What has until recently been a cool, and pleasant summer could take a turn for some growers in California if the heatwave affecting the country intensifies.

Temperatures in Delano, California, known for its table grape and citrus production reached 110 degrees (43 Celsius) on Sunday. 

On June 14, David Espinoza from Hronis. Inc told FreshFruitPortal.com, “This morning, around 11 a.m. we had 90 degrees (32 Celsius) and a soft, cool breeze, very pleasant. It is normal at this time of the year to have temperatures of around 100 degrees (37 Celsius).” 

Their concern, however, is  “if it goes over 110 (43 Celsius), then that is considered a heat wave and that affects us a lot during grape harvest because some varieties don't resist.”

In some parts of the country, like Death Valley, known for its record-breaking temperatures, reached life-threatening temperatures of 125 degrees (51 Celsius).

Protecting the product

At Hronis, they must keep the fields drip irrigated to keep the plants hydrated so they do not collapse. 

“The good thing is that the canopy has grown a lot which protects the grape bunch, providing some shade,” says Espinosa.

Additionally, harvesting the extra bunches before the heat hits is important to release stress from the tree. 

The Centers for Disease Control and Prevention (CDC) has shared some tips for staying safe during the heatwave. Make sure to stay hydrated all the time, wear sunscreen and try limiting time spent outdoors as much as possible. 

Watermelons during the heatwave

Another fruit currently in season in California is watermelon, and the effects on this crop are different. 

Mark Arney, executive director of the National Watermelon Promotion Board (NWPB) tells FreshFruitPortal.com that, “Like most row crops, irrigation is key in helping watermelon crops maintain- especially with the prevalent heatwave much of the nation is experiencing this Summer. Most of the commercially harvested watermelon crops nowadays are under some type of irrigation such as overhead, drip or pivot. We don't see many watermelon fields being dry-farmed (without irrigation) for reasons such as the current drought conditions.” 

Arney adds that heat brings benefits to the development of the fruit. 

“Heat units during the day, to a point, help increase the brix ( sugar expressed as a percent of soluble solids) levels which is a good thing. Thus, we are seeing high-quality and sweet watermelons prevail so far this Summer,” he says.

“Watermelon is excellent for rehydration which is perfect for people suffering from the extreme heat,” adds Arney.