Effects of nutrients on diseases of lettuce Downy mildew of lettuce

Effect <strong>of</strong> Anthracnose and KNO 3
Effect <strong>of</strong> Anthracnose and Ca(NO 3 ) 2
100
Kong
100
Kong
90
Explore
Anthracnose incidence (% plants infected)
90
80
70
60
50
40
30
20
Explore
Seagull
Alpinas
Anthracnose incidence (% plants infected)
80
70
60
50
40
30
20
10
Seagull
Alpinas
10
0
Low Medium High
0
Low Medium High
Calcium nitrate (%)
Potassium nitrate (%)
* No disease observed on “no nitrogen” treated plants
* No disease observed on “no nitrogen” treated plants
Effect <strong>of</strong> Anthracnose and (NH 4 ) 2
Conclusion
100
Kong
• Form <strong>of</strong> N more important than rate
Anthracnose incidence (% plants infected)
90
80
70
60
50
40
30
20
10
Explore
Seagull
Alpinas
• Results variable
‣ Best plant growth = highest disease
‣ High KNO 3 increased downy mildew infection
‣ High Ca(NO 3 ) 2 reduced anthracnose but also
reduced plant growth
• Variety important
0
Low Medium High
• Balanced nutrient schedule
Ammonium nitrate (%)
* No disease observed on “no nitrogen” treated plants