessed for their impact on strawberry growth, yields, AM root colonization, and nutrient uptake. Grass-based cover crop treatments, particularly pearl millet, produced the most aboveground biomass. In both years, all cover crop treatments reduced summer weed biomass compared with the control. Neither cover crop nor AM treatments had an effect on overall strawberry plant growth or yields in either year, although some differences existed at specific growth periods. The results suggest that cover crops are a viable strategy for reducing summertime weeds and that background, native populations of AM fungi in the soil may be just as effective as a commercially available species. It is likely that no overall yield benefit was found among treatments for two reasons: 1) nutrients, especially nitrogen, were not limiting; and 2) the cover crop growth window may have been too short for a significant impact on strawberries over two seasons.
  • Authors:
    • Perri, E.
    • Ayadi, M.
    • Benincasa, C.
    • Gharsallaoui, M.
    • Khlif, M.
    • Gabsi, S.
  • Source: Scientia Horticulturae
  • Volume: 128
  • Issue: 1
  • Year: 2011
  • Summary: Nowadays, lots of efforts are made in Tunisia for the exploitation of wastewater in agriculture in order to face a very elevated mobilization of resources in water (90%). At Sfax, a Governorate placed in the South of Tunisia, the annual rainfall rarely exceeds 200 mm, so the climate is fairly arid. The significant water deficit can be reduced with the reuse of treated wastewater (TWW). The Sfax wastewater originated from the municipal wastewater treatment plant (WWTP) localized at 5 km in the south of Sfax, Tunisia. This WWTP is an aerated lagoon process receiving industrial wastewaters. Its treatment capacity is 24,000 m 3/day. Part of TWW is sent to the olive crops of El Hajeb, as part of a proposed wastewater use in agriculture. Already the wastewater is used to irrigate olive trees and intercrops such as cotton, oats and sorghum silage (Charfi et al., 1999). The aim of the present work was to determine the impact of the irrigation utilizing wastewater on the quality of the oil. The oils analysed were extracted from olives hand-picked directly from the tree and from olives that have fallen under the trees. Moreover, a study on the olive storage has been made in order to evaluate in which way the collection of the fruit could influence the quality of the oil. The results obtained showed that: - Olive trees benefit from this contribution of water; - irrigation by wastewater has a significant effect in the fatty acid composition; - oils relative to olive trees irrigated with wastewaters are more sensible to the oxidization especially after olive storage; - oils coming from olive trees irrigated with wastewaters are richer in polyphenols; - oils extracted from fallen olives are of poor quality essentially after olives storage and when olive trees are irrigated by wastewater.
  • Authors:
    • Carvalho, S. A. de
    • Setin, D. W.
  • Source: Citrus Research and Technology
  • Volume: 32
  • Issue: 1
  • Year: 2011
  • Summary: Citrus Sudden Death (CSD) a citrus disease of indeterminate causal agent, imposed changes to the Sao Paulo state citrus nursery tree production, with the substitution of the Rangpur lime for tolerant rootstocks as Swingle citrumelo, which, however, is less resistant to water deficit. The use of inarched nursery trees, combining resistance to water deficit and to CSD, can be interesting for planting in areas of risk, sparing the need of irrigation. The objective of this research was to evaluate different containers and grafting methods for the production of Valencia sweet orange nursery trees with double-rootstocks: Rangpur lime and Swingle citrumelo. Two containers (0.05 dm 3 and 0.25 dm 3 leaching tubes) and two grafting methods (inarching and spliced approach grafting) were evaluated for production of double-rootstocks. The comparison was performed against the single patterns (Rangpur lime or Swingle). Plant growth before and after grafting was evaluated in the final evaluation, the volume and mass of roots and mass of scion dry matter were measured. Single and double rootstocks grown initially in tubes of 0.25 dm 3, and Valencia nursery trees produced on the same container, demonstrated higher growth. Valencia nursery trees on Swingle citrumelo and Rangpur lime double rootstocks presented similar growth to trees grafted on Swingle citrumelo single rootstock. However, considering the potential of such type of nursery trees, its production may be held by sowing different rootstocks in the same tube of 0.25 dm 3, performing the graft by inarching method and the transference to bags where the canopy bud is grafted.