| Crop | Plant Part to Sample | Time of Sampling |
|---|---|---|
| Alfalfa | Midstems for NO3-N, PO4-P, K Leaves for SO4-S Tops for Mo, B |
1/10 Bloom |
| Asparagus | Fern needles 4" tip section | September |
| Cabbage/Lettuce | Midrib of wrapper leaf | Heading |
| Cantaloupe/Cucumber | Petioles of 6th leaf/ from growing tips 6-8 true leaves |
Early fruit set |
| Corn | Midrib from young mature leaf Midrib from leaf opposite ear Leaf - young mature Leaf opposite ear |
Before ear formation After ear formation Before ear formation After ear formation |
| Cotton | Young, mature petiole | June thru Sept 15 |
| Onion/Garlic | “Y” leaf from 6” plant height to pre-harvest |
Pre-harvest |
| Sorghum/Milo | Young mature leaf | Pre-harvest |
| Tomato | Petiole of recently matured leaf (4th leaf from growing tip) | Early Bloom, 1" Fruit, lst Color |
| Wheat/Barley | 2” of above-ground stem | 6” tall to pre-harvest |