This study determined the adoption level of 11 soil management practices and the factors which affected them in Ikorodu Local Government Area of Lagos State of Nigeria. A sample of 160 farmers was obtained by stratified random sampling from 8 villages in the Ikorodu area. Data were collected by use of questionnaire and field observations.
It was found that farmers' knowledge of the innovations made maximum contribution towards adoption with positive regression coefficient. Contact with extension agents made negative significant contribution to adoption of the 11 soil management techniques listed in Table 4. The reason for this surprising result is that village extension workers concentrated on other aspects of crop production and neglected detailed information dissemination on soil fertility management. Other findings are: (1) the combined application of organic and inorganic fertilizers in the same soil recorded lowest adoption score of 0.51; (2) there was a positive relationship between cosmopoliteness and farmers' knowledge of the practices; (3) a positive significant relationship between farmers' leadership status and knowledge of the practices was found.
The average adoption score was 3.1 (31%) . The average age of farmers was 38 years; they had poor education level and average farm size was 2.4 ha. The study concluded that adoption level of the innovations and the condition of soil fertility in Ikorodu villages depend on agricultural extension services and the extent to which farmers' characteristics permit the acceptance of new soil management techniques. It was suggested that extension workers should be trained on soil management innovations regularly; and community awareness programme on the innovations should be promoted through the use of television and radio broadcasts to the rural farmers.

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This experiment was conducted to study varietal differences in dry matter increment (W) and water use efficiency (WUE) using eight chilli pepper cultivars under greenhouse condition. Treatments were daily irrigation levels of 100% (Control: C) and 40 to 50% (Dry: D) of the daily evapotranspiration (ET) of the control. Significant varietal differences in W and WUE were observed. The coefficients of variation were ranged from 21.4% (C) to 31.5% (D) for W, and from 17.9% (C) to 31.5% (D) for WUE. A greater varietal difference in the water stress treatment than in the control was observed for both W and WUE. There was a significantly positive correlation between W and WUE, and also a closely positive correlation was noted between WUE and the net assimilation rate (NAR) . These results suggested that the varietal difference in W was strongly controlled by NAR through WUE regardless of the presence of water stress. The cultivar with a higher NAR also displayed a higher WUE and a greater W. NAR showed a closely positive correlation with evapotranspiration per mean leaf area (ET/LA) in the control, but it didn't showed a significant correlation in the water stress treatment. However the results of multiple regression analysis showed that NAR in the water stress treatment was controlled by both ET/LA and the mean dry weight of non-photosynthetic organs per mean leaf are (CW/LA), and the coefficient of multiple regression was signifi-cant. Ratio of standard partial regression coefficient, which indicates the ratio of contribution of ET/LA and CW/LA to NAR, was 60% for ET/LA and 40% for CW/LA. These results suggested that varietal difference in NAR was restricted by the photosynthetic rate in the absence of water stress, although it was controlled by the photosynthetic rate as well as by factors that were related to respiration in the case of water stress.

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Variation in sago palm in Thailand was studied based on zymograms of peroxidase, esterase, acid phosphatase and sorbitol dehydrogenase using polyacrylamide vertical slab gel electrophoresis (PAGE) and zymo-gram of esterase using disc gel isoelectric focusing (IEF) . Based on the zymograms of the five enzymes, isozyme variation among 6 individual sago palm plants from 15 populations each (90 in total) in southern Thailand were compared.
Difference among zymograms of enzymes within the respective populations was limited. Difference among zymograms of enzymes in 90 sago palm plants was also limited. Major isozyme banding pattern of each enzyme among the plants was observed based on major bands. Zymograms of peroxidase and esterase by PAGE were classified into one type of isozyme banding patterns, namely 100% of type 1. Zymograms of acid phosphatase, sorbital dehydrogenase by PAGE showed two and three types, mainly type 1 (87%) and type 1 (95%), respectively. Zymograms of esterase by IEF were classified into one type, namely 100% of type 1. It was also observed that 80% of the 90 sago palm plants showed the same combination of isozyme banding patterns, namely type 1 for peroxidase zymogram by PAGE, type 1 for esterase zymogram by PAGE, type 1 for acid phosphatase by PAGE, type 1 for sorbitol dehydrogenase zymogram by PAGE and type 1 for esterase zymogram by IEF.
The present results, showing a low isozyme variation among populations and growing regions, suggest that the genetic background of these sago palm plants is closely related to each other or the present sago individual plants may be derived from one ancestor or plants with very limited ancestry.
Zymograms among 10 palm species including sago palm were also compared. It was suggested that sago palm plants could be distinguished from the other palm species by the present zymogram techniques and the 10 palm species could also be distinguished from each other.

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For the improvement of water-use efficiency in tropical tree seedlings, we evaluated the application of two materials, a super-absorbent polymer (SAP), which increases the water-holding capacity of soil, and a plant growth retardant (PGR), which reduces the foliage size and transpiration rate.
When SAP or PGR was applied, the survival of the tree seedlings was extended. Simultaneous application of both materials enhanced this effect, which was ascribed to the increase of the water retentivity by SAP and the decrease of the transpiration rate associated with leaf area reduction by PGR respectively. In Acacia, the amount of daily water consumption decreased by the application of SAP or PGR, and water-use efficiency was improved. However in some species of trees, for example, in species with broad leaves and a high transpiration rate, such improvement was not always observed.
It is thus important to carry out furthèr studies to determine the application dose of PGR most suitable for the reduction of the transpiration rate and for the rapid recovery of growth retardation after transplanting.

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The factors that affect farmers' technology adoption in rice farming in Sri Lanka were examined by estimating the technology adoption function for land preparation, crop establishment, and weeding operations based on district level data. Wage rate in rice farming, farm size, technology transfer by migrant farmers, irrigation conditions, adoption rate of modern varieties, crop establishment method, temperature, and dummy variables for region, season and year were included in the analysis. The estimation revealed that, in spite of the remarkable regional diversity, either wage rate or farm size was a significant determinant in farmers' technology adoption, indicating that the farmers try to adopt ‘appropriate technology’consistent with the theory of induced technical change. Irrigation conditions, technology transfer, modern varieties, and crop establishment methods are the factors found to be significant in the technology adoption function for certain operations. Besides these factors, how-ever, dummy variables for some regions remained highly significant, implying that some important region specific factors remain to be identified.

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Starting with the release of Rayong 3 in Thailand in 1984, the CIAT-related cassava cultivars officially released by Asian national programs now total to twenty four. Besides these, there are a far greater number of clones pre-released and left to the farmers' adoption without official naming. In the early years, clones previously selected at CIAT tended to become officially released cultivars of national programs, but recently more cultivars are locally selected from the crosses made locally or at CIAT using local and CIAT cross parents. The countries of origin for the parentage of those cultivars include more than ten countries, mostly Latin American, testifying to the functioning of an international breeding network. Rayong 3, Rayong 60 and Adira 4 in Indonesia are estimated to be planted now in more than 50, 000 ha each and the total acreage planted with all these improved cultivars is estimated to have surpassed 300, 000 ha. The additional economic effects (harvested roots on farms alone) generated by the adoption of new cassava cultevars in Thailand, Indonesia, China and the Philippines in the years upto 1993 are estimated at 128 millon US dollars. This far outweighs the estimated cost of the CIAT cassavaa breeding program and the cassava breeding programs in these four countries in the past 20 years (11.3 and 5.5 millon US dollars respectively) . Through this process, the breeding programs in Thailand, China, Indonesia, Vietnam, Philippines and Malaysia have gained momentum. I conclude that, even with this largely neglected crop cassava, we are fulfilling the most important role of the international agricultue research organization (CGIAR), i. e., the improvement and utilization of crop germplasm in collaboration with national programs.

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