Dec 17, 2008
India – SOP improves quality of horticultural crops
India is one of the world’s biggest producers of horticultural crops such as fruits (banana, mango, grapes), vegetables, tea and tobacco. During recent years, there is a clear trend from producing large amounts of crops towards optimal product quality. Parameters such as fruit size and coloration, high contents of valuable ingredients (vitamins, minerals...), suitable processing and keeping characteristics have become more and more important.
Balanced fertilization is a prerequisite for high quality horticultural crops. The ratio of the major nutrients nitrogen (N), phosphorus (P) and potassium (K) has be in accordance to the physiological needs of the crop plant. Besides that, essential nutrients such as calcium (Ca), magnesium (Mg) and sulphur (S) as well as the so-called micro-elements (iron, copper, zinc, manganese and boron) have to be applied in appropriate doses in order to fulfil the specific requirements of horticultural crops.
In a series of field experiments at different sites in India, K+S KALI has tested Sulphate of Potash (SOP) as a natural K and S source for high value crops like tea, mango and tomato.
Unlike KCl (= Muriate of Potash, the most common potash fertiliser in India), SOP is virtually free from chloride (Cl) and thus the ideal fertiliser for all chloride-sensitive horticultural crops.
SOP has been tested over the last years in tea plantations of UPASI at Valparai (Tamil Nadu). It was found that SOP-treated tea bushes produce higher qualities in comparison to those having been supplied with MOP. Made tea had higher contents of volatile flavour compounds. As a consequence, made tea from SOP-treated bushes was scored higher by a taster test panel.
In tomato field trials made in Coimbatore SOP treatments significantly improved yield and fruit quality parameters. Tomato fruits accumulated more lycopene (the red colour pigment) and vitamin C as the standard treatment supplied with MOP.
The experiments will be continued with different horticultural crops including citrus and vegetables.