PARASITIC NEMATODES \ Jlottor of ^L)Iio2!
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INTEGRATED CONTROL OF PLANT - PARASITIC NEMATODES "•'??ss^. f ABSTRACT THESIS ^*? SUBMITTED TO THE ALrGARH MUSLIM UNIVERSITY, ALIGARH IN PARTIAL FULFILMENT OF THE REQUIREMENTS m i' -' i f^OR THE DEGREE OF \ jlottor of ^l)iIo2!opJ)p ^^ POTANY ABDUL HAMID WANI DEPARTMENT OF BOTANY ALIGARH MUSLIM UNIVERSITY ALIGARH (INDIA) 1996 / ... No. -f ABSTRACT Plant-parasitic nematodes cause severe losses to economic crops. These pests are traditionally controlled by physical, chemical, cultural, regulatory and biological methods. However, each has its own merits and demerits. Therefore, in the present study attempts have been made to use integrated strategies for the control of nematodes. The focal theme of the present study is to use several control strategies in as compatible manner as possible, in order to maintain the nematode population below the threshold level so that economic damage is avoided and pollution risks to environment and human health is averted. Summary of results of different experiments is presented hereunder: I. Integrated control of nematodes with intercropping, organic amendment/nematicide and ploughing (field study). Investigations were undertaken to study the combined effect of organic amendment with oil cakes and leaves of neem and castor/ carbofuran, intercropping of wheat and barley with mustard and rocket- salad and ploughing on the population of plant-parasitic nematodes and crop yield. There was found significant reduction in the population of all the nematodes and improvement in yield of all the test crops, viz. wheat, barley,mustard and rocket-salad. Among different treatments, carbofuran proved to be highly effective in reducing the population of plant-parasitic nematodes followed by neem cake, castor cake, neem leaf, castor leaf and inorganic fertilizer in both normal and deep ploughed field. Deep ploughing proved to be highly efficacious than normal ploughing Likewise, highest reduction in nematode population was observed in beds where mustard and rocket-salad was grown singly followed by mix- crops, viz. wheat+mustard or wheat+rocket-salad, barley+ mustard or barley+rocket-salad. Similarly, yield of all the test crops improved greatly due to combined effect of organic amendment/nematicide, intercropping and deep ploughing. Highest yield was observed in neem cake treated beds followed by beds treated with castor cake, neem leaf, castor leaf, carbofuran and inorganic fertilizer. Maximum yield was observed in crops grown singly than those grown in different combinations. The residual effect of treatments of the preceding experiments also persisted in the following season when okra cv. Prvani Kranti was grown. Here again neem cake of the preceding crops remained most efficacious both with respect to nematode control and improvement in plant growth and pod yield in both normal and deep ploughed fields. It was followed by castor cake, neem leaf, castor leaf, carbofuran and inorganic fertilizer. Deep ploughing proved to be more effective than normal ploughing. Highest reduction in nematode population was noted in beds where mustard and rocket-salad was grown alone in the preceding season followed bywheat+mustard or wheat+rocket-salad, barley+ mustard or barley+rocket-salad. II. Integrated control of nematodes with cropping sequences and ploughing (field study). In this study, combined effect of cropping sequences and ploughing was studied on the population of plant-parasitic nematodes and plant growth under field conditions. There was significant reduction in the population of plant-parasitic nematodes and improvement in the plant growth of all the test crops involved in the cropping sequence. Highest reduction in the total population of the nematodes was observed in the cropping sequence wheat-chilli-fallow. It was followed in order of efficiency by cropping sequences lentil-cowpea-mung, chickpea-okra- chilli. mustard-mung-tomato and tomato-fallow-okra in both normal and deep ploughed field. However, deep ploughing proved to be most effective than normal ploughing. Likewise, highest reduction in the population of root-knot nematode, Meloidogyne incognita was observed in the cropping sequence wheai-chilli-fallow. It was followed by cropping ssquenctslentil-cowpea-mung, mustard-mung-tomato, chickpea-okra- chilli and tomato-fallow-okra. Similarly, population of stunt nematode, Tylenchorhynchus brassicae was suppressed greatly in the cropping sequence lentil-cowpea-mung followed by sequences wheat-chilli-falloM', chickpea-okra-chilli and tomato-fallow-okra. In a similar way different cropping sequences have a similar effect on the other nematodes. Fallowing after susceptible crops like tomato and chilli in the 2nd and 3rd season of cropping also played important role in the reduction of nematode population. III. Integrated control of nematodes with plant resistance and organic amendment (pot study). Investigations were undertaken to evaluate resistance in 12 cultnars/accessions of lentil alone and in presence of soil treatment with neem cake against root-knot nematode, Meloidogyne incognita. Two cultivars/accessions (DPL-34, DPL-25) were highly resistant and three cultivars/accessions (DPL-26, DPL-23 and DPL-29) were moderately resistant. Rest of the cultivars showed varying degree of susceptibility depending upon the reduction in the degree of root-galling, increased root-nodulation and better plant growth. Further reduction in root-gallng and improvement in root-nodulation and plant growth was observed in all the cultivars/accessions when they were grown in pots amended with neem cake. The uninoculated plants showed more improvement in plants than inoculated ones. IV. Integrated control of nematodes with organic nmendments in different combinations (pot study). It was also observed from the present study that soil amendment with oil cakes of neem, castor and leaves of neem, castor and Persian lilac/bakain alone and in different combinations caused significant reduction in the population of root-knot nematode and improvement in root-nodulation (in case of lentil), plant growth and chlorophyl content of okra and lentil. Combined application of organic amendment proved to be most efficacious than individual application. Highest improvement vsas observed in necm cake * caslor cake treated plants followed by plants treated with neem cake+neem leaf, neem cake+Persian lilac leaf.neem cake+castor leaf, castor cake+neem leaf.castor cake+Persian lilac leaf, castor cake +castor leaf, neem leaf+Persian lilac leaf, neem leaf+castor leaf, castor leaf+Persian lilac leaf, neem cake, castor cake, neem leaf. Persian lilac leaf and castor leaf. Similarly, soil amendment with dry crop residues of mustard, rocket- salad and marigold in different combinations and at different doses brought about significant inhibition in the root-knot development caused bvM ///cog/z/^o and improvement in root-nodulation (in case of lentil), plant growth and chlorophyl content of okra and lentil. Maximum improvement was observed in plants treated with dry crop residues of marigold+rocket-salad at higher doses followed by plants treated with dry crop residues of marigold+mustard, mustard+rocket- salad, marigold, rocket-salad and mustard respectively. Lower doses also caused reduction in root-knot development and improvement in root- nodulation (in case of lentil), plant growth and chlorophyl content of okra and lentil but to a lesser extent. V. Intregrated control of nematodes with seedtreatment and soil amendment (pot study). Studies were also undertaken to evaluate the effect of seed treatment with extract of mustard, rocket-salad, rice polish and pyridoxine hydrochloride solution (Vitamin B^) alone and alongwith soil treatment with oil cakes and leaves of neem and castor on the root-knot development caused by theiool-knot nematode. Mcloidogyiw iiico^^inia and loot- nodulation (in case of lentil), plant growth and chlorophyll content of okra and lentil. There was found significant reduction in the root-knot development due to seed soaking in different concentrations of leaf extract of mustard and rocket-salad for different durations. Highest reduction was observed in 'S' concentrations of the extracts after 24h duration of seed soaking followed by S/2 and S/10 concentrations. Root- uodulation, plant growth and chlorophyll content also increased with an increase in the concentration of extracts and seed soaking duration. Highest improvement was observed in 'S' concentrations after 24h duration of seed soaking followed by S/2 and S/10 concentrations of leaf extract of mustard and rocket-salad. It was observed from the present study that seed soaking in different concentrations of rice polish extract and pyridoxine hydrochloride solution (Vitamin B^) caused suppression in the root-knot development caused by root-knot nematode, Meloic/ogyne incognita and improvement in root-nodulation (in case of lentil), plant growth and chlorophyll content of the okra cv. Prvani Kranti and lentil cv. K-75, Highest reduction in root-knot nematode population and improvement in root-nodulation (in case of lentil), plant growth and chlorophyll content was observed in 'S' concentration of rice polish extract and 0.5% concentration of pyridoxine hydrochloride (Vit. B^) solution after 12h duration of seed soaking. It was followed by seed treatment witli other concentrations of rice polish extract and pyridoxine hydrochloride for different durations. Furthermore, when the treated seeds of okra cv. Prvani Kranti and lentil cv, K-75 with different concentrations of leaf