7 research outputs found
Responses of the weed Digitaria Abyssinicia (A. Rich.) Stapf to selective grass herbicides in Ugandan cotton
PhD ThesisSuccessful weed control is essential for economical cotton production in Uganda. Weeds
compete with cotton for moisture, nutrients and light. The greatest competition usually
occurs early in the growing season. Therefore, post emergence herbicides such as
fluazifop-butyl and sethoxydim were used in this study to control the grass weed species
which grow faster than cotton during its initial growth stage. Field trials were conducted
on the sandy loam/loam soils at Namulonge Research Institute and Bukalasa Technology
Verification Centre in Uganda during the 1995/96 and 1997/98 cotton seasons to
investigate the control of the tropical couch grass (Digitaria abyssinica (A. Rich. ) Stapf)
using the post emergence herbicides. This weed is a rhizomatous grass and difficult to
control. The efficacy of the reduced dose rates of the grass selective post emergence
herbicides sethoxydim and fluazifop-butyl was investigated for the control of D.
abyssinica and other grass weed species in cotton so as to determine the appropriate dose
rate(s). The herbicides were supplemented with two hand weedings. Hand weeding (5
times) during the growing season was included in the treatments.
The results obtained from the field trials showed the potential of reduced dose rates in the
control of grasses. The application of fluazifop-butyl (138,162 and 188 g a. i. ha 1) and
sethoxydim (405,502 and 579 g a. i. ha 1) gave a significant density reduction of D.
abyssinica and other annual grasses at 35 days after herbicide application. No significant
differences were observed amongst the dose rates of both herbicides in the percentage
weed control of D. abyssinica and other grass weed species in the two seasons. The
percentage weed control ranged between 79-96%. The assessment showed that fresh and
dry weights of D. abyssinica shoots/foliage were reduced by 70-80% irrespective of the
dose rates for both herbicides at the two sites during the two seasons.
Reduced dose rates below half of the full dose rates were investigated in the greenhouse
in UK. A markedly reduction of D. abyssinica shoots and rhizomes was noted following
the application of fluazifop-butyl (38,66,94,188 g a. i. ha 1) and sethoxydim (116,203,
290,579 g a. i. ha 1) compared to the control. An average percentage reduction of 43.2-
62% for fresh and dry shoots, and 65.9-78% for fresh and dry rhizomes was observed.
Although analysis of variance indicated that there were no significant differences amongst
dose rates, low percentage reduction was noted from the lowest dose rate of fluazifopbutyl
(38 g a. i. ha 1).
1
As part of the plant stress assessment, results indicated that sethoxydim and fluazifopbutyl
inhibited chlorophyll accumulation in the treated leaves of D. abyssinica. A
reduction of 40-70% of chlorophyll content was noted. It was noted that sethoxydim had
higher inhibitory effect on chlorophyll content than fluazifop-butyl. Results obtained from
the measurements of fluorescence parameters showed significant reduction of Fv/Fm in
the leaves of D. abyssinica due to sethoxydim and fluazifop-butyl, suggesting significant
alteration of the normal fluorescence yield. Interference with the normal fluorescence of
D. abyssinica was associated with the inhibition of the flow of electron transport which
resulted to plant stress. Further investigation on plant stress was studied by comparing the
activity levels of the intracellular proteases of D. abyssinica and cotton plants after the
application of sethoxydim. The activity level of alanyl aminopeptidase was not affected
by the herbicide both in D. abyssinica and cotton. It was however noted that there was
significant decrease in the activity levels of argninyl aminopeptidase (arginyl-ap) (36.1%)
and tripeptidyl aminopeptidase (Tap) (51.8%) in the treated plants of D. abyssinica with
time after herbicide application. While in cotton, significant increase was observed in the
activity level of and tripeptidyl aminopeptidase with time after herbicide application.
Therefore it can be assumed that the activity levels of these enzymes in the two plant
species may have an influence on their responses to the herbicide.
Data on crop performance indicated that seedcotton yields realised from herbicides dose
rates combined with two hand weedings were high as or higher than the yields obtained
from the hand weeding (5 times). Seedcotton yields were noted high (1793-2993 kg/ha) in
1995/96 compared to 1997/98 (665.1-1184.2 kg/ha). The present study has indicated that
integration of reduced dose rates with two hand weeding supplements can reduce the
number of weedings and improve cotton production.World Bank Project/NARO (National Agricultural Organisation
Uganda governmen
Willingness of farmers to adopt rice intercrops in the Lake Victoria Crescent Agro-ecological Zone of Uganda
Intercropping, particularly with legumes, is a food security and soil fertility management strategy of small-holder, resource-poor farmers in sub Saharan Africa. Understanding the extent of and factors affecting farmers’ willingness to adopt intercropping practices is central to decisions to promote this practice. We assessed the socio-economic factors affecting the farmers’ choice to adopt an emerging rice intercrop technology in the Lake Victoria Crescent Agro-ecological Zone (LVCAZ) of Uganda. A household survey was conducted with 171 rice farmers in Kiboga, Kayunga and Luwero districts. Logistic regression analysis was used to model the willingness of farmers to adopt the rice intercrops. Results show that approximately 60% of the farmers are willing to adopt the practice. The willingness to adopt is higher with higher level of education of household heads, contact with extension agents and training, ease of access to rice seed and membership to farmer groups. On the other hand, farmer experience with rice cultivation negatively affects willingness to adopt the technology. The implication of our findings is that extension agents, especially the National Agricultural Advisory Services, should work with farmer groups to create awareness of the benefits of rice intercrops, link them with research institutions such as the National Agricultural Research Organization to enable them access seed. The Participatory Market Chain Approaches that have already shown success in potato value chains should be promoted so that commercial rice farmers have alternative markets for secondary crops from the intercrops. Further studies into the economic and social and environmental benefits of these practices are required to shed light on their sustainability. Keywords: Rice intercrops, adoption, willingness, Lake Victoria Crescent Zone, Ugand
Increasing women’s access to reliable markets through collective marketing
French version available in IDRC Digital LibraryWhile some household challenges emerged from collective marketing, the project enabled women to participate in male-dominated marketing activities and to benefit from the income generated. The project identified 65 mixed farmer groups and linked them to the Community Enterprise Development Organization (CEDO) which supplies bean seed on credit to farmer groups to produce grain on a contractual basis. Group marketing has been identified as one of the most viable ways of increasing women’s participation in agricultural marketing and improving their access to market information, as well as strengthening their bargaining power.Cultivate Africa’s Future Fund (CULTIAF
Accroître l’accès des femmes à des marchés ables grâce à la commercialisation collective
English version available in IDRC Digital LibraryCultivate Africa’s Future Fund (CULTIAF
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Electronic support tools for identification and management of rice weeds in Africa for better-informed agricultural change agents
International audienceWe developed an interactive electronic weed identification tool, AFROweeds, and an online network, Weedsbook, for agricultural change agents to aid communication and offer assistance to rice farmers with specific weed problems. We collected quantitative and qualitative data to assess effectiveness and usefulness of these products with potential users. With the online version of AFROweeds, used on an electronic tablet, average weed identification time in the field was 7 min 6 s with 44% successful identifications. Poor mobile network coverage and slow internet were the main reasons for the relative long identification time and low success rate. A second trial was done with the offline version, pre-installed on a tablet. The average identification time was 6 min 34 s, with a success rate of 75%. The online network Weedsbook, established alongside AFROweeds, was assessed by the test users as a useful additional aid, enabling agricultural change agents and agronomists to exchange information or request assistance on all aspects of weeds and weed management. The potential improvements of both products are discussed
Is bean really a women’s crop? Men and women’s participation in bean production in Uganda
Background
Common bean one of the grain legumes that was traditionally considered a subsistence crop and therefore a woman’s crop in Uganda was prioritized for commercialization. This has transformed the crop from being a subsistence crop (food security crop) to a commercial crop with more men engaged in its production. Little is known about the possibility of gender conflicts in production activities as the crop finds market.
Methods
The study uses gender-disaggregated survey data from 500 men and 625 women in central Uganda. Both bivariate and multivariate methods were used to access the notion of bean being a women’s crop based on gender participation intensities (a pairwise t test and Tobit regression model).
Results
Seventy-three percent male-headed and 87% female-headed households had membership in farmers groups. Bean crop was majorly owned by women. Seventy-five percent of the studied bean plots were intercropped with other crops. On average, both men and women operated at one bean plot per season estimated. Winnowing (4.26), post-harvest handling and storage (4.25), sorting (4.22), planting (4.04) and weeding (4.00) were the five top most activities that rural women heavily participated in. The following are the top most five activities that men participated in: site selection (3.94), spraying against pests and diseases (3.81), bush clearing (3.77), fertilizer application (3.73) and harvesting beans (3.73). Bean consumption (1.3%), marketability (17.5%), distance to plot (8.1%), education (1.3%) and color (18.1%) had significant influence on women participation intensities. Household size (5.8%), farming as primary occupation (42.7%) and bean color (30.8%) had significant influence on men bean participation intensities.
Conclusions
The study revealed there was significantly no bean production activity that was purely done by only men or only done by women. Thus, bean cannot be classified as a women’s crop based on participation intensities since men offered support in a number of activities. In order to close the gender gap in bean production, there is need to target both men and women with gendered interventions and address issues of traditional norms