Nutrient requirements in three Victorian radiata pine nurseries with contrasting soils

Zinc deficiencies are rare in pine seedlings with less than five documented cases in bareroot nurseries. One temporary deficiency occurred after soil was land-leveled (i.e., topsoil removed) and another occurred on a peat soil after more than 2,200 kg of agricultural lime was applied before sowing. Farmers also observe zinc deficiencies on (1) over-limed areas and (2) where Zn-demanding crops are grown on areas where topsoil was removed during land leveling. Since ZnSO4 is a naturally occurring pesticide, sometimes height growth increases are due to pest control. In pathogen-rich soils, pine growth may be improved more by the fungicidal effect than by a growth benefit from added sulphur and zinc. As a result, a pseudo-deficient response is possible when growth of non-deficient seedlings increases after treatment with large amounts of ZnSO4 or ZnCl2. In some trials, claims of a Zn deficiency have been made without supporting evidence from foliar tests or from tests using pathogen-free soil. Although fertilization with Zn increased seedling growth at pine nurseries in New Zealand, India, Russia, and Wisconsin, only at the Sweetwater Nursery in New Zealand did foliar tests prove a Zn deficiency.

Section: Zn Removed At Harvestmentioning

confidence: 99%

Zinc fertilization in bareroot pine seedbeds

South

2023

“…Foliage of bareroot pine seedlings averaged 950 μg g -1 Mg in Australia (Flinn et al 1980;Hopmans and Flinn 1983), 750 μg g -1 Mg in New Zealand (Knight 1978b) and 1,000 to 1,100 μg g -1 Mg in the southern United States (Boyer and South 1985;Starkey and Enebak 2012). At a nursery experiment in Fleet England, yellow-tip Pinus contorta seedlings had slightly more than 600 μg g -1 Mg but those treated with 6.7 kg ha -1 of MS contained 850 μg g -1 Mg (Aldhous and Atterson 1966).…”

Section: Tissue Analysismentioning

confidence: 99%

Use of magnesium in bareroot pine nurseries

South

2022

Pines with visible magnesium (Mg) deficiencies (i.e. yellow tips on needles) occur in bareroot nurseries throughout the world. The occurrence of “yellow-tips” is rare when soil pH is above 6.5 but they have occurred on sands (pH < 6.0) with less than 25 μg g-1 Mg. If yellow-tips occur in the summer, the foliar content of yellow tips is usually less than 1,000 μg g-1 Mg. Some nurseries do not produce “yellow-tip” seedlings when irrigation water contains sufficient Mg. Factors favoring a deficiency include low soil pH, high calcium in irrigation water, frequent fertilization with nitrogen and potassium and applying too much gypsum. Although various Mg fertilizers are available, many nursery managers apply dolomite or potassium-magnesium sulfate before sowing seeds and a few also apply magnesium sulfate in July or August. Soil tests are used to determine when to fertilize before sowing and foliage tests determine when to apply Mg to green seedlings. Nursery managers who follow S.A. Wilde’s forest-based soil recommendations may apply magnesium sulfate to green seedlings even when seedbeds contain adequate levels of Mg. When deficiency is minor, chlorosis on needle tips usually disappears before the fall equinox and, when applied at this time, Mg fertilizers have little or no effect on height growth. This paper reviews some of the past and current uses of Mg in bareroot nurseries and highlights a need for additional research.

“…There are six approaches to fertilizing bareroot nurseries with boron: (1) rely on boron in irrigation water and rainfall and apply boron when visual deficiency symptoms appear; (2) apply an insoluble boron fertilizer to soil (e.g. 2 kg ha -1 B) approximately once every four to eight seedling harvests; (3) apply soluble boron before sowing when soil tests indicate low boron (Stone et al 1982;Dumas and Patterson 2005); (4) test soil a month after sowing and apply soluble boron to areas with < 0.4 μg g -1 B; (5) test foliage in July and apply soluble boron to seed lots with < 8 μg g -1 B in foliage; and (6) routinely apply soluble boron to seedlings in July or after the summer equinox (Hopmans and Flinn 1983;Landis et al 1989;Rodríguez-Trejo and Duryea 2003).…”

Section: Barerootmentioning

confidence: 99%

Use of boron in conifer and hardwood nurseries

South

2021

Nursery seedlings with visual boron (B) deficiencies are rare, especially for broadleaf species but they may have occurred in conifer nurseries in Florida, Oregon and the UK. Factors favoring a deficiency include high soil pH, high soil calcium and low soil moisture (i.e. withholding irrigation). Symptoms of a boron deficiency in pine include dead terminals, resin exudation from buds, dark green foliage, and terminal needles with less than 3 μg g-1 B. Chlorosis is an iron deficiency symptom but is not a boron deficiency symptom. At some nurseries (with more than 2% organic matter and more than 0.05 μg g-1 B in irrigation water), seedlings do not have a hidden hunger for B. As a result, there are no published trials that demonstrate a positive growth response from adding boron to managed nursery soils (when seedbed density is not reduced by boron). This review highlights some of the past and current uses of B in nurseries with a focus on deficiency and toxicity effects.