What temperature should processing potatoes be stored at and why? | 8-12 degrees, to prevent acrylamide build up |
Successful potato storage depends on what 9 factors? | storage system, air flow, temperature, humidity, variety, drying and pull down, duration, end market, pest and diseases |
What are the 3 sprout suppressant options in the UK | Maliec hydrazide, ethylene and spearmint oil |
What does irrigation Field Capacity (FC) mean? | Soil saturation is at 0.05 bar |
What is permanent wilting point (PWP)? | moisture content when only unavailable water remains |
What is available water capacity (AWC)? | Water available between FC and PWP |
What is soil moisture deficit (SMD)? | Quantity of water required to reach FC again |
How can you distinguish early from late blight? | early blight lesions are compartmentalized between leaf veins whereas late blight lesions travel over veins with a white halo underneath |
What is late blight commonly confused with due to similar symptoms? | Early blight and magnesium deficiency |
What potato fungicide is experiencing resistance to late blight? | Fluazinam |
Name a good potato variety for foliar and tubor late blight resistance | Athlete Carolus |
When should contact fungicides be used? | At rosette stage, during low pressure applications and end of programme to protect against zoospores |
When should systemic fungicides be used? | When the canopy is growing |
When should translaminar fungicides be used? | When the canopy is stable |
What type of fungicide product should always be applied if adverse weather is due to disrupt the blight programme? give an example active ingredient | Translaminar, mandipropamid |
What are high risk factors for Rhizoctonia in potatos | 40-45% AWC, 10 degrees and porous soil |
What seed treatment will protect against Rhizoctonia and Silver Scurf? | Fludioxinil |
What soil treatment will protect against Rhizoctonia, black dot and Silver Scurf? | Azoxystrobin |
Where can Blackleg inoculum be found? What are high risk factors for its development? | Seed, wet cold seedbed |
What weed vectors blight? | Black nightshade |
What is the desired DM% for pre-pack, baker and salad potatoes? Why? | 18-20%, prevent bruising and tubor diseases |
What is the desired DM% for processing potatoes? Why? | 20-25%, for better fry colour |
Name a blight resistant variety | Jackie |
What colour is G.Palida cyst? | Pale/ white |
What colour is G.Rostochiensis cyst? | Dark / golden |
Name a variety with resistance to G.Palida | Lanorma |
Describe the Hutton criteria | When the temperature is no less than 10 degrees, 90% humidity for 6 hours per day, over 2 consecutive days |
How can potato wounds be "cured"? | 10 degrees, 70% humidity for 10 days after harvest, then reduce temperature by 1 degree per day |
What market is ethylene used for and why? | Fresh only, it causes acrylamide build up in processing potatoes |
What type of resistance do Peach Potato Aphids exhibit? | Kdr and MACE |
Describe MACE resistance | It confers to resistance to the dimethylcarbamates, pirimicarb and triazamate - Modified Anti Choline Esterase |
Describe Kdr resistance | Is associated with Pyrethroids |
Describe the two categories of common insecticide resistance | Metabolic and Target Site |
Name a variety with Late Blight resistance | Jackey |
Name a variety with resistance to G.Palida | Lanorma |