DSpace Repository :: Browsing by Author "Nchore, S. B."

Browsing by Author "Nchore, S. B."

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Diversity of Plant Parasitic Nematodes of Tree Tomato (Solanum betaceum Cav.) In Kiambu and Embu Counties, Kenya
(Middle East Journal of Agriculture Research, 2020) Waswa, Stanlous Juma; Waceke, J. W.; Nchore, S. B.
Surveys were conducted in five areas representing different agro-ecological zones (AEZs) in Kiambu and Embu counties in Kenya during January to April 2019 cropping season to determine population density, genera diversity and distribution of plant parasitic nematodes associated with tree tomato farming systems. Nematodes were extracted from 200cc of soil or 5g of roots using modified Baermann technique. The nematode diversity and evenness in the study areas were determined using Shannon and Simpson’s indices respectively. Soil nutrients were determined using Mehlich double acid digestion. A structured questionnaire was used to get information on farming practices from sampled farmers. Meloidogyne spp. was the most dominant genera followed by Pratylenchus spp. and Helicotylenchus spp. in both soil and root samples. Githunguri recorded significantly high mean number of 15.92 and 4.29 nematodes in soil and root samples respectively. Kiambaa had the highest diversity index of 1.59 and 0.86 in soil and roots respectively while genera richness was highest in Kiambaa with 13 nematode genera in soil. Simpson’s index of evenness was highest in Kiambaa with 0.69 and 0.47 in soil and root samples respectively. Githunguri had the high egg mass index of 2.00. Soil texture and elements of C, P, K and N together with farming practices may have contributed to the nematode community structure in the study areas.
Efficacy of Selected Agro Industrial Wastes in Managing Root-Knot Nematodes on Black Nightshade in Kenya
(Hindawi Publishing Corporation, 2012) Nchore, S. B.; Waceke, J.W.; Kariuki, G. M.
Black nightshade is commercially cultivated in Kenya as a source of nutrition and income to the rural populations. Besides insect pests, root-knot nematodes (RKN) are important production constraints of this vegetable. Little information is available on the efficacy of Tithonia diversifolia Hemsl (TD) and agro-industrial wastes of pyrethrum marc (PM) and tea residue (Tres) on RKN. Greenhouse experiments were conducted to determine the optimum levels of amending soils with TD, PM, vegetable waxy resins (VWR), Tres and cattle manure (CM) at their respective rates for management of RKN. The amendments were incorporated into the soil 14 days before sowing the seeds. Thereafter 21-day-old seedlings were inoculated with ten egg-masses, with four replications arranged in randomized complete block design. Plant growth and disease parameters were assessed and subjected to ANOVA. Disease severity and population reduced significantly at levels 2 and 3 for most amendments with the highest top biomass recorded in CM, TD and PM. Higher levels of Tres and VWR caused stunting and reduced biomass. Lower severity occurred in VWR, Tres, PM, and CM at 20%, 28.0, 9.0, and 9.0 g/kg soil, respectively, with reproduction ranging from 0.3 to 3.7 recorded on amended soils with Tres at 32.0 g/kg, TD at 8 g/kg soil and CM at 9.0 g/kg. Higher yields, lower severity and reproduction were found on soil with PM, Tres, TD, CM and VWR at 9.0, 28.0, 8.0, 9.0 g/kg soil, and 20.0%, respectively. These amendments are alternatives in ecofriendly management of RKN and other plant parasitic nematodes.
Incidence, prevalence and management of root-knot nematodes (meloidogyne spp.) on selected indigenous leafy vegetables in Kisii and Trans-Mara Counties, Kenya
(2013-03-21) Nchore, S. B.; Waceke, J.W.; Kariuki, G. M.
Solanum nigrum L., Cleome gynandra L. and Amaranthus spp. are some of the indigenous leafy vegetables (ILVs) that contribute to food diet, income generation, good nutrition and health to resource-poor farmers in Kisii and Trans-Mara counties. The production of ILVs is constrained by inadequate land, diseases and pests of which, root-knot nematodes (RKN) are the most damaging pests to vegetable crops causing about 30 % yield losses globally. However, there is no information about the incidence, prevalence and management of RKN on ILVs in Kenya or worldwide. A survey was conducted in Kisii and Trans-Mara to determine the incidence and prevalence of RKN in ILVs and the available germplasms were screened for response to Meloidogyne spp. in greenhouse. Five organic amendments (OAs) commonly used in the areas of study for ILVs cultivation were also evaluated for their effects on RKN on C. gynandra, S. nigrum, S. villosum and Amaranthus spp. in greehouse and field tests. The amendments included: tea (Camellia sinensis (L.) Kuntze) residues (Tres) and rejects (Trej), decomposed cattle manure (CM), goat manure (GM) and Tithonia diversifolia manure (Td). The amendments were incorporated into the sterilized soil in micro-pots and the field at recommended rates. Unamended soils served as controls. After ninety (90) days, the disease and plant growth parameters were assessed. The study revealed that, 62.8 % of the farms surveyed were infected with RKN. The disease incidence was generally higher in the black nightshades from Kisii compared to those from Trans-Mara, while disease incidence in spider plants and amaranths was generally higher in Trans-Mara compared to Kisii Counties. Black nightshades were susceptible to RKN with green berried recording higher reproduction and galling index compared to susceptible check, while amaranths and spider plants had lower scores «15.0 %) in the screening experiment. All OAs significantly (P<0.05) reduced final populations, rate of galling and reproduction of RKN relative to unamended soil. The reduction in such parameters greatly varied with the type of the OA and the host plant. Generally, Tres and Trej were most effective (P<0.05) against RKN galling followed by Td, while CM and GM were the least. However, corresponding decrease in ILV growth was observed in Tres and Trej amendment while, the other OAs showed significant growth increase under greenhouse conditions. As for managing RKN on ILVs,:Tres and Trej were the most effective inhibitor to its build-up followed by Td manures. Percentage increase in black nightshades and amaranth shoot height and biomass was obtained in soils amended with Td, CM and GM compared to Trej and Tres in pots yet in the field Tres increased plant growth significantly. Further studies are imperative to correctly identify all the prevailing races of Meloidogyne spp. across various soil types in the study areas in addition to determination of the mechanisms of control by the OAs for proper nematode management.
Response of African Leafy Vegetables to Mel oi dogyne Spp. in Kenya
(2013-06-30) Nchore, S. B.; Kariuki, G.M.; Kariuki, G. M.
Rf it was concluded that Sng, Snp and Svo were susceptible and good hosts, Meloidogyne species severely damages vegetables in nursery and field establishments. Seven African leafy vegetables (ALVs) [Solanum villosum orange (Svo), S. nigrum green (Sng), S. nigrum purple (Sp), A. cruentus (Ac), A. dubius (Ad), A. hypochondriacus (Ah), and Cleome gynandra purple stemmed (Cgp) relative to susceptible Solanum lycopersicum L. cv. Moneymaker (To)] identified in various AEZ in western Kenya in November 2011 from potential farmers, were screened in the green-house from February-May 2012, for their response to Meloidogyne spp. The experiment was laid-out in CRBD with four replications. Each ALV was planted in a 12-cm diameter micro-pot filled with 1 kg autoclaved soil-sand (1:2) medium. Ten egg-masses of Meloidogyne species raised on Moneymaker tomato were hand-picked and placed at the rhizosphere of each ALV per pot for comparison with un-inoculated control and susceptible check. 75 days after inoculation data on shoot height (SH), fresh shoot and root weight, galling index (GI) and reproduction factor (Rf) were collected. The response varied (P<0.05) among the ALVs from very susceptible to resistant with the highest GI in Sng and lowest in Ah relative to the check. Nematode Rf was lowest in Ah and Cgp and highest in Sng compared to the check. Meloidogyne spp. significantly reduced SH in Sng, Ac, Ad, Svo, Ah, Snp and Cgp relative to the check with heavy galling recorded in Sng and check. Based on GI and Ad was tolerant, Ah was poor host while Ac and Cgp were fair hosts.
Response of micropropagated tissue culture banana (Musa spp.) to acclimatization using arbuscular mycorrhiza fungi
(African Journal of Pure and Applied Sciences, 2023-11-17) Wahome, C. N.; Ombori, O.; Maingi, J.; Njeru, E. M.; Nchore, S. B.; Kimiti, J. M.; Muthini, M.
The production of banana seedlings through tissue culture provides a reliable source of numerous, disease free, quality plantlets. However, the micropropagation process is faced with a number of challenges. In this study we are focusing on the improvement of survival and growth of the resultant plantlets during the acclimatization process. The viability of arbuscular mycorrhiza fungi (AMF) symbiont in the acclimatization process was assessed. Tissue culture bananas (Kienyeji, Kiganda and Ng’ombe local cultivars) were inoculated with single species AMF Rhizophagus irregularis and Funneliformis mosseae as well as commercial AMF Rhizatech. The survival rate was assessed and plant growth evaluated at a two week interval. Destructive harvesting was conducted followed by assessment of root, shoot and total biomass. The results demonstrated that Kiganda treated with Rhisophagus irregularis and Funneliformis mossae recorded better survival rates compared to treatments with NPK fertilizer and commercial AMF (Rhizatech). Kienyeji cultivar however had a better survival rate when treated with commercial AMF (Rhizatech). Ng’ombe cultivar was very resilient having 100 % survival rate when treated with indigenous AMF, commercial AMF (Rhizatech) and NPK. There were significant differences in the shoot dry weight, root dry weight and biomass in the three banana cultivars. Kiganda and Kienyeji cultivars had the highest biomass when treated with Funneliformis mossae of 0.52 g and 0.83 g respectively. The results in this study confirm that the use of AMF in the acclimatization process improves the overall seedling output of the micropropagation process during the nursery stage of production.
Use of agro-industrial waste and organic amendments in managing root- knot nematodes in black nightshade in selected parts of Kenya
(African Crop Science Societ, 2011) Nchore, S. B.; Waceke, J.W.; Kariuki, G. M.
A study was conducted in both greenhouse and field to determine the use of agro-industrial waste and organic amendments in the management of root-knot nematodes (RKN) in Solanum nigrum. Treatments included cattle manure (CM), goat manure (GM), Tithonia diversifolia (Td) and agro-industrial wastes of tea [Camellia sinensisresi due (Tres)] and pyrethrum [Chrysanthemumcineraria foliumVis.] pymarc (Pm) and vegetable waxy resins (VWR). They were incorporated in sterilized soil at their respective rates into 1 kg plastic pots and S. nigrum seedlings planted, across the treatments, two weeks later. Ten egg-masses were inoculated into three pots for each amendment with uninoculated and unamended pots serving as controls. Field experiment was also conducted on plots measuring 1.2x3.2 m in Kisii County, with unamended plots serving as control. The experiments were arranged in randomized complete block design with four replications. All experiments were terminated 60 days after inoculation and data on plant growth and disease parameters collected. The results revealed suppression of RKN population and reproduction by the various amendments compared to their controls in both field and greenhouse. Improved plant growth was also recorded in all the amendments in both tests except for Tres. However, higher levels of Tres and VWR application caused stunted growth despite significant reductions in GI,Rf and J2 populations. These organic amendments can be used as alternatives in eco-friendly management of Meloidogyne species and other plant parasitic nematodes.

Browsing by Author "Nchore, S. B."

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