Table 2.

The influence of penconazole and chitin/chitosan-based soil amendments on pathogen severity of apple scab (Venturia inaequalis) on Malus sylvestris (crab apple) containerised seedlingsa.

TreatmentLeaf scab severitybSPADFV/FMPIABS
Control (water)3.8d19.9c0.700de3.61d
Penconazole1.0a38.4g0.813g7.65h
Chitin (2.0%)–14.3ab0.564b1.47a
Chitin (1.5%)–15.9b0.639c2.75bc
Chitin (1.0%)1.6b34.9f0.800fg6.06f
Chitin (0.5%)2.2c31.3e0.770f4.97e
Chitin (0.25%)3.6d22.8d0.728e4.43e
Chitosan (2.0%)–13.5a0.497a1.34a
Chitosan (1.5%)–16.0b0.550b2.45b
Chitosan (1.0%)1.5b34.2f0.803fg6.82g
Chitosan (0.5%)3.8d19.4c0.711de3.17cd
Chitosan (0.25%)3.7d20.0c0.690d3.47d
Significance of Treatment (T)< 0.001< 0.001< 0.001< 0.001

  • ↵aNumbers within a column followed by a common letter are not significantly different according to Tukey’s Honest Significant Difference test (P = 0.05).

  • ↵bMean of 100 leaves from 10 trees (10 leaves per tree) placed in a completely randomised block design.