 |
| NWP Sorghum field nearing maturity |
is progressing rapidly. Reported yields have been variable but most reports have been encouraging. Some sorghum has been harvested but for the most part the area crop is just reaching physiological maturity. Harvest aid application decisions to prepare the area cotton crop for harvest are being deliberated.
At this point cotton harvest aid applications will be weather driven, as it is unlikely that significant heat unit (HU) accumulations to further develop fiber will occur. Using historical weather data from 1980-2010 only 14 total HU are expected in October (14 HU is less than one normal August day). For best results harvest aid applications should be made on warm sunny days with an extended outlook of warm conditions.
Some factors that increase the performance of harvest-aid chemicals include the following:
- Warm, calm, sunny weather
- Soil moisture relatively low but sufficient to maintain cotton plant without moisture stress
- Soil nitrogen levels relatively low
- Leaves active and uniformly expanded on plants
- Little or no secondary growth evident on plants
- Plants with a high percentage of open bolls that have shed some mature leaves
Conversely, some of the factors which negatively affect harvest-aid chemical performance include:
- Applications made under cool (below 60o F), cloudy conditions
- Prolonged periods of wet weather following treatment
- Plants in vegetative growth state with low fruit set
- Plants severely moisture stressed at time of treatment
- High soil moisture and nitrogen levels
- Plants exhibiting secondary growth
- Poor spray coverage
Harvest-aid product selection, tank mix partners and rates vary with environmental and crop conditions. The “2013 High Plains and Northern Rolling Plains Cotton Harvest-Aid Guide” contains a set of tables which suggest harvest aid products based on crop and environmental conditions. The full guide can be viewed at http://goo.gl/WkxFz4
