The Influence of Age on the Cation-Anion Balance in the Leaves of Brussels Sprouts (Brassica olerace var. gemmifera)

Abstract

Leaves of the same plant but of different ages vary considerably in chemical composition. Younger leaves usually contain relatively high concentrations of nitrogen, phosphorus and potassium, whereas older leaves offen contain a relatively high concentration of calcium (23). As a consequence, there may be marked variations from leaf to leaf in the contribution of various constituents to the cation-anion balance, and these could reflect differences with age in metabolic behaviour. An investigation has therefore been made with leaves of Brussels Sprouts of variations with age in the constituents that contribute to the cation-anion balance in the plant. M a t e r i a l s a n d M e t h o d sBrussels Sprouts p l a n t s (Brussica oleracea v a r . gemmifera) were collccted f r o m the Institute gardens shortly before use. Leaves were selected from each p l a n t to provide samples of v a r y i n g age, each sample consisting of three leaves. The petioles a n d midribs were discarded. O r g a n i c acid estimations were m a d e on boiling w a t e r extracts of the fresh p l a n t material. O t h e r analyses were carried o u t on material dried a t 85OC to constant weight.

Internal Browning of Brussels Sprouts: A Calcium Deficiency Disorder1

“…Another aspect of the Ca distribution problem is associated with age or position on the plant. Calcium generally accumulates in the oldest or lower leaves on a plant (Table 3) (7,10). On the other hand, Ca appears to be much more uniformly distributed in sprouts from different parts of the plant (our data and 10).…”

“…The levels at which deficiency symptoms of N, P, K, Mg, Mn, and S appeared in mango leaves grown in sand culture have been reported (7). Based on fertilizer studies (10,11,12), tentative standards for desirable levels of macronutrient elements in leaves have been set for Florida mango (8).…”