Response of Root Branching and Shoot Water Potentials of French Beans (Phaseolus vulgaris L.) to Soil Moisture and Fertilizer Potassium

Abstract

Extensive branching patterns of roots and the maintenance of adequate water within shoots enables plants to overcome water stress. However, information on the relationship between fertilizer potassium, root branching patterns and shoot water potentials of food legumes grown under different soil moisture regimes is scarce. Thus, an experiment was conducted in a phytotron to ascertain the effect of fertilizer potassium on root branching patterns and shoot water potentials of a popular tropical food legumes (Frenchbeans Phaseolus vulgaris L). The plants were grown in a sand medium with 0.1, 0.8 or 3.0 mM of potassium under a suboptimal and optima) soil moisture regime. Root lengths and dry weights were enhanced by potassium, especially under a suboptimal soil moisture regime. The branching patterns changed due to potassium, where the numbers of second and third order roots increased under both soil moisture regimes, although the impact was greater in plants grown with low soil moisture. Plant water contents measured in terms of shoot water potential, relative water contents, rurgid weight: dry weight ratio and water uptake capacity were also increased by potassium. A positive relationship was observed between root branching patterns and water potentials with increasing potassium levels especially in plants grown under suboptimal soil moisture conditions. Shoot growth and nodulation was also promoted by potassium. The ability of plants to develop a more extensive branching pattern of roots by inducing a greater number of second and third order roots and changing the root branching habit from a herringbone to a dichotomous type to maintain a greater shoot water potential especially under low soil moisture regimes is presented.

Physiological Changes of Wheat Varieties Under Water Deficit Condition

“…Plants grow under high moisture regimes maintain a higher water retention capacity (WRC) which might be due to lower destruction of plant tissues by moisture deficit (Sangakkara et al, 1996). WRC was decreased markedly in the studied varieties due to water stress at booting, anthesis and grain filling stages (Table 4).…”

“…Measurement of water saturation deficit (WSD), water retention capacity (WRC) and water uptake capacity (WUC) were calculated as follow by Sangakkara et al (1996) The collection of data was analyzed statistically and the treatment means were adjudged by LSD Test (Gomez and Gomez, 1984) by package program STATISTIX-10.…”

The effects of silicon and titanium on safflower (Carthamus tinctorius L.) growth under moisture deficit condition

“…The turgid mass (T M ) of the leaves was measured before having the leaves oven-dried at 80 °C for 72 h until constant mass and then reweighted (D M ). The fresh mass, turgidity, and dry weights of the leaf segments were used to determine hydration and relative water content according to Sangakkara et al (1996).Accordingly, hydration was determined as H (%) = 100 -100 (D M / F M ) and relative water content (RWC) was determined as…”

Morpho-physiological response of Acacia auriculiformis as influenced by seawater induced salinity stress

“…With the increase of salinization period and salinity level, mean values of WUC and WSD were increased, while salinization had less effect on the mean value of the water retention capacity of Acacia auriculiformis plants (Table 2). In this regard, at 150 days after treatment imposition with 12 dS m -1 salinity level, Shoot or root distribution = Fresh Mass/Length Shoot or root density = Dry Mass/Length Water Uptake Capacity (WUC) was measured by using the following formula (Sangakkara et al, 1996):…”

“…Where, TW = Turgid weight of the leaf FW = Fresh weight of the leaf DW = Dry weight of the leaf The water saturation deficit was measured by the following formula (Sangakkara et al, 1996):…”