G. M. WARD. Can. J. Plant Sci. Downloaded from by on 04/07/18

Transcription

1 SULPHUR DEFICIENCY AND TOXICITY SYMPTOMS IN GREENHOUSE TOMATOES AND CUCUMBERS G. M. WARD Research Station, Agriculture Canada, Harrow, Ontario. Received 30 July I 975, accepted 4 Sept Weno, G. M Sulphur deficiency and toxicity symptoms in greenhouse tomatoes and cucumbers. Can. J. Plant Sci. 56: Symptoms of sulphur deficiency and toxicity on greenhouse tomatoes (Lycopersicon esculentum Mill.) and cucumbers (Cucumis sativis L.) were produced experimentally in sand culture and are described in detail. The principal morphological effect was a general depression of growth and fruit production. A S content of less than O.25Vo in any plant tissue was associated with severe deficiency. The distribution of S in various plant tissues is shown. On a provoqu6 artificiellement des sympt6mes de toxicit6 et de carence en soufre sur des tomates (Lycopersicon esculentum Mill.) et des concombres (Cucumis sativis L.) de serre cultiv6s dans du sable. L'effet morphologique principal a 6t6 une r6duction g6n6rale de la croissance et de la production des fruits. Une teneur en soufre inf6rieure d 0,254o dans les tissus v6g6taux a 6t6 reli6e ir des symptomes de carence grave. L'auteur donne la distribution du soufre dans les divers tissus v6e6taux. Sulphur is recognized as an essential plant nutrient. Agricultural crop plants in Ontario and in most of Canada appear to be well supplied with sulphur because many soils have adequate reserves of this element and also because fertilizer materials such as gypsum and single superphosphate which contain a certain amount of sulphate sulphur have been used in great abundance in the past. Another possible source of sulphur in some areas of Ontario is the air pollution arising from certain industrial plants and from a few gas and oil wells. Rainwater passing through the atmosphere washes the sulphur compounds onto the agricultural land in significant quantities. Plants are also able to absorb gaseous sulphur which is converted to sulphate (Alway et al. 1937). An additional source of sulphur in greenhouse vegetable culture is 'magnesium sulphate fertilizer which is applied regularly to prevent magnesium deficiency, particularly on the light sandy soils of southwestern Ontario. Can. J. Plant Sci.56: 133-r37 (Jan. 1976) As a consequence, sulphur deficiency is rarely ifever reported and sulphur is seldom considered as a nutrient amendment even though it is a macronutrient in terms of requirement in the plant. Very little work has been done on sulphur nutrition except with forage crops (Martin and Walker 1966). The only plant analyses quoted by Chapman (1966) for tomato were done by Nightingale in 1932 and there are no references to cucumber. However, Roorda van Eysinga and Smilde (1968, 1969) have produced color plates of experimentally induced deficiency symptoms in greenhouse tomatoes and cucumbers which are somewhat more definitive than those found in some earlier publications. They state that sulphur deficiency is unknown in commercial glasshouses. The experiment reported in this paper was conducted for the purpose of determining the level of sulphur in tomato and cucumber tissues associated with the onset of deficiency symptoms and to observe the distribution of this element in the various 133

2 t34 CANADIAN JOURNAL OF PLANT SCIENCE plant tissues under different nutrient concentrations. An attempt was also made to produce a toxicity response. MATERIALS AND METHODS Tomato plants, Lycopersicon esculentum Mill. cv. Vendor, and cucumber plants, Cucumis sativis L. cv. Toska 70, were grown from seed in 4-liter pots of washed white sand. They were watered and feitilized as requlred with deionized water and Hewitt's (1966) standard nutrient solution, modified to eliminate all sulphates, e.g. Mg, Cu, Mn and Zn were all supplied as chlorides. KHTPO4 was substituted for NaH2POa since all available sources of the latter salt contained measurable sulphate impurities. The K concentration was corrected by adjusting the KNOr level. The white sand was washed several times with distilled water but was found to have no sulphur contamination. Sulphur as a nutrient was supplied as Na2SOa in varying amounts to produce the treatments indicated in Table l. Three seedlings were raised in each pot but only single plants of uniform size were retained for the experiment. Four pots of tomato plants and four of cucumbers provided replicates for each treatment. Day temperature in the greenhouse was controlled at 22 C, night temperature 17 C, relative humidity 657c; the time of year was February-April. No supplementary light was used. Sulphur deficiency and toxicity symptoms developed on plants in various treatments at different times. When they became sufficiently characteristic of the disorder, a detailed description was recorded and color pictures were taken (on file with author). Samples of leaf tissue were taken for analysis from relevant treatments on several different dates. The total fruit yield of cucumbers was measured and Treatment no. Table I. Description of treatments Standard amount (Hewiu 1966) T3 T4 ppm s )4 l2 6 0 meq/liter Siin 30 J l.j 0.7s o recorded, but tomato fruit did not ripen during the time of the experiment and no yields were obtained. At the end of the experiment two whole plants from selected treatments were taken for analysis. Individual plant tissues were segregated and corresponding tissues from the two plants were composited. The samples for analysis were weighed, dried at 80 C, weighed again, ground in a Wiley mill and analyzed for S by the gravimetric BaSOr procedure as described by Ward and.johnston (962). RESULTS AND DISCUSSION Visible symptoms of S toxicity began to appear first on cucumbers in treatment I (Tl) 2l days after seeding. Deficiency symptoms began to appear on cucumbers in at 26 days after seeding and gradually intensified (Table 2). Samples of leaves showing symptoms in Tl and and corresponding normal leaves from were taken for analysis at 32 days from seeding. The S content (dry weight basis) of these three samples was Tl, O.52Vo;,0.517o; and, O.l5Vo. No distinctive symptoms had appeared on tomato plants in any treatment at 32 days other than a slight stunting in. At 45 days, deficiency symptoms were quite distinct in tomatoes and the appearance of the cucumbers had changed considerably (Table 2). Samples of standard indicator leaf tissue were taken from all treatments at this date (Table 3). The results show that tissue levels of S were proportional to the treatments except for Tl, cucumber, which is not an excessively high S content. The gradient from to in tomato was small. The experiment was terminated at 77 days from seeding. Visible symptom appearance had not changed significantly in either cultivar from the description in Table 2 at 45 days. The plants had grown and produced fruit and stunting was more pronounced in certain treatments. No fruit, however, had set on tomatoes in. In both cultivars, the plants in T3 and T4 resembled those in and it was not considered useful to analyze whole plants.

3 WARD-SULPHUR DEFICIENCY IN TOMATOES AND CUCUMBERS r35 Table 2. Description of sulphur deficiency and toxicity symptoms at two stages ofgrowth Stage ofgrowth Treatment General description of symptorns Cucumber: 32 days Tl -t2 T3,T4, Tomato:32 days Tl- Cucumber:45 days Tl Tomato:45 days T3,T4 Tl T3,T4 Severely curled leaf tips, necrotic spottiog on some leaves, chlomtic margins followed by necrosis, bottorn leaves nonnal Dark green leaves, lush vigorous growth, normal cotror erd size Same as Top leaves pale green with a yellowish ca$ over the whole leaf; yellowing, starts at the veins and progresses outwards leaving a mottled appeafi]me, smaller leaves than in, some slighdy serrated, botiom leaves nearnonnal color Good growth, no signs of abnormality Ht 35 cm, 8 leaves, lower leaves severely curled under and rrccrotic, top leaves normal but small and with long intemodes between Ht 7l cm, l0 leaves, normal healthy green colon, fndt set on most nok Same as, no signs of abnormality The analytical data in Table 4 once again show that tissue content of S was proportional to the treatment application of S fertilizer in both cultivars. They also show that in general there is a small decreasing gradient in S content in normal plants from bottom to rop () which disappears under deficiency conditions (, Table 3. Sulphur content of standard leaf tissue sampled at 45 days Ht 43 cm, pale yellow leaves Ht 23 cm, 7 leaves, very pale green-yellow and hard foliage, leaves; curved downward almost to the stem, top leaves de4ly serrated, few fruit set Ht 3l cm, l0 leaves, slight stunting, no other sigoa. of abnormality Ht 35 cm, l0 leaves, large healthy plants, good leaf color, buds starting to open Same as, but buds not showing yet Same ht as but smaller, less vigorous plants, f rliage normal Ht 20 cm, 8 leaves, foliage yellow but not as pale a$ cocffi leaves in, leaves narrow and serrated, particularly young leaves, veins remain dark and reddish purple, no buds S as % ofdw Treatment Tomato Cucumber T3 T fl ). The plants received no S application during growth, b'tlt atl tissues were found to contain small percentages" Using individual tissue weights, tlp total amount per plant was calaulated to be 3-8 mg in tomatoes and 6.7 mg in cucurnbers. These small quantities came from the seed and from undetected contaminafion- A similar calcul&tion was made for plants which had received the reqommended S application for normal grourth (Hewitt 1966). The total sontent per plant was calculated to be mg in tomatoes and mg in cucumbers. These figrues represent levels of A.54Va and 0-45% S for whole normal plants- In order to obtain an approximation of crop removal of S by greenhouse tomafoes and ctrcumb rs" th se percentages were used with dry weight values for complete mature crop ptrants, includine all harvested fruit- from former

4 136 CANADIAN JOURNAL OF PLANT SCIENCE Table 4. Sulphur content of plant tissues sampled at 77 days SasToDW Tomato Cucumber Leaf I (bottom) '7 8 9 l0 ll t2 l3 l4 l5 l6 l7 l8 l9 20 2l 22 ZJ 24 Top Fruit Top I /2 of stem Bottom I /2 of stem t.54 t r.6l 1.5'7 t.54 t.37 t.4l t.20 t.20 l s.92 t r t o4.o4.05.ll o experiments (Ward 1964, 1967) to show that tomatoes absorb S at the rate of kg/ha (89.4 lb/acre) and cucumbers at 67.3 kgiha (60.0 lb/acre). Crop removal of S by alfalfa was reported to be 52 kglha (46 lb/acre) (Martin and Walker 1966). This places S in approximately the same range of nutrient requirement as P and Mg, which is much higher than the range usually considered adequate for the micronutrients. The T3 and T4 plants appeared to be absorbing enough S to maintain normal growth and fruit production. The data in Table 4 for tissues from the Tl plants show that although these plants were fertilized with ten times as much S as the plants in, in no case did the S concentration in the tissue increase to even r.2l 1.47 t.4l t l.3l I.31 t.32 t t.o r t t.t2.18.r2.23.o r r O4.r0.o7.06.ll.32 -zj n2.004.oo2 twice the amount found in corresponding normal tissue in. Although some leaf malformations were apparent in Tl, particularly in cucumbers, the principal effect of excess sulphur was depressed growth. These observations correspond with findings by Chapman (1966) where he indicates that toxicity symptoms have been associated with a range of S values from 0.23 to l.23vo in various species and tissues and a value of 1.877o is quoted as an intermediate range for lower blades of tomato. Consideration was given to the possibility that plant malformations and depressed growth in Tl might have been caused by high total salt concentration arising from the heavy application of NazSOa. However, the characteristic

5 WARD-SULPHUR DEFICIENCY IN TOMATOES AND CUCUMBERS t3t symptoms of this condition were not apparent. There was no wilting and no root damage. The experiment was continued for a long enough period to obtain a small yield of cucumber fruits which were harvested on three different dates as they matured. The toxic treatment. Tl. restricted the number of fruit that were set, but those that did set grew to a normal size and shape (Table 5). There was no sisnificant difference in production in, T3-andT4. The plants set fewer fruit, but all were of the large and extra large grades. The plants produced no fruit. The results of this experiment confirm the diversity of distribution of S between tissues of the two cultivars. It is difficult to define a range of sufficiency for this element, but tissue levels below 0.25qo indicate severe deficiency. Depression of growth and fruit production was the most Treatment no. T3 T4 Table 5. Yield of cucumber fruits No. of fruit from Avg weight 4 plants (g) 5 t2 l3 t prominent effect of either deficiency or excess ofs. ALWAY, F. J., MARSH, A. W. and METHLEY, W. J Sufficiency of atmospheric sulphur for maximum corn yields. Soil Sci. Soc. Amer. Proc. 2: CHAPMAN, H. D Diagnostic criteria for plants and soils. Univ. of Calif. Div. Agric. Sci.. Riverside. Calif. HEWITT, E. J Sand and water culture methods used in the study of plant nutrition. 2nd ed. Commonwealth Agric. Bur. Tech. Commun.22. MARN, W. E. and WALKER, T. W Sulphur requirements and fertilization of pastures and forage crops. Soil Sci. l0l: ROORDA VAN EYSINGA, J. P. N. L. and SMILDE, K. W Nutritional diseases in glasshouse tomatoes. Cen. Agric. Publ. Doc. Wageningen, Netherlands. pp. 2O-21. ROORDA VAN EYSINGA, J. P. N. L. and SMILDE, K. W Nutritional disorders in cucumbers and gherkins under glass. Cen. Agric. Publ. Doc. Wageningen, Netherlands. pp WARD, G. M Greenhouse tomato nutrition - A growth analysis study. Plant Soil 2l: WARD, G. M Greenhouse cucumber nutrition - A growth analysis study. Plant Soil 26: WARD, G. M. and JOHNSTON, F. B. t962. Chemical methods of plant analysis. Can. Dep. Agric. Publ p. 35.

6 This article has been cited by: 1. Flávio Henrique Silveira Rabêlo, Luiz Tadeu Jordão, José Lavres A glimpse into the symplastic and apoplastic Cd uptake by Massai grass modulated by sulfur nutrition: Plants wellnourished with S as a strategy for phytoextraction. Plant Physiology and Biochemistry 121, [Crossref] 2. Francisco Augusto Mora Solís, Henrique Paulo Haag, Keigo Minami, Walter João Diehl Nutrição mineral de hortaliças: LIV - acumulação de nutrientes na cultura do pepino (Cucumis sativus L.) var. Aodai cultivado em condições de campo. Anais da Escola Superior de Agricultura Luiz de Queiroz 39:2, [Crossref] 3. H. Weber, J.R. Sarruge, H.P. Haag, A.R. Dechen Nutrição mineral de hortaliças. XXXVII. deficiências de macronutrientes em cubiu (Solanum topiro Humb. & Bonpl.). Anais da Escola Superior de Agricultura Luiz de Queiroz 38:2, [Crossref]