The authors have declared that no competing interests exist.
An experiment was conducted in the field of Plant Pathology Division, BARI, Joydebpur to evaluate the efficacy of available plant nutrient for the development of purple blotch disease and tip-burn of onion. Eight different treatments viz. Potassium (MP fertilizer), Phosphorus (TSP fertilizer), Boron (Boron fertilizer), Zinc (ZnSO4 fertilizer), Calcium (CaSO4 fertilizer), Copper (CuSO4), Silicon (silica gel) and Manganese (MnSO4 fertilizer) were tested against purple blotch disease and tip-burn of garlic. The present study revealed that soil and foliar application of plant nutrients viz. Potassium, Phosphorus, Boron, Zinc, Calcium, Copper, Silicon and Manganese gave appreciable reduction of purple blotch disease and tip-burn incidence and increased plant growth parameters such as shoot and root growth as well as yield of garlic. Among the nutrients Potassium, Phosphorus, Silicon, Zinc and Calcium were performed better for reducing purple blotch disease severity, tip-burn disease incidence and increasing plant growth as well as yield of garlic. Application of Boron and Manganese also performed better than control. So, soil and foliar application plant nutrients Potassium, Phosphorus, Silicon, Zinc, Boron and Manganese may be recommended for tip-burn and purple blotch disease management and for garlic production in Bangladesh.
Garlic (
The experiment was conducted in the field of Plant Pathology Division, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur during robi 2015-16, 2016-17 and 2017-18 cropping seasons. There were 9 treatments viz. T1= Spray in the furrow soil during transplanting + Foliar spray of Potassium (MP fertilizer @2% water solution), T2= Spray in the furrow soil during transplanting + Foliar spray of Phosphorus (TSP fertilizer @2% water solution), T3= Spray in the furrow soil during transplanting + Foliar spray of Zinc (ZnSO4 fertilizer @1% water solution), T4= Spray in the furrow soil during transplanting + Foliar spray of Silicon (Silica gel @2% water solution), T5= Spray in the furrow soil during transplanting + Foliar spray of Boron (Boro fertilizer @1% water solution) T6= Spray in the furrow soil during transplanting + Foliar spray of Calcium (CaSO4 fertilizer @1% water solution), T7= Spray in the furrow soil during transplanting + Foliar spray of Manganese (MnSO4 fertilizer @ 1% water solution), T8= Spray in the furrow soil during transplanting + Foliar spray of Copper (CuSO4 @1% water solution) and T9= Control (only used recommended dose of fertilizers). The unit plot size was 2 m x 2.5m. RCB design was followed with 3 replications. The variety BARI Rashun-1 was used. The treatments were applied four times viz. 1st application at the time of seedling transplanting, 2nd application 40-45 days after seedling transplanting, 3rd application 15 days after 2nd application and 4th application 15 days after 3rd application. Standard cultivation recommended by BARI was followed to grow garlic
Data were recorded on purple blotch disease severity, tip-burn incidence, plant growth parameter such as plant height, shoot weight, root length and root weight and yield per unit area. Data on plant growth parameters were recorded 65 days after seedling transplanting. Disease data were recorded 15 days after 4th time treatments application. Data were calculated in terms of disease incidence and disease severity (PDI) by following formulae:
The 0-5 disease scoring scale was used to estimate the disease severity (PDI-Percent Disease Index) of purple blotch complex of onion for each unit plot under each treatment. The scale was followed by Islam
0 = no disease symptoms in the plant
1 = a few spots towards the tip, covering less than 10% leaf area
2 = several dark purplish brown patches covering less than 20% leaf area
3 = several patches with paler outer zone, covering up to 40% leaf area
4 = long streaks covering upto 75% leaf area or breaking of leaves / stalks from the centre
5 = complete drying of the leaves/ stalks or breaking of the leaves / stalks from the base
The percent data were converted into arcsine transformation values before statistical analysis. Data were analyzed statistically by using the MSTATC program. The treatment effects were compared by applying the least significant different (LSD) test at P=0.05 level.
Average plant height of onion under control was 27.27 cm plant-1 in the first year, 44.67 cm plant-1 in the second year and 39.33 cm plant-1 in the third year (
Soil and foliar application of different plant nutrient with dose | Plant height (cm) | Plant weight (gplant-1) | ||||
2016-17 | 2017-18 | 2018-19 | 2016-17 | 2017-18 | 2018-19 | |
Potassium (MP fertilizer @2%) | 36.40 a | 57.00 a | 54.00 a | 15.37 a | 22.53 a | 23.17 a |
Phosphorus (TSP fertilizer @2%) | 38.80 a | 53.93 ab | 54.00 a | 15.80 a | 21.87 ab | 22.00 a |
Zinc (ZnSO4 fertilizer @1%) | 33.60 b | 53.20 b | 53.00 a | 13.87 b | 21.47 ab | 21.90 a |
Silicon (Silica gel @2%) | 38.67 a | 53.43 b | 51.67 a | 15.27 a | 20.73 ab | 21.30 a |
Boron (Boro fertilizer @1%) | 31.87 bc | 49.07 cd | 51.33 a | 12.53 c | 19.53 bc | 20.37 ab |
Calcium (CaSO4 fertilizer @1%) | 31.73 bc | 51.40 bc | 49.67 a | 12.20 c | 21.40 ab | 19.93 ab |
Manganese (MnSO4 fertilizer @1%) | 33.47 b | 53.13 b | 51.33 a | 12.80 c | 19.87 ab | 20.37 ab |
Copper (CuSO4 @1%) | 29.40 cd | 47.47 de | 42.00 b | 10.27 d | 16.93 cd | 17.10 bc |
Control | 27.27 d | 44.67 e | 39.33 b | 8.20 e | 15.93 d | 14.20 c |
LSD (P=0.05) | 2.507 | 3.523 | 4.987 | 0.7683 | 2.79 | 3.963 |
In first year, the plant weight of garlic was 8.20 g plant-1 under control. It increased to 10.27-15.80 g plant-1 due to soil and foliar application of different nutrients (
Soil and foliar application of different plant nutrients showed positive effects on root growth of garlic as compared to control (
Soil and foliar application of different plant nutrient with dose | Root length (cm) | Root weight (gplant-1) | ||||
2016-17 | 2017-18 | 2018-19 | 2016-17 | 2017-18 | 2018-19 | |
Potassium (MP fertilizer @2%) | 8.60 a | 6.73 a | 8.00 a | 1.00 ab | 1.73ab | 2.60 ab |
Phosphorus (TSP fertilizer @2%) | 7.73 ab | 7.07 a | 7.73 a | 1.07 a | 1.87a | 2.93a |
Zinc (ZnSO4 fertilizer @1%) | 7.20 bc | 6.60 a | 7.73 a | 0.80 bc | 1.80 ab | 2.67 ab |
Silicon (Silica gel @2%) | 8.67 a | 6.47 a | 7.27 a | 1.33 a | 1.87 a | 2.77 ab |
Boron (Boron fertilizer @1%) | 7.47 bc | 6.73 a | 7.17 a | 0.73 cd | 1.80 ab | 2.47 ab |
Calcium (CaSO4 fertilizer @1%) | 7.27 bc | 6.73 a | 7.47 a | 0.73 cd | 1.67 ab | 2.73 ab |
Manganese (MnSO4 fertilizer @1%) | 7. 80 ab | 6.60 a | 7.47 a | 0.93 abc | 1.67 ab | 2.33 bc |
Copper (CuSO4 @1%) | 6.73 cd | 5.20 b | 5.83 b | 0.77 c | 1.53 b | 1.83 cd |
Control | 6.10 d | 4.67 b | 5.23 b | 0.53 d | 1.20 c | 1.57 d |
LSD (P=0.05) | 0.968 | 0.654 | 1.099 | 0.232 | 0.268 | 0.581 |
In all the years, the incidence of tip burn of garlic was reduced significantly over control due to soil and foliar application with different plant nutrients compared to control (
Soil and foliar application of different plant nutrient with dose | Tip burn incidence of garlic | Reduction of tip-burn incidence (%) | ||||
2016-17 | 2017-18 | 2018-19 | 2016-17 | 2017-18 | 2018-19 | |
Potassium (MP fertilizer @2%) | 33.33 d(35.22) | 25.00 c (29.92) | 39.67 c(38.99) | 53.50 | 57.15 | 46.63 |
Phosphorus (TSP fertilizer @2%) | 40.00 cd(39.15) | 23.33 c (28.85) | 40.33 c(39.41) | 44.19 | 60.00 | 45.74 |
Zinc (ZnSO4 fertilizer @1%) | 46.67 bc(43.09) | 26.67 c (31.07) | 41.33 c(40.00) | 34.88 | 54.28 | 44.40 |
Silicon (Silica gel @2%) | 35.00 d(36.18) | 25.00 c (29.80) | 40.67 c(39.62) | 51.16 | 57.15 | 45.28 |
Boron (Boro fertilizer @1%) | 46.67 bc(43.08) | 28.33 c (32.14) | 45.67 c(39.50) | 34.88 | 51.43 | 38.56 |
Calcium (CaSO4 fertilizer @1%) | 51.67 b(45.96) | 25.00 c (29.92) | 48.00 bc(43.85) | 27.91 | 57.15 | 35.42 |
Manganese (MnSO4 fertilizer @1%) | 43.33 bcd(41.07) | 28.33 c (32.14) | 40.67 c(39.61) | 39.54 | 51.43 | 45.28 |
Copper (CuSO4 @1%) | 53.33 b(46.91) | 48.33 b (43.08) | 53.33 b(46.92) | 25.58 | 17.14 | 28.25 |
Control | 71.67 a(57.98) | 58.33 a (49.83) | 74.33 a(59.53) | - | - | - |
LSD (P=0.05) | 6.788 | 6.788 | 6.918 | - | - | - |
All the treatments significantly reduced purple blotch disease severity compared to control during three consecutive years. In the first year all the treatments significantly reduced the purple blotch disease severity than control (
Soil and foliar application of different plant nutrient with dose | Severity of purple blotch disease of garlic (PDI) | Reduction of severity of purple blotch disease (%) | ||||
2016-17 | 2017-18 | 2018-19 | 2016-17 | 2017-18 | 2018-19 | |
Potassium (MP fertilizer @2%) | 24.67 b(29.76) | 24.00 d (29.30) | 28.00 c (31.93) | 57.95 | 58.14 | 50.00 |
Phosphorus (TSP fertilizer @2%) | 24.00 b(29.21) | 24.00 d (29.32) | 28.67 c (32.37) | 59.09 | 58.14 | 48.78 |
Zinc (ZnSO4 fertilizer @1%) | 25.00 b(29.94) | 25.33 cd (30.22) | 29.33 c (32.77) | 57.39 | 55.82 | 47.63 |
Silicon (Silica gel @2%) | 23.67 b(29.02) | 26.00 cd (30.65) | 29.00 c (32.56) | 59.66 | 54.65 | 48.21 |
Boron (Boro fertilizer @1%) | 27.00 b(31.31) | 26.67 cd (31.08) | 31.00bc (33.82) | 53.98 | 53.48 | 44.64 |
Calcium (CaSO4 fertilizer @1%) | 27.00 b(31.30) | 27.33 c (31.52) | 29.67 c (32.99) | 53.98 | 52.33 | 47.02 |
Manganese (MnSO4 fertilizer @1%) | 25.00 b(29.96) | 26.67 cd (31.08) | 30.33 c (33.41) | 57.39 | 53.48 | 45.84 |
Copper (CuSO4 @1%) | 27.67 b(31.70) | 45.33 b (42.32) | 36.00 b (36.85) | 52.84 | 20.93 | 35.71 |
Control | 58.67 a(50.05) | 57.33 a (49.22) | 56.00 a (48.46) | - |
|
- |
LSD (P=0.05) | 5.386 | 2.06 | 3.051 | - | - | - |
In all the years, soil and foliar application of different plant nutrientsgave signicantly higher yield of garlic (
Soil and foliar application of different plant nutrient with dose | Yield (tha-1) | Yield increased over control (%) | ||||
2016-17 | 2017-18 | 2018-19 | 2016-17 | 2017-18 | 2018-19 | |
Potassium(MP fertilizer @2%) | 5.28 b | 6.77 a | 7.15 a | 40.15 | 37.67 | 33.98 |
Phosphorus(TSP fertilizer @2%) | 5.28 b | 6.47 a | 6.79 ab | 40.15 | 34.78 | 30.48 |
Zinc(ZnSO4 fertilizer @1%) | 5.20 bc | 5.96 a | 6.61 b | 39.23 | 29.19 | 28.59 |
Silicon(Silica gel @2%) | 6.42 a | 6.47 a | 6.69 ab | 50.78 | 34.78 | 29.45 |
Boron(Boro fertilizer @1%) | 4.75 bc | 6.26 a | 6.68 b | 33.47 | 32.59 | 29.34 |
Calcium(CaSO4 fertilizer @1%) | 4.20 c | 5.96 a | 6.45 b | 24.76 | 29.19 | 26.82 |
Manganese(MnSO4 fertilizer @1%) | 5.19 bc | 5.96 a | 6.51 b | 39.11 | 29.19 | 27.50 |
Copper(CuSO4 @1%) | 4.18 cd | 4.85 b | 5.35 c | 24.40 | 12.98 | 11.78 |
Control | 3.16 d | 4.22 b | 4.72 d | - | - | - |
LSD (P=0.05) | 1.03 | 1.03 | 0.471 | - | - | - |
From this study it is observed that application different plant nutrient have significant effect on plant growth, decreased purple blotch diseases severity and tip burn incidence as well as increase yield of garlic. Among the nutrients MP fertilizer, TSP fertilizer, ZnSO4, Silica gel, Boron fertilizer and CaSO4 were performed better than other treatments for reducing purple blotch disease severity, tip-burn and increasing plant growth as well as yield of garlic. Different workers reported that the use of fertilizers produces a more direct means of using nutrients to reduce the severity of many diseases
The present study revealed that soil and foliar application of plant nutrients viz. Potassium, Phosphorus, Boron, Zinc, Calcium, Copper, Silicon and Manganese gave appreciable reduction of purple blotch disease and tip-burn incidence and increased plant growth parameters such as shoot and root growth as well as yield of garlic. Among the nutrients Potassium, Phosphorus, Silicon, Zinc and Calcium were performed better for reducing purple blotch disease severity, tip-burn disease incidence and increasing plant growth as well as yield of garlic. So, soil and foliar application plant nutrients Potassium Phosphorus, Silicon, Zinc, Boron and Manganese may be recommended for tip-burn and purple blotch disease management and for garlic production in Bangladesh.