While the sporadic rainfall during the first two weeks of July was a big help as the 2020 potato crop neared row closure, many areas of the province still requires some moisture.
"It was pretty uneven across the province," said Lorraine MacKinnon, the potatoes and vegetables specialist with the Department of Agriculture and Land. "The central area especially is looking pretty dry but the crop overall is in really good shape."
Rainfall totals over 24 hours on July 8 and 9 showed variations from a low of 4.8 millimetres in Foxley River to the high of 14.5 millimetres during the same period in Long Creek. Similarly, a rainfall on July 6 produced less than five millimetres in the Kensington area and over 30 millimetres in West Cape.
MacKinnon said the hot, dry June produced significant insect movement although she said there were no significant problems. In a potato pest report issued July 9, the risk of late blight was rated as high across the province due to weather conditions although no late blight spores had been trapped in PEI or New Brunswick.
There were some early blight spores trapped in several areas of Prince County and Botrytis spores had also been detected in some areas across the Island. MacKinnon said the life cycle of the Colorado Potato Beetle is advanced this year compared to the last several and there could be second generation adults by the end of July.
That opinion was shared by Ryan Barrett, who is the Research Coordinator/Agronomy Lead with the PEI Potato Board. In an agronomy update issued July 6, Barrett noted he had found Colorado Potato Beetles in multiple fields but there was not significant damage levels. He too was seeing multiple generations in the same field. Barrett said he is expecting a number of other insects like aphids, European corn borer, tarnished plant bug to also be ahead of schedule.
Both MacKinnon and Barrett said weed control has been a challenge so far this year. Barrett explained many pre-emerge herbicides had limited effectiveness this spring due to a lack of soil moisture. He noted "A number of growers are doing some additional passes with hillers/cultivators to keep the weeds under control."
The research coordinator added "Overall, I’ve been very pleased with what I’ve seen on emergence. There is very little evidence of unemerged seed pieces or “ragged” emergence from what I’ve seen. Have seen a couple of examples where seed pieces are starting to break down a bit early, but they already have a plant up and through the ground now."
Barrett noted there were a number of reports of blackleg late last season that ended up being problematic during storage. He urged growers to keep a close eye on their crop throughout the season and watch for any blackleg symptoms.
"Some of the newer strains of blackleg thrive in hot and dry conditions and cause issues later in the plant’s lifecycle, enabling infected plants to set tubers and either infect seedlots or produce tubers that will break down in storage," he noted.