The effect of soil water on root production of peach trees in summer

Abstract

The effect of soil water supply on peach root production in summer was studied in the Goulburn Valley area of northern Victoria. Under commercial irrigation practice roots do not grow in summer. Field experiments showed that when the soil was kept moist by frequent irrigation (every 3–4 days), the concentration of roots in the surface soil nearly doubled in a single season. Furthermore, observation through glass plates showed that this enhanced root growth occurred throughout summer. When roots were kept inactive in dry soil until midsummer and thereafter irrigated frequently, they immediately responded and grew rapidly. The increased root growth did not impair fruit production. In a glasshouse experiment, with glass-fronted chambers, a relationship between root elongation, root concentration and the drying rate of the soil was found. Each experiment supported the hypothesis that soil drying rate determines the growth of roots in the surface soil. Where there was a high concentration of roots, a low irrigation frequency, and high transpiration, the rate of soil drying was rapid and roots grew slowly. It is suggested that manipulation of root growth by regulation of soil water supply may be an important method of studying root-top interactions.

Root foraging in response to heterogeneous soil moisture in two grapevines that differ in potential growth rate

“…Various attempts have been made to describe root foraging responses to soil moisture heterogeneity (Richards & Cockroft, 1975; Coutts, 1982; Fort et al ., 1998; Green & Clothier, 1999; Steudle, 2000); however, we are unaware of any studies that have evaluated the role of a plant's potential growth rate. Using a system where genetically identical shoots were grafted on to two genetically diverse root systems, one of known high growth potential (HSV) and one of lower growth potential (LSV), we provide evidence that growth predisposition influenced root responses in both space and time across a gradient in plant water stress.…”

“…During periods of decreased water availability, increased root production or fine lateral initiation has been observed in field‐grown tomatoes (Reid & Renquist, 1997) and perennial ryegrass ( Lolium perenne ; Jupp & Newman, 1987). As soil dries, plants typically reduce root growth (Richards & Cockroft, 1975; Steudle, 2000; Comas et al ., 2005) and carbon allocation (Kosola & Eissenstat, 1994) to those roots in dry portions of soil and preferentially grow roots in regions of high soil moisture (Coutts, 1982; Fort et al ., 1998; Green & Clothier, 1999).…”

Influence of temperature and water potential on root growth of white oak

“…During the period between budburst and leaf senescence, I*"'' was the critical factor controlling RER. Deans (1979), Roberts (1976), and Richards and Cockroft (1975) reported that root growth tended to decrease with decreasing soil moisture even in periods when soil temperature was increasing. Root growth of white oak was similar except that soil water deficits in the range of -0.4 to -0.8 MPa induced greater root production than did higher levels of f'^"'' which produced high RER but low NR.…”

Effect of Fruit Crop Load on Peach Root Growth

“…It is fairly well known that root growth in temperate fruit trees exhibits strong seasonal periodicity and can be affected by crop load (Atkinson, 1980). Peach appears to be no exception, and several researchers have reported clear peaks of root growth in the spring and after harvest but there is some controversy over whether the peaks in root growth are coordinated with periods of shoot growth, crop demands for assimilates or soil growth conditions (Richards and Crockroft, 1975;Williamson and Coston, 1989;Glenn and Welker, 1993). Furthermore, the goal of all the previous peach studies was to describe the natural patterns of root growth under field conditions using root observation boxes or mini-rhizotrons but not necessarily to quantify root growth potential.…”