Over the last 14 days, dry conditions have persisted in South and Central Ontario with minimal precipitation other than isolated showers and thunderstorms in some regions.  Figure 1 shows the 14 day accumulated precipitation for Southern Ontario and Eastern Canada from AAFC’s Canadian Drought Monitor.

Figure 1: 14 day accumulated precipitation as of 14 June, 2018.

As we consider the previous 30 days, much of the southern part of the province is well below normal precipitation amounts for this time of year (Figure 2).

Figure 2: 30 day percent of average as of 14 June, 2018.

With dry conditions continuing across much of the province, it is important to be continually monitoring precipitation amounts and frequency in your hop yard.

Water availability to hops is essential during the vegetative growth stages and inflorescence development through to cone maturity.   Studies have shown that supplemental irrigation can improve yield and quality of hops and may positively affect alpha acid concentrations. Most recommendations suggest 7.5 L of water per plant per day (~2 U.S. gal/plant/day) is adequate for plant growth, however , some more recent information on Evapotranspiration (ET) rates of hops suggest the plant may require even more water, up  to 19 L/plant/day (~5 U.S. gal/plant/day) for optimal plant growth.  Always remember to include rainfall amounts when calculating how much supplemental irrigation should be applied.

The OMAFRA FactSheet ‘Monitoring Soil Moisture to Improve Irrigation Decisions‘ provides good information on irrigation practices and the tools available for monitoring soil moisture.  It is available online in HTML format or you can request a hard copy from Service Ontario.