Faculty of Agriculture and Environmental Studies

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Plant Propagation: A Teaching Resource Packet with Emphasis on Agroforestry and Fruit Trees in East Africa
(Cornell University, Ithaca, NewYork, USA, 1992) 68. Mudge, K. W; Mwaka, A.; Isutsa, D. K.; Musoke, R.; Foster, D.; Ngoda, B. J. M.; ; ;
The products and services provided by trees have always been used in farming. In the past, trees grew naturally on farm lands. The rise in population, and resulting increased demand for wood products, has led to loss of tree cover through cutting down of trees without replacement. Land shortage is common in most parts of Uganda, and therefore land for establishing separate wood plantations is not available. Agroforestry becomes the most obvious and appropriate alternative. Agroforestry is a term used for land-use systems in which trees or shrubs are grown together with crops or combined with livestock. Trees can be combined with other components, either simultaneously being grown in a field with crops, or in rotation where trees are grown first then cut and replaced with crops. Agroforestry is a technology through which the problems of poor agricultural production, wood shortages and environmental degradation can be addressed. Trees provide many products such as fuelwood, poles, shade, fodder, fruits, medicine and timber. Trees planted as contour hedges for soil and water conservation help reduce water and soil loss and improve infiltration rate. Trees also maintain soil fertility through nutrient recycling, nitrogen fixation and improving soil structure. Trees are also used as windbreaks, for providing shade and beautifying the landscape. Trees suitable for agroforestry should have characteristics that are highly beneficial to farmers. This usually depends on the technology or tree arrangement desired by the farmer and the final products needed. For instance, a fast-growing aggressive tree species may be very useful for rotational systems but may compete too much with crops. Table 9. Desirable characteristics of agroforestry trees for selected practices Tree characteristics Improved Boundary Scattered in Contour fallow planting crop fields planting Nitrogen fixing – – Fast growing – – – Coppicing – – – Deep rooted – – – Light canopy – – Suitable for fodder – – Compatibility with crops – – – Quick recovery – – – Lots of biomass – – 6.3 Propagation of trees There are three methods of propagating trees: ● Seed ● Vegetative propagation ● Collecting wild seedlings (wildings). Most trees are raised from seed. Successful raising of seedlings and growing of trees depends on timely availability of good-quality seed.
A protocol for rooting and growing apple rootstock microshoots.
(1998) Isutsa, D. K.; Pritts, M. P.; Mudge, K. W.; ; ;
Microshoots of apple (Malus domestica Borkh.) rootstocks G. 65, G.30 and G.11 were transferred from stage II axillary shoot cultures to stage III rooting media containing 10 levels of indole-butyric acid (IBA) for four weeks to determine optimal conditions for rooting. Microshoots were inverted or left in an upright position. Rootstocks and microshoot position affected rooting and survival; the highest rooting was 30% for G.65 inverted with 2 mgcntdotL-1 I13A, 100% for G.30 upright with 3 mgcntdotL-1 IBA, and 100% for G.11 inverted with 1 or 2 mgcntdotL-1 IBA. No single set of conditions provided consistent rooting in vitro, and plants were not always of high quality. In a second experiment, microshoots were rooted and acclimatized ex vitro in a custom-built fog chamber to assess the effect of two carbon dioxide levels (450 or 1350 mumolcntdotmol-1) and three light levels (30, 50 or 100 mumolcntdotm-2cntdots-1). All rootstocks rooted equally well ex vitro, but survival varied. Plantlets had the highest dry mass, leaf area and growth rates under high light conditions compared to medium light or low light conditions. Supplemental carbon dioxide had no consistent effect. If plants survived fog chamber conditions, subsequent survival in the fog tunnel and greenhouse was 100%. Thus, these rootstocks can be rooted successfully in the fog chamber at high light conditions, which yielded high quality plants. A third experiment was conducted to evaluate the effect of chilling for four weeks at 3.3degreeC, or spraying with gibberellic acid 3 (GA3) on post-rooting dormancy, a problem which frequently occurs with recently rooted apple microshoots. Chilled plants had greater dry mass than control or GA3 plants, and the GA3 effect was short-lived. The ex vitro procedure suggested by these experiments could reduce the time associated with rootstock micropropagation to at most 6 months.
Malus germplasm varies in resistance or tolerance to apple replant pathogens in a mixture of New York orchard soils.
(American Society for Horticultural Science, 2000-04) Isutsa, Dorcas K. 1; Merwin, Ian A.; ; ;
We tested 40 seedling lots and 17 clonal accessions - representing 941 genotypes and 19 species or interspecific hybrids of Malus - for their resistance or tolerance to apple replant disease (ARD) in a mixture of five New York soils with known replant problems. Total plant biomass, root necrosis, root-infesting fungi, and root-lesion nematode (RLN; Pratylenchus penetrans Cobb) or dagger nematode (DN; Xiphinema americanum Cobb) populations were evaluated in apple seedlings and clones grown for ≃60 days in the composite soil. In addition to phytophagous nematodes, various Pythium, Cylindrocarpon, Fusarium, Rhizoctonia and Phytophthora species were isolated from roots grown in the test soil. Plant growth response was categorized by a relative biomass index (RBI), calculated as total plant dry weight in the pasteurized field soil (PS) minus that in an unpasteurized field soil (FS), divided by PS. Nematode reproduction on each genotype was defined by a relative reproduction index (RRI), calculated as final nematode populations in roots and soil (Pf) minus initial soil populations (Pi), divided by Pi. The RBI, RRI, and other responses of accessions to ARD soil were used to rate their resistance, tolerance, or susceptibility to apple replant disease. None of the accessions was completely resistant to ARD pathogens in our test soil. Seedling accessions of M. sieversii Roem. and M. kirghisorum Ponom. appeared to have some tolerance to ARD, based upon their low RRIs and RBIs. Three clonal rootstock accessions (G.65, CG.6210, and G.30), and four other clones (M. baccata Borkh. - 1883.h,M. xanthocarpa Langenf. - Xan, M. spectabilis Borkh. - PI589404, and M. mandshurica Schneid. - 364.s) were categorized as tolerant to ARD. The disease response of other accessions was rated as susceptible or too variable to classify. We concluded that sources of genetic tolerance to ARD exist in Malus germplasm collections and could be used in breeding and selecting clonal rootstocks for improved control of orchard replant pathogens.
Grazing Behaviour of Saanen and Toggenburg Goats in Sub-Humid Tropical Conditions of Kenya
(2001-03-22) Njoka-Njiru, E. N. *; Ojango, J. M.; Ambula, M. K.; Ndirangu, C. M.
The behavior of 6 Toggenburg and 6 Saanen female goats, grazing on natural vegetation in a modified sub-humid tropical environment of Kenya, was studied during the dry (January and February) and wet (April and May) seasons in 1997. The two exotic breads grazed for 12 h daily. Observation on feeding, standing, lying and ruminating was done chronometrically at five minute intervals between 0600 and 1800 h. These grazing times were based on the current practice of small holder farmers. During the dry period, the average feeding standing, lying and ruminating time per 12 h period for Saanens was 5.63, 4.57, 1.80 and 1.50 h respectively while that for Toggenburgs was 7.26, 3.21, 1.53 and 1.96 h, respectively. In the wet (Green) season, the mean feeding, standing, lying and ruminating time per Saanen in both seasons. It was also observed that standing occurred more often in Saanens than the Toggenburgs in the dry season. During the wet period, Saanens ruminated significantly longer than the Toggenburgs. The health status of the animals was determined by analyzing the respiratory frequency, heart rate, rectal temperature, hemoglobin, erythrocytes and leucocytes of the experimental animals. All the clinical and physiological parameters were within the normal physiological range of healthy goats. It was concluded that differences in the grazing behavior of Saanens and Toggenburgs in the modified tropical environment of Kenya, do exist.
Evaluation of Sorghum (Sorghum bicolor) as Replacent for Maize in the Diet of Growing Rabbits (Oryctolagus cuniculus)
(2002) Muriu, J. I.; Njoka-Njiru, E. N. *; Tuitoek, J. K.; Nanua, J. K.
Thirty six young New Zealand white rabbits were used in a randomised complete block (RCB) design with a 3×2 factorial treatment experiment to study the suitability of sorghum as substitute for maize in the diet of growing rabbits in Kenya. Six different diets were formulated to contain 35% of one of the three different types of grain (maize, white sorghum or brown sorghum) and one of the two different levels of crude protein (CP) 16 or 18.5% and fed to growing rabbits for a period of six weeks. The tannin content of the grains was 0.05, 0.52 and 5.6% chatechin equivalents for maize, white and brown sorghum respectively. Weaning weight at 35 days of age was used as the blocking criterion at the beginning of the experiment. Results of feed intake, weight gain, feed conversion efficiency, feed digestibility, as well as the blood parameters, indicated that white sorghum was not significantly different from maize. Animals fed on diets containing brown sorghum had a lower average daily gain (ADG) and a poorer feed conversion efficiency (FCE) (p<0.01) in comparison with those fed on diets containing maize or white sorghum. The 18.5% CP level gave a better FCE (p<0.05) compared with the 16% CP level. However, increasing the level of CP did not improve the utilisation of any of the grains. It was concluded that white sorghum could effectively substitute maize in the diet of growing rabbits. On the other hand, the use of brown sorghum in the diets of growing rabbits may compromise their growth rate. This may be due to the high concentration of tannins in the brown sorghum
Effect of time of pruning and lungs on non-structural carbohydrates of tea (Camellia sinensis L.).
(2003-03) Bore, John K.; Ng'etich, Wilson; Isutsa, D. K.; ; ;
An experiment was conducted at Kipkebe Estate, Sotik, Kenya, with the aim of establishing the effects of pruning time and resting period on total non-structural carbohydrate (TNC) reserves, regrowth and yield of tea. In this experiment, tea bushes were freely left unplucked for 45 and 90.d before pruning. Control treatments were continuously plucked until pruning. Results showed that TNC was significantly (P<0.05) increased at pruning time. October pruning significantly increased leaf, stem, and root TNC. A longer resting period of 90 d significantly increased leaf and root TNC to 294 and 230 g kg -1, respectively. Generally, TNC declined after pruning and thereafter increased. Root TNC significantly correlated with regrowth period, diebacks and yield. Generally, the best resting period for increased TNC, regrowth and yield, is between 45 and 90 d. The best pruning time is October, if drought stress can be avoided.
Rapid micropropagation of passion fruit (Passiflora edulis Sims.) varieties.
(2004-02) Isutsa, D. K.; ; ;
Lack of adequate, healthy plants can hamper production of passion fruits (Passiflora edulis Sims.). Seed propagation results in undesirable variability, inadequate and seasonal supply. This research aimed at rapid generation of P. edulis plants through modified ex vitro rooting techniques. Yellow (P. edulis var. flavicarpa) and purple (P. edulis var. edulis) passion fruit shoot tops were proliferated in vitro to stage II shoots, half of which were rooted ex vitro and the other half were conventionally rooted in vitro. The design was completely randomized for each variety. Plantlets were assessed after 30 days. Data were analyzed using the MSTAT programme. After proliferating yellow passion fruit on a medium containing 22.2 μM 6-benzylaminopurine (BAP), its rooting ex vitro was significantly better (96% rooting, three roots per shoot, 92% survival) than rooting in vitro (62% rooting, one root per shoot on 24.5 μM indole-3-butyric acid medium, 50% survival). Purple passion fruit proliferated satisfactorily only on a medium containing both 22.2 μM BAP and 11.6 μM gibberellic acid 3. Like difficult proliferation, and compared to yellow passion fruit, its rooting and survival also proved difficult and poor (47% rooting, one root per shoot on 21.5 μM naphthalene acetic acid medium in vitro, 32% survival) and (66% rooting, two roots per shoot ex vitro, 60% survival). Thus, the various passion fruit varieties have different requirements for micropropagation. The key finding was that ex vitro rooting is possible and significantly better than in vitro rooting of passion fruit shoots.
Effect of Intercropping Herbaceous Legumes with Napier Grass on Dry Matter Yield and Nutritive Value of the Feedstuffs in Semi-arid Region of Eastern Kenya
(2006) Njoka-Njiru, E. N.; Njarui, M. G.; Abdulrazak, S. A.; Mureithi, J. G.
Semi-arid region of Kenya is faced with inadequate quantity and low quality of livestock feeds. Research was conducted in the semi-arid region of eastern Kenya to investigate the contribution of two legumes, Seca (Stylosanthes scabra cv. Seca) and Siratro (Macroptilium atropurpureum cv. Siratro) to seasonal total fodder productivity and nutritive value when intercropped with Napier grass (Pennisetum purpureum cv. Bana). The treatments consisted of Napier grass planted as pure stand and intercropped with legumes. During the production phase, the grass and legumes were harvested for dry matter yield after every 8 weeks for a period of four wet seasons and two dry seasons between April 2002 and September 2004. Overall total herbage yield of the mixtures was higher than those of sole fodder grass with the grass constituting the major component of the yield. Seca was more productive and had a relatively stable yield than Siratro. It accounted for higher proportion of total DM yield of 15 - 34%. in Napier compared to Siratro which had less than 5% except in the drier season when yield failed. Total DM yield was highest during the short rains of year 2002 and declined thereafter in subsequent seasons and was lowest during the dry seasons. It was observed that crude protein of Napier grass was significantly ( P< 0.05) enhanced by inclusion of the legume in the intercrop (CP 9.64 - 9.96% of DM) compared to sole Napier grass (CP 8.14% of DM). Napier grass intercropped with Seca was more degradable than sole Napier grass. It can be concluded that Seca formed a better association with fodder grass than Siratro and is recommended for intercropping in the semi-arid region of eastern Kenya.
Effects of mulch and cultivar on strawberry productivity under tropical highland conditions.
(2006) Isutsa, Dorcas Khasungu *; ; ;
A study was conducted to determine effects of four mulches (cut grass, clear polyjilm, black polyjilm, and none) on productivity of four strawberry (Fragaria x ananassa Duch) cultivars (Pajaro, Aiko, Fern and Douglas) under tropical hig~land conditions. It was hypothesized that polyjilm would hasten growth and increase yield more than cut stargrass (Cynodon dactylon), or no mulch, through warming soil, improving nutrient uptake and conserving moisture. The experiment was set up as split plots in randomised complete block design; mulches were assigned to main plots, whereas cultivars were assigned to sub-plots. Each of the sixteen treatments was replicated three times. Cultivars were planted at the beginning of long rains in March 2002. Data were recorded from the fourth month after planting (MAP) and analysed. Polyjilm hastened growth from 2 to over 5 stolons, 18 to 30 leaves, 31 cm to 35cm diameter at 4 MAP, and increased flowering and yield from 9 to 12 flower stalks, 22 to 29 berries, and 30 g to 35 g berry fresh weight at 9 MAP. Most of the time, black polyjilm growth and yield parameters were higher than those for cut grass or no mulch. Positive effects of cut grass mulch developed slowly, while those of clear polyjilm mulch diminished over time. Nine months after planting, black polyjilm gave significantly (P0.05) interact with cultivar, implying that it does not alter the potential of cultivars grown under tropical highland conditions.
Current characteristics of cassava mosaic disease in post-epidemic’ areas increase the range of possible management options.
(Association of Applied Biologists, 2006-06-05) Mallowa, S. O.1; Isutsa, D. K.1; Kamau, A. W.1; Obonyo, R.2; Legg, J.P 2,3; ; ;
As a case study to document the current characteristics of cassava mosaic virus disease (CMD) in postepidemic areas, surveys were carried out, in 2003 and 2004, in Siaya District of western Kenya. This was an area affected by a severe CMD pandemic in the late 1990s. Data recorded on cassava varieties were CMD incidence, severity index and number of adult whiteflies. Farmers (174) were interviewed on their understanding of the disease and their knowledge and practice of management interventions. Cassava cultivation was being reestablished, but local landraces predominated. Resistant varieties were present 13% in 2003, and 4% in 2004, of the surveyed fields. Adhiambolera was the most common variety, occurring in 35% and 40% of fields in 2003 and 2004, respectively, and had an average CMD incidence of 82% in 2003 and 73% in 2004. By contrast, the CMD-resistant variety Migyera had a low mean incidence (28% in 2003). The overall incidence for both years was 71%, consisting of 61% as a result of infection through planting diseased cuttings and 10% as a result of whitefly infection. In 2003, the total incidence was 72% and the average severity 2.7 (severity index), while in 2004 the incidence was 78% and the severity 2.6. There were significant severity variations in each division of the Siaya District during the 2 years except for Karemo and Ukwala. The abundance of whiteflies on the top five leaves of plants was low in 2003 but high in 2004, with means of 1 and 16, respectively, over the same seven divisions in both years, although this variation was thought to be because of seasonal factors. East African cassava mosaic virus-Uganda was the predominant geminivirus present in every division. Phytosanitation by farmers was minimal, as evidenced by 29% of farmers using a selection of CMD-free stems for planting and 15% using hand-roguing for CMD management. Occurrence of more than 25% CMD-free plants in 2004, moderate CMD severity and limited spread provide a conducive environment for the use of phytosanitation as a CMD control measure that can be immediately used by farmers growing their own cassava varieties.
Effects of Mineral Supplementation On Milk Yield of Free-ranging Camels (Camelus dromedaries) in Northern Kenya.
(2006-11) Onjoro, P. A.; Njoka Njiru, E. N. *; Ottaro, J. M.; Simon, A. 1; Schwartz, H. J. 1
ABSTRACT : The effects of different mineral supplementations on the milk yield of free-ranging Somali camels were investigated in two phases in a semi-arid region of northern Kenya during the dry and wet seasons in 2002 and 2003. In phase 1, twelve (12) lactating camels were selected at random to form four (4) groups each consisting of three camels. The first group served as the control and as a result received no mineral supplementation. In addition to the control diet the other groups received oral doses of minerals as follows over a 60-day period: T1 (P), T2 (High Cu low Co) and T3 (Low Cu high Co). The daily milk yield and blood mineral profiles were measured during the wet and dry seasons. The mean daily milk yield increased from 3.4 L/d to 4.3±0.3 L/d and 5.2 L/d in the dry and wet seasons, respectively. Fifteen (15) lactating camels were selected at random to form five groups each consisting of three replicates. The control group did not receive any mineral supplement. The other four groups in addition to the control diet, received the following treatments: T4 (Common Salt), T5 (High Co), T6 (High Co+P) and T7 (Low Co+P). Mineral supplement T6 produced significantly higher milk yield (5.4±0.5 and 6.5±0.7 L/d) during the dry and wet seasons. Both T6 and T7 had significantly higher milk yield than T4 and T5. During both phases, the blood Ca and P level significantly increased in camels receiving T1, 6 and 7. Animals that received only the trace mineral supplements had lower blood P compared to the ones receiving supplementary P and also the control. Supplementation of lactating camels with Co and P significantly (p<0.05) increased milk yield). Effect of common salt, commonly given by farmers, on milk yield was insignificant. It was concluded that mineral supplementation to lactating camels was beneficial, and that mineral supplements should include P and Co. Further research is required to establish P and Co requirements of lactating camels. (1) (PDF) Effects of Mineral Supplementation on Milk Yield of Free-ranging Camels (Camelus dromedarius) in Northern Kenya. Available from: https://www.researchgate.net/publication/260087255_Effects_of_Mineral_Supplementation_on_Milk_Yield_of_Free-ranging_Camels_Camelus_dromedarius_in_Northern_Kenya [accessed Nov 20 2019].
Effects of minerals in the forage, blood and milk on production of lactating free-ranging camels (Camelus dromedaries) in northern Kenya.
(2006-11) Onjoro, P. A.,; Njoka-Njiru, E. N.,; Ottaro, J. M.; Nanua, J. N.
The effects of different mineral supplementations on the milk yield of free-ranging Somali camels were investigated in two phases in a semi-arid region of northern Kenya during the dry and wet seasons in 2002 and 2003. In phase 1, twelve (12) lactating camels were selected at random to form four (4) groups each consisting of three camels. The first group served as the control and as a result received no mineral supplementation. In addition to the control diet the other groups received oral doses of minerals as follows over a 60-day period: T1 (P), T2 (High Cu low Co) and T3 (Low Cu high Co). The daily milk yield and blood mineral profiles were measured during the wet and dry seasons. The mean daily milk yield increased from 3.4 L/d to 4.3±0.3 L/d and 5.2 L/d in the dry and wet seasons, respectively. Fifteen (15) lactating camels were selected at random to form five groups each consisting of three replicates. The control group did not receive any mineral supplement. The other four groups in addition to the control diet, received the following treatments: T4 (Common Salt), T5 (High Co), T6 (High Co+P) and T7 (Low Co+P). Mineral supplement T6 produced significantly higher milk yield (5.4±0.5 and 6.5±0.7 L/d) during the dry and wet seasons. Both T6 and T7 had significantly higher milk yield than T4 and T5. During both phases, the blood Ca and P level significantly increased in camels receiving T1, 6 and 7. Animals that received only the trace mineral supplements had lower blood P compared to the ones receiving supplementary P and also the control. Supplementation of lactating camels with Co and P significantly (p<0.05) increased milk yield). Effect of common salt, commonly given by farmers, on milk yield was insignificant. It was concluded that mineral supplementation to lactating camels was beneficial, and that mineral supplements should include P and Co. Further research is required to establish P and Co requirements of lactating camels.
Effect of Planting Pattern of Two Herbaceous Forage Legumes in Fodder Grasses on Productivity of Grass/Legume Mixture in Semi-arid Tropical, Kenya.
(Universidad Autónoma de Yucatán, 2007-01) Njarui, D. M. G. 1; Njoka, E. N. 2; Abdulrazak, S. A. 2; Mureithi, J. G. 3
An experiment was conducted to investigate the effect of planting pattern of legumes on the growth, persistence and productivity of grass/legume mixture in the semi-arid tropical Kenya. The legumes, Seca and Siratro were planted either as single or double rows between rows of Napier grass and giant panicum. Plant population, growth and productivity of the mixture were monitored for a period of 4 wet seasons; short rains (SR) 02, long rains (LR) 03, SR 03 and LR 04 and two dry seasons (DS) 03 and DS 04. There was significantly (P<0.05) more plants that survived from double rows of legumes (15 plants m-2) than from single rows (10 plants m-2). Legumes planted in double rows between grass rows covered more plot than when planted in single rows with Siratro covering more plot than Seca. However, legumes planted in double rows had no significant (P<0.05) dry matter (DM) yield advantage over single rows and did not benefit or impede growth (tiller and canopy cover) of the fodder grasses. The productivity of the associated fodder grasses was not affected and hence combined total DM yield (grasses + legumes) were not significantly different. Napier grass was more vigorous, had more tillers, large canopy and consequently was more productive than Panicum. On the basis of combined DM production, Napier grass/Seca was most productive while Napier intercropped with Siratro and Panicum intercropped with either Seca and Siratro showed similarity in DM. Seca was more productive than Siratro and overall the proportion of the legume to total DM was highest during the dry season than wet season. Dry matter was highest during the SR 02 and declined progressively with seasons and was lowest during the dry seasons.
Effects of integrated nutrient sources on growth and yield of strawberry grown under tropical high altitude conditions.
(Horticultural Association of Kenya, 2008) Odongo, T.; Isutsa, Dorcas K.; Aguyoh, J. N.; ; ;
Strawberries are popular both in fresh and processed forms because of their enormous values. Low soil fertility is among major factors constraining strawberry productivity in Kenya. Consequently, effects of cattle farmyard manure (FYM) (0, 18, 36, and 54t/ha) in combination with triple super phosphate (TSP), equivalent to 0, 17, 34 and 68kg/ha phosphorus on strawberry productivity, were tested in split plots embedded in randomized complete block design, replicated three times. Farmyard manure formed main plots, whereas TSP formed sub-plots. Each treatment had 10 plants spaced at 0.3m´0.45m in double rows per plot, measuring 0.6m´1.5m. The plots were mulched with black polyfilm, irrigated with 2.5.cm diameter drip lines, and separated with a 0.5m trench. The study was done in three seasons (August 2003-July 2004, Feb. 2004-Jan. 2005, and July 2005-June 2006). Each season was conducted in new plots. Growth and fruit yield were assessed from 3 to 6 and 6 to 12 month after planting, respectively. Since seasons 1 and 2 data were not significantly different they were pooled and reported as season 1, whereas the different season 3 data were reported separately as season 2. Generally, the 54t/ha FYM promoted the highest growth, although not significantly different. Phosphorus (P) significantly (P<0.05) increased root biomass, and root: shoot biomass ratio. The effects of FYM, P and interaction on fruit yield were not consistent. The 36 and 54t/ha FYM resulted in the highest fruit weight in seasons 1 and 2, respectively. Phosphorus did not significantly (P>0.05) influence fruit weight, although 17 and 34kg/ha P yielded highest in seasons 1 and 2, respectively. The effect of interaction on cumulative yield was not significant in both seasons. Thus the observed variation was also attributed to soil and seasonal effects. Based on the current results, 36 t/ha to 54t/ha FYM and 17 kg/ha to 34kg/ha P are recommended for enhancing strawberry productivity under conditions similar to the ones for the present study. Phosphorus should only be applied where soil tests show deficiency.
Evaluation of manure from goats fed Panicum basal diet and supplemented with Madras thorn, Leucaena or Gliricidia.
(2008) Saha, Hemedi Mkuzi; Kahindi, R.K.; Muinga, R.W.
An experiment was carried out to assess the effect of supplementing a Panicum hay basal diet with leaves of Madras thorn (Pithecellobium dulce), Leucaena (Leucaena leucocephala) or Gliricidia (Gliricidia sepium) on the quality and quantity of goat manure. Twelve Small East African goats aged eight months on average and weighing 9.7kg (±1.52) were randomly assigned to four treatments. Panicum hay fed ad libitum plus 100g of maize bran constituted the control diet. The remaining three treatments consisted of the control diet supplemented with iso-nitrogenous levels of Leucaena, Gliricidia or Madras thorn, respectively. Crude protein concentrations in the forages were 3.5, 21, 23 and 25% for Panicum hay, Gliricidia, Madras thorn and Leucaena, respectively. The supplements were therefore offered at 19.5g DM/kgW0.75 Madras thorn, 18.6g DM/kgW0.75 Leucaena and 22.5g DM/kgW0.75 Gliricidia. Daily total dry matter intake increased significantly (P<0.05). On supplementation from 229 for the control diet to 365, 387 and 398g for the diets supplemented with Madras thorn, Gliricidia and Leucaena, respectively. Animals supplemented with the legumes retained (p<0.05)mMore N (3.5, 3.6 and 3.7g N/day for Leucaena, Gliricidia and Madras thorn, respectively) than the control treatment (0.6 g N/day). Legume supplementation increased (p<0.05) daily weight gains from 2g per day for the control treatment to 19, 22 and 25g per day for diets supplemented with Gliricidia, Madras thorn and Leucaena, respectively. The effect of supplement on growth rate was not different between the legumes. Goats fed on legume supplements produced (p<0.05) more faeces (135g, 142g and 150g DM per day for goats fed Madras thorn, Gliricidia and Leucaena treatments, respectively) than those on the control diet (92g DM). The daily faecal DM outputs expressed as percentage of body weight were 1.13, 1.27 and 1.30% for the control diet supplemented with Madras thorn, Gliricidia and Leucaena, respectively, as compared with 0.98%, for the control diet alone. Legume supplementation in goats increased (p<0.05) faecal N content from 0.2 to 1.7% but had no effect on the C, P or K contents. Supplementation of a poor quality basal diet with legume forage is therefore recommended since, in addition to improving the performance of goats, it would increase the amount of manure produced and improve its quality.
Growth of ranunculus cutflower under tropical high altitude conditions. 2: Effects of GA3 and shade on light intensity and temperature modification
(Horticultural Association of Kenya, 2009) Mayoli, Rose N.; Isutsa, Dorcas K.; Tunya, G.O; ; ;
Customer needs of a different flower are increasing over time worldwide. Many bulbous plants including ranunculus fit the category of a different flower because they are not known. Ranunculus(Ranunculus asiaticusL.),commonly known as Persian Buttercup or Asiatic Crowfoot,is a bulbous plant native of the cool Mediterranean basinregion. The growth of GA3and shade-treated ranunculus cutflower in relation to lightintensity (LI) and temperature under tropical high altitude conditions is not documented. An experiment was conducted to determine these relationships.The fixed factors were four GA3levels (0, 100, 500, 1500 mg/L) and three shade levels (0%, 40% and 80%shade). The experiment was set up in split plots arranged in randomised complete block design, replicated three times and repeated once. Tuberous roots were soaked in the respective GA3solutions for 10 minutes followed by planting under the shaded plots.Data were recorded from sprouting through tuberous root formation stages.The relationship of sprouting was negative quadratic with LI, positive linear with soil temperature (ST) in season 1 (cool), and negative linear with ST in season 2 (warm). The relationship of time to flower formation with LI was negative linear in season 1 and positive linear in season 2. The relationships of flower stem length with LI and air temperature (AT) were negative linear. The relationships of flower buds per stem, flower stem diameter, flower head diameter and tuberous root fresh weight with either LI or AT were negative quadratic. Therefore, shade modifies both LI and temperature that then interact in influencing growth of GA3-treated ranunculus. About 40000 lux LI and moderate seasonal temperature, both prevailing under 40% shade are ideal for best growth of ranunculus. Shade should be applied as follows: 0%, 40% and 80% in cool, warm and hot seasons, respectively.
Growth of ranunculus cutflower under tropical high altitude conditions.
(Horticultural Association of Kenya, 2009) Mayoli, Rose N.; Isutsa, Dorcas K.; Tunya, G.O; ; ;
Cutflower production and marketing is partly challenged by lack of new, exciting and improved varieties to satisfy customer needs of a different flower. Ranunculus (Ranunculus asiaticus L.) is a bulbous plant that originated in the Mediterranean basin region where growth and development take place optimally in cool, moist winter season. The extent of dormancy breaking and growth of this flower in tropical conditions is not known. Consequently, the present research studied the effects of shade and gibberellic acid (GA3) in breaking dormancy and reducing high light intensity and high temperature so as to assure optimal growth of R. asiaticus under tropical conditions. The fixed factors were: four GA3 levels (0, 100, 500 and 1500 mg/L) and three shade intensities (0%, 40% and 80% shade). The experiment was laid out in split plots arranged in randomised complete block design, replicated three times and repeated in two seasons. Tuberous roots were soaked in the respective GA3 concentrations for 10 minutes followed by planting under shaded plots. Data were recorded from sprouting through tuberous root formation stages. Season 1 (June to November 2006) was characterised by cool temperatures, whereas season 2 (December 2006 to April 2007) was characterised by warm temperatures. The 80% shade promoted significantly longer stems. Nevertheless, early flowering, highest quality flower stem diameter, flower bud initiation, flower head diameter and tuberous root fresh weight resulted for 40% shade. These quality parameters were highest in tuberous roots that had been soaked in 100 mg/L GA3 pre-plant. Therefore, growers in tropical high altitudes should use 80%, 40% and 0% shade in hot, warm and cool seasons, respectively. Pre-soaking of the tuberous roots in 100 to 500 mg/L GA3 is optional, depending on the desired growth magnitude and speed desired.
Performance of growing Small East African Goats offered Rhodes grass hay and supplemented with a 1:1 mixture of Maerua angolensis: Zizyphus mucronata leaf browses.
(Livestock Research for Rural Development 22 (9) 2010, 2010) Ondiek, J. O. *; Abdulrazak, S. A. ***; Njoka, E. N. ***
A 56-day experiment was conducted to examine the contribution of Maerua angolensis and Zizyphus mucronata, mixed on a 1:1 ratio as a supplement to growing Small East African Goats fed a basal diet of Chloris gayana hay. Twenty goats were assigned to five treatments of: 0, 15, 20, 25 and 30 g DM kg-1W0.75, assigned as MZ0, MZ15, MZ20, MZ25 and MZ30. The total extractable phenolics (TEPH) and total extractable tannins (TET) for Maerua angolensis (11.4, 3.01 mg kg-1 DM) were lower than for Zizyphus mucronata (72.3, 41.2 mgkg-1DM) and the mixture had average values (41.9, 22.1 mg kg-1 DM), respectively. The Chloris gayana hay had low crude protein content (54 g kg-1 DM). Intake of hay and of total DM, and coefficients of apparent digestibility of diet proximate components, increased with supplementation. The control animals (MZ0) lost weight and the supplemented groups gained weight with best growth on the MZ20 diet. Rumen pH was in the normal range but rumen ammonia N was low for the control diet (8.99 mg 100ml-1), increasing with supplementation to 11.3 - 12.7 mg 100ml-1. There was a positive linear relationship between rumen ammonia level and live weight change. It is concluded that the 1:1 mixture of Maerua angolensis:Zizyphus mucronata with a CP of 261g kg-1 DM is an adequate protein supplement for growing Small East African Goats when fed a low quality (5.4% CP) basal diet of Chloris gayana hay.
Chemical and mineral composition, in-vitro gas production, in-sacco degradation of selected indigenous Kenyan browses
(CIPAV Foundation, 2010) Ondiek, J . O.; Abdulrazak, S. A. *; Njoka, E. N. **
Abstract Proximate and mineral composition, in-sacco degradation and in-vitro gas production was conducted using fifteen indigenous Kenyan multipurpose tree and shrub (MPTS) leaf browse to assess their potential as goat feed. The species selected from a field survey were Maerua angolensis, Acacia brevispica, Acacia mellifera, Acacia tortilis, Acacia hockii, Zizyphus mucronata, Grewia bicolor, Acacia elatior, Acacia nilotica, Balanites aegyptiaca, Acacia senegal, Acacia abyssinica, Bridelia micrantha, Albizia amara and Albizia coriaria. The CP levels ranged from 112gkg-1DM for Bridelia micrantha to 321 gkg-1DM for Maerua angolensis; the NDF ranged from 218 to 601 gkg-1DM for Acacia hockii and Albizia amara, respectively. The TEPH and TET were in the range of 1.52-26.4 and 0.301-24.4gkg-1DM, respectively. The major minerals Ca, P, Mg, Na and S were in the ranges of 6.51-28.1, 0.838-3.18, 0.442-8.51, 0.318-0.711 and 1.12-2.45gkg-1DM, respectively. The microelements varied widely (mgkg-1DM) as follows: Fe (51.3-267), Mn (13.8-38.5), Cu (4.81-74.9), Mo (13.9-43.4), Co (1.76-17.4), Zn (12.2-93.2) and Se (19.5-124). In-sacco DM degradation at 48hrs shows Zizyphus mucronata was highest followed by Maerua angolensis with degradability of 93.3% and 88.6%, respectively. Gas production (volume (ml)/200mgDM) levels (a+b) ranged from 19.2 to 52.2 in Bridelia micrantha and Maerua angolensis, respectively. The overall levels of nutrients and degradation showed variations but most of the forages were moderate to high in the nutrient composition and degradability parameters. The ranking of the forages in order of increasing nutritive value into three categories of five species was as follows: low (Bridelia micrantha< Albizia amara< Acacia hockii < Acacia nilotica< Acacia tortilis); medium (Acacia abyssinica< Grewia bicolor< Albizia coriaria< Acacia elatior) and high (Balanites aegyptiaca< Acacia mellifera< Acacia senegal< Zizyphus mucronata< Maerua angolensis). It is concluded that Maerua angolensis and Zizyphus mucronata are outstanding and they have potential for ruminant feed and more so as protein supplements to low quality tropical basal diets.
Effects of Supplementing Chloris gayana Hay and Maerua angolensis with Graded Levels of Maize Germ Meal on Voluntary Feed Intake, Diet Digestion, Nitrogen Balance and Average Daily Gains of Growing Small East African Goats
(2010-07) Ondiek, James; Abdulrazak, Shaukat; Njoka, E. N.
Maerua angolensis and graded levels of maize germ meal were offered to Small East African goats to assess the effects on voluntary feed intake, diet digestion, nitrogen balance and growth. The M. angolensis was offered at a rate of 20 g kg-1 W0.75 to all animals and maize germ meal treatment diets was given at five graded levels (0, 15, 20, 25, and 30 gDM kg-1 W0.75) designated as MG0, MG15, MG20, MG25 and MG30, in a completely randomized block design with 4 animals per treatment with the basal diet of Rhodes grass (Chloris gayana) hay fed ad libitum. The CP levels were 320, 200 and 61.4 g kg-1 DM for M. angolensis, maize germ and C gayana hay, and NDF contents were 449, 393 and 528 g kg-1 DM, respectively. The DMI was 461-599 g DM d-1 which increased with energy supplementation (P<0.05) although the supplemented groups did not differ and the goats consumed the feed at 3.72-4.53% of their live weight. The ADG was 4.92, 23.7, 26.4, 34.4 and 35.7 g d-1, respectively, with MG25 and MG30 being similar (P>0.05). The rumen NH3-N was in the normal range of 1.85-2.63 mg100 ml-1 while the nitrogen balance was in the range of 2.90-7.68 mg N/100 ml for MG0 and MG30, respectively. The DM, OM, CP, ADF and NDF digestibility was improved with supplementation, but supplemented animals had similar values (P>0.05). It is concluded that the maize germ meal supplemented at 25 g DM kg-1 W0.75 had high rumen NH3-N, N-retention and ADG 8.16 mg-1 100 ml, 6.25 g Nd-1 of 34.4 g d-1, respectively, and this can be used together with M. angolensis at 20 g DM-1 W0.75 to make use of the tree forage and low quality basal diet for growing Small East African Goats.

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