Outlook on Agriculture

Since Henry Power in 1663 successfully revived eelworms which had been frozen in vinegar for a few hours, there has been much interest in cryopreservation. As liquid nitrogen and other cooling agents became more widely available a standard method involving a single cooling rate for the cryopreservation of fungi was proposed by Hwang in 1960. This method was used until the early 1980s, but an increasing number of recalcitrant strains were found. Research at the time was empirical and based on attempts to find the universal cryoprotectant which would protect all fungi irrespective of the cooling rate. The real need was to go back to basics and study the response of the living cell to freezing and thawing. The use of cryogenic light microscopy to study fungi provided a major breakthrough, and showed that cooling rates which cause shrinkage or ice formation should be avoided. Further work is required particularly on membrane structure and the mechanism by which intracellular ice causes injury, as well as the effects of the age of the culture, hyphal structure and growth requirements. Cryopreservation is the only method of preservation which will store fungi and other cells for extremely long periods of time without detectable genetic or morphological change.

Beekeepers produce honey and wax, but the most Important aspect of beekeeping is the pollination of crops. Beekeeping with the western honeybee is threatened by the ectoparasite Varroa jacobsoni. which was first found on the eastern honeybee. If they are to provide the required number of colonies for pollination, and to produce honey and wax, beekeepers must be able to control the Varroa mite in their colonies. Without annual chemical treatments the colonies become heavily damaged and will eventually die, but using chemicals leads to residues in the honeybee products. Knowledge of the biology of the Varroa mite and its relationship with the honeybee colony now makes it possible to control the mite using biotechnical methods rather than chemicals. All such control treatments involve changes in colony management and Increased running costs, and therefore put up the prices of the products. The latest approach to the problem is selection of Varroa-tolerant honeybee strains.

It is cereals that are relied on to meet the food needs of the majority of the world's people. And for very good reasons: they are relatively easy to grow and harvest, and convenient to handle, store and cook. They also have high nutritional values. The development and spread of high-yielding wheat, rice and maize varieties in the 1960s and 70s — at a time when prospects of widespread famine loomed large in the minds of policymakers — increased the importance of cereals. It also postponed by about half a century the threat of the Malthusian catastrophe. But to what extent can we continue to hope for increases in cereal yields to help meet the increasing food demand of our spiralling population, especially when we seem to be running out of additional land to bring under cultivation? Perhaps instead of continuing to put all our eggs in one basket, we should consider examining the role of other food crops as well. In South Asia, potato appears to be a promising crop to consider. It yields 2–3 times more than cereals, and also provides more energy and protein per hectare.

Alley farming was developed as a means of maintaining soil fertility in fields under permanent cultivation in Africa, as population pressure makes the traditional practice of slash-and-burn combined with fallowing unsustainable. It is an agroforestry system under which food crops are grown in alleys formed by hedgerows of leguminous trees and shrubs. Studies have shown that it works, but farmers are only taking it up very slowly. Recent work suggests that land tenure might be a factor in the spread of alley cropping.

Maize is a major food crop in southern and eastern Africa. It is widely grown by smallholders, and forms an important part of the transformation of smallholder agricultural systems that has taken place this century. But, despite commendable efforts in technology development at both the national and the international level, agricultural productivity is well below that necessary to help create strong, healthy African economies. No single solution is likely to be found for this problem. In this paper, two major possible foci are outlined. First, there is a need to match advances in crop improvement (through breeding) with developments in crop management. Second, and directly associated with the search for improved crop management methods, a concerted effort, involving public and private agricultural service agencies, as well as local farmer groups, NGOs, and other rural associations, is needed so that priorities are set correctly, that the right questions are asked, and that the solutions found are delivered quickly to those who need them.

Cassava makes an important contribution to improving food security and rural incomes in sub-Saharan Africa, as it is tolerant of drought and poor soil and its cultivation does not require much labour. However, the fresh roots are bulky and perishable and need to be processed before they can be marketed; processing also removes the cyanogens which make many varieties poisonous in their raw form. Cassava roots are turned into granules, flours, pastes and chips, with a wide range of flavours and appearances for different areas and markets. Many different processing techniques are used, some of which make intensive use of fuelwood while others require a plentiful water supply. These requirements, as well as the need for a good transport and marketing infrastructure, limit the expansion of cassava production in sub-Saharan Africa, but technical solutions are being found.

The big gap between the production and consumption of edible oil in India is met by imports of more than a million tonnes annually, which have become a heavy drain on the country's slender foreign exchange resources. It is an urgent necessity to augment edible oil production, without prejudice to the cultivation of other agriculturally important crops. The olive offers an edible oil very much valued in the world market, and efforts to introduce its cultivation are desirable. The special properties of this oil and the soil and climatic conditions required for olive cultivation are described and the possibilities are discussed for its introduction in the marginal lands of India, particularly Rajasthan and adjoining areas.

Nigeria is an agricultural country, most of the vegetable needs of its people being provided by small farmers who seldom use high-input technology. Over the last 20 years, there has been an encouraging upward trend in inorganic fertilizer consumption, but it is very difficult to estimate how much of this chemical fertilizer is used for vegetable production. There is a need for information which could be used to monitor national trends in fertilizer use on vegetables so that the government can predict future needs and advise manufacturing industry and farmers accordingly. Although increases in the yield and mineral content of vegetables through the use of chemical fertilizers have been recorded, several problems still preclude their use. Possible ways to overcome the problem and benefit vegetable growers are discussed.