EFFECT OF SALINE IRRIGATION WATER ON GROWTH, NUTRIENTS COMPOSITION AND YIELD OF ONION (Allium cepa L.) VARIETIES
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Date
2019-06
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JAU, JUNAGADH
Abstract
A pot experiment was conducted at Department of Agricultural Chemistry and Soil Science, College of Agriculture, Junagadh Agricultural University, Junagadh to assess the “Effect of saline irrigation water on growth, nutrients composition and yield of onion (Allium Cepa L.) varieties” during the winter season of 2017-18.
The pot experiment comprised four levels of salinity viz., <2.0, 4.0, 6.0 and 8.0 dS m-1 and five different varieties viz., V1- GJWO-3, V2- GJRO-11, V3-Talaja red, V4- Pilli patti and V5- PWF-131 in Factorial Completely Randomized Design with replicated three times. The experimental soil was medium black calcareous, clayey in nature which was slightly alkaline in reaction, pH2.5 8.0, EC2.5 0.58 dS m-1, low in available nitrogen (242 kg ha-1), medium in phosphorus (34.20 kg ha-1), high in available potassium (298 kg ha-1), sulphur (23.50 kg ha-1). Micro nutrient status was medium in available iron (6.25 mg kg-1), high in manganese (15.20 mg kg-1), low in available zinc (0.45 mg kg-1) and high in available copper (1.25 mg kg-1).
The experimental result revealed that the growth, yield and yield attribute, quality parameters, bio-chemical parameters, nutrient contents and nutrient uptakes were significantly influenced by the different varieties of onion. The highest plant height (49.33 cm), fresh straw yield (37.03 g), fresh weight of bulb (39.21 g), volume of bulb (25.67 cm3), bulb dry weight (3.90 g) and quality parameters viz., neck thickness and TSS among different tested varieties of onion.
Bio-chemical parameters viz., the highest proline accumulation (0.96 μmole / gf.wt) was found with variety V4 (Pilli patti). Among the different tested varieties, variety V4 (Pilli patti) produced significantly higher RWC, chlorophyll a, chlorophyll b and total chlorophyll content in comparision of onion at 45 DAT.
The sodium concentration in leaves of onion observed lowest (0.173 %) and potassium and calcium highest (0.213 % and 0.584 %) at 45 DAT with variety V4 (Pilli patti). The nitrogen, phosphorus, potassium and sulphur content in bulb and straw at harvest was remain unaffected to different variety of onion. In case of calcium and magnesium content found significant with variety V4 (Pilli patti) in bulb
ABSTRACT
and straw at harvest, while sodium content found lowest with variety V4 (Pilli patti) in straw at harvest.
Na+/K+ ratio observed significant lowest with variety V4 (Pilli patti) in bulb and straw at harvest, while Ca++/Na+ ratio observed significant highest with variety V4 (Pilli patti) in leaves at 45 DAT and at harvest.
The concentration of macro (N, P, K and S) and micro (Fe, Mn, Zn and Cu) nutrient in bulb and straw at harvest remained unaffected due to varietal difference. The maximum uptake of major nutrients (N, P and K) and micro nutrients (Fe, Mn, Zn and Cu) were recorded with variety V4 (Pilli patti) in bulb, straw and its total uptake.
Application of saline irrigation water treatment S1 (<2.0 dS m-1) was observed superior in rest of the levels in plant height (44.73 cm), no. of leaves per plant (5.30), fresh straw weight (34.40 g), fresh weight of bulb (33.77 g), volume of bulb (22.55 cm3) and quality parameters viz., neck thickness and TSS among different salinity levels recorded significant at S1 (<2.0 dS m-1), in case of proline accumulation (0.75 μmole/gf.wt) was found highest S4 (8.0 dS m-1), while RWC, chlorophyll a, chlorophyll b and total chlorophyll content observed significant at salinity level S1 (<2.0 dS m-1), than other salinity levels in onion at 45 DAT. Sodium content observed lowest and calcium highest at S1 (<2.0 dS m-1) in leaves at 45 DAT. The concentration of macro (N, P, K and S) and micro (Fe, Mn, Zn and Cu) nutrients in bulb and straw at harvest were remain unaffected. In case of calcium and magnesium content found significant at salinity level S1 (<2.0 dS m-1) in bulb and straw at harvest, while sodium content found lowest at level S1 (<2.0 dS m-1), in bulb and straw at harvest. Micro nutrients (Fe, Mn, Zn and Cu) were remain unaffected by different levels of saline irrigation water. Lowest Na+/K+ ratio and highest Ca++/Na+ ratio found at level S1 (<2.0 dS m-1) in leaves at 45 DAT and in bulb and straw at harvest. Maximum uptake of major nutrients (N, P and K) and micro nutrients (Fe, Mn, Zn and Cu) were recorded highter at level S1 (<2.0 dS m-1) in bulb, straw and its total uptake. The various macro and micro nutrient available in soil found non-significant to different salinity levels. The significantly lowest EC2.5 and soil pH2.5 were recorded under application of saline irrigation water S1 (<2.0 dS m-1) after harvest of crop.
Based on the result, it can be concluded that the variety V4 (Pilli patti) was found the tolerant onion cultivar responding to application of saline irrigation water. This variety (Pilli patti) perform better with different salinity tolerance criteria like the highest mean bulb yield (20.90 g plant-1), as well as mean salinity index (55.75 %) and lower value of yield decline at high salinity level EC (6.40 dS m-1) for 50 % threshold yield. Being the lower value of regression slope (b) for this variety, the yield of this variety is least sensitive to salinity as compared to remaining other varieties.