Fisiologiese blaarabnormaliteite en bolopbrengs by katoen (Gossypium hirsutum L.) soos deur kalium-, kalsium- en boorvoeding beïnvloed

Abstract

Physiological leaf abnormalities and boll yield of cotton (Gossypium hirsutum L.) as affected by potassium, calcium and boron nutrition. A pot trial with a sand medium and two levels each of K, Ca and B nutrition, factorially arranged, was carried out with cotton over a period of 13 weeks. A low level of B nutrition resulted in stunted plants. The high K level suppressed Ca uptake, resulting in a K X Ca interaction. A low boll yield and distorted leaves in the growing point were associated with deficient Ca nutrition. A high K level had a detrimental effect only at the low Ca level. Necrotic lesions, that may be confused with infection by Xanthomonas malvacearum (E.F. Smith) Dowson, occurred on leaves at the low Ca and B levels. Damage to cell walls in the spongy parenchyma or to phloem cells of the leaf veins preceded the development of necrotic lesions. Transparent spots were the result of a group of enlarged cells containing almost no chloroplasts, which developed between the two epidermal layers.