29 soybean varieties were grown to raise seeds which were assessed for storability and viability. Emergence test involved pre-storage, 3 accelerating aging stresses (methanol, ethanol, hot water) and storage under ambient conditions (post-storage test) for 5-7 months. Varieties 342-356 D performed well under accelerating aging stress and in ambient storage tests, and 713-09D showed promising performance. The varieties showed resistance to the purple stained disease but showed reduction in viability with storage. Methanol stress was more effective than ethanol and hot water

Factors influencing post harvest losses and final product quality are discussed:- selection of suitable varieties based on agronomic and physicochemical factors; environmental conditions; time and method of harvesting and proper in-field packaging and control of disease in storage.

Factors influencing post harvest losses and final product quality are discussed:- selection of suitable varieties based on agronomic and physicochemical factors; environmental conditions; time and method of harvesting and proper in-field packaging and control of disease in storage

The international germplasm exchange for tuber crops is hampered by the risks of introducing, through vegetative materials, diseases and pests to noninfected areas. Since tuber crops are vegetatively propagated, their conservation as germplasm is also a problem. At IITA, we have used meristem culture to eliminate disease in tuber crops: disease-free plants can be distributed in vitro to requesting national programs. Disease-free sweet potato has been distributed to more than 40 countries throughout the world, and cassava to over 30 countries in Africa. Minimal growth storage is used at IITA to conserve germplasm of sweet potato and yams. Over 600 clones of sweet potato germplasm are held in vitro. Arrangements for in vitro tuber crops germplasm exchange are described

This publication contains the proceedings of an international symposium on wheat production and research in tropical environments, held in Mexico on 24-28 September, 1984. In addition to the 43 contributed papers, it includes 16 country reports describing the situation on wheat production in Northeast Argentina, subtropical areas of Bolivia, Costa Rica, Ecuador, subtropical areas of Mexico, Nigeria, Bangladesh, the hotter parts of India, Pakistan, the Southern region of China, Indonesia, Philippines, Thailand, and the subtropics of Australia. The contributed papers discuss wheat breeding; disease and disease control; agronomic practices and management; seed production, storage, and distribution; and socioeconomic and agroeconomic implications of growing wheat in tropical or subtropical environments.

This publication contains the proceedings of an international symposium on wheat production and research in tropical environments, held in Mexico on 24-28 September, 1984. In addition to the 43 contributed papers, it includes 16 country reports describing the situation on wheat production in Northeast Argentina, subtropical areas of Bolivia, Costa Rica, Ecuador, subtropical areas of Mexico, Nigeria, Bangladesh, the hotter parts of India, Pakistan, the Southern region of China, Indonesia, Philippines, Thailand, and the subtropics of Australia. The contributed papers discuss wheat breeding; disease and disease control; agronomic practices and management; seed production, storage, and distribution; and socioeconomic and agroeconomic implications of growing wheat in tropical or subtropical environments

Short-term and long-term methods of storing in vitro cultures exist. The short-term methods are most effective for shoot cultures, the long-term for cell suspensions. Effective storage techniques for the other culture systems, however, are not available. Germplasm can be exchanged internationally as shoot cultures; such exchange requieres phytosanitary procedures. Other aspects of in vitro conservation, including acquisition, disease indexing, genetic stability, and chracterization, must be developed. The International Board for Plant Genetic Resources (IBPGR) has established an Advisory Committee on In Vitro Storage, reviewed in vitro conservation techniques, and recommended increased attention to crops other than model systems and to specific methods. IBPGR has also initiated major research into priority crops and key techniques, and is coordinating a worldwide survey and information service on in vitro conservation

Artificial inoculation of potato stems or tubers with Corynebacterium sepedonicum and Erwinia carotovora var. atroseptica resulted in more severe infection than inoculation by either alone. Some plants raised from tubers inoculated by both pathogens showed conspicuous stunting. The development of mixed disease symptoms during vegetative growth, the daughter tubers with latent infection, and tuber rot during storage were influenced by the relative ratio of one organism to other, the subsequence of inoculation, and intervals between first and second inoculations. In mixed inoculation tests, severe disease symptoms appeared more conspicuous for the pathogen which was instantly mixed and inoculated in high ratio, or when this pathogen was first inoculated alone then followed by the other pathogen after different intervals.

Results revealed that at 4 gr a.i. and 2 gr a.i. per liter water was effective against the disease. It remained highly effective even when the treated planting materials were stored at room temperature up to 6 days before planting. Beyond 6 days, however, a decreasing trend of the control effects was observed but it still provided more than 50% control of the disease even up to 10 days storage. The data also showed that as a result of the heart-rot control, Alliette treated plants showed remarkable improvement of root and top growth. Generally, higher percentage increase in growth was obtained in plants treated with the fungicide and stored for 3-4 days prior to planting