XXVl International Symposium on Crop Protection

Abstract

The millet head worm, the larval stage of the Noctuidae moth Raghuva albipunctella has become the most serious pest of millet in the Sudan. The adults emerge seven weeks after the first effective rainstorm of over 30 mm, which coincides with the heading of most millet varieties. The female lays eggs on newly emerged millet heads. Larvae enter the head and mine within the head, eating the bases of the flowers pushing up the severed florets in a characteristic spiral trace. Long‐maturing varieties and delayed planting are both effective in reducing the incidence of infestation but are impractical in the environmental conditions in Western Sudan. Varietal tolerance has been identified and should be used as one aspect of control. Synthetic pyrethroids reduce incidence but do not significantly increase yield. The use of triple superphosphate fertilizer increases yield and reduces the incidence of the head worm by reducing the time interval from planting to heading and resulting in the emergence of the main heads prior to the emergence of the pest.     

The First Caribbean Plant Protection Symposium 1974

Abstract

A graticule for the determination of spray droplet size is described.     

Technological Economics of Crop Protection and Pest Control

Abstract

THE SCIENTIFIC PRINCIPLES OF CROP PROTECTION. Dr Hubert Martin. Edward Arnold (Publishers) Ltd, London, 1973. ISBN 07131 2382 6. pp. viii + 423. Price £12.00.

APHID TECHNOLOGY. Edited by H. F. van Emden. Academic Press, London and New York, 1972. ISBN 0 12 714150 2, pp. xiv + 344. Price £6.00.

BIBLIOGRAPHY OF THE APHIDIDAE OF THE WORLD. Clyde F. Smith Technical Bulletin No. 216 North Carolina Agricultural Experiment Station, 1972. pp. 717. Price not given.

THE AUSTRALIAN SELECTIVE WEED CONTROL HANDBOOK 1973. J. T. Swarbrick. Herbicide Recommendations, 3A Ipswich Street, Toowoomba 4350, Australia, pp. 203. Price not given.

GUIDE TO HAND-OPERATED AND ANIMAL-DRAWN EQUIPMENT. Intermediate Technology Development Group, London. pp. 84. Price £1.50.

NITROGEN FERTILIZATION AND MANAGEMENT IN TROPICAL RICE. P. A. Sanchez. North Carolina Agricultural Experiment Station Technical Bulletin No. 213, 1972. pp. 31.

TROPICAL PEST BULLETIN No 2. Analytical method for assessing yield losses caused by pests on cereal crops with and without pesticides. E. Judenko. The Centre for Overseas Pest Research, College House, Wrights Lane, London W8 5SJ, 1973. ISBN 0 85135 061 5. Price 40p. pp. 31     

Systems Analysis Applied to Crop Protection1)

This paper reviews the biological problem of crop protection from a systems analysis point of view, and discusses the commonalities in the biological and mathematical form of the population models used to describe the interactions between trophic levels (e.g. herbivore–plant). The historical development of the mathematical models is presented. The uses of these models in crop production are discussed.     

A Backstage Look at Crop Protection and Environmental Quality

Abstract

A list of weeds and their maximum intensity of infestation observed in agricultural areas in the southwestern Arabian Peninsula is presented.     

The Role of Forecasting in Crop Protection Decision Making: an Economic Viewpoint1

In making crop protection decisions, farmers have to answer two questions: what type of control measure(s) should I adopt? How should I apply this (these) measure (s), when, how frequently, etc.? The answer to these questions will depend upon: a) the dimensions of pest attack and the damage it causes, b) farmers' goals, c) the range of protection measures available to them which they can use, and d) the information available, in the form of monitored and forecast information. It is within this context that the role of forecasting is considered. An analysis is made of the possible impact that forecast infomation can have on farmer decision-making, particularly with regard to the accuracy of the forecast and the time at which it is available. This leads on to the problem of assessing the value of a forecast at a regional level, against which the costs of providing such information can be set. Finally, situations in which forecast information is likely to be of greatest value (and of least value) are identified, and implications are drawn concerning the institutional and other changes that could be taken to allow better use to be made of forecast information. Lorsque les agriculteurs decident de proteger leurs cultures, ils doivent repondre aux deux questions suivantes: quel est le mode d'intervention a choisir et comment, quand et a frequence faut-il intervenir. La reponse dependra notamment: de I'etendue de I'infestation et de L'importance des deglts; des buts que s'est assignes L'arboriculteur; de la gamme de methodes dont il dispose; des previsions qui lui sont fournies. La prevision est condideree dans ce cadre, puisqu'elle est susceptible d'infuler sur les decisions de L'agriculteur dans la mesure ou elle est etablie avec precision et au bon moment. I1 est donc utile d'evaluer L'inter6t economique d'une prevision regionale en faisant intervenir le cofit de celle-ci. Enfin, il est fait etat de situations dans lesquelles la prevision est profitable ou non. Suivant les cas, certaines modifications structurelles peuvent s'imposer afin de mieux tirer benefice des previsions.     

A Data Bank on Crop Losses: First Experiences1)

The third of a series of Agro–ecological Atlases on Cereal Growing in Europe, published under the auspices of the European Cereal Atlas Foundation, will deal with pests and diseases of cereals. Information was collected and stored in a data bank before processing. Data processing leads to two kinds of outputs: 1. Loss maps of Europe show the mean annual loss due to each cereal pest and disease by means of isoloss curves; 2. Risk maps of Europe for selected pests and diseases show the relative risk incurred by the cereal crop in each climatic area as determined by the climate of that area, areas with equal risk being separated by isorisk curves.