By Vikram Bisht/MAFRD
June 23, 2015, MB – Cull piles are still around in some areas and are a major concern, reports Vikram Bisht, with the potato and horticultural crops department at Manitoba Agriculture, Foods and Rural Development, in the latest potato disease report.
It is extremely important to remove the cull piles to prevent spread of diseases to the neighbouring fields.
Overall, like many other crops, the potatoes appear to growing very well. Plant height in many places has reached 20 inches or higher and space within-rows is covered.
The accumulated heat units, P-Days, in potato growing regions are in the range of 183 to 190 from the June 1 emergence.
P-Days in the range of 170 to 280 indicate that the plants are in tuber initiation stage. In-field observations show a range from hooking to nearly 30 millimetres (just over one inch).
The recent rains have increased the disease severity risk values (DSVs) for late blight, mostly in the south-east part of the province; but the accumulated DSVs are still far below the critical value of 18, an initial threshold of late blight occurrence if the inoculum is present in the surrounding area.