Scheme of potato’s sampling on nitrate analysis
The level of nitrate – nitrogen in potato petioles must be interpreted in relation to the stage of plant development. With an adequate supply of nitrate – nitrogen in the soil, the level in the petiole will be much higher in early season than later when plants are more mature and the soil nitrogen supply has been reduced.
Nitrogen fertilizer application should be sheduled to supplement the N available from soil sources according to the crop’s N requirements during different growth stages. The potato plant’s growth cycle can be divided into four growth stages based on top and tuber growth and nutrient uptake.
|I||VEGETATIVE – describes plant development from planting until the start of tuber initiation|
|II||TUBERIZATION – lasts 10 to 14 days with tubers being formed at the tips of the stolons but not appreciably enlarging. The plant may have a few open flowers at the end of this stage|
|III||TUBER GROWTH – the phase where tuber growth in linear if all growth conditions are optimum|
|IV||MATURATION – the period during which the veins start to yellow, leaf loss is evident, and tuber dry weight increases are mainly from translocation of materials from the tops and roots into tubers.|
- – for the analysis on nitrate – nitrogen use potato’s petiole;
- – petioles – that part of the plant connecting the leaf blade with the stem;
- – select the fourth or fifth leaf from the top, when the plants are growing rapidly;
- – as rate of growth slows down, the second or third leaf can be used;
- – strip away the leaf tissue and place the petioles in paper bags;
- – collect 25-30 petioles at random from each sample area;
- – submit samples to the laboratory immediately.
You can sample the potato sample for analysis on nitrate nitrogen – download here