TY - JOUR
T1 - A foliar spray of micronutrient solutions induces local and systemic protection against powdery mildew (Sphaerotheca fuliginia) in cucumber plants
AU - Reuveni, Moshe
AU - Agapov, Vladimir
AU - Reuveni, Reuven
PY - 1997
Y1 - 1997
N2 - single spray of solutions of 0.005M H3 BO3, 0.0025M CuSO4, and 0.0025 MnCl2, on the upper surface of the first true leaf of cucumber plants 2 h before inoculation with a conidial suspension of Sphaerotheca fuliginea, induced systemic protection against powder mildew in leaves 2 and 3 without causing any damage on the induced leaf (first leaf). A similar level of systemic protection was observed when plants were induced by micronutrients, 2, 24 and 72 h before challenge with S. fuliginea. The level of protection induced by various concentrations varied from solution to solution. In general, the systemic protection induced by K2HPO4 was similar to that by the microelements. Spraying of a 1:1 mixture of phosphate and micronutrient solutions did not improve the systemic protection over that obtained with each of the solutions alone. Increasing the inoculum concentration of S. fuliginea increased the number of powdery mildew colonies produced on both induced and non-induced plants and has relatively affected the systemic protection on induced plants. A single foliar spray of micronutrient solutions, as a prophylactic treatment, on the upper surface of all the leaves of 3-leaf stage cucumber plants significantly inhibited powdery mildew development. A single spray of MnCl2 on leaf 1 elevated peroxidase activity in the soluble fraction and caused an enhancement of β-1,3-glucanase content in the ionically bound fractions of leaf 2 of non-inoculated plants. Forty-eight hours after inoculation, the level of both fractions of the enzymes increased in non-treated plants and decreased (β-1,3-glucanase) or remained unchanged (peroxidase) in treated (induced) plants as compared to non-treated plants. The possible mechanism for this protection, and the use of microelements and phosphate solutions as inducers for systemic protection and as agents for disease control are discussed.
AB - single spray of solutions of 0.005M H3 BO3, 0.0025M CuSO4, and 0.0025 MnCl2, on the upper surface of the first true leaf of cucumber plants 2 h before inoculation with a conidial suspension of Sphaerotheca fuliginea, induced systemic protection against powder mildew in leaves 2 and 3 without causing any damage on the induced leaf (first leaf). A similar level of systemic protection was observed when plants were induced by micronutrients, 2, 24 and 72 h before challenge with S. fuliginea. The level of protection induced by various concentrations varied from solution to solution. In general, the systemic protection induced by K2HPO4 was similar to that by the microelements. Spraying of a 1:1 mixture of phosphate and micronutrient solutions did not improve the systemic protection over that obtained with each of the solutions alone. Increasing the inoculum concentration of S. fuliginea increased the number of powdery mildew colonies produced on both induced and non-induced plants and has relatively affected the systemic protection on induced plants. A single foliar spray of micronutrient solutions, as a prophylactic treatment, on the upper surface of all the leaves of 3-leaf stage cucumber plants significantly inhibited powdery mildew development. A single spray of MnCl2 on leaf 1 elevated peroxidase activity in the soluble fraction and caused an enhancement of β-1,3-glucanase content in the ionically bound fractions of leaf 2 of non-inoculated plants. Forty-eight hours after inoculation, the level of both fractions of the enzymes increased in non-treated plants and decreased (β-1,3-glucanase) or remained unchanged (peroxidase) in treated (induced) plants as compared to non-treated plants. The possible mechanism for this protection, and the use of microelements and phosphate solutions as inducers for systemic protection and as agents for disease control are discussed.
KW - Induced resistance
UR - http://www.scopus.com/inward/record.url?scp=0030660401&partnerID=8YFLogxK
U2 - 10.1023/A:1008671630687
DO - 10.1023/A:1008671630687
M3 - Article
AN - SCOPUS:0030660401
SN - 0929-1873
VL - 103
SP - 581
EP - 588
JO - European Journal of Plant Pathology
JF - European Journal of Plant Pathology
IS - 7
ER -