The plant on the right is deficient in boron.
Boron
Boron is one of the 'Big Four' nutrients
Boron (B) is necessary for uptake and efficient use of calcium in the plant. It is a calcium synergist and a temperature regulator. Boron is essential for cell division and development, particularly in the growing points of shoots and roots, also promoting flowering. It affects pollination, pollen viability, fruit and seed set. It is required for the movement of sugars (e.g. energy) within the plant and hence plays a significant role in photosynthesis.
Typical Boron deficiency symptoms include
Hollow stems in cabbages and cauliflowers;
Woody taste in strawberries;
Poor seed set generally;
Crosswise cracking of celery stalks;
External and internal cork in apples;
Lop-sided fruit and heavy fruit shedding of citrus; ‘shot’ berries and poor fruit set in grapes;
Flower shedding with deformed and bumpy fruit.
It also affects growing tips (i.e. dieback) and leaves. Small clover leaves may indicate boron deficiency.
In the soil boron is an anion and therefore is found mainly the soil solution or complexed with humus.
Marine soils may have high B reserves. Deficiencies can be worse in long dry spells and in high pH soils. Kiwi Fertiliser recommends Organibor, a natural magnesium-calcium borate from Argentina. Organibor is non-toxic. however, it is relatively slow acting, particularly in a dry season, so may need to be applied early in the season, or some Ulexite may need to be added as well, particularly for short-term crops such as turnips. Organibor boron levels in the soil stay higher for longer with Organibor.
Without boron, the plant cannot transfer sugar from leaves to the roots. This process is also interrupted by various cultural practices, i.e. girdling.
In animals, boron helps regulate both calcium release into the blood and calcium absorption. Boron helps convert vitamin D into an active form which facilitates calcium absorption. Silicon and calcium together are cell strengtheners but they both require boron to deliver their benefits. Boron encourages silica to form silicic acid which then moves into the plant to form nutrient highways which then help to move the poorly translocated calcium into the plant. Required at 2ppm in the soil.
