Agricultural Sciences

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The response of Green Beans(Phaseoulus Vulgari)to varying application rates of Boron
(2010-12-02) Manda, Jastine Peter
Green Beans(Phaseoulus Vulgari) is a very important crop,feeding a large number of people in in the world.However,bean yields are low,hence many methods resulting in increased green bean yield maybe of great importance.Boron(B)is one of the most important micronutrients neccessary for bean growth and yield.A widespread deficiency of boron has been reported in Zambian soils.This is a limitation to the potential yields of green beans,therefore,additions of B to the crop could contribute to higher yields.Currently, the University of Zambia recommends the addition of up to 2kg/ha B as a way of addressing boron deficiency in most crops grown.It is not well known,however,whether increasing supply rates of B applied would make a difference in yield.A study was carried out to correlate two methods of boron analysis with plant B uptake,and to determine whether B fertilizer application would improve crop performance.The hypothesis of this research was that since B is often deficient in soil,soil and foliar application of B ought to increase green bean yield.In the laboratory,16 soils that included pairs from cropped and fallow land were extracted for B using hot-water extraction and acid extraction. Aparallel study was carried out in green houseA green bean crop was grown in each of the soils for a six week period.In the field,five rates of B were applied at 0,2,4,6 and 8 kg/ha,to two green bean crops.One foliar application at 0.45g/1 was also used as one of the treatments giving a total of six treatments.The field experiments were conducted at York Farn in Lusaka Province in Zambia while the pot experiment was conducted in greenhouse at the University of Zambia.Extractable B values were obtained in the laboratory, and B uptake in the green house.In the field,plant height,pod length,packout rate and yield were obtained.Results indicated that there was no good correlation between each of the two extraction methods with plant uptake.Foliar application of B at 0.45g/1 also did not significantly increase bean yield.The results also showed that in both field and green house experiments increasing rates of B did not influence(p<0.05)plant height,pod length,yield and quality of green beans.The early crop which was grown perely on drip irrigation did slighly better than the second crop which received some rainfall.During the first crop,the pods were 6% longer than the control compared to only 1% in the second crop.The length of pod was found to be strongly related to yield increase of green beansThe yields were 28% more than the control in the first crop and 15.6% more in the second crop.The fruit quality was not affected by increasing rates of B.However,higher packout rates were obtained in the first crop compared to the second.These preliminary results suggest that green bean yields and quality may be better when grown in winter season.Soil application was more effective than foliar application in the greenhouse while the opposite was true in the field trial.
The Agroecology of Faidherbia Albida on the Tonga Plateau of Southern Zambia
(2010-12-07) Wahl, Trent Carl
Faidherbia Albida is a tree species indigeous to semi-arid regions of Africa that substantially increases maize(Zea mays)yields in its immediate vicinity.In southern province of Zambia,F.albida is widely used in indigeous maize farming systems and this has apparently increased over the past two decades.Using a combination of interviews,group meetings,and observations,this study developed a holon agroecological analysis of the contexts that have shaped past and current uses of F.abida by farmers on the Tonga Plateau:cattle,land tenure,maize,soil,and government agricultural policy.We observed a bimodal age distribution of the trees in agricultural fields and posit that the missing cohorts were removed as weeds as a result of evolving notions of what constituted modern farming practices in the merging maize economy.With subsequent research and social promotion of the beneficial effects of F.albida,farmers are now being encouraged to allow the trees to grow in thier fields.This advice took root in farmer knowledge contexts because of positive regard for F.albida and timeless injunctions against cutting mature specimens.This case study illustrates the use of holon agroecology to develop a rich appreciation of how evolving contexts have shaped farmers' behaviour in Southern Zambia.
Farmer to consumer direct marketing: Consumer preferences and characteristics
(The University of Zambia, 2011) Banda, Ngawo
The aim of this study was to evaluate the effect on carcass characteristics of Cobb 500 broiler chickens of supplementing cowpea meal with Methionine and Lysine only as well as supplementing the cowpea with Methionine, Lysine and Threonine. A total number of 100 day old chicks were used. An experimental diet containing soya bean meal supplemented with Methionine and Lysine was used as control. Each treatment had three replications in a Completely Randomized Design (CRD) and each replicate had eleven chicks. After 42 days of the experiment, three chickens were randomly selected from each replicate, slaughtered, eviscerated and cut into breast, thigh and drumstick and fat removed from the abdomen for evaluation of carcass characteristics. The average weights of the breast muscles, thighs, drum sticks and abdominal fat were used in the analysis. There was no significant difference among treatments (P<0.05) though birds on soya bean containing diet had a better performance compared with either of the other treatments. However, cow pea with Threonine amino acid showed better performance than that only supplemented with Methionine and Lysine. Key words: Cowpeas, Threonine, carcass characteristics, broilers.
Inheritance of Weevil Resistance in Maize
(2011-01-25) Lebaka, Ntjapa, Gabriel
The study of the inheritance and gene action of weevil resistance in maize was undertaken using a 12 parent half diallel design. Seven resistant inbred lines were obtained from CIMMYT-Zimbabwe and five susceptible lines were obtained from soils and crop Research Branch(SCRB), Zambia. The lines were planted and crossed at Golden Valley Agricultural Research Trust(GART) in the 1998/99 growing season. The F2 and self ed parental lines were raised at UNZA field station in the winter of 1999 under irrigation. Because of the loss of some crosses and inbred lines due to unsuccessful seed production, 8 parents and 28 crosses were used in genetic analysis. For each of these entries three replicates each of 100 grams was prepared and put in a clean glass jar of 0.5 liter volume. The jars were randomly arranged on three shelves in a controlled environment room at 25+_2degrees Celsius and at 70+_5% relative humidity. Each entry appeared once on each shelf and each shelf was treated as a block. Twenty adult unsexed maize weevils were placed in each jar containing grain and the jars were closed with cotton cloth securely tied with the rubber bands to prevent the insects from escaping. After 21 days the jars were opened and all the insects were removed. The jars were left standing in this environment for 42 days. The jars were then opened and the insects and dust were sieved through a 5 millimeter sieve. The number of adult insects emerging were counted and recorded. The weight of the remaining grain was taken and weight loss was calculated. The grain was put back into the respective jars which were laid back on the shelves to stand for another 30 days after which the jars were removed. The same procedure was repeated and data of number of insects recovered and weight loss was recorded. These were added to the previous readings to give total number of emerged insects and total weight lost for each sample. Three replicates each of 50 grams for each entry was prepared and placed in a plastic bag. This grain was for determining the grit in the grain. The grain samples were then milled at constant speed for 60 seconds in a small electric powered mill. The meal was weighed and sieved through 0.5 millimetre sieve to separate grit from the fine meal. The remaining grit was weighed and hardness was expressed as percent grit of the total meal. Data for percent grit was transformed using square root transformation and the data for number of insects was transformed using logarithmic transformation. Straight scale was used for weight loss. The analysis of weevil resistance involved using Griffing's diallel analysis method 2 assuming fixed effects. Heritability and relative dominance estimates were made under random effects model. General combining ability(GCA) and specific combining ability(SCA)effects were significant for number of insects and weight loss at both infestation periods. At 63 days infestation period,GCA accounted for 49 and 71.42% of the total genetic variation for weight loss and number of insects, respectively. Broad sense heritabilities were76.25 for weight loss and 54.09 for number of insects. Narrow sense heritabilities were 29.01 for weight loss and 15.18 for number of insects. However at 93 days infestation, GCA to SCA ratios changed for both weight loss and number of insects.GCA accounted for 69.28% for weight loss and 72.42% for number of insects. Relative dominance was 0.84 for weight loss and 0.80 for number of insects. Broad sense heritabilities were 46.66 for weight loss and 63.16 for number of insects.Narrowe heritability was 17.37 for weight loss and 24.27 for number of insects. Grain hardness did not appear to influence grain weevil resistance as judged by insignificant correlation coefficients between percent grit and weight loss and percent grit and number of insects. For percent grit both GCA and SCA were significant but SCA effects accounted for 87.16%of the total genetic variation. Relative dominance for this trait was in the range of over dominance(3.89).These findings suggested that recurrent selection for general combining ability or reciprocal recurrent selection for reduced grain weight loss as a measure of weevil resistance can be an appropriate breeding method to improve weevil resistance in maize. The same cyclic selection methods would be appropriate for reducing the number of insects after infestation which is another measure of weevil resistance in maize. Results indicate that selection for weight loss would result in faster progress at 63 days infestation while number of insects would result in faster progress at 93 days infestation period. Recurrent selection for specific combining ability would be an appropriate breeding method for grain hardness. However progress from selection would be slow and a big population would be required as narrow sense heritability was too low.
Weed control in commercial Sorghum(Sorghum bicolor L.) Varieties under Zambian Conditions
(2011-01-26) Makungu, Melvin Chongo
Commercially grown Sorghum is slowly replacing maize in the expanding opaque beer brewing industry in Zambia. The lack of an established weed control package for commercial Sorghum production has compelled farmers to use herbicide weed control methods recommended for maize in commercial Sorghum Fields.Against this background a 5x 2 factorial experiment with a split plop design comprising five weed control methods and two Sorghum hybrid varieties, was set up at UNZA Field Station and Blue Gun Farm in the 1994/95 rainy season. The first objective of this experiment was to test the efficacy of two herbicides(i.e.,Atrazine and Cyanazine) for weed control in commercial Sorghum production under Zambian conditions. The second objective of this experiment was to determine the cost effectiveness of using the two herbicides for weed control in Sorghum fields. Atrazine (Gesaprim 50%FW)was applied at rates of 3.5l/ha and 2.01/ha. Cyanazine(Bladex 50%SC) was applied at a rate of 2.01/ha. Zero weeding and clean weeding treatments were also included in the study as controls. Weed control methods, thus comprised the five levels that were assigned to the sub plots. Sorghum Hybrid varieties, comprised the two levels that were assigned to the main plots and included two commercial sorghum hybrids, viz, MMSH 413 and MMSH 375.Assessments of weed cover(%)and crop cover(%)were carried out at 2,5,8 and 11 weeks after sowing. Other parameters that were determined include plant height,panicle length, grain per panicle, panicles per plant,plants per hectare and 1000 sorghum grain weight. Economic analysis was conducted by subtracting the explicit sorghum production costs from the value of expected sorghum sales. Results obtained from both locations show significant differences in the weed control efficacy of the three herbicide treatments at 5 weeks after sowing.This is the critical period for weed contol in Sorghum. The most effective herbicide treatment was Atrazine(Gesaprim 3.51/ha) because it reduced the weed cover to 11% of the total flora. This was followed by Atrazine(Gesaprim 2.01/ha)which reduced the weed cover to 22% of the total flora. The least effective herbicide treatment was cyanazine(Bladex 50% SC 2.01/ha) with a weed cover of 33% of the total flora. Economic analysis show that the most economical weed control method for both Sorghum varieties was the usage of Atrazine(Gesaprim 50%FW 3.51/ha)which had a net profit of 85.4% associated with its average grain yield of 2.9 tons. This was followed by by Atrazine(Gesaprim 50%FW 2.01/ha)with an average grain yield of 1.8 tons/ha and a net profit of 14.9%. The least economical herbicide treatment was Cyanazine (Bladex 50% SC 2.01/ha) with a net profit -21.5% associated with its average grain yield of 1.2 tons/ha.
Combining ability for grain yield of quality protein maize (QPM)(zea may L) under low soil nitrogen
(2011-01-26) Langa, Marcos
Maize (Zea mays L.) is the main staple food crop in the Southern Africa Development Community (SADC) region. The nutritional superiority of Quality Protein Maize (QPM) in both human and animal nutrition ,especially in monogastric animals, has been clearly and repeatedly demonstrated. Numerous studies have been carried out in several countries around the world with infants, young children and adults recovering from severe malnutrition when fed on diets. The QPM varieties currently being grown by farmers in the region were not bred for production under conditions of low soil fertility however, due to economic hardships and lack of access to credit facilities small holder farmers grow maize with inadequate levels of nitrogen. This study aims at assessing the performance of QPM maize under low nitrogen conditions. A total of 11 QPM lines selected for their differential performance under low nitrogen conditions were studied. Trials were carried out under low N conditions at two environments in Mozambique and one in Zimbabwe in the 2003/04 season. Differences among entries (genotypes) were significant (P<0.05) for grain yield , anthesis date, number of plants , in the combined analysis of variance across environments. Genotypes by environment interactions were significant (9<0.05) for grain yield; anthesis date number of plants. Partitioning of these interactions revealed that the crosses by environment mean squares were highly significant for all traits except stem lodging. The relative importance of general and specific combining ability effects, GCA and SCA, respectively, for grain yield, maturity, senescence and number of ears per plant was assessed Parents demonstrating highly significant, positive GCA effects for yield include lines 3,4,7, and 11 for grain yield. GCA and SCA effects were not significantly different from each other for grain yield. For plant height line 4 contributed tallness to progeny as was shown by its positive GCA effects for PH (9.443), while line 7 contributed to reducing the height (-4.312). SCA effects for the hybrid are negative indicating a net reduction in height compared to other crosses effects. There was a balance between GCA and SCA in contributing to total sums of squares for GY (35%-65%), AD (82%-18%), ASI(30%-70%),EPP (14%-86%),NP (45.8%54.2%).The study showed that it is possible to develop QPM hybrids and populations that have improved yield under low nitrogen conditions
Combining Ability For Drought Tolerance in Common Beans
(2011-01-26) Makunde, Godwin Simbarashe
The common bean (P. vulgaris. L) is an important crop in Africa. The seeds are used dry or green for human consumption and leaves are occasionally used as a leaf vegetable. As a legume beans are capable of fixing nitrogen into the soil for subsequent crops.Though important as a food crop and in soil amelioration, common bean is exposed to a number of abiotic and biotic stresses, one of which is drought, exceeded in magnitude only by bean diseases. The recent land ownership in Zimbabwe have seen the opening up of new lands for agriculture, mainly cropping, resulted in marginal areas, characterized by drought environments, being put under a wide range of crops. The majority of the small scale farmers are found in these areas and this call for the development of appropriate bean varieties. The characterization of the bean germplasm so as to know the inheritance of important traits for drought tolerance is cardinal since the genetic improvement for drought tolerance is seen as a better approach for crop security than complex knowledge based agronomic practices. This study was therefore carried out to estimate the general and specific combining abilities for drought tolerance in 25 f2 populations of Andean x Andean and 24 populations of Andean x Mesoamerican bean gene pools and determine the mode of gene action for drought tolerant traits. The two f2 populations were subjected to irrigated and water stressed conditions. Significant differences were observed in grain yield, days to 50% flowering , 100-seed weight and days to maturity at 5% level for the Andean x Andean and Andean x Mesoamerican f2 populations under water stressed conditions. Red Canadian Wonder gave a desirable GCA for grain yield(0.11), days to 50% flowering (-0.57) and days to 95% maturity (-1.71) under water stressed conditions in the Andean x Andean f2populations. Also SAB259 had also desired GCA for grain yield (0.05), days to 50% flowering (-0.51)and days to 95% maturity(-0.11) in the same populations. In the Andean x Mesoamerican F2 populations only two parents SER 16 (-0.59) and SEC16(-0.46) had desired GCA for days to50% flowering. However, Red Canadian Wonder had good GCA for grain yield (0.06) and days to 95% maturity (-1.11) in the Andean x Mesoamerican F2 populations under water stress. Overall Red Canadian Wonder proved to be a good parent for most of the measured traits in the two populations and can be used as a parent when breeding for both intermittent and terminal drought. SCA(dominance) effects where higher than the GCA(additive) effects for grain yield, days to maturity and days to 95% flowering under both irrigation and water stressed conditions for both the Andean x Andean x and Andean Mesoamerican F2 populations. Choosing parents for crosses on merit alone reduces the genetic variance for addictive effects(GCA) and increases the relative importance of dominance gene effects(SCA). This was the case with the crosses that were used in the study since the male parents were selected basing on their history of drought tolerance and female parents due to their high productivity in Zimbabwe without previous studies of combining ability.Since dominance gene effects are non-fixable, it may be difficult to start selections based on yield under drought in the early breeding cycles.Selection methods such as single seed descent and bulk method could be of practical benefit in populations exhibiting low addictive gene effects for individual traits with selection beginning at F5 upwards.
Decomposition and Nitrogen Release From Leucaena leucocephala,senna siamea, and Flemingia macrophylla Litter in managed alleys for maize in Zambia:Infuence of inorganic-N and litter Quality
(2011-01-27) Makaza, Kasirayi
The effects of litter quality and inorganic nitrogen (N) on rate of decomposition and N release pattern by three leguminous woody species were investigated under field conditions by the litterbag technique. The species studied in 1994/1995 were Leucaena leucocephala, Senna siamea and Flemingia macrophylla. This study was superimposed on an existing alley cropping trial. In the on-going experiment , maize (variety MM 603,3-way cross), was the companion crop and the leguminous species comprised the alley hedgerows. Nylon litterbags with 4 mm mesh size were each filled with 20 g of dry leaf prunings of each species. Five litterbags of each pruning type were randomly buried in a subplot of each treatment. At each sampling time, one bag representing each pruning type was removed from each subplot. The samples were cleaned , dried , weighed and analysed for N, polyphenol and lignin contents. Decomposition rate constants (kD) and N release rate constants (kN) were calculated from exponential decomposition equations. The mean(kD) of the plant litter ranged from 0.30 to 0.12wk-1, decreasing in the order , L. leucocephala,>S. siamea> F. macrophylla. Analysis of variance of the mean kD values showed that L. leucocephala, and S. siamea decomposed significantly (P<_0.01) faster than F. macrophylla. It was also observed that the level of inorganic N had a significant effect on decomposition rate. Residues in plots which received 68 and 112 kg N ha-1 had similar decomposition rate which were faster((P<-0.05) than those for 0 and 34 kg N ha-1. Negative partial correlations were recorded between kDs, on one hand and lignin and polyphenol contents(P<-0.01), C:N ratio (P<-0.01) and lignin + polyphenol:N ratio (P<-0.01) and inorganic N level (P<-0.01). These results show that both the chemical composition of plant residues and level of inorganic fertilizer N applied increased the rate of plant residue decomposition. The mean (kN) ranged from 0.151 to 0.114wk-1, decreasing in the order L. leucocephala,>S. siamea> F.macrophylla. There were however , no significant species on N level effects on kN. Generally, net N release was obtained in the first 2-3 weeks followed by immobilization thereafter in all species. Positive partial correlations(P<-0.05)were recorded with initial N- content ( P<-0.05) suggested that it affects decomposition rates. Negative partial correlations were recorded between initial lignin and polyphenol contents and kN. Lignin and polyphenols are thought to have caused N immobilization through the formation of resistant complexes. There was no significant species effect on maize yields . A significant N fertilizer effect on yield was obtained at 68 kg N ha-1. This result probably indicates the need for moderate fertilizer N addition to incorporated residues in alley cropping.
Classifyning winter wheat environments into adaptive zones as a basis for recommending a reduction in the number of international winter wheat performance nursery test sites
(2011-01-27) Lungu, Maleka Davies
Classifyning winter wheat environments into adaptive zones as a basis for recommending a reduction in the number of international winter wheat performance nursery test sites
Evaluation of three forage Legumes and Intercropping pattern for improved productivity of maize( Zea mays L.)
(2011-01-27) Mate, Albert Mbuyoti
The objectives of the study was to determine a maize/ forage legume combination and an appropriate row arrangement that would result in high maize grain and total stover / legume straw yield, enhanced crude protein content of the maize stover /legume straw and increased crude protein content of the maize grain and stover. This would form a basis for the good quality feed for cattle during the dry season. The treatments consisted of the maize(variety MM 603)Intercropped with the three legume species, namely cowpea (vigna unguiculata(L) Walp) sirato(macropitilium atropureum) and archer (Macrotyloma axillare) in either 1:1 or 2:1 row arrangement . A randomised complete block design was used with four replications. Data was collected on the following parameters: maize plant height, legume spread, maize grain and stover yield and crude protein content, legume straw yield and crude protein content as well as the legume straw and maize stover non-detergent fibre content. Analysis of variance (ANOVA), separation of means and correlation analysis were carried out on the field and laboratory data collected. The maize/forage legume combinations and their row arrangements did not increase the maize grain yield and the crude protein content of the maize grain and stover. However, the addition of the forage legume straw to the maize stover enhanced the crude protein content of the dry matter yield by about 3-4 times i.e. 3.3 to 4.6% in the maize stover and 13.8 to 16.4% in the forage legume straw. The plant height of the sole maize (2) of 1.48m was significantly taller and had a higher crude protein content of 11.15% in the maize grain than the sole maize(1) and the intercrops. Cowpea exhibited the highest plant spread of 1.88m which positively correlated(r =0.84)** with straw yield but was the least in crude protein content of the straw (13.4%). Cowpea was able to grow and complete its life cycle being an annual crop compared to archer and siratro which are perennials and hence were still growing at the time of harvesting the maize crop. The results demonstrated that maize can be intercropped with the three forage legumes in either 1:1 or 2:1 row arrangement and result in improved quality and quantity of the total dry matter which can be fed to livestock. However, the maize crop could not directly benefit from nitrogen from the three forage legumes. There is therefore, need for further research to look at nitrogen transfer to companion maize over several growing seasons with emphasis also on factors that affect nodulation and capacity of companion forage legumes to fix and transfer nitrogen. The effect on digestibility should also be investigated.
The Agronomic effectiveness of Liquid Manure extracts derived from comfrey(Symphytum officinale)and tithonia( tithonia diversifolia).
(2011-01-27) Mambwe, Dina
Greenhouse and field studies were conducted to evaluate manure extracts and their effect on crop yield and selected soil chemical and microbial properties. For the green house study, comfrey and tithonia plant materials were each used at rates of 0.0625, 0.0935, 0.125 and 0.156 kg per litre of water. The experiment was laid out as a completely randomized design. For the field studies, six combinations of comfrey and tithonia were used at 0 kg, 0.156 kg comfrey, 0.156 kg tithonia,0.0781 kg comfrey + 0.0781 kg tithonia, 0.117 kg comfrey + 0.0391 kg tithonia and 0.0391 kg comfrey + 0.117 kg tithonia per litre of water. The experiment was laid out as a randomized complete block design two sites; Kasisi Agricultural Training Centre (KATC) and Mount Makulu Agricultural Research Station (MARS) were used for the field studies, rape and tomato were used as test crops. Application of manure extracts increased biomass yield of rape to between 2.8g (DM) per pot(comfrey 0.0625 kg) and 12.79g(DM) per pot (tithonia 0.125kg). The leaf biomass increased with increased biomass of comfrey, while no particular pattern was observed for tithonia. Similarly, the application of manure extracts increased the biomass yield of tomato to between 6.67g (DM) per pot (comfrey 0.0625 kg) and 13.99g(DM) per pot(tithonia 0.0938 kg). Mixing of comfrey and tithonia residues in the preparation of their manure extracts resulted in increased tomato yield to between 5.2 tons ha-1(0.0391 kg comfrey +0.117 kg tithonia) and 9.5 tons ha-1( 0.156 kg comfrey) for KATC and 32.7 tons ha-1 (0.156 kg comfrey) and 40.2 tons ha-1 (0.156 kg tithonia) for MARS. Furthermore soil pH, P,K,Ca,Mg were positively influenced by the application of manure extracts. Although the extracts had high EC values, these did not have a drastic effect on the soil.
Genotype and Nitrogen fertilizer influence on Grain yield and protein content of wheat(Triticum aestivum L.)
(2011-02-01) Makhale, Gerard Lekula
The grain yield of wheat in Lesotho is low because of poor soil fertility, and the wheat is regarded by the millers to be of poor quality and therefore of less value. A field study was therefore conducted at three sites in Lesotho( Maseru, Leribe and Mafeteng) to evaluate the influence of genotype and nitrogen application on grain yield and quality of wheat (Triticum aestivum L.) The varieties assessed were Tugela DN, Betta DN, SST 124 and caledon at a seeding rate of 50kg ha-1. Nitrogen was applied at five rates of 0,20,40,60, and 80 kg N ha-1. The experiment was arranged in a split-plot design, with varieties as the main- plot factor and nitrogen rates as the sub-plot factor. The treatment combinations were replicated three times . Grain yield and yield parameters (thousand-kernel weight , grain number per head, number of heads per square meter and harvest index) were measured. Quality parameters were protein content percent and mixograph development time. Grin yield significantly (P<_0.05) increased with Application at Leribe averaging 3000 kg ha-1. Number of heads per square meter was also significantly(P<_0.05) increased while thousand kernel weight was significantly (P<_0.05) decreased at rates of N application higher than 40kg N ha-1. At Maseru and Mafeteng applied N had no effect on grain yield. Infact grain yield decreased with application of N over 20kg N ha-1 at Mafeteng. The number of heads per square meter also significantly(P<_0.05) decreased, suggesting poor emergence or tillering. At Maseru the thousand kernel weight was significantly (P<_0.05) decreased with increasing nitrogen application. Across the three sites grain yield increased significantly (P<_0.05) when N was applied over 20kg N ha-1. The number of heads per square meter also significantly (P<_0.05) decreased at higher rates of N application. Applied N fertilizer (P<_0.05) increased grain protein content. However, the protein contents of wheat at Maseru and Mafeteng were higher, averaging 11% and 15% respectively. This observation is probably due to a concentration effect of protein content due to small grain size.Mixograph development times were within the acceptable range of 2.5-4.0 minutes for wheat from all the three sites. The four varieties did not significantly differ in grain yield or quality at all the three locations. However, they significantly differed in mixograph development times with Tugela DN giving the highest value averaging 4.0 minutes, and the lowest being caledon at 2.5 minutes. This study has shown that wheat yields and quality in Lesotho can be improved by applying before recommendations of N fertilizer rates and management strategies under dry land conditions can be made to farmers in Lesotho.
The response of green Beans(Phaseoulus Vulgari) To varying Application rates of Boron
(2011-02-01) Manda, Peter Jastine
Green bean (Phaseolus Vulgari) is a very important crop, feeding a large number of people in the world. However , bean yields are low, hence any method resulting in increased green bean yield may be of great importance. Boron (B) is one of the most important micronutrients necessary for bean growth and yield . A widespread deficiency of boron(B) has been reported in Zambian soil. This is a limitation to the potential yield of green beans , therefore , additions of B to the crop could contribute to the higher yields. Currently , the University of Zambia recommends the addition of up to 2 kg/ha B as away of addressing boron deficiency in most crop s grown. It is not well known , however, whether increasing supply rates of B applied would make a difference in yield. A study was carried out to correlate two methods of boron analysis with plant B uptake, and to determine whether B fertilizer application would improve crop performance. The hypothesis of this research was that since B is often deficient in soil, soil and foliar application of B ought ncrease green bean yield. In the laboratory , 16 soils that included pairs from cropped and fallow land were extracted for B using hot –water extraction and acid extraction. A parallel study was carried out in the green house . A green bean crop was grown in each of the soils for a six week period . In the field, five rates of B were applied at 0, 2, 4, 6 and 8 kg/ha, to two green beans crops. One foliar application at 0.45g/1 was also used as one of the treatments giving a total of 6 treatments. The field experiments were conducted at York Farm in Lusaka province Zambia while the pot experiment was conducted in the green house at the University of Zambia. Extractable B values were obtained in the Laboratory , and B uptake in the green house. In the field , plant height , pod length, pack out rate and yield were obtained. Results indicated that there was no good correlation between each of the two extraction methods with plant uptake. Foliar application of B at 0.45 g/l also did not significantly increase bean yield. The results also showed that in both field and green house experiments increasing rates of B did not influence (p<0.05)plant height, pod length, yield and quality of green beans. The early crop which was grown purely on drip irrigation did slightly better than the second crop which received some rainfall. During the first crop, the pods were 6% longer than the control compared to only 1% in the second crop. The length of pod was found to be strongly related to yield increase of green beans. The yields were 28% more than the control in the first crop and 15.65 more in the second crop The fruit quality was not affected by increasing rates of B. However, higher packout rates were obtained in the fist crop compared to the second. These preliminary results suggest that green bean yields and quality may be better when grown in winter season. Soil application was more effective than foliar application in the greenhouse while the opposite was true in the field trial.
Response to selection for Pupal Weight with and without assortative mating in Tribolium Castaneum
(2011-02-09) Mwenya, Mulenga,Nelson Wilson
Joint effects ofn pre-selection mating system (RA) and percent truncation selected(20%;50%;0%(control) were studed in a 2x2x3 factorial experiment with 5 replicates to examine direct response to selection for pupal weight(PW), and correlated responses for larval weight(LW) and papation time(PT)in tribolium Castaneum.Prior to selction two groups, each with 50 males mated to 100 females were either R-mated for 3 generations.At generation 3,6 lines were formed in each group,one of each selection mating system-selction intensity combinations,and selection began,Each line was maintained during 2 generations of selection by 10 pair-matings.
Occurrances and distribution of some tobacco viruses in Southern,Central and Lusaka provinces in Zambia
(2011-02-18) Mayunga, David, Samuel
Nine tobacco fields of small and large scale farmers in Southern,Central and Lusaka provinces of Zambia were surveyed for the occurrence and distribution of virus diseases during tobacco growing season in 1997.Three tobacco fields in each province were selected for virus detection and sample collection.During this survey,infected tobacco plants were examined and disease symptoms recorded.Virus infected weed occurring in or near the tobacco crop were included to determine if they served as virus reservoir along with potential insect vectors.Virus infected tobacco leaf samples were inoculated on a panel of differential hosts to identify the commonly occurring viruses on tobacco in Zambia.Sap from field infected and symptomatic greenhouse plants were tested serologically using DAS-ELISA.Viruses were identified if they gave positive reaction against antisera from Agdia Inc.,USA.Virus particle morphology was also studied in some cases by electron microscopy. The results indicated that at least four viruses-tobacco mosaic(TMV),potato virus Y(PVY),alfalfa mosaic(AMV) and tobacco ringspot(TRSV)occur in tobacco in Zambia. Tobacco mosaic virus(TMV) was recovered in 77% of diseased samples while PVY was recovered in 66.6% and TRSV in 22%. Obviously TMV and PVY are the more common occurrence.The prevalence of TMV and PVY in all the three provinces indicate that these viruses could be responsible in limiting tobacco production in Zambia. It is therefore important that the scope of the virus disease occurring in Zambia should be broadened to identify all the viruses and their impact on tobacco if satisfactory management strategies are to be worked out.
Determination of the variability of colletotrichum Truncatum, the causal agent of Anthracnose of Soyabean (Glycine max( L) Merr.) in Zambia
(2011-02-18) Mayonjo, David Onesmo
Soyabean (Glycine max (L) Merr.) has become an important crop in Zambia. Its increased production is hampered by several foliar diseases of which the anthracnose caused by Collectotrichum truncatum appear to be the most prevalent, than red leaf blotch cause by Dactuliochaeta glycines reported before. A study on anthracnose of soyabean disease was undertaken to determine the level of variability that exists in the pathogen populations in Zambia. Ten samples of anthracnose of soyabean were collected from the provinces of Central, Lusaka and Southern. Isolates Ct-01, Ct-02,and Ct-03 were collected from Central province (Kabwe); Ct-04, Ct-05, Ct-06, and Ct-07 from Lusaka province ( Lusaka-West and South), and Ct-08, Ct-09, and Ct-10 from Southern province (Mazabuka). Isolation were made following conventional mycological methods and the identification was confirmed by the International Mycological Institute, England. Isolates were characterized on the basis of acervulus size, colony features and its growth rate on potato Dextrose Agar (PDA) and Malt Extract Agar (MEA). The conidial size , germ tube elongation during conidial germination and pathogenicity of the isolates to three soyabean cultivars were also determined. The isolate Ct-07 had the largest acervulus diameter and Ct-03 had the lowest. After eight days of growth, Ct-04, Ct-05, Ct-07, and Ct-09 had greater colony diameter on PDA whereas these isolates produced significantly smaller colonies on MEA. In comparison, Ct-01, Ct-03, Ct-06, and Ct-08 had reduced growth rate and produced smaller colonies on PDA. After eight hours of growth on water agar, isolates Ct-04 and Ct-09 developed the longest germ tubes as compared to Ct-06 and Ct-08. Conidial size also showed significant differences among isolates. Differences in colour of conidial ooze emanating from the acervulus and the colony margin were also noticed among isolates at 25 degrees Celsius. The colour of aerial hyphae showed differences on the two media, but the majority of the isolates produced white hyphae which later turned grey.The isolates differed in ther ability to infect soyabean cultivars. Isolates Ct-01, Ct-07 and Ct-09 infected kaleya, Hernon-147 and Santa Rosa the tested cultivars whereas Ct-02, ct-04, and ct-08 infected only kaleya and Hernon-147. Isolates Ct-05 and Ct-10 attcked only kaleya and Santa Rosa and Isolates Ct-03 and Ct-06 infected only Kaleya and Santa Rosa respectively. The resullts indicate that the ten isolates of Colletotrichum truncatum posses considerable morphological and physiological variability and therefore their control measures should be directed after knowing which one of the trains of the pathogen is in the population.
Quality and Yield stability of Orange Fleshed Sweet Potato( Ipomoea batatas(L.)lam.) Varieties in Different Agro-Ecologies.
(2011-02-18) Mbwaga, Zabron
Orange fleshed sweet potatoes Ipomoea batatas (L.)Lam) has high B-carotene content which is useful in preventing vitamin A deficiency. Unfortunately suitable varieties of orange fleshed absent. The results from Participatory Rural Appraisal (PRA) conducted in three villages of southern highlands of Tanzania revealed that, most varieties grown are white and cream fleshed. Yields mentioned to be very low ranging from 4.5 to 7.0 t ha-1. A gap difference of 15.5t ha-1 from potential yield mean were estimated. Based on the above findings a study was conducted to determine the adaptability of orange fleshed sweet potato varieties in different agro-ecologies , so as to identify varieties which can suit to the wider environments. Specifically determining beta-carotene and yield stability across different environments. Multilocational field trials involving 12 yellow/orange –fleshed sweet potato varieties were conducted at six different locations (altitude range from 495 and 1798 meters above sea level) in the southern highlands of Tanzania. A randomized complete block design was employed. Tuber yield and B-carotene content of the roots were determined at maturity. B-carotene concentration of the roots was analysed by high performance liquid chromatograph method. Results showed that genotype and environment influence d B-carotene concentration of sweet potato roots. Varieties 199024.1, SPK004, 101055 and Resisto produced high concentrations of B-carotene. These were 28.74, 28.30, 27.8 and 27.7ug/100g respectively. Out of these, varieties 199004.2 (b=0.89) and 101055(b=0.78) considered to have stable performance in terms of B-carotene and stable performance suggested wider adaptation. The B-carotene content in sweet potato roots showed no clear trends with increasing or decreasing altitude for most of the varieties tested. Yields were significantly different (P<0.05) among varieties and across sites. Varieties, Resisto 440443, SPNO, 102020.2, 199024.1 and Carot-Dar displaced near the center of AMMI biplot. These were considered stable in terms of yield performance, according to addictive Main effect and Multiplicative Interaction (AMMI) biplot. Out of the varieties, varieties 440443 and 199024.1 had high yield and stability. These varieties were considered to have wider adaptation .Storage root yield and B-carotene showed low significant negative correlation ( r=-0.1092, P<0.05), while, yield and dry matter, B-carotene and dry matter content were none significantly correlated. This effect signified possibly of getting varieties that can combine these traits at high levels through conventional breeding. Further study was recommended to explore the nature of sweet potato B- carotene content variation with environments.
Participation of Smallholder Farmers in Agricultural Extension service in Zambia: An Evaluation of the Ministry-operated extension service in Mumbwa District of Central Province
(2011-02-21) Makasa, Victor
The study evaluates the public agricultural extension service delivery in Zambia with respect to the participation of smallholder farmers. The study describes the extension service implementation, establishes the smallholder farmers’ level of access to extension and finds out the factors that influence farmer’s participation in agricultural extension. The study was carried out in Central Province of Zambia in Mumbwa District. An interviewer-administered questionnaire survey of 100 smallholder farmers, randomly selected, together with the review of secondary information and semi-structured interviews with seven extension staff were all part of the study methodology. A review of academic literature highlighted that community participation is a wide subject and that top-down and bottom-up approaches to development form the two ideal extreme ends of the participation continuum, but a more interactive form of participation is what is required. It was also argued that genuine participation leads to enhanced service delivery, efficiency, effectiveness, adoption of appropriate farming practices and sustainability. The study revealed that extension workers found it difficult to secure farmer participation and that they relied much on the local leaders’ interventions rather than their tact, persuasion and demand–driven extension packages. Access to the extension service was found to be very low and participation of smallholder farmers was found to be below average compounded by infrequent extension activity in the area. The little participation that occurred was found to be high on passive and incentive-driven participation and low on interactive participation. Factors influencing the participation of the farmers were numerous and ranged from farmers’ personal to farm to livelihood characteristics. The study also revealed that extension workers needed to have their conditions of service improved, their means of operation made available to them, and also rewards for good performance to be put in place. In addition the study observed that farmers would be willing to participate in extension activities that address their various needs and consequently it is extremely vital that extension services are relevant to these needs. A vigorous gender sensitization was recommended. It was recommended that the disadvantaged/vulnerable sub-groups of smallholder farmers be given more attention if their participation is to be secured. Extension workers also needed to have their skills in participatory procedures enhanced.
The performance of different landraces of Bambara groundnuts grown at different plant population densities in the Lusaka province of Zambia
(2011-02-21) Mkangama, Catherine
Although Bambara groundnuts (Vigna subterranea (L.) Verdc.) has a high production, utilization and economic potential in Zambia, its production is still very low (average yield being below 750kg/ha) with many underexploited research areas for its improved production.The objectives of this trial which was conducted during 1990/91 growing season in a four replica split-plot using four landraces and five planting densities as main plot and sub-plot factors respectively, were to examine some environmenttal influence on performance of Bambara groundnut, to identify suitable landraces of Bambara groundnut for Lusaka province of Zambia and to find out if the landraces differed in their planting density requirement. The results indicate no significant differences in yield and growth performance among landraces in which case none of them can be grown in the area because of Cercospora leafspots and Fusarium wilt. However, the results were seriously affected by adverse weather conditions and diseases. The highest yield was only 8.7 g/plot. The established plant population densities could not be maintained throughout the experiment due to high plant deathrate caused by Fusarium wilt disease. Thus, no clearcut recommendations can be made from this experiment. Therefore, a repeated experiment is important for more accurate and reliable conlusions
Problems of Economic Development and Growth in Zambian Agriculture-An Evaluatuion of the Role of Capital formation in Agricultural Productivity
(2011-02-21) Mbevya, Kayola wizazi kapunzha
Economic development and growth in Zambia has bee n thought to b sustainable through the development of agriculture in the broad context of rural development. However, agriculture is a complex and diverse industry. Its dimensions embrace a broad spectrum of activities and its problems as intricate, “deep” and diverse as the industry itself. Despite investment programs and political encouragement agriculture in Zambia has ben growing in terms of output at a rate lower than the growth in consumption and contribution to the Gross Domestic Product(GDP) has stagnated at about 11.48 percent over the period 1975 to 1980. Zambia has therefore continued to face shortfalls in its major staple food, which is maize, since 1970. In addition to this shortfall, changing consumption patterns have accelerated the demand for wheat grains and this demand has expanded tremendously over the period 1970 to 1980. Production of other agricultural commodities has assumed an upward trend but does not satisfy the entire Zambian demand. In 1963, 20.5 percent, 35.6 percent and finally 41.4 percent in 1969, 1974 and 1980, respectively (1, page 3). Those persons who migrated were mostly young able-bodied male and also mostly literate. Reacting to what constituted a major rural-urban drift creating a shortage of labor in the rural sector and agriculture in particular, taken together with the need to rapidly increase the productivity of agriculture, the government encouraged the rapid mechanization and adoption of other expensive type technologies. Due to limitation in data, this creative component attempts to evaluate the impact of this capital accumulation approach by regressing a production function of the Cobb-Douglas form. The equation specifies output in agriculture as a function of labor, land and capital embodied in investments of a capital nature. The results show that capital’s contribution to output is negligible and this finding leads to an examination of alternative strategies and policy options to stimulate agricultural productivity and attain desirable distributive impacts consistent with economic development as defined in this paper and also to meet the objectives of the government as stated in the planning documents.

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