Analysis of sweet potato (Ipomoea batatas) from the highlands of Papua New Guinea: relevance to the incidence of Enteritis necroticans

1984 ◽  
Vol 32 (3) ◽  
pp. 469-473 ◽  
Author(s):  
James H. Bradbury ◽  
Janis Baines ◽  
Brendon Hammer ◽  
Merle Anders ◽  
John S. Millar
Keyword(s):  
Papua New Guinea ◽  
Sweet Potato ◽  
Ipomoea Batatas ◽  
New Guinea ◽  
Enteritis Necroticans

Alternaria bataticola. [Descriptions of Fungi and Bacteria].

1991 ◽  
Author(s):  
J. C. David
Keyword(s):  
Papua New Guinea ◽  
Sweet Potato ◽  
Geographical Distribution ◽  
Leaf Spot ◽  
Ipomoea Batatas ◽  
Central Africa ◽  
New Guinea ◽  
Wind Dispersal ◽  
Airborne Conidia

Abstract A description is provided for Alternaria bataticola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Ipomoea batatas. DISEASE: Leaf spot of Sweet Potato. GEOGRAPHICAL DISTRIBUTION: Africa: Central Africa, Burundi. Asia: Japan, Papua New Guinea. TRANSMISSION: By wind dispersal of airborne conidia.

Elsinoe batatas. [Descriptions of Fungi and Bacteria].

1992 ◽  
Author(s):  
A. Sivanesan
Keyword(s):  
Hong Kong ◽  
Papua New Guinea ◽  
Sweet Potato ◽  
Geographical Distribution ◽  
Ipomoea Batatas ◽  
New Caledonia ◽  
New Guinea ◽  
Cook Islands ◽  
Caroline Islands ◽  
Sabah And Sarawak

Abstract A description is provided for Elsinoe batatas. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Ipomoea batatas. DISEASE: Leaf and stem scab of sweet potato. GEOGRAPHICAL DISTRIBUTION: Australia, Brazil, Brunei, Caroline Islands, China, Cook Islands, Fiji, Guadalcanal ?, Guam, Hong Kong, Japan. Malaysa (including Sabah and Sarawak), New Caledonia, Niue, Papua New Guinea. Taiwan, Tonga, Vanuata. TRANSMISSION: By waterborne spores and through cuttings.

scholarly journals Kinetics of potassium release in sweet potato cropped soils: a case study in the highlands of Papua New Guinea

Solid Earth ◽  
2015 ◽  
Vol 6 (1) ◽  
pp. 217-225 ◽  
Author(s):  
B. K. Rajashekhar Rao
Keyword(s):  
Land Use ◽  
Papua New Guinea ◽  
Sweet Potato ◽  
New Guinea ◽  
Population Increase ◽  
Mineral Fertilizers ◽  
Volcanic Soils ◽  
First Order ◽  
Release Pattern ◽  
K Release

Abstract. The present study attempts to employ potassium (K) release parameters to identify soil-quality degradation due to changed land use patterns in sweet potato (Ipomoea batatas (L.) Lam) farms of the highlands of Papua New Guinea. Rapid population increase in the region increased pressure on the land to intensify subsistence production mainly by reducing fallow periods. Such continuous cropping practice coupled with lack of K fertilization practices could lead to a rapid loss of soil fertility and soil-resource degradation. The study aims to evaluate the effects of crop intensification on the K-release pattern and identify soil groups vulnerable to K depletion. Soils with widely differing exchangeable and non-exchangeable K contents were sequentially extracted for periods between 1 and 569 h in 0.01 M CaCl2, and K-release data were fitted to four mathematical models: first order, power, parabolic diffusion and Elovich equations. Results showed two distinct parts in the K-release curves, and 58–80% of total K was released to solution phase within 76 h (first five extractions) with 20–42% K released in the later parts (after 76 h). Soils from older farms that were subjected to intensive and prolonged land use showed significantly (P < 0.05) lower cumulative K-release potential than the farms recently brought to cultivation (new farms). Among the four equations, first-order and power equations best described the K-release pattern; the constant b, an index of K-release rates, ranged from 0.005 to 0.008 mg kg−1 h−1 in the first-order model and was between 0.14 and 0.83 mg kg−1 h−1 in the power model for the soils. In the non-volcanic soils, model constant b values were significantly (P < 0.05) higher than the volcanic soils, thus indicating the vulnerability of volcanic soils to K deficiency. The volcanic soils cropped for several crop cycles need immediate management interventions either through improved fallow management or through mineral fertilizers plus animal manures to sustain productivity.

Integrated Nutrient Management Research with Sweet Potato in Papua New Guinea

2003 ◽  
Vol 32 (3) ◽  
pp. 173-182 ◽  
Author(s):  
Alfred E. Hartemink
Keyword(s):  
Papua New Guinea ◽  
Sweet Potato ◽  
Tuber Yield ◽  
Poultry Litter ◽  
New Guinea ◽  
Potato Yield ◽  
Inorganic Fertilizer ◽  
Nitrogen Fertilizers ◽  
Organic N ◽  
Potato Yields

This paper summarizes a series of field experiments that investigated the effects of organic and inorganic nutrients on sweet potato tuber yield in the humid lowlands of Papua New Guinea. In the first experiment, plots were planted with Piper aduncum, Gliricidia sepium and Imperata cylindrica, which were slashed after one year, whereafter sweet potato was planted. Sweet potato yield was lowest after Gliricidia fallow, but no yield differences were found after piper and imperata fallow. In the second season, there was no significant difference in sweet potato yields. The second experiment consisted of a factorial fertilizer trial with four levels of N (0, 50, 100, 150 kg ha–1) and two levels of K (0, 50 kg ha–1). Nitrogen fertilizers increased yield in the first season, but depressed tuber yields in the second and third seasons. Potassium fertilizer had no effect on marketable tuber yield. The third experiment consisted of a comparison between N from inorganic fertilizer and poultry litter at four rates (0, 50, 100, 150 kg ha–1). No difference was found between the inorganic fertilizer and poultry litter, and the highest yields were found at 100 kg N ha–1. In the second season no significant response was observed. Although yield variation was considerable, this series of experiments has shown that sweet potato yield can be significantly increased by inorganic or organic N applications. Sweet potato yields after fallows were less variable than after inorganic nutrient inputs. Inputs of inorganic fertilizer or poultry litter may strongly increase or decrease tuber yields.

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