Over the weekend (6/25-6/26) cotton planted on April 11 began to bloom. Generally 850 heat units are required to produce a bloom. This April planted cotton crossed that threshold on 6-23. Evaluations from two planting date trials (Flex varieties and Liberty Link varieties) are shown below (Table 1). Each trial has been treated twice for weeds and once for plant bugs. Roundup OriginalMax and Sequence on the Flex trial and Ignite and Ignite plus Dual Magnum on the Liberty Link trial. Centric was applied for plant bugs. WideStrike varieties in the Liberty Link trial were also treated with Ignite and Ignite plus Dual. HNR = height to node ratio, NAWF = nodes above white flower, FFB = node of first fruing branch. Table 2 gives an indication of where cotton should be at different growth for height to node ratios.
Table 1. Plant evaluations from April 11 planted cotton, 2011.
| Height | Nodes | HNR | NAWF | FFB | ||
| Trial | Variety | inches | no. | no. | no. | |
| Flex Trial | FM 1740B2F | 28 | 15 | 1.9 | 10 | 4 |
| PHY 375 WRF | 29 | 14 | 2.1 | 10 | 4 | |
| DP 0912 B2RF | 28 | 14 | 2.0 | 10 | 4 | |
| ST 4288 B2RF | 25 | 15 | 1.7 | 10 | 5 | |
| PHY 499 WRF | 29 | 14 | 2.1 | 9 | 5 | |
| AM 1511 B2RF | 29 | 15 | 1.9 | 11 | 4 | |
| Average | 28.0 | 15 | 1.9 | 10 | 4 | |
| Liberty Link | BX 1252LLB2 | 23 | 14 | 1.6 | 8 | 6 |
| Trial | FM 1773LLB2 | 21 | 15 | 1.4 | 8 | 7 |
| FM 1845 LLB2 | 21 | 13 | 1.6 | 7 | 6 | |
| ST 4145LLB2 | 20 | 13 | 1.5 | 9 | 4 | |
| PHY 499 WRF | 24 | 14 | 1.7 | 8 | 6 | |
| PHY 375 WRF | 25 | 14 | 1.8 | 9 | 5 | |
| Average | 22.3 | 14 | 1.6 | 8 | 6 |
Table 2. Height to node ratios for cotton PGR decisions. (Jost et al. 2005)
| Growth Stage | Normal | Stressed | Vegetative |
|
HNR (inches/node) |
|||
| Seedling | 0.5-0.75 | – | – |
| Early Squaring | 0.75-1.2 | 0.7 | >1.3 |
| Large Square – First Flower | 1.2-1.7 | <1.2 | >1.9 |
| Early Bloom | 1.7-2.0 | <1.6 | >2.5 |
| Early Bloom + 2 weeks | 2.0-2.2 | <1.8 | >2.5 |
Jost, P., S. M. Brown, S. Culpepper, G. Harris, B Kermerait, P. Roberts, D. Shurley, and J. Williams. 2005. 2005 Georgia Cotton production guide p 37-39.
Heat Unit accumulation continues to be above average. Table 3 indicates heat unit accumulation at Jackson, TN for 6 planting dates with departure from normal and current growth stage.
Table 3. Heat unit accumulation at Jackson, TN 2011.
| 24-Jun | Departure | ||
| Planting Date | Heat Units | Normal | Growth Stage |
| 11-Apr | 877 | 157 | Blooming |
| 21-Apr | 843 | 155 | ~2 days till bloom |
| 5-May | 759 | 146 | Mid-size to large squares |
| 19-May | 665 | 156 | Several squares |
| 1-Jun | 482 | 116 | Beginning squaring |
| 15-Jun | 186 | 19 | 1-2 leaf |
What was the soil temperature when cotton was planted on 4/11 & 4/21? We received 16″ to 18″ of rain at Belle Eagle the last two weeks of April, how did your April planted cotton survive that?
Richard
Soil temps were in the low 60’s. Cotton germinated in four days, and took 9 to fully emerge. The rain beat it back, but help keep the thrips off. Generally it takes 60 days from planting till bloom. For this early planted cotton it took nearly 70 days! Definately delayed and looked bad until June 1st. Will be interesting to see how it yields.