Growth and uptake of N, P, K and B by Pinus radiata D. Don in response to applications of borax

Abstract

Leader dieback associated with B deficiency in P. radiata D. Don plantations was treated with borax applied at rates of 50, 100 and 150 kg ha -1. This initially increased B in foliage from 5 to 40, 80 and 110/xg g-~ respectively, and was followed by a rapid decline and stabilisation at around 25/xg g-I for the duration of the study. Annual fluctuations in foliage B levels were strongly correlated with rainfall during the preceding spring and summer. Uptake of N, P and K increased as a result of applied B and comparison of the distribution of these nutrients in crowns of fertilized and unfertilised trees six years after application indicated continued uptake of these nutrients probably as a result of improved root growth due to B. Foliage concentrations of B like N, P and K, increased in young needles towards the upper crown and this, together with a decline in needle concentrations of B as foliage aged, indicated some redistribution of B from older to new foliage. A limit of 5/zg g-1 was found below which little redistribution seems to occur.Application of B prevented further leader dieback, improved apical dominance and height growth and increased volume production by 25 m 3 ha-1 at age 8 years. Differences between application rates of B were not significant in terms of growth.

Growth dynamics and mycorrhizas of Norway spruce ( Picea abies) seedlings in relation to boron supply

“…Boron deficiency is known to lessen shoot height growth in many coniferous species (Hopmans and Flinn 1984;Veijalainen et al 1984;Stone 1990;Hopmans and Clerehan 1991). Measurement of the height of B-deficient trees is somewhat questionable, however, as those trees usually have multileadered crowns due to the effects of the condition on apical dominance.…”

Boron Mobility in Two Coniferous Species

“…Hopmans and Clerehan (1991) found that the B concentrations in Pinus radiata were highest in the old needles in trees with little boron (4±7 mg kg À1 ), but in B-fertilized trees, the concentrations were highest in the current needles. Based on their results, Hopmans and Clerehan (1991) postulated that there was internal redistribution of boron in Pinus radiata trees. According to Ziegler (1975), sucrose is the only carbohydrate translocated in the phloem of Norway spruce.…”

Leaf life span and the mobility of “non-mobile” mineral nutrients – the case of boron in conifers

“…Consistent with Dugger's (1983) ideas Wikner (1983) suggested that B was not mobile in Norway spruce. In contrast, it has been suggested that B is mobile in Scots pine (Helmisaari 1990b, Wikner 1983 and Monterey pine (Hopmans and Clerehan 1991). In this section we reassess published data for these species, and present previously unpublished data for lodgepole pine.…”

“…In Monterey pine (Pinus radiata) Hopmans and Clerehan (1991) found that B concentrations were slightly higher in older needles than in current year needles of trees with little boron (4-7 mg kg -1 ) (r = 0.79, P = 0.42), but in B-fertilized trees, the concentrations were lower in older needles than in current needles (r = -0.99, P = 0.008, Fig. 5).…”

“…5). Based on these data Hopmans and Clerehan (1991) postulated that there was internal redistribution of boron in trees of this species. Schoettle and Smith (1999) and analysis methods by Barrick and Schoettle (1996).…”