VARIETAL RESPONSE AND BIOCHEMICAL ANALYSIS OF DIFFERENT POTATO CULTIVARS AGAINST ROOT KNOT NEMATODE (MELOIDOGYNE INCOGNITA) AND ITS NUTRITIONAL MANAGEMENT
| Amjad Shahzad Gondal (amjadshahzad@live.com) |
| Department of Plant Pathology, University of Agriculture Faisalabad |
| March, 2013 |
Abstract |
| Research wok was design to identify resistant potato germplasm against root knot nematode (Meloidogyne incognita) infection. A field trial was conducted in the research area of Department of Plant Pathology, University of Agriculture Faisalabad. Thirty six (36) potato verities/ cultivars relocated five times were sown in four years sick plot containing root knot nematode (Meloidogyne incognita) in RCBD layout. Root knot nematode reproduction and host damage was accessed by recording nematode root galls and egg mass indices, root weight, shoot weight, , number of leaves, fruit weight, rate of reproduction and final population of nematodes. Experiment revealed a considerable variation in response against Meloidogyne incognita infection among the genotype tested but none of the single cultivar was immune. The cultivar FD-19-2 was highly susceptible followed by FD-8-1, SH-692 and SH-5. All other cultivars had less galling index with low fecundity rate indicating their ability to suppress the adult female reproduction. The cultivar FD-1-3 scored least number of galls and egg mass indices followed by FD-49-62, SH-339 and SH-332. Potato crop requires proper crop nutrition and disease management strategies as it endures significant yield losses due to root knot nematode (Meloidogyne incognita) infection. The study aimed at determining the change in the leaf nutrient contents of different resistant and susceptible potato cultivars against RKN (M. incognita) infection. Five moderately resistant cultivars viz. FD-74-67, SH-332, SH-339, FD-1-3 and FD-49-62 and five susceptible cultivars viz. FD-19-2, FD-8-1, SH-692, SH-5 and FD-69-1 cultivars were accessed for change in leaf Nitrogen (N), Phosphorus (P) and Potassium (K) contents. Leaf nitrogen (N) and phosphorus (P) contents were determined by Kjeldahl Extraction Method and potassium (K) contents were determined by atomic absorption spectrophotometer. Susceptible cultivars were found to be deficient in these contents. Significant increase (P<0.05) in leaf NPK contents was observed in resistant cultivars under nematode stress compared to inoculated. Maximum leaf nitrogen (N) of 5.96% was noted in resistant cultivar FD-1-3 while minimum as 3.52% in susceptible potato cultivar FD-19-2. Lead phosphorus (P) content recorded maximum as 0.225 % in FD-1-3 and minimum as 1.48% in FD-19-2. Minimum leaf potassium (K) 0.33 and maximum 0.48 was recorded in FD-19-2 and FD-1-3 respectively. The effect of foliar application of micro-power, humic acid and plant protector containing benzoic acid was examined for the management of root knot nematode (Meloidogyne incognita) in a susceptible potato cultivar FD-8-1. Application of plant protector significantly reduced the number of galls and egg masses and promotes overall plant growth followed by micro power and humic acid as compare to control. Foliar application of plant protector 4% endorsed the number of leaves, shoots development, tuber weight and decreased the root weight followed by micro-power 4% plant protector 2% and humic acid 4%. Minimum number of root galls and egg masses was recorded in case of plant protector 4% followed by micro-power 4%, micro-power 2% and plant protector 2%. Nematode fecundity rate was observed to be maximum in case of control with poor plant growth and maximum number of galls and egg masses. The significantly lower number of galls and egg masses and enhanced plant growth in case of plant protector containing benzoic acid @ 4% concentration indicated to be best one. |
