Crop development
Harvest delay in cotton and wheat: losses from over-ripening
The crop has ripened but has not been harvested on time. Over-ripe wheat sheds grain and sprouts in the ear, while open cotton bolls get soiled and lose grade. A late harvest also pushes back the sowing of the next crop.
Crops: Cotton, Wheat, Vegetables, Orchards
When it is dangerous
The risk only arises after the harvest window; before physiological maturity it makes no sense. For cotton in Uzbekistan the harvest window runs roughly from September to mid-November, and the exact window depends on the crop and district. Rain, wind or frost over a ripe crop increase the losses.
Causes
- Shortage of machinery or labour
- Weather delays
- Harvest not organised on time
Signs on the field
- After ripening the field stays unchanged for a long time and does not turn to bare soil
- Grain shedding and sprouting in the ear in wheat
- Soiled open cotton bolls
- Neighbouring fields are harvested, this one is not
How ClusterOS notices it
ClusterOS estimates when a crop is ready from its development, and whether it has been harvested from Sentinel-2 optical images: harvest causes a sharp drop in greenness. Sentinel-1 radar can see harvest through clouds, but its signal is still being checked for Uzbekistan and so far helps only partly. Clouds in optical images, lodging or hail also cause a sharp drop in greenness, so we check whether the drop falls within the harvest window. Late ripening, planned field drying and the usual pause between cotton pickings are not treated as a delay.
What to do
- Check harvest readiness and machinery logistics
- Record the crop's purpose, harvest method and picking dates – without them the timing is only approximate
- Watch the forecast: rain, wind and frost over a ripe crop increase losses
- Plan the harvest around the sowing dates of the next crop
Questions
Why is a late cotton harvest costly?
Open bolls left standing in the field get soiled, and the cotton loses grade. Rain, wind or frost over a ripe crop add to the losses. A late harvest also delays sowing of the next crop.
How can a satellite tell that a field has been harvested?
Harvest shows up as a sharp drop in greenness in optical images and a typical change in the radar signal. If neither appears by the end of the harvest window, the field has most likely not been harvested. Clouds and lodging can blur the picture, so picking dates from the farm make the assessment more accurate.
Learn about this risk on your fields before it becomes a loss
We will show ClusterOS on your own fields: history since 2019, crop stage and all 24 risks.
Other risks in «Crop development»
Scientific basis
- Schlund M., Erasmi S. (2020) Remote Sensing of Environment 246:111814, DOI: 10.1016/j.rse.2020.111814
- Detection of Crop Seeding and Harvest through Time-Series Sentinel-1 InSAR (2020), Remote Sensing 12(10):1551, DOI: 10.3390/rs12101551
- Detecting Phenological Development of Winter Wheat and Winter Barley Using S1/S2 (2021), Remote Sensing 13(24):5036, DOI: 10.3390/rs13245036