Resumo
Sisal (Agave sisalana Perrine) growing in various localities of the State of São Paulo is often heavely damaged by "leaf basal necrose", whose symptoms are identical with the "leaf foot disease" reported from Java, East Africa and Belgian Congo. The affected leaves show in the initial stages small spots of black, slightly shrivelled tissue on the lower part of the leaf. These gradually spread out. During the later stages the affected leaves bent over at this point. Only approximately mature leaves of plants between 18 to 30 months old are affected. This disturbance was first observed in Anapolis, Araraquara and Campinas. It was thought to be due to K deficiency in the soil. In order to prove this a small fertilizer experiment was established at Campinas mainly to study the effect of potassium sulfate as a control measure for this "disease". The experiment also included calcium carbonate and control plots, each treatment being replicated three times. The results demonstrated that the trouble can be easily controled by the use ot potassium sulfate applied in the first year of cultivation (two years after planting in the nursery). At all plots not treated with K the typical black spots appeared on the leaves about one year after planting. Considerable damage was caused by this physiological disturbance in all these plots, up to 86,6% of the plants and 15,4% of all leaves being damaged at the three control plots 18 months after planting. The "leaf basal necrose" is until now the single prevalent and destructive "disease" of sisal in the State of São Paulo, where the plant is generally cultivated on K deficient soils. This explains its occurrence in almost all plantations. To avoid this disturbance sisal should be cultivated on rich soils and fertilised with K sulfate if grown on poor ones.
A necrose da base da fôlha do sisal
J. C. Medina
SUMMARY
Sisal (Agave sisalana Perrine) growing in various localities of the State of São Paulo is often heavely damaged by "leaf basal necrose", whose symptoms are identical with the "leaf foot disease" reported from Java, East Africa and Belgian Congo.
The affected leaves show in the initial stages small spots of black, slightly shrivelled tissue on the lower part of the leaf. These gradually spread out. During the later stages the affected leaves bent over at this point. Only approximately mature leaves of plants between 18 to 30 months old are affected.
This disturbance was first observed in Anapolis, Araraquara and Campinas. It was thought to be due to K deficiency in the soil. In order to prove this a small fertilizer experiment was established at Campinas mainly to study the effect of potassium sulfate as a control measure for this "disease". The experiment also included calcium carbonate and control plots, each treatment being replicated three times.
The results demonstrated that the trouble can be easily controled by the use ot potassium sulfate applied in the first year of cultivation (two years after planting in the nursery). At all plots not treated with K the typical black spots appeared on the leaves about one year after planting. Considerable damage was caused by this physiological disturbance in all these plots, up to 86,6% of the plants and 15,4% of all leaves being damaged at the three control plots 18 months after planting.
The "leaf basal necrose" is until now the single prevalent and destructive "disease" of sisal in the State of São Paulo, where the plant is generally cultivated on K deficient soils. This explains its occurrence in almost all plantations. To avoid this disturbance sisal should be cultivated on rich soils and fertilised with K sulfate if grown on poor ones.
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AGRADECIMENTOS
Agradecemos a colaboração prestada pelos srs. George Oscar Jensen, que procedeu às análises minerais das fôlhas; Renato Catani, que determinou o potássio trocável; Ernesto Zink, que traduziu a bibliografia em língua alemã e holandesa, e C. A. Krug, que fez a revisão do sumário em inglês.
LITERATURA CITADA
- 1. Doop, J. E. A. den Kalimangelerscheinungen bei sisal und maniok (Kassave) Die Ernährung der Pflanze 33: 108-110. 1937.
- 2. Doop, J. E. A. den The utilisation of sisal waste in Java and Sumatra. Part III. The East African Agr. Jour. 4: 343-351, 1938-39.
- 3. Doop, J. E. A. den Groene bemesting, kunstmest in andere factoren in Sisal-en Cassave-productie. Der Bergcultures 9: 1293-1298. 1935.
- 4. Drummond Gonçalvez, R. Doença do sisal. O Biológico 2: 253-254. 1936.
- 5. Drummond Gonçalves, R. Manchas da fôlha do sisal. O Biológico 5: 179-180. 1939.
- 6. Drummond Gonçalvez, R. Doença da fôlha do sisal. O Biológico 7: 296-297. 1941.
- 7. Medina, J. C. Relatório do Serviço de Genética do Instituto Agronômico. 2: 308-309. 1940-41 (Não publicado).
- 8. Morstatt, H. Blattkrankheiten der Sisalagave. Der Tropenpflanzer 33: 307-312. 1930.
- 9. Rombouts, J. Duas moléstias do henequen (Agave sisalana). O Campo 8: n.ş 86: 60. 1937.
- 10. Staner, P. e G. Verplancke. Un Etat pathologique du sisal au Congo Belge. Bul. Agr. Congo Belge 21: 864-866. 1930.
- 11. Silberschmidt, K. Doença do sisal. O Biológico 2: 341. 1936.
- 12. Vageler, P. Em Grundriss der Tropischen und Subtropischen Bodenkunde, pg. 235, 236, 239. Zweite Auflage, Verlag. f. Ackerbau M.B.H., Berlin. 1938.
Datas de Publicação
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Publicação nesta coleção
29 Jun 2010 -
Data do Fascículo
Abr 1943
