Abstract
Summary. Critical potassium (K) concentrations for the
diagnosis of K deficiency were determined in various shoot parts of faba bean
(Vicia faba L. cv. Fiord) and chickpea
(Cicer arietinum L. T1587) plants grown at K rates of
0–240 mg K/kg in a K-deficient soil in the glasshouse. Shoot growth
of both species increased with rates of K applied and with plant age but faba
bean was more responsive to K application than chickpea. Potassium
concentrations in plant parts greatly increased with increasing K supply. In
faba bean, K concentrations in all shoot parts decreased with plant age
irrespective of K supply while in chickpea K concentrations in leaves of
K-deficient plants increased with plant age but those in stems decreased. For
both species, young leaves had higher K concentrations than old tissues,
especially in K-deficient plants. A greater proportion of leaf K was stored in
the petioles when K supply was adequate than when K was deficient.
Critical K concentrations were determined using the hand-fitted curve and
Mitscherlich model at 90% maximum shoot weight and the 2-phase linear
model. The critical concentrations varied between plant parts and among the
methods used. Critical values decreased with leaf age and were higher in leaf
petioles than in leaf blades. Critical K concentrations, developed from
hand-fitted curves, in the 1st plus 2nd and 3rd plus 4th leaf blades of faba
bean, and leaf petioles below the youngest fully expanded leaf (YFEL) of
chickpea were similar between days 48 and 73 for faba bean and between days 55
and 80 for chickpea. It is recommended that the critical values for the
diagnosis of K deficiency at 7–8-leaf stages are 1.3–1.5%
in YFEL, 1.1–1.2% in the 1st plus 2nd leaf blades below the YFEL
and 1.8–2.0% in whole shoot of faba bean, and
1.4–1.5% in YFEL, 2.7–2.8% in the 1st plus 2nd leaf
petioles and 2.1–2.2% in whole shoot of chickpea. The gradient of
K concentration between young and old leaves occurred before a decrease in
shoot growth and may be used for the prognosis of K deficiency.
Subject
General Agricultural and Biological Sciences
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献