FOREWORD

The purpose of the symposium is to stimulate co-operation in the practical application of meteorological information to potato cultivation, to improve potato production and quality, decrease the damage due to pest and diseases and increase the economic benefits of potato growing.

Clearly, the formulation and application of such practical knowledge is an interdisciplinary activity, that can result in major economic benefits.

I am therefore very pleased that the organization of the symposium and the publication of these proceedings is the result of an effective interdisciplinary co-operation between the Royal Netherlands Meteorological Institute (KNMI), the International Centre for the Potato (CIP), the International Society for Horticultural Science (ISHS), the European Association for Potato Research (EAPR) and the World Meteorological Organization (WMO).

I wish to thank the Government of the Netherlands and the Director and staff of the KNMI for hosting the symposium and for the excellent facilities provided to 90 participants from 45 countries. I acknowledge with gratitude the major contribution by the Director and staff of CIP and am confident that it will be followed up by co-operative activities between CIP staff and national Meteorological Services. I wish to express my great appreciation to the Secretary-General of the ISHS and his staff, and to Professor C.J. Stigter, vice-president of CAgM, for having participated in the editing and publication of these proceedings. I sincerely hope that the proceedings will help to disseminate the available information on the methods and benefits of application of meteorological information to improve potato production in the temperate, sub-tropical and tropical zone countries and thus help to eliminate hunger in many parts of the world.

G.O.P. Obasi
Secretary-General


OPENING SPEECH

R.H. Sawyer
Director, C.I.P.

Symposuim on the Agrometeorology of the Potato Crop

I would like to thank the World Meteorological Organization for sponsoring this symposium. The fact that this symposium is being held indicates a recognition of the increasing importance of potatoes by international organizations which have concentrated mainly on cereals up until now.

Potatoes deserve this increasing attention. Potato production in the developing world is increasing faster than any other major food crop and as countries reach self-sufficiency with cereals and look for diversification, potatoes become a principal alternative.

So where does agrometeorological data fit into the picture? What can a meeting such asa this accomplish? First and most important is a sharing of information on where potatoes are presently being grown successfully around the world, the climates to which potatoes can successfully be adapted. Second, the information will correct the statistics going into the models that international organizations are using to give advice to their clients. Third, we will be correcting a false impression that the potatoes are only a cool climate crop. Let us face the facts, that the potato comes from the tropics, and has been adapted to cool Northern latitude climates utilizing only a small portion of the genetic variability available. Countries across the developing world with both highland and lowland climates are now exploiting the genetic potential previously untapped and putting the potato into the warm tropical climates.

A look at where potatoes are presently being grown will clearly show the potato to be more flexible to a wide variety of climates than any other major plant food, and we have only started to utilize, to tap the genetic variability. Over half of the production of potatoes in the developing world today is in warm climates where more than one crop can be produced annually in the same field or soil, and thus we must think of the potato in terms of the annual farming system for the maximum use of sun, soil and water to produce calories and well balanced protein. We must stop talking simply about production per cropping season, an attitude coming from the North or South latitudes where there is only one crop per year which is seasonal. We must talk about production per unit of space per day or production per unit space per year. For example, some of the potato varieties which give modest yields and mature in 60 to 70 days in tropical climates, may be far more efficient than Northern latitude climates where yields are higher but 120 days are required for maturity.

Some of the new approaches to potato production, particularly new approaches to planting materials such as use opf true seed and rapid multiplication methods are specifically pertinent to certain climates where tuber seed has been a major limiting factor up until now. We heve yet to learn the climatic limitations for these new techniques in potato production.

May thanks to all of you attending this symposium for the help you are giving to the development of a new type of knowledge base about the climates where potatoes can be grown succesfully. We must remamber that in large parts of the world, the potato is very new crop almost 200 years behind what has taken place in Europe and North America. Up to date knowledge of agrometeorology of the potato crop today will be most helpful to all of us trying to fit this highly nutritious crop into the food systems of the developing world.


CONCLUSIONS AND RECOMMENDATIONS

C.J. Stigler
Vice-President, Commission for Agricultural Meteorology
World Meteorological Organization

D.A. Rijks
Chief, Agrometeorological Division, World Climate Programme
World Meteorological Organization

In the opening session the necissity of diversification of agricultural production was mentioned in a strong plea for increasing potato growing in the tropics whereas the concept that the potato is only a cool season crop was argued to be not valid. THe truth of these two points became very clear during the symposium. To achieve such diversification and increase potato growing outside areas where it has been cultivated up to now, an improved excahnge of information was considered essential. Therefore, the first part of the conclusions is a summary of the discussions on improving the flow of information. The remainder of the comclusions and recommendations of this symposium have been grouped in an order that follows the objectives stated at the beginning of the conference.

THE "STREAMS OF INFORMATION"

It has become evident that one should distinguished the specific target groups to whom agrometeorological information should be directed, in both temperate areas and the tropics. Table 1 shows these divesified information streams schemtically. The first distinction to make is between researchers, advisory and extension services, and farmers. Within these categories, one has to distinguish between those working in temperate zones and those working in the tropics and, within each of these zones, between the large commercial farmers in need of more advanced information and smaller farmers. This division is approximate because a spectrum of different farmer groups exists in almost every society, however, this symposium is not the place for identification of a finely detailed diversification of target groups. A distinction should also be made within groups of farmers. In the matrix that thus comes into existence, the different agrometeorological information streams from and to Meteorological Institute and Services (MI), may be drawn (Table 1). For all these streams the quality of information depends on:

• the quality of operational meteorological services, existence of an agrometeorological unit, specializations within this unit, and facilities put at their disposal,
• the quality of the agricultural research institutes, specializations of their staff, existence of application-oriented units and facilities put at their disposal,
• the quality of the advisory and extension services, specializations of the staff and their knowledge of existing farming systems and relevannt modifications, and facilities put at their disposal,
• the quality of communication between farmers and existing services and degree of farmers' participation in implementation and validation of research. These in turn depend on the farmers' socio-economic and educational situation and on the degree to which information strategies are adapted to each of the target groups.

The conclusion and recommendation related to each of these streams are:

INFORMATION STREAMS: MI ---(R1 + R2)

CONCLUSIONS

Information on driving variables of models

It appears' that the main bottlenecks are the non-availability of near real-time routine data and of some derived data, in a sustainable form. It was suggested that in some cases researchers could collaborate by making routine measurements at their own sites. From available routine data. Collaboration between meteorologists and agronomists to indentify needs and to increase the potential to meet these needs is most important, both for planning strategy models and for decisions on day-to-day operations. Research to reduce the gaps between potential and actual yeilds still appears the most effective means to provide results rapidly, nevertheless, there is also a need for research to increase potential yeild..

RECOMENDATION

• the symposium recommends that close contacts between research people and organizations providing meteorological information should be stablished to: (a) make available the required data, precisely defined for each pourpuse by the research community, in near real-time, at least in a provisional form, (b) allow identification of suitable measuring methods of the data required and tests of these methods in joint validation projects.

INFORMATION STREAMS : MI —- R3

CONCLUSIONS

Available information to derive suitable approaches and models

Little knowledge appears to be available for modelling that fits the specific conditions of the tropics. A number of constraints has been identified, among which are: lack of weather forecasts, lack of communication, lack of near real-time weather data, lack of research data on climate and ecophysiology of the potato in general and of deferred time weather data relevant to potato/climate research in particular. There is a need for: good, simple, tested, predictive models, seasonal weather data bases appropriate for models; and data on seasonal ground-water reserves. All these data are required on the macroscale. On the microscale, there is a great need for field data of the warm tropical environment.

RECOMMENDATION

• the symposium recommends that much attention and support be given to training and equipping staff of research organizations and of agrometeorological services to enable them to acquire knowledge and, subsequently, develop models on weather and commercial potato growing in the tropics and to make available the data necessary to calibrate and validate such models.

INFORMATION STREAMS: MI —- R4

CONCLUSIONS

Weather advisories

In addition to the constraints mentioned above with respect to research for larger farmers, constraints for the research oriented to help small low external input farmers in the tropics are the lack of resources and the lack of flexibility of production conditions available to those farmers to implement the results of such research. It was argued that in marginal situations - be they socio-economic and/or climatic - models are not the approach that is most likely to yield the information needed for management decisions. In these cases production advisories on the use or modification of the microclimate (mulching, shading, surface modification) will be more successful and these will have to be developed in tune with the existing farming systems.

RECOMMENDATION

• the symposium recommends that increased attention and support be given to training and equipping staff of research organizations and agrometeorological services to enable them to develop, test and validate, in farmers' fields and conditions, weather advisories for low external input farming in which the potato is used as a component.

INFORMATION STREAMS: (MI + R1/R2) —- (AE1 + AE2)

CONCLUSIONS

Special services

There is a need for the establishment or strengthening of specialized advisory services, for example, the forecasting of blight. Two trends were distinguished: the present semi-empirical systems seem to develop into more complicated ones using knowledge from crop growth and crop environment generation models; the use of network station observations and basic parameters seems to be replaced by measurement of weather parameters close to or in some cases within the crop, using automatic weather stations and other adapted equipment. Forecasts to the farmers will increasingly be transmitted using improved regionally adapted radio advisories and operational hardware offered by the information sciences. The consequences of these trends should be taken into account by such special services.

RECOMMENDATION

• the symposium recommends that special services should be established or strengthened in which meteorologists, agronomists, plant pathologists and others collaborate, and which deal with validating and operating farmer-friendly forecasting and warning systems for economically important diseases and other economically important aspects of potato growing.

INFORMATION STREAMS: (MI + R3/R4) —- (AE3 + AE4) —- (F3 + F4)

CONCLUSIONS

The main conclusion was that these information streams are virtually non-existent or at best slowly developing

The reasons are the constraints already mentioned with respect to the information streams from and to researchers working for these groups in the tropics and the known problems in the development and functioning of agricultural extension services in the tropics. A few examples were given to justify the conclusion that such information streams, if fully developed, could lead to advisories that can increase yields obtained under farmers' conditions. With respect to post-harvest potato storage, in the context of the knowledge on supply and demand patterns, adaptive research on multi-purpose farm buildings appears to be lacking almost completely. Such research is much needed especially to apply appropriate, location-specific technology for relatively small scale storage instead of transferring unadapted technology.

RECOMMENDATIONS

• the symposium recommends that great attention and support be given to equipping and training staff of advisory and extension services to enable them to be an effective intermediary between researchers and small farmers;
• the symposium recommends that agrometeorologists take part in a broad systems approach with respect to potato growing in the tropics, to see potato storage and post-harvest losses in the appropriate context of the farming system of which they are part. Production should be measured not simply in tons/na of potatoes only but in terms of quantity and quality of all food produced and supplied to the consumer, and taking all cost aspects into account.

INFORMATION STREAMS: (MI + AE1/AE2) —- (F1 + F2)

CONCLUSIONS

Direct computerized and other weather information

It was indicated that services have come into existence, often still in an experimental form, that provide detailed basic and derived information directly to selected larger farmers. A better agreement should be developed between such information and the actual planning strategies and operational decisions of the farmers concerned. There is a comparable need of smaller farmers for information geared to their specific conditions. However, they have fewer financial means to obtain that information, including hardware, and meteorological services will have to play a larger role in satisfying the needs of these target groups.

RECOMMENDATION

• the symposium recommends that national meteorological services, together with agricultural services and other governmental and private advisory bodies, (a) identify the information and production advisories with a meteorological component required by large and by small farmers, and (b) develop ways to supply this information in a timely manner for each technical and economic application identified.

CONCLUSIONS RELATING TO THE DEFINITION OF INFORMATION REQUIREMENTS

1. It was noted and clearly illustrated that appreciable differences exist between maps of areas estimated to be suitable for potato growing and those of areas in which the potato is known to be actually grown. Apparently both the potato and the farmer do better than was thought and it is recommended that the criteria used in the mapping of suitable areas be adapted, and that climatic conditions that lead to successful cultivation of the potato be derived from, maps indicating the areas where potatoes are actually grown.
2. The description of successful climatic conditions should include a description of the onset of the season and the required length of season. It should specify conditions of temperature, humidity and water balance, and their upper and lower limits for effective growth and development and for resistance to various diseases. Determination of the upper, lower and optimum values can help in the formulation of models; this formulation requires a multi-disciplinary approach. The description should include the influence of climatic conditions on fertilizer and water up-take. It should include a description of the weather factors that produce maximum yield.
3. Information is required on the frequency of hail and its impact on growth. Also required is information on the frequency and timing of drought, as it reduces yield when it occurs early in the season, and as it reduces quality when it occurs late in the season. A description of the risks of flooding and lodging is required.
4. The potato physiologists are requested to describe the threshold values for heat-, frost-, drought- and salinity-tolerance, whereupon climatologists can describe the frequency of occurrence of such conditions in different regions.
5. A study is required to elucidate the influence of temperature on production characteristics of the potato.
6. Plant pathologists were asked to specify the lower, optimum and upper values of temperature, humidity, rainfall and duration of leaf wetness for the occurrence of the major diseases of the potato in any one region. Upon receipt of this information, climatologists can asses the risk for such diseases in any given area, and meteorologists can issue real-time warnings prior to their occurrence.
7. No special demands were made for agrometeorological information by plant breeders, other than those relating to the study of genotype/environment interaction. It seems that potato breeders are satisfied with the information they are able to obtain from meteorological institutes and services, perhaps because in breeding research mostly climatic data are required. It also has been pointed out that research on microclimate manipulation should be done in conjunction with, and in addition to, attempts to increase resistance and tolerance to environmental extremes through breeding. Such breeding and the avoidance of such extremes through microclimate modification both have their limits.

   CONCLUSIONS ON THE CHOICE, TEST AND ADAPTATION OF METHODS TO PROVIDE INFORMATION

8. Any methods used should relate to the farming system as a whole and not only to potato growing. They should in particular pay attention to the practice of inter-cropping.
9. Particular attention should be paid to microclimate management and the influence of operations such as mulching and shading on the temperature regimes in and near the soil. Microclimate management can enhance the value of drought resistant varieties and improve root penetration and optimal exploitation of soil-water resources.
10. It was suggested that a summary should be made of methods that use weather information to determine:
    1. production characteristics and yield of poratoes;
    2. optimum sowing dates for rain-grown potatoes;
    3. the water relations of rain-grown potatoes;
    4. the nature of water deficits and their probable time of occurrence during the season;
    5. irrigation scheduling.
11. Standardized methods should be developed to describe the optimum weather requirements of varieties throughout the season. It was suggested that a summary should be made of methods using weather information to predict the development of major pests and diseases and insect movement so that more use could be made of such methods for pest and disease control.
12. The discussion on constraints in modelling was mostly concerned with availability of data. Two essential points were made: first, it was illustrated that models are often more successful in simulating yield differences or differences in environmental conditions than absolute yields or actual conditions, which is useful information in planning and scheduling of agricultural operations; second, warnings have been given with respect to the level of sophistication of models advocated for operational use; they should not aim at a level which requires inputs that are too difficult to obtain or imply too much risk for the users of such models. Simple operational models are indeed required for which the level of sophistication does not form an internal constraint.
13. Modellers were asked to develop two types of models that use weather information to forecast yields:
    1. simple but tested production models, where empirical parameters can be calibrated for site and season, and
    2. sophisticated models which in principle would work everywhere and would reflect the effect of changes in weather on final yield. It was realized that results from sophisticated models might not easily be transferable because of ignorance on associated questions.

    CONCLUSIONS RELATING TO DATA COLLECTION

    Instrumentation for measuring environmental parameters.

14. Radiation equipment was discussed in detail. The possibility of estimating radiation from sunshine duration and cloudiness was mentioned. Some ideas on measuring leaf wetness were presented. Other areas associated with the most important parameters in potato growing were identified, namely: soil moisture conditions, temperature in the topoclimate (soil and air) and, especially with respect to diseases, relative humidity and wind. It was proposed that the possibility to estimate soil temperature from air temperature be further tested.
15. The availability on the market of automatic stations was mentioned and it was suggested that such automatic stations might be equipped with programmes for calculating the possible incidence of major pests and diseases.
16. It was suggested that a conclusion on appropriate equipment should have been formulated but not much information was presented to permit the formulation of such a conclusion. During discussions, doubt was expressed whether researchers from different countries would be able to agree on the identification of suitable measuring equipment. It appears that research on appropriate equipment for use in the tropics is stagnating.
17. The meeting agreed that often no separate data collection network would have to be established but that a great deal of data could be collected through co-operative work with existing networks. It might be useful to continue to provide training in data collection methods, The establishment of interagency data banks was supported.

    CONCLUSIONS ON THE PROVISION OF INFORMATION

18. There was general agreement that the practical implementation of the provision of information should be an interdisciplinary effort, using models when appropriate. Information on recent weather and weather forecasts may be used to produce forecasts for pest and disease development, for fertilizer requirements and for growth, development and yield of the potato. Information on microclimate modification practises may be used to guide farmers in effecting microclimate improvements. The assessment of the economic value of such information would have to be undertaken separately in each country.
19. It was suggested that a list should be made of all organizations and persons providing operational information.
20. It was suggested that an agrometeorological information stream towards planners and policy makers could have been identified. This group would need social and economic rather than technical information. However, nowhere in the papers or discussions was such information elaborated. Nevertheless, this target group is important because the means put at the disposal of meteorological services and institutes, researchers and extension services are allocated by them to a large extent. It may be concluded that the successful use of jointly validated information by the other target groups should demonstrate the economic benefits of agrometeorological information, and thus provide the necessary public relations material to planners and policy makers.

    CONCLUSION ON THE DISSEMINATION OF INFORMATION

21. It was noted that the information disseminating technology varied with countries: extension services, radio broadcasts, telephone answering services, computer interrogation services, and the written press. For the choice of information technology, the required form and frequency of information, which are quite different in temperate and tropical countries, should be taken into account.

    CONCLUSION ON THE ASSESSMENT OF TECHNICAL AND ECONOMIC BENEFITS

22. Little information on this subject was presented at the symposium. It was suggested that CIP and WMO should consult about methods to collect and publish such information.

On behalf of proffesor G.O.P. Obasi, the Secretary-General of WMO, I wish to extend a warm welcome to all of you at this joint symposium on the agrometeology of the potato crop. The origin of this workshop lies in the desire of colleagues in agrometeorology and agriculture, especially in the countries of Europe and the near east, to make wider and better use of meteological information to reduce the costs and risks of potato growing, improve the quality and yield and avoid, in so far possible, agricultural pollution.

The goals of this workshop are:

• to define more precisely the meteorological information that is needed in the planning and day-to-day operations in all aspects of potato growing;
• to select and adapt techniques and methods to furnish such information;
• to define the data required, the instruments for measurements and the adta collection procedure that will permit routine delivery of such information;
• to establish procedures for the dissemination of such information;
• to evaluate the technical and economic value of the information;

Achieving these goals will require close inter-disciplinary cooperation. I am particularly pleased that such co-operation has already been initiated as witnessed by the activities of the cosponsors of this symposium: the International Potato Center; the International Soceity for Horticultural Science (ISHS); the European Association for Potato Research (EAPR); the Royal Netherlands Meteorological Institute (KNMI); and the World Meteorological Organization, also represented here by Mr. C. Stigter, vice president of the WMO Commission for Agricultural Meteorology.

I sincerely hope that the decisions, conclusions and recommendations of this symposium will reflect the present knowledge on the contributions of agrometeorological information in potato growing and provide an outlook on the future needs for additional information.

On behalf of professor Obasi, I wich to thank the government of the Netherlands for having offered to host this symposium, and Mr. H.M. Fijnaut, director of the Royal Netherlands Meteorological Service, for his enthousiastic and generous support, which permits us to meet here today. I wish thank the cosponsors for their contributions towards the organization of this symposium. A special word of thanks goes to Messrs. Kamp and Lablans of the KNMI, Messrs. Van der Borg and Van Bommel of ISHS and Mr. Van der Zaag of EAPS and the manager and staff of the International Agricultural Center for their contributions of the technical and practical preparations for this meeting and for the excursion on Saturday.

I wish you success in the meeting and a pleasant stay in Wageningen.


D. Rijks
World Meteorological Organization.