19 Jun, 2024
As we know soil testing is crucial before planting and for on-going crops management to assess nutrient balance and soil pH, which affects nutrient availability. However, soil tests may not always represents the actual nutrient levels in the plants.
For example, a soil high in a certain nutrient might not translate to high levels in the plants, or the plants might have adequate nutrients despite a soil test indicating a deficiency. Factors like plants growth, soil characteristics (such as pH and compaction), and environmental conditions (like rainfall or drought) can impact this discrepancy. Therefore, while petiole analysis is generally more reliable for evaluating plants nutrient status. Combining both soil and plant tests offers the most accurate picture of fertility and necessary adjustments during crop production.
Total content of Macronutrients (Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulfer), and Micronutrients (Iron, Manganese, Zinc, Copper, Boron, and Mollybdenum etc). Additionally, any other parameters are also analysed according to requirement.
For making effective INM schedule the knowledge of movement of ionic forms of nutrients in soil and plant system should be known for their availability and uptake pattern.
As we know, soil is the storehouse of nutrients and water for plants, similarly, petioles and leaves are storehouse of nutrients within the plant body. Among the above-mentioned methods, plant tissue analysis is the best way to monitor nutrient levels and requirements for higher yields while crops are standing in the field. By directly tracking the deficient plant nutrients, farmers can adjust their fertilizer programs and potentially reducing costs on excess. We accurate identification is essential for effective fertilizer management.
For tissue analysis, we use different plant parts as a sample, such as petioles and leaf blades. However, petiole analysis and leaf blades are most preferred for nutrient assessment. Basically, the plant analysis has been done for more commercial crops to prevent the production losses due to nutrient deficiency.
Plant tissue testing mostly performed in: -
According to growth stages and types of crops/plants the recommended plant parts are different. Here we provide some recommendations of time and plant parts for nutrients analysis in important plants/crops.
Crops |
Plant Part and Stage of Growth |
Sample Size (Leaf) |
|
Grapes |
5th petiole from base at bud differentiation (45 Days after April Pruning) for yield. Petioles opposite to bloom (45 Days after October Pruning) for quality fruits. |
50 |
|
Pomegranate |
8th leaf from the apex at bud differentiation in 15th April flush for February crop and from August flush for June crop. |
50 |
|
Banana |
20 cm 2 leaf portion along the midrib of the 3rd youngest fully expanded leaf at full bloom stage or flowering stage. |
15 |
|
Mango |
4–7-month-old Petioles with leaf from middle of shoot. |
30 |
|
Sugarcane |
3rd leaf from top at 3-5 month after planting |
|
|
Tomato |
Leaf adjacent to inflorescences at mid-bloom |
|
|
Mandarin |
Basal 6-month-old leaf from current growth in marc |
50 |
|
Acid lime |
Basal leaf at 5 month-age from current season’s growth |
50 |
|
Sweet Orange |
Basal leaf 6- month-age from current season’s growth emerged in March to September |
50 |
|
Lemon |
Basal 6- month-old leaf from current season’s growth |
50 |
|
Guava |
Third pair of leaf from apex in August/December |
30 |
|
Ber |
5th leaf from tip of secondary and tertiary shoot in June |
50 |
|
Fig |
Basal leaf from mid-summer growth |
40 |
|
Custard apple |
5th leaf from growing point in May/June |
50 |
(Source: Bhargava,B.S., 1999. Leaf analysis for diagnosing nutrients need in fruit crops)