Plantas daninhas na pós-colheita de milho nas várzeas do rio São Francisco, em Minas Gerais.

Realizou-se um estudo na região do Alto São Francisco, Minas Gerais, no final da safra agrícola 1997/1998, visando identificar as plantas daninhas que permanecem nas áreas após a colheita do milho e sua distribuição ao longo da área estudada, destacando-se as mais importantes. As observações foram realizadas em 12 municípios. Em cada local foi lançado, por cem vezes, um quadrado de 0,50 x 0,50 m, a espaços de 10 m. Dentro do quadrado foram contadas as espécies e registrado o número de indivíduos de cada uma delas. Foram encontradas 151 espécies em 35 famílias, sendo Asteraceae a mais bem representada, com 25 espécies. As espécies com maior Índice de Valor de mportância (IVI) foram: Ageratum conyzoides, Sida glaziovii, Conyza bonariensis, Gaya sp., Sida rhombifolia e Blainvillea biaristata. As plantas daninhas remanescentes nas áreas recém-colhidas são fonte de alimento para insetos polinizadores e inimigos naturais das pragas; adequadamente manejadas, elas podem favorecer a manutenção do equilíbrio nos agroecossistemas

The performance of advanced sorghum lines under diverse environments

No Abstract

Weed profiles and management assessment for increased finger millet production in Uganda

Finger millet (Eleusine coracana   L. Gaertn.), a staple and food security crop in Uganda, is appreciated for its nutritional value, tolerance to water deficits, and good storage qualities; however, production requires a lot of labour, particularly for weed control. Thus, there is need to develop weed management strategies that are profitable. Research was conducted on-farm in three districts of eastern Uganda, to evaluate the agronomic and economic efficiency of one or two weedings, with row seeding as compared to broadcast sowing. Weedings were at two or four weeks after sowing. The four treatments were in a randomised complete block design arranged in split-plots with sowing patterns in main plots and weeding frequencies in the sub-plots. Digitaria scalarum   was difficult to control and was judged to be the most serious weed. Finger millet yield was least under broadcast sowing with one weeding, but was increased by 44.7% with a second weeding at four weeks after sowing. Higher grain yields were obtained with row spacing plus one weeding than with broadcast sowing and two weeding treatments. Yield was not significantly increased by a second weeding under row seeding. Weed population density for row seeding was 50% of that for broadcast sowing. Row seeding was four times more costly than broadcast sowing due to extra labour requirement, but weeding costs were less and returns were greater. The second weeding increased the variable costs of production with broadcast seeding by 55%, but the profit margin increased by 88% and the returns were greater. Second weeding with direct seeding increased variable production costs by 65% but the returns for the second weeding were 289%. Weeding twice is especially profitable with broadcast sowing, but also with row seeding

Prospects and constraints of finger millet production in Eastern Uganda

(African Crop Science Journal 1999 7(4): 569-584

Prospects and Constraints of Finger Millet Production in Eastern Uganda

Finger millet (Eleusine coracana L.) is a major staple and cash crop in northern, eastern, western and southwestern Uganda. However, research on the crop has been limited. As such, a survey was conducted in eastern Uganda (Kumi, Pallisa and Kamuli districts) to establish the status of the crop, its production constraints and prospects for its development. A semi-structured questionnaire was administered to fifty households per district, during the period October-December, 1998. Land productivity has declined considerably in the study districts and low soil fertility is a major factor in this respect. Production of the crop is hampered by many constraints, the major ones being inadequate labour for weeding and harvesting, frequent drought, pests and diseases, and soil exhaustion. The region is highly dependent on oxen for land preparation. Finger millet production activities are generally gender neutral. The crop is grown almost exclusively once a year. Inter-cropping and crop rotation are common practices in finger millet production, and the role of finger millet as a cash crop is on the increase. Prospects for development of the crop lie in increasing yield through generation of labour-saving technologies, particularly for weeding and harvesting, and development of farmer-friendly packages for pests and disease management, drought mitigation and soil fertility management. A follow-up on-farm soil fertility management study was conducted to investigate the response of finger millet sown in rows or broadcasted, to various soil fertility management regimes. Row planting resulted in significantly (P<0.05) better finger millet growth and yield than broadcasting. Combined application of P and N, or P and manure gave the highest yields. Application of N alone delayed flowering and physiological maturity of the crop by 1 and 2 weeks, respectively. There was no significant (P<0.05) effect of planting pattern or fertiliser treatment on threshing percentage.L\u2019eleusine (Eleusine coracana L.) est une d\ue9nr\ue9e de base et une culture de revenu dans l\u2019Est, Nord, Nord-West et Soud-Ouest de l\u2019Uganda. Cependant, la recherche sur cette culture a \ue9t\ue9 tr\ue8s limit\ue9e et ainsi une enqu\ueate a \ue9t\ue9 conduite dans l\u2019Est de l\u2019Uganda (Kumi, Pallisa et Kamuli districts) pour \ue9tablir la situation de la culture, les contraintes de production et les perspectives pour son d\ue9veloppement. Un questionnaire semi-structur\ue9 a \ue9t\ue9 administr\ue9 sur 50 m\ue9nages par district, durant la p\ue9riode Octobre-D\ue9cembre 1998. La productivit\ue9 de la terre a baiss\ue9 consid\ue9rablement dans les districts \ue9tudi\ue9s et la faible fertilit\ue9 du sol constitute un facteur principal \ue0 cet \ue9gard. La production de cette culture est handicap\ue9e par plusieurs contraintes, les principales \ue9tant le travail unad\ue9quat du sarchage et de la recolte, fr\ue9quente s\ue9cheresse, pestes et maladies et l\u2019\ue9puisement du sol. Le r\ue9gion est hautement d\ue9pendante de l\u2019ox pour la pr\ue9paration de la terre. Le activit\ue9s de production de l\u2019\ue9leusine sont g\ue9n\ue9rallement de sexe balanc\ue9. La culture est faite presque exclusivement une fois l\u2019ann\ue9e. L\u2019association et la rotation des cultures sont pratiques communes dans la production de l\u2019eleusine et son importance en tant que culture de revenu s\u2019accroit. Les perspectives de d\ue9veloppement se trovent dans l\u2019augmentation des rendements par la g\ue9n\ue9ration des technologies qui all\ue8gent le travail, en particulier pour le sarclage, la recolte et le d\ue9veloppement des paquets sains pour les agriculteurs dans la gestion de pestes et maladies, la mitigation de la s\ue9cheresse et la gestion de la fertilit\ue9 de sol. Un suivi d\u2019essai en milieu r\ue9el de gestion de la fertilit\ue9 du sol a \ue9t\ue9 conduit pour \ue9tudier la r\ue9ponse d\u2019\ue9leusine sem\ue9e en lignes ou \ue0 la vol\ue9e dans differents r\ue9gimes de gestion de la fertilit\ue9 du sol. La plantation en lignes a favoris\ue9 significativement (P<0.05) une meilleure croissance d\u2019\ue9leusine et du rendement plus que la plantation \ue0 la vol\ue9e. L\u2019application combin\ue9e du P et d\u2019N ou du P et de la fumure a donn\ue9 des rendements plus \ue9lev\ue9s. L\u2019application d\u2019N seul a retard\ue9 la floraison et la maturit\ue9 physiologique de la culture d\u2019une et deux semaines respectivement. Il n\u2019y avait pas d\u2019effect significatif (P<0.05) de mode de plantation ou du traitement d\u2019engrais sur le pourcentage de battage

Enhancing innovation processes through local competitive agricultural technology funds in Uganda-experiences and lessons.

No Abstract