Best weather to spray coffee
The weather window for spraying coffee — Delta T, humidity, wind, inversion and rain — plus dense canopies, slopes, drones and the preset values in the app.
Coffee is a perennial shrub with a dense, layered canopy, often planted on slopes. Many of its applications — fungicides and insecticides — need thorough coverage inside the canopy, which usually means finer droplets. Finer droplets are more sensitive to evaporation and drift, so the weather window is tighter than for field crops.
The weather window
- Delta T: 2–7 °C in the app's preset — a lower upper limit than the usual 8, because fine droplets lose water quickly. See Delta T.
- Humidity: 60 % or more in the preset, for the same reason. See humidity and dew point.
- Wind: light and steady. With fine droplets, drift risk rises quickly with wind. See wind speed for spraying.
- Inversion: on slopes, cold air drains downhill and pools in valleys on calm, clear nights. See thermal inversion.
- Rain: leave the rainfast period clear, and remember that runoff on slopes can move product towards streams. See rain and spraying.
Crop-specific considerations
Dense canopy. Reaching the inner leaves and the underside of leaves is what makes a fungicide or insecticide work in coffee. The droplet class, the water volume and the equipment all matter, and good coverage is harder to achieve in hot, dry air.
Slopes and terrain. On hillsides, wind is channelled along valleys and changes direction around ridges, so the forecast wind for the area may not match the wind in your block. Measure on site. For drones, terrain following and the manufacturer's recommended height above the canopy are essential. See drone spraying weather.
Streams and springs. Coffee is often grown near watercourses in hilly country. Respect label buffers, and avoid spraying before heavy rain on steep ground.
Flowering. Coffee flowers attract pollinators. Follow the label's pollinator statements and avoid bee-hazardous applications during flowering while bees are foraging.
Typical applications
Fungicides for leaf diseases, insecticides for insect pests, herbicides between rows, and foliar nutrition in some programmes.
Setting it up in PulveCast
Choose the Coffee preset. It sets Delta T to 2–7 °C, humidity to 60–95 % and Fine as the ideal droplet class; in automatic mode the app suggests a coarser class when the wind would push drift risk into the red. Crop presets are part of Pro; the free Custom preset lets you enter the same values.
Other crops
- Best weather to spray soybeans
- Best weather to spray corn (maize)
- Best weather to spray sugarcane
- Best weather to spray cotton
- Best weather to spray wheat
- Best weather to spray rice
- Best weather to spray citrus
- Best weather to spray vineyards
- Best weather to spray potatoes
- Best weather to spray pastures
Frequently asked questions
Why does the coffee preset use a Delta T of 2 to 7?
Coffee applications often use fine droplets to cover a dense canopy. Fine droplets evaporate quickly, so the preset lowers the upper Delta T limit to 7 and raises the minimum humidity to 60 %.
Can drones spray coffee on slopes?
Drones are used on sloping coffee where regulations allow. Use terrain following, keep to the manufacturer's height above the canopy, and check the wind on site, since slopes channel and redirect it.