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Nutritional disorders in glasshouse tomatoes, cucumbers and lettuce
192
The general standard o f production of this book, except for the photographic illustrations, is very high. With one notable exception (the unfortunate transposing of the fungicide names in Figs. 4.6 and 4.7) there are few editorial errors. However, although the b o o k gives useful detail on individual vegetable diseases it hardly lives up to the title, which leads the reader to expect a more comprehensive treatment than is given of the topic in general. W.F.T. HARTILL DSIR, Plant Diseases Division Private Bag, Auckland N e w Zealand
GLASSHOUSE CROPS
Nutritional Disorders in Glasshouse Tomatoes, Cucumbers and Lettuce, b y J.P.N.L. R o o r d a van Eysinga and K.W. Smilde. Pudoc, Wageningen, The Netherlands, 1981, 130 pp., 77 photos (full colour), 253 references, cloth Dfl. 70.00, ISBN 90-220-0737-5. This b o o k is a revised amalgamation of the three previous ones b y the same authors (Tomatoes w 1968, Cucumbers and Gherkins -- 1969, Lettuce -- 1971). The layout is very much as before, with one disorder described on each right-hand page, and the coloured plate or plates illustrating it on the facing page. The contrast and colour balance of many of the plates has changed rather dramatically (and unfavourably in most cases) since the previous edition. Deficiencies of 12 major and minor elements are described and illustrated, including some such as sulphur, which have n o t y e t been seen in the commercial situation. However, with increasing use of unconventional substrates and nutrient film technique, this is no bad thing. Four toxicities (nitrogen, boron, manganese and zinc) are also included, but the pages on tipburn and aluminium toxicity in the previous lettuce b o o k l e t have been dropped. The form o f the text is somewhat different from before. For each disorder there is one paragraph describing the symptoms, another on the incidence (i.e. circumstances in which the disorder may occur), recommendations for preventing or curing the disorder, and a list of references. The latter, although n o w very numerous, have been separated from the text so that the reader no longer knows to what particular point they refer. This, I feel, is a retrogade step. Also, the analytical values for deficient, normal, and excessive concentrations of elements in leaves have been removed from the paragraph on the overall syndrome description and placed in tables in the back of the book. Whether y o u prefer this is a matter of taste, but the units n o w used -- mols or millimols per kg -- could prove rather confusing to those of us weaned on percentages and p.p.m. The value of a b o o k o f this kind depends u p o n the degree of success which the user achieves in diagnosing crop problems, and this in turn de-
193 pends on the clarity and comprehensiveness of the illustrations and the accompanying descriptions, and the extent to which they represent the disorders as they are likely to occur in the commercial context. This last requirement is particularly difficult for the authors to satisfy, because of the ever-changing combinations of growing substrate and crop variety, which can m o d i f y the expression of s y m p t o m s quite markedly. (The new b o o k does n o t say h o w the disorders were induced: one gathers from the earlier t o m a t o volume that either peat or water culture were used, with the appropriate element withheld.) The descriptions of the disorders are generally very thorough, b u t by no means all the s y m p t o m s mentioned are visible in the photographs. In such cases, some additional "close-ups" would have been useful. One rather notable omission, for example, is a picture of boron-deficient t o m a t o fruit which, judging by the picture in the 1961 edition of Wallace's b o o k ("Mineral Deficiencies in Plants"), could be the cause of a commercial disaster of major magnitude. In a few cases, such as calcium deficiency in lettuce, the photograph does n o t agree with the verbal description, nor indeed, in this particular case, with the writer's own experience. Because of the reduction in contrast already mentioned, some pictures have lost a lot o f " p u n c h " even to the extent of the s y m p t o m becoming almost invisible. An example is magnesium deficiency in lettuce, where the mottling is now very hard to discern. When diagnosing disorders from visual s y m p t o m s there is often the possibility of confusion with other nutritional or non-nutritional problems, and it would have been useful to include comments where this is the case. For example, a "nutritional leafroll" is quite c o m m o n in glasshouse tomatoes, and is variously ascribed to very favourable nutrition, or to ammonium toxicity. Some explanation of this could well have been included on the t o m a t o - c o p p e r deficiency page, where the most obvious s y m p t o m in the photograph is also leafroll. Another possible improvement would be the inclusion of a brief glossary to explain terms such as pericarp, serrate, and petiolule, which could have n o t only growers but even scientists reaching for their A-level text-books. Despite these criticisms, this is surely the most comprehensive b o o k available on the subject at present. One cannot b u t admire the faultless English in a work of Dutch origin. The rather high U.K. price of £17.50 no d o u b t reflects the high price of books in The Netherlands. What the grower has to consider is, however, n o t only "Can I afford to b u y it?" b u t also "Can I afford n o t to b u y it?". When one considers the value of such crops, the answer to the second question is almost certainly " N o " .
A. SCAIFE National Vegetable Research Station Wellesbourne Warwick, Gt. Britain
The general standard o f production of this book, except for the photographic illustrations, is very high. With one notable exception (the unfortunate transposing of the fungicide names in Figs. 4.6 and 4.7) there are few editorial errors. However, although the b o o k gives useful detail on individual vegetable diseases it hardly lives up to the title, which leads the reader to expect a more comprehensive treatment than is given of the topic in general. W.F.T. HARTILL DSIR, Plant Diseases Division Private Bag, Auckland N e w Zealand
GLASSHOUSE CROPS
Nutritional Disorders in Glasshouse Tomatoes, Cucumbers and Lettuce, b y J.P.N.L. R o o r d a van Eysinga and K.W. Smilde. Pudoc, Wageningen, The Netherlands, 1981, 130 pp., 77 photos (full colour), 253 references, cloth Dfl. 70.00, ISBN 90-220-0737-5. This b o o k is a revised amalgamation of the three previous ones b y the same authors (Tomatoes w 1968, Cucumbers and Gherkins -- 1969, Lettuce -- 1971). The layout is very much as before, with one disorder described on each right-hand page, and the coloured plate or plates illustrating it on the facing page. The contrast and colour balance of many of the plates has changed rather dramatically (and unfavourably in most cases) since the previous edition. Deficiencies of 12 major and minor elements are described and illustrated, including some such as sulphur, which have n o t y e t been seen in the commercial situation. However, with increasing use of unconventional substrates and nutrient film technique, this is no bad thing. Four toxicities (nitrogen, boron, manganese and zinc) are also included, but the pages on tipburn and aluminium toxicity in the previous lettuce b o o k l e t have been dropped. The form o f the text is somewhat different from before. For each disorder there is one paragraph describing the symptoms, another on the incidence (i.e. circumstances in which the disorder may occur), recommendations for preventing or curing the disorder, and a list of references. The latter, although n o w very numerous, have been separated from the text so that the reader no longer knows to what particular point they refer. This, I feel, is a retrogade step. Also, the analytical values for deficient, normal, and excessive concentrations of elements in leaves have been removed from the paragraph on the overall syndrome description and placed in tables in the back of the book. Whether y o u prefer this is a matter of taste, but the units n o w used -- mols or millimols per kg -- could prove rather confusing to those of us weaned on percentages and p.p.m. The value of a b o o k o f this kind depends u p o n the degree of success which the user achieves in diagnosing crop problems, and this in turn de-
193 pends on the clarity and comprehensiveness of the illustrations and the accompanying descriptions, and the extent to which they represent the disorders as they are likely to occur in the commercial context. This last requirement is particularly difficult for the authors to satisfy, because of the ever-changing combinations of growing substrate and crop variety, which can m o d i f y the expression of s y m p t o m s quite markedly. (The new b o o k does n o t say h o w the disorders were induced: one gathers from the earlier t o m a t o volume that either peat or water culture were used, with the appropriate element withheld.) The descriptions of the disorders are generally very thorough, b u t by no means all the s y m p t o m s mentioned are visible in the photographs. In such cases, some additional "close-ups" would have been useful. One rather notable omission, for example, is a picture of boron-deficient t o m a t o fruit which, judging by the picture in the 1961 edition of Wallace's b o o k ("Mineral Deficiencies in Plants"), could be the cause of a commercial disaster of major magnitude. In a few cases, such as calcium deficiency in lettuce, the photograph does n o t agree with the verbal description, nor indeed, in this particular case, with the writer's own experience. Because of the reduction in contrast already mentioned, some pictures have lost a lot o f " p u n c h " even to the extent of the s y m p t o m becoming almost invisible. An example is magnesium deficiency in lettuce, where the mottling is now very hard to discern. When diagnosing disorders from visual s y m p t o m s there is often the possibility of confusion with other nutritional or non-nutritional problems, and it would have been useful to include comments where this is the case. For example, a "nutritional leafroll" is quite c o m m o n in glasshouse tomatoes, and is variously ascribed to very favourable nutrition, or to ammonium toxicity. Some explanation of this could well have been included on the t o m a t o - c o p p e r deficiency page, where the most obvious s y m p t o m in the photograph is also leafroll. Another possible improvement would be the inclusion of a brief glossary to explain terms such as pericarp, serrate, and petiolule, which could have n o t only growers but even scientists reaching for their A-level text-books. Despite these criticisms, this is surely the most comprehensive b o o k available on the subject at present. One cannot b u t admire the faultless English in a work of Dutch origin. The rather high U.K. price of £17.50 no d o u b t reflects the high price of books in The Netherlands. What the grower has to consider is, however, n o t only "Can I afford to b u y it?" b u t also "Can I afford n o t to b u y it?". When one considers the value of such crops, the answer to the second question is almost certainly " N o " .
A. SCAIFE National Vegetable Research Station Wellesbourne Warwick, Gt. Britain