The significant role of plants in both cycling of trace elements and contaminating the food chain has been well illustrated for various ecosystems. Plants can accumulate trace elements, especially heavy metals, in or on their tissues due to their great ability to adapt to variable chemical properties of the environment, thus plants are intermediate reservoirs through which trace elements from soils, and partly from waters and air, move to man and animals.
Leafy vegetables are regarded as group whose leaves and stems are eaten as vegetables.They also have an abundance of vitamins and minerals within them. The primary minerals present in green vegetables are magnesium, iron, calcium, potassium, vitamins C, E and K amongst others. Studies have shown that leafy vegetables have greater potential of accumulating heavy metals in their edible parts than grain or fruit crops as fruits and seeds have low transpiration rates.
(1)Celery, broccoli and cauliflower - the use of Boron will lead to a reduction in internal browning and stem cracking caused by deficiency.
(2)Cabbage - High potassium can lead to increasing head weight and earlier maturity in cabbage,
(3)Lettuce & Spinach - Crops such as Lettuce can suffer from physiological disorders such as tip burn caused by calcium imbalance. Ca+Mg can help overcome these problems. They can also increase head weight and keep the produce in marketable condition for longer with less wastage at the point of sale.