Effect of phosphorus applications under different types of salinity in tomato
Loading...
Date
2016
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU
Abstract
Two screen house experiments were conducted to study the relative tolerance of tomato (Var. Hisar Arun) and interactive effect of phosphorus with different types of salinity on tomato crop. In first experiment, the treatment consisted of two types (Cl- and SO42- dominated) with the four levels 0, 2, 4, 6 and 8 dS m-1 of salinity. In the second experiment, interactive effect of different phosphorus levels (0, 12.5, 25 and 50 ppm) with chloride and sulphate dominated salinity was investigated on yield, fruit quality and nutrient content of tomato. Both the experiments were replicated thrice in a completely randomized design and the desired types of salinity were created using chloride and sulphate salts of the Na+, Ca+ and Mg2+. Salinity induced early flowering in tomato and this advancement was more pronounced in chloride dominated salinity as compared to sulphate dominated salinity. With the increasing salinity levels from 0 to 8 dS m-1 there was a decrease in the plant height, number of fruits, yield and mineral composition of tomato. SO42- salinized plants had better vegetative growths as compared to that of Cl- salinized plants. The overall reduction of fresh fruit yield at an ECe of 2, 4, 6 and 8 dS m-1 under Cl- and SO42- dominated salinity was 8.1 and 3.4, 26.4 and 16.2, 40.0 and 28.1 and 51.5 and 42.5 per cent, respectively as compared to non-saline conditions. Thus there is more than 50% yield reduction at 8 dS m-1 in chloride salinity.
There was a significant increase in TSS, firmness, ascorbic acid and titratable acidity of tomato fruit with increasing level of salinity due to water and ionic stress created by both types of salinity. However, values of all these fruit quality parameters decreased with increased application of P due to stress mitigation by P under saline soil conditions. The increased levels of P from 0 to 50 ppm in soil resulted in increase of both growth and fruit yield of tomato irrespective of types and levels of salinity. Cl-1 content of plants decreased and N, P, K and SO42- content of plant was increased with application of P. A synergistic relationship between P and SO42- and an antagonistic one between P and Cl-1 ions was established. The mean ECe, water soluble Na+, Ca+, Mg2+, Cl- and SO42- increased with increase in the salinity level from 0 to 8 dS m-1 and these increasing concentrations in soil affect the tomato crop. These concentrations decreased significantly as applied P increased in soil. Therefore, P mitigates the effect of salinity.
Description
Keywords
Planting, Inorganic acid salts, Vegetables, Fruits, Irrigation, Yields, Developmental stages, Biological development, Acidity, Food preservation