Studies on severe infectious bovine rhinotracheitis in Britain

A severe form of infectious bovine rhinotracheitis was confirmed in recently purchased fattening cattle in the north east of Scotland during the winter-housing period of 1977-78. During the remainder of 1978 and the subsequent winter-housing period, many similar incidents were investigated. The first signs of illness noticed by the farmer were slight dullness, reduced appetite, serous ocular and nasal discharge, an increased rate and depth of respiration and the drooling of saliva. Pyrexia (103 - 107.

Effect of Nitrogen Fixation on Yield and some Yield Component of Common Bean (Phaseolus vulgaris L.) Genotypes under Moisture Stress

Moisture stress is a worldwide production constraint for common beans and biological nitrogen fixation. The effect of drought has been widely reported and is an important environmental factor resulting in crop yield losses. This study aims at assessing the effect of nitrogen fixation on yield and some yield component of common bean (Phaseolus vulgaris L.) genotypes under moisture stress levels. Experiments were carried out in screen house and field at Sokoine University of Agriculture. The genotypes used were Kijivu, Yellow, Msolini, Masusu, Kasukanywele, Uyole 04, Mbulamtwe, Bilfa-Uyole and G 51495 A, a non-nodulating genotypes as a check. The soil moisture was maintained at 100, 75, 50 or 25% of the soil’s field capacity. Moisture stress reduced yield up to 67%. Genotypes Yellow (2.9 and 11.2g/palnt), Msolini (3.3 and 10.7g/plant), Masusu (3.6 and 7.7g/plant) and Bilfa Uyole (4.1 and 7.2g/plant) were observed to have some degree of drought tolerance based on its response under moisture stress environments for yield. These results suggest that moisture stress has a substantial impact on the general performance of common bean genotypes. Selection of superior performing genotypes under moisture stress, and integrating them into the breeding programs is an important to increase crop productivity. Keywords; N2-fixation; Drought; Nodulation; Legume

Evaluation of Common Bean (Phaseolus vulgaris) Genotypes for Resistance to Root Rot Disease Caused by Pythium aphanidermatum and Pythium splendens under Screen House

The most important economic species of the genus Phaseolus is the common beans (Phaseolus vulgaris L.) which is widely cultivated and arguably the most significant leguminous for direct human consumption. It is an important source of dietary protein, calories, dietary fibres and minerals particularly iron and zinc. Root rot disease caused by Pythium pathogen is one of the major production constraint in bean growing areas within East Africa. In Tanzania, control measures used by farmers are fungicidal seed treatments which are less effective and not environmentally friendly, soil drainage and crop rotation which are not sustainable in the disease management. This study focused on the evaluation and selection of promising common bean genotypes for resistance to Pythium root rot disease from 100 bean genotypes sourced from Tanzania, CIAT and Andean Diversity Panel (ADP). Inoculum of Pythium aphanidermatum and Pythium splendens were used for challenging the beans genotypes under controlled environment. Experiment was set by randomized completely block design (RCBD) with three replications. Disease severity was assessed based on 1-9 scale; 1 being non-pathogenic and 9 being highly pathogenic. The response of common bean genotypes to P. aphanidermatum and P. splendens and their interactions were statistically different (P<0.0001). Two bean genotypes ADP-014 and ADP-080 showed promising trait of resistance, 38 genotypes showed moderate resistant trait and 57 were susceptible to Pythium root rot disease. Keywords: Inoculum, Leguminous, Pathogenic, Resistant trait, Severity

Farmers’ Perceptions on Salinity Problems in Irrigated Fields in Kilosa District

Soil salinity contributes to one of the most serious ecological and environmental problems in most of the irrigation schemes in Tanzania. Understanding farmers’ perceptions of soil salinity and its effects on crop productivity is important in promoting soil and water conservation practices. A study was conducted in Chanzuru and Ilonga villages in Kilosa District in 2016 to determine farmers’ perceptions on soil salinity problems in the District. Therefore, a socio-economic survey was carried out on 60 respondents.  Data were collected using the semi-structured questionnaires. The data were analyzed using SPSS descriptive statistics and chi-square test. The finding of the study showed that farmers perceived salinity more on the basis of location than they did on the basis of socio-demographics.  The main causes of soil salinity as perceived by farmers were poor quality of irrigation water and poor drainage systems. Some socioeconomic and demographic characteristics that significantly influenced the farmers’ perceptions were sex and household size. The perceptions of farmers in the study area varied significantly from village to village, with their socio-demographic determinants. Farmers adapted the strategy of crop diversification and increase in farm size as a response to the problem of salinity occurring in their fields. Farmer perception on salinity should therefore be used as entry point by stakeholders to develop intervention programs that help to solve the problems occurring in the farmers’ fields. Key words: Salinity, farmers’ perception, problem confrontation index, crop diversification, irrigation water, scheme, sources of information, extension servic

GGE BIPLOT ANALYSIS OF YIELD STABI LITY FOR ANDEAN DRY BEAN ACCESSIONS GROWN UNDER DIFFERENT ABIOTIC STRESS REGIMES IN TANZANIA

Large seeded Andean dry beans (Phaseolus vulgaris L.) are most preferred in Africa. However, low soil fertility and increasing drought stress conditions due to climate change are among the challenges faced by farmers in this region. The purpose of this study was to identify Andean genotypes with yield stability and to identify the best environments for selection of this trait. GGE-Biplot analysis was used to examine 183 Andean bean genotypes in Tanzania. Results indicated significant environment (E), genotype (G) and genotype x environment (GE) effects for seed yield. The environment explained 46%, genotype 20%, and GE 34% of the total (G + E + GE) variation. Two principal components explained 41.21% (PC1) and 26.35% (PC2) of GGE sum of squares. The Andean genotypes, ADP-102 (Jessica)- purple mottle, large seed, bush plant habit, released by Selian Agriculture Research Institution (ARI) in Tanzania; ADP-220 (G5625)- red, large seed, vine plant habit, from Central America; ADP-276 (G13654) - brown, medium seed, vine, from Mexico; and ADP-648 (‘Red Kloud’) large red kidney, with bush plant habit, were stable across environments and can be recommended for general adaptation across environments. An individual location for selection for yield stability was not identified, thus justifying the continued need for multiple test sites

EVALUATION OF THE RESPONSES OF EIGHT RICE (Oryza sativa, L.) GENOTYPES TO VARIOUS CONCENTRATIONS OF NaCl IN A CONTROLLED ENVIRONMENT

Salinity is an ever increasing problem that reduces rice yield in many rice fields around the world. Developing salt tolerant rice (Oryza sativa L.) genotype is one of the solutions to the problem of salinity. This experiment was carried out in the Department of Crop Science and Horticulture at SUA to assess the salinity tolerance of 8 rice genotypes at the seedling stage. Ion accumulation in plants and dry matter content along with molecular markers were used to evaluate the tolerance of each rice genotype. The genotypes were IRRI 112, IRRI 124, FL 478, IRRI 113, IR65912-4B-10-3, IRRI 128, NERICA-L-19 and SUAKOKO-10. In this experiment, the genotypes were exposed to three salinity levels in a randomized complete block design arranged in factorial with three replications. The salinity levels were 100 mM NaCl, 50 mM NaCl and 0 mM NaCl. The homogenous mixture of sand, farm yard manure and rice husk (ratio of 6:2:10 respectively) was used as the planting medium for all rice genotypes. The soil texture was sandy clay-loam. The growth of the genotypes, ion accumulation and dry matter contents were significantly (p ≤ 0.05) affected by increase in NaCl concentration. Two Saltol SSR markers (RM7075 and RM562) were used to determine the presence of salinity tolerance (saltol) gene in rice genotypes.  Based on the SSR markers, ion accumulation and dry weight of plants, two genotypes (IR65192-4B-10-3, and IRRI112) along with FL478 were selected as salt tolerant while two (IRRI-113 and IRRI-128) were moderately tolerant, and three (NERICA-19, SUAKOKO-10 and IRRI-124) were the most susceptible genotypes.  Therefore, two susceptible parents (NERICA-19 and SUAKOKO-10) were selected and two donor parents (FL478 and IR65192-4B-10-3) were selected. Keywords: salinity stress; NaCl concentration; genotypes; markers; seedling stage; Oryza sativa;

Description of Baetao-Manteiga 41 and ‘Yunguilla’ superior Andean common beans for Tanzanian production environments

An international effort was initiated with the evaluation of a diverse set of largeseeded Andean common beans (Phaseolus vulgaris L.), the Andean Diversity Panel, in sub-Saharan Africa. Several entries in the panel have been selected for extensive characterization on the basis of high performance acrossmultiple location × year trials in Tanzania—conducted both on station and on farm. Baetao- Manteiga 41, tested asADP-190, has a commercialKablanketi (light purple speckled) seed type, and ‘Yunguilla’, tested as ADP-447, has a commercial Calima (red mottled) seed type. Both lines exhibited yield stability, vigorous growth under low fertility conditions, angular leaf spot resistance, andmoderate common bacterial blight resistance; Yunguilla also possessed rust resistance. These two lines were tested, selected, and characterized cooperatively by Sokoine University of Agriculture (SUA), the Tanzanian Agricultural Research Institute (TARI), the USDA-ARS, and the Agricultural Research Council (ARC) of South Africa, and in collaboration with local farmers in Tanzania

GGE BIPLOT ANALYSIS OF YIELD STABI LITY FOR ANDEAN DRY BEAN ACCESSIONS GROWN UNDER DIFFERENT ABIOTIC STRESS REGIMES IN TANZANIA

Large seeded Andean dry beans (Phaseolus vulgaris L.) are most preferred in Africa. However, low soil fertility and increasing drought stress conditions due to climate change are among the challenges faced by farmers in this region. The purpose of this study was to identify Andean genotypes with yield stability and to identify the best environments for selection of this trait. GGE-Biplot analysis was used to examine 183 Andean bean genotypes in Tanzania. Results indicated significant environment (E), genotype (G) and genotype x environment (GE) effects for seed yield. The environment explained 46%, genotype 20%, and GE 34% of the total (G + E + GE) variation. Two principal components explained 41.21% (PC1) and 26.35% (PC2) of GGE sum of squares. The Andean genotypes, ADP-102 (Jessica)- purple mottle, large seed, bush plant habit, released by Selian Agriculture Research Institution (ARI) in Tanzania; ADP-220 (G5625)- red, large seed, vine plant habit, from Central America; ADP-276 (G13654) - brown, medium seed, vine, from Mexico; and ADP-648 (‘Red Kloud’) large red kidney, with bush plant habit, were stable across environments and can be recommended for general adaptation across environments. An individual location for selection for yield stability was not identified, thus justifying the continued need for multiple test sites

HERITABILITY AND RELATIONSHIP BETWEEN DROUGHT TOLERANCE TRAITS AND YIELD IN GROUNDNUTS (ARACHIS HYPOGAEA L.) UNDER DIFFERENT WATERING REGIMES

A research article article was submitted to Asian J Agri Biol, 2016, volume 4Improvement of groundnuts for drought tolerance could increase production in drought prone areas.This study aimed at determining the heritability estimates and relationship of HI and SCMR with yield and yield components using 30 groundnut genotypes planted under different watering regimes, so as to speed up the selection and breeding of groundnut genotypes tolerant to drought. A completely randomized design arranged in a split plot experiment with four replications was conducted in screen house in Morogoro, Tanzania. Data collection was done on plant height, number of pod/plant and pod yield/plant. Drought tolerant traits measured included, harvest index (HI), SCMR at 40, 60 and 80 DAS. Broad-sense heritability was calculated for HI, pod yield, number of pod/plant and SCMR. Results showed that number of pods/plant, SCMR at 60 DAS and HI were significantly related to pod yield in all watering condition. Heritability of the traits ranged from 0.22 to 0.59 with HI having highest value and number of pods lowest in WW while in WS condition heritability was generally lower from 0.04 to 0.45. Due to SCMR at 60 DAS, number of pods/plant and HI having moderate heritability and significant correlation with pod yield under water stress condition, these could be useful criteria in drought tolerance selection