An empirical analysis of purchasing's strategic role in the firm is presented. This study uses data collected from high level purchasing executives at the Director/VP level representing a large cross industry sample of 739 firms. The data analysis is rigorous. Using data from 571 of the 739 firms, correlation analysis and exploratory factor analysis is performed. Data from the remaining 168 firms is used to conduct structural equation modeling. This is the first attempt to examine a structural model of strategic purchasing and its influence on supplier evaluation systems, buyer–supplier relationships, and firm's financial performance. Scales are developed to measure each construct and are shown to be reliable. Five hypothesized relationships are presented and supported by the literature. The first, second, and third hypotheses link strategic purchasing to supplier evaluation systems, buyer–supplier relationships and firm's financial performance, respectively. The fourth hypothesis links supplier evaluation systems to buyer–supplier relationships. And, the fifth hypothesis links buyer–supplier relationships to firm's financial performance. The results of the data analysis provide support for each of the five hypotheses above. The implications of this research are that a strategic purchasing function is important to the success of the firm. Firms that have a strategic purchasing function are more likely to implement a supplier evaluation system. This provides purchasing with a better understanding of which suppliers are performing well and which suppliers are not performing well. Increased emphasis on strategic purchasing and supplier evaluation systems are critical for firms seeking to establish long‐term relationships with their suppliers. Based on the findings of this study, strategically managed long‐term relationships with key suppliers can have a positive impact on the firm's financial performance.

Since the early 1980s, the diffusion of Just-In-Time (JIT) manufacturing from Japanese manufacturers to U.S. manufacturers has progressed at an accelerated rate. At this stage of the diffusion process, JIT implementations are more common and more advanced in large U.S. manufacturers than in small; consequently, U.S. businessmen's understanding of issues associated with JIT implementations in large manufacturers is more developed than that of small manufacturers. When small manufacturers represent about 96 percent of all U.S. manufacturers, investigation of JIT implementations in small, as well as large, manufacturers is warranted. This survey study investigates JIT implementation differences between small and large U.S. manufacturers. Ten management practices that constitute the JIT concept are used to examine implementation of JIT manufacturing systems. Odds ratio were constructed to determine if an association exists between implemented versus not implemented and manufacturer size for each JIT practice. Ten changes in performance attributed to JIT implementation are also assessed and examined in the study. Logistic regression models are used to examine the relationships between implementation status of each of the JIT practices and of each of the changes in performance in small and large manufacturers. The results of the study show that the frequencies of the 10 JIT management practices implemented differ between the two groups of manufacturer size, and an association exists between the JIT practices implemented and manufacturer size. Moreover, the changes in performance attributed to JIT implementation vary, depending on implementation status of specific JIT management practices and manufacturer size.empirical study, just-in-time manufacturing, performance, manufacturer size, logistic regression

The focus of this paper is on purchasing and supplier involvement in the firm. Using the resource-base view of the firm, hypotheses are developed concerning purchasing/supplier involvement, strategic purchasing and firm's financial performance. A model of the hypothesized relationships is offered and empirically tested using structural equation modeling. The model is tested using data collected in 1999. Each factor in the model is measured by a number of scale items. Based on the results of confirmatory factor analysis, an overall fit of the model to the data is achieved. Both convergent and discriminate validity is demonstrated. The research findings reveal that the hypotheses tested in the model are supported. Purchasing/supplier involvement has a positive impact on strategic purchasing, and strategic purchasing has a positive impact on firm's financial performance. The paper concludes with some research implications, limitations of the study and suggestions for future research.

SUMMARY Across Europe, total nitrogen deposition is increasing and, of this total, atmospheric ammonia can contribute up to 50–80%. Average deposition of ammonia in the UK is likely to be around 15–20 kg ha−1 yr−1, while in The Netherlands, which has some of the highest rates of deposition, this value is likely to be between 40 and 50 kg ha−1 yr−1. It is argued that because of the processes of assimilation and nitrification this ammonia is an acidifying pollutant. Ammonia taken up by plants is most likely to be directly assimilated and this uptake can have a strong effect on the nutrient imbalances of the plant. With root uptake in particular, anions are taken up in preference to cations. However, simple soil/plant nutrient measurements are unlikely to be a definitive means of monitoring ammonia pollution. This is because the processes of ammonia metabolism and acidification affect soil ion activity, mycorrhizas, plant uptake, and foliar leaching. These effects interact with acidity per se, and are compounded by the strong correlative co‐deposition of ammonia with sulphur. Evidence for uptake of gaseous and wet deposited ammonia by leaves is presented. The exact mechanism of ammonia toxicity is still not really clear, but could be due to physiological perturbation, rather than to the direct toxicity of the ion. Assimilation of ammonia by leaves releases protons which can cause cellular acidosis, and has important implications for acid‐base regulation in cells. This regulation depends on intrinsic features of the plant's metabolism, that is in turn dependent on the ecology of root versus leaf nitrogen nutrition under normal conditions. Certain species are more acidic in a leaf physiological sense and tend to be prone to damage by pollutants. Likewise, acidic habitats are particularly prone to damage through both eutrophication and the different capacities of plants both to utilize and to buffer against this nitrogen enrichment. The current evidence from The Netherlands suggests that the part this plays in perturbing the ecosystem should not be underestimated.

This article develops a classification scheme of planning process sophistication in small firms, categorizes small firms according to planning process sophistication, and examines the relationship between planning process sophistication and the financial performance of a select group of small, mature firms. The study overcomes several methodological shortcomings of prior research on strategic planning and firm performance. Multivariate analysis of variance is used to identify statistically significant differences between the financial performance data of firms that employ structured, strategic plans and those that do not. The results confirm previous research on strategic planning and financial performance. Finally, recommendations are made for future research.

\ 7 \ This paper examines the relationship between planning process sophistication and the financial performance of a select group of small firms in a growth industry. Multivariate analysis of variance is used to identify statistically significant differences between firms that employ sophisticated plans and those that do not. The results support previous research on strategic planning and financial performance.

SUMMARYCucumber {Cucumis sativus L.) was grown in an irradiated soil:sand mixture in PVC tubes containing a root compartment, a hyphal compartment and a hyphal ''P-labelling compartment. At 23 d from sowmg 20 /