Project title: Sensitivity of selected potato varieties to metribuzin depending on the level and duration of its distribution in plant leaves

Number: N N310 144735

Financing institution: Ministry of Science and Higher Education

Implementation period: 12 months (2008/2009)

Name and role of employees (project manager, main contractor):

project manager: dr hab. Józef Kaps

main contractor: mgr inż. Janusz Urbanowicz

Place of implementation or if it was a project implemented in cooperation – cooperation of other units: Institute of Plant Breeding and Acclimatization – National Research Institute, Seed and Potato Protection Institute in Bonin

Cost (project value): 50,000

What was involved (purpose): Aim of the study: – assessment of the effect of postemergence use of metribuzin on plants of selected potato varieties; – analysis of the level of metribuzin in potato leaves and the rate of its disappearance; – studying the effect of metribuzin on the size and structure of yield and on selected quality characteristics of tubers; – an attempt to explain the mechanism of differential reaction of potato varieties to metribuzin; – searching for practical solutions aimed at minimizing the phytotoxicity effect – using a growth stimulator.

The results of the study: In studies on the sensitivity of potato plants to metribuzin used after emergence at a dose of 0.35 kg.ha-1, five varieties were tested: Denar, Lord, Molli, Satina and Sonda. Symptoms of the phytotoxic reaction lasted from 21 to 35 days. It was found that the strength of the phytotoxicity effect is determined by the morphological diversity of leaves of individual potato varieties and the number of stomata on the upper surface of the leaf blade. The Probe variety – with the highest sensitivity among the examined varieties, was characterized by clustered leaves and the largest number of stomata on the upper surface of the leaf blade, amounting to 71.3 pcs / mm2. The insensitive (Satina) variety was characterized by loose leaves with a large amount of free space between the leaves and the smallest number of stomata. Very sensitive (Probe) and sensitive (Molli) cultivars to the post-emergence use of metribuzin reacted by reducing the yield and diminishing tubers. The yield losses of these varieties were: 40.7% and 21.8%, respectively. There was no negative effect of metribuzin on the content of starch and dry matter in tubers, nor was there a negative impact on the quality of tubers (darkening of raw and cooked flesh, palatability, as well as flaw defects – hollowness and rust blotch). In laboratory studies on the rate of metribuzin decomposition in potato leaves, a close relationship has been proven, statistically confirmed between the degree of varietal sensitivity and the level of metribuzin residue. The level of metribuzin residue in the leaves of the very sensitive variety (Probe) was 0.167 mg / kg, and the non-sensitive variety (Satina) 0.005 mg / kg, seven days after metribuzin application. In order to minimize the effects of the phytotoxic reaction of potato varieties after the application of metribuzin, the biostimulator Asahi SL was used twice in greenhouse experiments, which reduced the duration of the symptoms of the phytotoxic reaction on potato plants by up to 7 to 14 days depending on the variety.

List of publications:

  1. Urbanowicz J. 2009. Sensitivity of selected potato varieties to metribuzin depending on the sub-level and duration of its decomposition in plant leaves. Doctoral dissertation, Bonin 2009: 124 pp.
  2. Urbanowicz J. 2010. Impact of postemergence use of metribuzin on the yield of selected potato varieties. 50th Session of Sciences. IOR – National Research Institute. Abstract. Poznan, 4-5 February 2010: 143.
  3. Urbanowicz J. 2010. Impact of different leaf structure on the phytotoxic reaction of potato varieties. Seed and potato protection. Conf. nauk.-schools. Darłówko Wschodnie, 20-21 May 2010. IHAR – PIB, ZNiOZ Bonin: 20-23.
  4. Urbanowicz J. 2010. Impact of postemergence use of metribuzin on the yield of selected potato varieties. Threshold. Plant Protection / Post. Prot. Plants 50 (2): 837–841.
  5. Urbanowicz J. 2010. Phytotoxic reaction of five potato varieties to the post-emergence use of metribuzin. Vol. I. Impact on yield and its structure. Biul. IHAR 257/258: 185-196.
  6. Urbanowicz J. 2010. Phytotoxic reaction of five potato varieties to the post-emergence use of metribuzin. Vol. II. Impact on selected quality characteristics of tubers. Biul. IHAR 257/258: 197-205.
  7. Urbanowicz J. 2011. Impact of a biostimulator on minimizing the phytotoxicity effect after applying metribuzin in potatoes. 51. Scientific Session IOR – PIB. Abstracts. Poznan, 17-18 February 2011: 342-343.
  8. Urbanowicz J. 2012. The effect of Asahi SL biostimulator on metribuzin phytotoxicity in potato cultivation. Message. Biul. IHAR 265: 109-113.
  9. Urbanowicz J. 2012. Reaction of potato varieties with different leaf structure to metribuzin used after emergence. Biul. IHAR 265: 115-128.
  10. Urbanowicz J. 2013. Correlation between the rate of decomposition of metribuzin residue in the leaves of selected potato varieties and a phytotoxic reaction. Scientific-training conference “Seed and potato protection”. Dźwirzyno, 16-17 May 2013. IHAR – PIB, ZNiOZ Bonin: 114-118. The doctoral dissertation made as part of the project by dr inż. Janusz Urbanowicz was awarded by the IHAR Scientific Council – PIB.