Responses of citrus (Citrus sinensis) to nitrogen-phosphorus-potassium (NPK) fertiliser on 2 soils of Rarotonga, Cook Islands 2. Effects of NPK fertiliser rate, soil properties, and leaf nutrient levels on yield and tree size

‘Cleopatra’ tangerine (Citrus reshni hort. ex Tanaka) is a commonly used rootstock in the piedmont of Meta department, Colombia for establishing of commercial citrus orchards. Have allowed a late production entrance rootstock and produced big plants when grafted with tangelo ‘Minneola’ (C. reticulata Blanco x C. paradise Macf), decreasing the productive efficiency in plants and hard crop practices. The evaluated performance were as follows: tree size, productive efficiency and fruit quality of tangelo ‘Minneola’ grafted in six rootstocks. It found that the cumulated production of 11 years was better with Citrumelo ‘Swingle’ (Citrus paradisi Macf. × Poncirus trifoliata (L.) Raf) with 1388.3 kg tree-1, followed by ‘Cleopatra’ (Citrus reshni hort. ex Tanaka) with 893.2 kg.tree-1, in last place was ‘Carrizo’ (Citrus sinensis Osb. × Poncirustrifoliata (L.) Raf) with 182.9 kg tree-1. The other rootstocks, had a medium production. The greatest height and canopy value, was found with ‘Cleopatra’ without significant differences with Citrumelo ‘Swingle’. In fruit quality no significant differences occurred.

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Soil properties and tree vigour in the Goulburn Valley

Australian Journal of Experimental Agriculture ◽

10.1071/ea9660204 ◽

1966 ◽

Vol 6 (21) ◽

pp. 204 ◽

Cited By ~ 3

Author(s):

B Cockroft ◽

JC Wallbrink

Keyword(s):

Soil Properties ◽

Surface Soil ◽

Fruit Trees ◽

Tree Size ◽

Secondary Importance ◽

Survey Technique ◽

Tree Vigour

A survey technique was used to correlate several field properties of soils with size of fruit trees in commercial orchards of the Goulbum Valley, Victoria. Where the surface soil was shallow (about 6 inches) its depth was the most important factor affecting tree size, but heaviness of the subsoil also had an effect. Where the surface soil was deep (about 10 inches), the important property was its mechanical composition, depth being of secondary importance.

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Leaf nutrient levels and the spatio-temporal distributions of Plutella xylostella and its larval parasitoids Diadegma insulare and Microplitis plutellae in canola

BioControl ◽

10.1007/s10526-009-9252-7 ◽

2009 ◽

Vol 55 (2) ◽

pp. 229-244 ◽

Cited By ~ 8

Author(s):

Rana M. Sarfraz ◽

Lloyd M. Dosdall ◽

Adam J. Blake ◽

B. Andrew Keddie

Keyword(s):

Plutella Xylostella ◽

Larval Parasitoids ◽

Nutrient Levels ◽

Diadegma Insulare ◽

Spatio Temporal ◽

Leaf Nutrient Levels

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Dissolved nutrients and organic particulates in water flowing over coral reefs at Lizard Island

Marine and Freshwater Research ◽

10.1071/mf9830835 ◽

1983 ◽

Vol 34 (6) ◽

pp. 835 ◽

Cited By ~ 35

Author(s):

CJ Crossland ◽

DJ Barnes

Keyword(s):

Organic Carbon ◽

Coral Reefs ◽

Organic Nitrogen ◽

Inorganic Nitrogen ◽

Dissolved Nutrients ◽

Reef Complex ◽

Nutrient Levels ◽

Lizard Island ◽

Nitrogen Phosphorus ◽

Benthic Zone

Concentrations of dissolved nutrients and organic particulates were measured in seawater flowing across the windward and leeward reef flats of the lagoonal reef complex at Lizard Island. Measurements were made during the day, at night, and at various stages of the tide over a period of several weeks. The reef complex, as a whole, did not consume or export statistically significant amounts of inorganic nitrogen, phosphorus, silicate, organic nitrogen or organic carbon. Depletion or elevation of nutrient levels in one benthic zone appeared to be balanced by production or consumption in downstream zones.

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Nutrient status of sugar cane in relation to leaf nutrient concentration

Australian Journal of Experimental Agriculture ◽

10.1071/ea9680606 ◽

1968 ◽

Vol 8 (34) ◽

pp. 606 ◽

Cited By ~ 2

Author(s):

ICR Holford

Keyword(s):

Sugar Cane ◽

Field Experiments ◽

Leaf Tissue ◽

Growth Period ◽

Nutrient Status ◽

Maximum Growth ◽

Nutrient Concentrations ◽

Ratoon Crop ◽

Nutrient Levels ◽

Leaf Nutrient Levels

The nitrogen, phosphorus, and potassium requirements of sugar cane were studied in relation to the concentration of these elements in the leaf tissue of three varieties of sugar cane grown commercially in Fiji. Percentage yields of sugar cane in fertilizer field experiments were highly correlated with leaf nutrient levels in the control plots, provided leaf sampling was carried out during the maximum growth period of mid- January to mid-May. For each nutrient there was a marginal zone of leaf concentration below which crops always gave significant yield responses to applied nutrients and above which crops failed to respond. Marginal zones for crops sampled during mid-March to mid-May were 1.4-2.0 per cent for nitrogen, 0.13-0.21 per cent for phosphorus, and 0.9-1.5 per cent oven dry leaf for potassium. Within the deficient range of leaf nutrient concentrations there was little relationship between optimum rates of fertilizer required to correct the deficiency and leaf nutrient levels of unfertilized cane. Because of the lateness of sampling, any indication of fertilizer requirement would only be applicable to a subsequent ratoon crop.

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Long-term nitrogen, phosphorus and potassium fertilization of cassava influences soil chemical properties in North Vietnam

Canadian Journal of Soil Science ◽

10.4141/s00-048 ◽

2001 ◽

Vol 81 (4) ◽

pp. 481-488 ◽

Cited By ~ 6

Author(s):

Hung Nguyen ◽

J J Schoenau ◽

K. C.J. Van Rees ◽

Dang Nguyen ◽

P. Qian

Keyword(s):

Soil Properties ◽

Chemical Properties ◽

Soil Chemical Properties ◽

Mineral Fertilizers ◽

Inorganic P ◽

Total Soil ◽

North Vietnam ◽

Nitrogen Phosphorus ◽

Soil Inorganic

The long-term effects of yearly fertilizer applications on soil chemical properties and nutrient availability are not well documented for cassava (Manihot esculenta) production in Vietnam. In 1990, research plots were established (randomized complete block design) with 12 treatments to test effects of different rates of N, P and K on soil properties in Acrisols (FAO-UNESCO Soil Classification) at Thai Nguyen University, North Vietnam. In June 1998, composite soil samples (0- to 10-cm and 10- to 20-cm depth) were collected from each plot. Nine years of N application significantly reduced the labile pools of soil inorganic P, total soil P and soil extractable K and Mg. Total soil N was only slightly increased in the 10- to 30-cm depth. Long-term applications of P significantly increased soil inorganic P fractions, but reduced concentrations and supply rates of nitrate and K. Moreover, 9 yr of K application significantly increased soil organic C (two depths), soil total N (10-30 cm) and soil extractable K in the 0- to 10-cm depth. Generally, the results show that long-term applications of mineral fertilizers in a ratio of N:P2O5:K2O of 2:1:2 (at the rates of 80 N:40 P2O5:80 K2O or 160 N:80 P2O5:160 K2O) are effective in maintaining the total content and availability of applied nutrients, but when applied alone are associated with decreases in other nutrients. Key words: Nitrogen, phosphorus, potassium fertilizers, cassava, ion exchange resin, soil properties

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