Keith Edmisten, Professor of Crop Science and Extension Cotton Specialist
Guy Collins, Extension Associate Professor – Cotton
We have made a few changes to the chart below to better define planting conditions. In addition, we cap DD60’s at a maximum value of 10 for each day. If you are computing DD60 accumulation on your own and a day is predicted to have 15 DD60’s, only use 10 for that day.
| Relationship Between Predicted DD-60s and Planting Conditions. |
| Predicted DD-60 accumulation for five days following planting |
Planting conditions
|
| 10 or fewer |
Very poor |
| 11 to 15 |
Marginal |
| 16 to 25 |
Adequate |
| 26 to 35 |
Good |
| 36-49 |
Very good |
| 50 |
Excellent |
| Avoid planting cotton if the low temperature is predicted to be below 50°F for either of the two nights following planting or predicted daily DD60’s is near zero for the day of planting. |
Soil temperature at a 3 inch depth was 60.8 degrees at 8 this morning (May 8th). That is below what we would like to see for planting cotton.
The DD60s predicted for the 5 days following planting at Rocky Mount are included in the table below. Adequate conditions are predicted starting tomorrow through the 11th, then we hit a cool spell from the 12th through the 14th. The safest thing to do is to plant the 9th and 10th and then resume planting on the 15th when soil temperatures reach 65. If you need to plant through some of this cool spell to finish planting on time, make sure you do not plant too deep (1/4-1/2 inches), use the highest cool germ seed you have available, do not use in-furrow fertilizers and consider raising seeding rates. Many people ask what percentage they should increase seeding rates. It is hard to make an across the board answer as your “normal” seeding rates vary and as well as planting methods, but somewhere in the neighborhood of 10-20% is probably right for most situations. In-furrow fungicides during this period could help as well.
| Planting date |
Daily DD60s |
DD60s for next 5 days |
Low temp |
Planting condition |
| May 8 |
0 |
16 |
44 |
Marginal* |
| 9 |
1 |
16 |
55 |
Adequate |
| 10 |
6.5 |
18.5 |
58 |
Adequate |
| 11 |
5.5 |
18.5 |
55 |
Adequate |
| 12 |
3 |
22.5 |
55 |
Marginal ** |
| 13 |
0 |
29.5 |
52 |
Poor ** |
| 14 |
3.5 |
39.5 |
55 |
Adequate ** |
| 15 |
6.5 |
46 |
56 |
Very good |
| 16 |
9.5 |
49.5 |
60 |
Very good |
| 17 |
10 |
50 |
61 |
Good |
| 18 |
10 |
50 |
61 |
Excellent |
| 19 |
10 |
|
63 |
Excellent |
| 20 |
10 |
|
66 |
|
| 21 |
10 |
|
68 |
|
| 22 |
10 |
|
69 |
|
*DD60’s are capped at 10 for any one day.
** Planting conditions have been reduced due to low temperatures at the time of seed imbibition.