Consumer demand for blueberries continues to grow making it an attractive crop for existing and new fruit growers. Blueberry culture can be challenging because of their unusual biological characteristics so care is needed to optimise yields and quality. Solufeed have a range of products to help the progressive grower achieve these aims.
Biology of Blueberries
Blueberries belong to the genus Vaccinium in the plant family Ericaceae. There are about 450 other species worldwide and those of commercial importance also include bilberries and cranberries.
Ericaceous subjects are characteristically calcifuge (lime-hating) and therefore naturally found growing in acidic soils such as marshes and heathland. Calcifuges cannot cope with alkaline soils, not as a direct result of the presence of hydroxyl or carbonate ions, but rather the effect of pH on iron availability. Under alkaline (pH>6.5) conditions iron becomes increasingly unavailable causing the classic symptoms of leaf chlorosis or yellowing which in turn leads to lost productivity.
Calcifuges also have different nitrogen needs, preferring the ammoniacal form to nitrate.
All this give a clue about the best cultivation and nutrition techniques for Blueberries.
Reflecting their origins, the optimum soil pH for blueberries is 4.5 - 5.5, with 5.5 being too high for some varieties. Consequently, much commercial production of Blueberries takes place in containers where pH can be more easily controlled. Here and especially where coir-based growing media is used, optimum pH is lower at 4.0 - 4.5. It is reported that pH's as low as 3.0 can be tolerated.
Special nitrogen requirements
Blueberries and other calcifuges have different nitrogen preferences to other crops. They are not able to utilise the nitrate (NO3) form effectively but rather prefer the ammoniacal form (NH4). This is because Blueberries lack adequate nitrate reductase activity to metabolise the NO3. Whilst both the NH4 and NO3 forms are taken up, the latter remains unused; this usually does no harm but there have been reports of leaf burn where high levels of NO3 containing fertilizers have been used. A practical consequence, of course, is that the NO3 in fertilizers is effectively wasted and it still contributes to EC but to no purpose. The best nitrogen sources for Blueberries are ammonium sulphate (readily providing NH4) and urea (which is naturally broken down to NH4). Otherwise, the fertilization of Blueberries is fairly straightforward but they are particularly sensitive to iron deficiency and care should be taken to avoid shortages.
The Solufeed Programme
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Having no root hairs as such, Blueberries form a symbiotic relationship with naturally occurring Ericoid Mycorrhizae. Biovin plays an important role in stimulating this relationship to create a living interface between roots and soil thereby improving root activity, nutrient uptake and plant growth. Biovin has been used successfully by growers all over the world since 1974 and much research resulting in scientific reports have been published.
- Stimulates plant health and resistance.
- Natural organic fertilizer (3:1:2).
- Also contains available Silicon.
- Very economical at comparatively low rates.
Application: Top dressing or combine with growing substrate.