We are very sad to say goodbye to Dr Lindsay Innes, OBE, FRSE who is retiring from the post of Book Review Editor that he has held for 15 years. During that time, Lindsay has worked tirelessly to ensure that regular readers of Experimental Agriculture have always been able to find out what books they should be reading, and why, by consulting the Journal's concise, incisive reviews by renowned experts from a bewildering range of fields. Lindsay, whose career description reads like a summary of all the top jobs in International Agricultural Research, always knew the best person to ask to review a book and the result was that we got the best reviews. We will miss him but we thank him sincerely for his work for the journal and we wish Lindsay the best of luck for the future.

Two groups of mature Marwari wethers were raced at 5 and to miles/hr respectively, for 30 minutes. Rectal temperature, respiratory frequency and pulse rate were measured initially, again immediately after the exercise, and subsequently four times at 20 minute interval. The rise in rectal temperature, respiratory rate and pulse rate in the animals raced at 10 miles/hr was 2·1°F, 86 and 22 counts/min. respectively. The corresponding values in the animals raced at 5 miles/hr were 0·9°F, 72 and 19 counts/min. The rise in rectal temperature due to stress was proportional to the degree of exercise. The magnitude of increase in the respiratory rate tended to be the same under both the treatments, and the trend in pulse rate was similar to that of respiratory rate.

Methods of determining the causes of year-to-year variation in yield are discussed. The types of data required for valid analysis, the need to build up a logical argument, and the use of direct experimentation to verify conclusions drawn from regression analyses, are considered.

The rate of regrowth in realtion to total dry matter yield is important for smallholders fodder crop production. A simple regression technique is used to compare the rates of regrowth of eight perennial fodder crops cut at the same time. A brief interpretation and discussion of results from data illustrative of the model' use in given.

The amount of starch in branches of Coffea arabica L. was studied by means of a method of visual scoring. In cropping branches, the variation in starch level was greatly, but not completely, determined by the growth of the crop. More knowledge of the formation and distribution of the products of photosynthesis is needed before a satisfactory explanation can be offered. Starch levels in non-cropping branches were higher than those in the cropping branches, but followed the same pattern of fluctuation. In general, translocation of starch occurred rapidly throughout the tree but some exceptions to this rule were found.

Soil, water and leaf analyses were carried out on samples from irrigated orchards in the Jordan Valley. Analysis of the soil for available phosphorus and potassium gave meaningful results. Analysis of the irrigation water showed that a high sodium and chloride content caused an increase of these ions in the soil, which led to undesirable effects such as chlorosis. Irrigation water class C3–S1 should only be used if there is an annual precipitation of about 300 mm. Leaf analysis showed changes in the composition of leaves with age, but only potassium varied significantly between varieties. Standards of leaf, soil and water composition are suggested for the growing of citrus.

The total N uptake, crude protein content, and recovery of N in rice grains varied with varieties. Increased levels of N application gave increases in total N uptake and crude protein content in the grains, though recovery of N in the grains decreased with increased levels of nitrogen application. Irrespective of varieties and levels of application, three split dressings of nitrogenous fertilizer gave greater total N uptake, crude protein content, and recovery of N in the rice grains than where all the N was applied at the time of transplanting of seedlings.

Observations that are frequencies rather than measurements often call for special types of statistical analysis. This paper comments on circumstances in which methods for one type of data can sensibly be used for the other. A section on two-way contingency tables emphasizes the proper role of χ2 a test statistic but not a measure of association; it mentions the distinction between one-tail and two-tail significance tests and reminds the reader of dangers. Multiway tables bring new complications, and the problems of interactions when additional classificatory factors are explicit or hidden are discussed at some length. A brief outline attempts to show how probit, logit, and similar techniques are related to the analysis of contingency tables. Finally, three unusual examples are described as illustrations of the care that is needed to avoid jumping to conclusions on how frequency data should be analysed.

Cultural standards and the husbandry techniques used on small farmers' fields are seldom the same as those practised on research and experimental Stations in the developing countries. The need for extensive agronomic experiments to be sited on small farmers' fields is emphasized. This method has been quite widely used with annual crops, but could with advantage be more generally adopted in perennial crops. Some of the advantages of this approach in agronomic investigations are illustrated by examples from work carried out in East Africa.

The quality of bean pods was influenced to a large degree by the variety, season of planting and the precise time of harvesting. The varieties Tenderette, Executive and Bush Blue Lake 274 were outstanding in their concentrated yield and pod quality. The development of seeds in the pods was faster in beans planted during the spring than in the autumn. Thickening of the pods during ripening was more rapid in the autumn than in the spring season. Outstanding differences were found between varieties with regard to the speed of seed development during pod ripening. As opposed to the outstanding differences between varieties with regard to quality characteristics, the differences with regard to yield were generally small and without economic importance.

The possibility of producing herbage of higher quality than that of tall fescue (Festuca arundinacea) in a continental climate with cold winters, hot summers and low precipitation was investigated, with and without irrigation, at Taigu, Shanxi, China. Tall fescue was compared with perennial ryegrass (Lolium perenne), meadow fescue (Festuca pratensis) and perennial ryegrass × meadow fescue in field swards, managed by cutting, during the year of sowing and in the three subsequent years. Perennial ryegrass yielded well in the year of sowing, but was low yielding subsequently; perennial ryegrass × meadow fescue yielded well in the year of sowing and in the following year. Both of these grasses had high rates of leaf appearance and extension and a high proportion of cell content in the dry matter. Tall fescue yielded well, but was low in proportion of cell content.

In any experiment the land will not be completely uniform and it is helpful to have ways of allowing for the variation. Some sources, for example altitude, will be obvious; some will be permanent but less obvious, such as depth of topsoil; and some may depend upon season and so be unpredictable. Various methods of local control have been suggested. Where the experimenter has good knowledge of the land it can be divided into blocks, each as far as possible uniform within itself. Then comparisons are made within the blocks rather than within the area as a whole. Where such knowledge does not exist, it is sometimes reasonable to make an assumption about the fertility pattern and make use of that, as in a row-and-column design like a Latin square. There is also the possibility of judging the fertility pattern from the data themselves and assessing the performance of a plot by reference to that of its neighbours.

The approach will be to generate bodies of data on the computer to form realizations of diverse fertility patterns and to use all methods on all realizations, noting success and failure.

When the variation forms a trend, blocks succeed only if they are aligned along fertility contours; the other methods do not depend upon orientation. Row-and-column designs can fail badly if the rows and columns interact. Some random variation is inevitable and it makes all methods less effective, especially nearest-neighbour methods, which can fail also when there are discontinuities. Random patches of different soil types are very difficult to deal with and any method might fail.

A technology for improving the productivity of short fallows using herbaceous legumes as cover crops was evaluated with farmers in the forest and savannah transition zones of Ghana. Legumes were relayed in maize 5–8 weeks after planting maize, depending on the legume species. An economic analysis of the technology compared with natural fallow over two cropping seasons (2001–2002) showed that the legume fallows were more profitable under the scenarios tested. Farmer assessment of the biological performance of the technology revealed the benefits of weed suppression and soil moisture conservation potential of the legume biomass as well as an improvement in the yield of the succeeding maize crop. However, farmers realized that planting legumes at close spacing and weeding before and after relaying are essential in the development of an appreciable biomass cover. The technology is suitable for farmers of all strata, in several major ecological zones of Ghana, and for planting on land with poorly secured tenure. However, at least two years of tenancy is required for the landless to derive some benefits from the legume fallow.

Internal browning disorders, including brown fleck (BF), in potato (Solanum tuberosum) tubers greatly reduce tuber quality, but the causes are not well understood. This is due, in part, to the highly variable data provided by visual value-based rating systems. A digital imaging technique was developed to quantify accurately the incidence of internal browning in potato tubers. Images of tuber sections were scanned using a flatbed scanner and digitally enhanced to highlight tuber BF lesions, and the area of affected tissue calculated using pixel quantification software. Digital imaging allowed for the determination of previously unused indices of the incidence and severity of internal browning in potato tubers. Statistical analysis of the comparison between digitally derived and visual-rating BF data from a glasshouse experiment showed that digital data greatly improved the delineation of treatment effects. The F-test probability was further improved through square root or logarithmic data transformations of the digital data, but not of the visual-rating data. Data from a field experiment showed that the area of tuber affected by BF and the number of small BF lesions increased with time and with increase in tuber size. The results from this study indicate that digital imaging of internal browning disorders of potato tubers holds much promise in determining their causes that heretofore have proved elusive.