331 Slices
Medium 9781780641836

8 The Chemical Ecology of Seed Persistence in Soil Seed Banks

Gallagher, R.S., Editor CAB International PDF

8

The Chemical Ecology of Seed

Persistence in Soil Seed Banks

Robert S. Gallagher,1* Mark B. Burnham2 and E. Patrick Fuerst3

Independent Agricultural Consultant, Clinton, South Carolina, USA;

2

Department of Biology, West Virginia University, Morgantown,

West Virginia, USA; 3Department of Crop and Soil Science,

Washington State University, Pullman, Washington, USA

1

Introduction

The endogenous chemical regulation of seed persistence in the soil seed bank is often assumed to occur by many seed and plant ecologists, but the subject receives only sparse direct coverage in the scientific literature. Priestly (1986) reviewed the experimental evidence to that date for seed persistence in the soil, but gives little mention to potential chemical regulators of that persistence. Baskin and Baskin (1998) provide a very comprehensive review of seed dormancy and germination, but their discussion of chemical regulators of seed dormancy is largely limited to plant hormones as germination inhibitors. Shirley (1998) reviewed the role of flavonoids in seeds, outlining their potential role in preventing pathogen infection, reducing lipid peroxidation (i.e. antioxidant activity) and promoting seed dormancy, but focused primarily on seeds of agronomic crops. Based on the insight from Shirley (1998), Gallagher and

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Medium 9781845938291

8. The Tomato Fruit Borer, Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae), an Insect Pest of Neotropical Solanaceous Fruits

Pena, J.E., Editor CAB International PDF

8 

The Tomato Fruit Borer,

Neoleucinodes elegantalis

(Guenée) (Lepidoptera: Crambidae), an Insect Pest of Neotropical

Solanaceous Fruits

Ana Elizabeth Diaz Montilla,1 Maria Alma Solis2 and Takumasa Kondo1

Corporación Colombiana de Investigación Agropecuaria, Corpoica, Colombia;

2

USDA/ARS, SEL, Room 133, Building 005, BARC-West, 10300 Baltimore Ave.,

Beltsville, Maryland 20705, USA

1

8.1  Introduction

The tomato fruit borer, Neoleucinodes elegantalis

(Guenée) (Lepidoptera: Crambidae) is one of the  most important pests in the production of

Solanaceae in South America. The larva of this insect develops inside the fruit, feeding on the mesocarp and the endosperm and caused

­damage that fluctuates between 13 and 77%

(Costa Lima, 1949). This insect is considered a quarantine pest for several countries in the

Americas (ICA and SOCOLEN, 1998; SAG, 2005;

USDA et al., 2005; SENASA, 2007). The objective of this chapter is to report several aspects of its biology, dynamics, damage, geographical range and integrated pest management and to provide information on species of the same genus.

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Medium 9781780642109

7: The Importance of Soil Quality in the Safe Practice of Urban Agriculture in Zimbabwe, Kenya and South Africa

Brearley, F.Q., Editor CAB International PDF

7 

The Importance of Soil Quality in the Safe

Practice of Urban Agriculture in Zimbabwe,

Kenya and South Africa

Lovemore Chipungu,1 Hangwelani H. Magidimisha,2

Michael Hardman3* and Luke Beesley4

1

School of the Built Environment and Development Studies,

University of KwaZulu-Natal, Durban, South Africa; 2Human Science

Research Council, Demography Governance and Service Delivery, Durban,

South Africa; 3School of Environment and Life Sciences, University of Salford, Salford, UK; 4Environmental and Biochemical Sciences,

The James Hutton Institute, Craigiebuckler, Aberdeen, UK

7.1  Introduction: Urban Soils as Vital

Pseudo-natural Capital

Urban soils, waters and wastes are a valuable natural capital asset for the world’s burgeoning urban population. The utilization of this capital is beginning to be recognized as fundamental to strategies for ensuring a safe and secure food supply in many countries. This idea of growing in the city, or ‘urban agriculture’, is a relatively new concept in certain parts of the world, although ample literature exists on the practice in the North American context (see, e.g. Mougeot,

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Medium 9781780642789

Sorghum (Sorghum vulgare Pers.)

Kumar, P. CAB International PDF

SORGHUM (Sorghum vulgare Pers.)

NITROGEN (N) DEFICIENCY

Symptoms

Plate 92. Deficient pale yellow crop (foreground) and a healthy green crop (background). (Photo by

Dr Prakash Kumar and Dr Manoj Kumar Sharma.)

1. Being a fast-growing grass species, sorghum is very sensitive to nitrogen deficiency. Deficiency symptoms appear even in mild deficiency. Nitrogen deficiency during any stage of crop growth may cause severe losses to the crop in terms of fodder production or grain yield.

2. Nitrogen-deficient plants are stunted with spindly stems and pale green to yellow leaves. The deficient plant produces fewer tillers.

3. Nitrogen is mobile in plants and under short supply conditions it is easily mobilized from older to younger leaves.

4. The deficiency symptoms appear first and become more severe on the older leaves (Plate 91).

5. A pale yellow chlorosis develops at the tip of old leaves and proceeds towards the leaf base along the midrib in a V-shaped pattern.

This is the specific symptom of nitrogen deficiency in sorghum.

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Medium 9781780643922

5 Where is the Host? An Analytic Autoethnographic Inquiry in Transformational Tourism

Reisinger, Y. CAB International PDF

5

Where is the Host? An Analytic

Autoethnographic Inquiry in

Transformational Tourism

Sagar Singh

Centre for Tourism Research and Development, Lucknow, India

Studies in the relationship between tourist and host experiences often revolve round the economic aspects because it is taken for granted that, since tourism is a business, this aspect of study cannot be eliminated. Host experiences, as studied by anthropologists and sociologists, are classified as often characterized by apathy or even dislike, especially where non-business stakeholders are taken into account. As a result, no clear picture emerges as to the nature of host perspectives that can lead to transformation of selves and ‘others’. This chapter, by utilizing the analytic authoethnographic approach, seeks to explain that host experiences are as much the other side of the coin as tourist experiences, and that a better insight is gained by looking at this relationship anthropologically, without minimizing the economic aspect. This can be done by utilizing an economic anthropology approach that complements and enhances Marxian theory.

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