Barnea Dor, Yermiyahu Uri, Rav-David Dalia, Elad Yigal
Department Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Institute, 68 Hamakabim Rd, Rishon LeZion 7534509, Israel.
The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel.
Plants (Basel). 2022 Apr 7;11(8):1007. doi: 10.3390/plants11081007.
It was previously shown that spraying with CaCl, MgCl, KCl, and KSO and high N and Mg concentrations in the irrigation water of potted cucumber plants reduced powdery mildew, while medium P and high K concentrations increased powdery mildew. In the present work, we tested the effect of irrigation with N, P, K, Ca, and Mg and spraying with salts on downy mildew () of cucumber (CDM). In potted plants, an increase in N concentration in the irrigation water resulted in a major increase in CDM severity, while an increase in K or Ca concentrations resulted in a gradual increase in CDM severity. An increase in P and Mg concentrations in the irrigation water resulted in a major CDM decrease. Spraying with Ca, Mg, and K salts with Cl and SO anions resulted in CDM suppression in most cases, and a negative correlation was obtained between the salt and anion molar concentrations and the CDM severity. Using NaCl sprays, both Na and Cl concentrations were negatively related to the CDM severity. MgCl (0.1 M Cl), KSO (0.1 M SO), MgCl + KSO, and monopotassium phosphate (MKP, 1%) sprayed under commercial-like (CL) conditions significantly reduced CDM by 36.6% to 62.6% in one disease cycle, while, in a second cycle, CDM was significantly reduced only by KSO and MKP. In conclusion, fertigation with P and Mg, and salt spraying decreased CDM, while only spraying under CL resulted in CDM suppression.
先前的研究表明，在盆栽黄瓜植株的灌溉水中喷洒氯化钙、氯化镁、氯化钾和硫酸钾以及高氮和高镁浓度可减少白粉病，而中等磷浓度和高钾浓度则会增加白粉病的发生。在本研究中，我们测试了用氮、磷、钾、钙和镁进行灌溉以及用盐喷洒对黄瓜霜霉病（CDM）的影响。在盆栽植物中，灌溉水中氮浓度的增加导致霜霉病严重程度大幅增加，而钾或钙浓度的增加导致霜霉病严重程度逐渐增加。灌溉水中磷和镁浓度的增加导致霜霉病大幅减少。喷洒含有氯离子和硫酸根离子的钙、镁和钾盐在大多数情况下可抑制霜霉病，并且盐和阴离子的摩尔浓度与霜霉病严重程度之间呈负相关。使用氯化钠喷雾时，钠和氯的浓度均与霜霉病严重程度呈负相关。在类似商业（CL）的条件下喷洒0.1M氯离子的氯化镁、0.1M硫酸根离子的硫酸钾、氯化镁 + 硫酸钾和磷酸二氢钾（MKP，1%），在一个病害周期内可使霜霉病显著降低36.6%至62.6%，而在第二个周期中，只有硫酸钾和磷酸二氢钾能显著降低霜霉病。总之，用磷和镁进行施肥灌溉以及喷洒盐可减少霜霉病，而只有在CL条件下喷洒才能抑制霜霉病。
