Made available in DSpace on 2016-04-28T14:59:00Z (GMT). No. of bitstreams: 1 Rejane Escrivani Guedes.pdf: 2537678 bytes, checksum: fa415f1591e33c3b7c367223fc134c67 (MD5) Previous issue date: 2008-03-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Cowpea genotypes submitted to organic management were evaluated for grain yield and green manure, as well as intercropped with corn, under field conditions of Serop?dica, state of Rio de Janeiro. In the year of 2005, 53 cowpea genotypes were compared at the Integrated Agroecology Produc tion System ( SIPA Km 47 Agroecologic Farm) relating to qualitative and quantitative agronomic traits. Data were treated by following univariate and multivariate statistical analysis. Significant differences were detected with respect to all the evaluated parameters. Genotypes EES-02, EES-08, EES-26, EES47, Feij?o-Caupi and Feij?o Mau? showed favourable attributes for immature (=green) grain yield. They presented determinate growth habit with moderate branchding and flowering stage up to 45 days after sowing, only differing by pod and grain colors. Univariete analysis demonstrated high variability among cowpea genotypes. However, multivariate analysis was more efficient to joint selected agronomic traits for identification of genotyp ic groups, which can be important in cowpea breeding programs. Cowpea and corn intercrops also submitted to organic cultivation were evaluated by means of two field experiments carried out at SIPA. In Experiment 1, the cowpea cultivars Mau?, BRS Mil?nio and Olho de Peixe were intercropped with corn (cv. AG-1051) to function as green manures. A randomized blocks design was employed in factorial 2x3 scheme (two corn plant spacing x three cowpea cultivars). In Experiment 2, Mau? cowpea and AG-1051 corn were intercropped for harvesting immature (=green) grains and spikes, respectively. Treatments consisted of four time intervals between cowpea and corn sowing. As for Experiment 1, corn planted in double rows favoured cowpea aboveground biomass production, probably due to a greater amount of light admitted into the system. Results from Experiments 2 indicated that intercrop with cowpea did not decrease corn yield which reached averages of 9,5 and 5,9 Mg ha-1 of ears with and without straw, respectively. Regarding cowpea grain yield of Mau? cultivar its single crop was superior to the intercrops exceeding 1400 kg ha-1. Treatment corresponding to 21 days of interval between cowpea and corn sowing differed from the other types of intecrops, with yield attaining 978,75 ka ka-1. It is concluded that the intercropping system can se adopted in the region without risks of lowering corn yield due to competition, being three weeks (21 days) the most adequate time interval between sowing. / Foi avaliado, em sistema org?nico de produ??o, o desempenho de gen?tipos de feij?o-caupi com potencial para produ??o de gr?os verdes e aduba??o verde, e em cons?rcios com o milho, nas condi??es da Baixada Fluminense, munic?pio de Serop?dica, estado do Rio de Janeiro. No ano de 2005, em ?rea do SIPA, (Sistema Integrado de Produ??o Agroecol?gica Fazendinha Agroecol?gica Km. 47 ), foram avaliados 53 gen?tipos de feij?o-caupi, segundo caracter?sticas fitot?cnicas qualitativas e quantitativas. Os dados foram submetidos a an?lise de vari?ncia univariada e a an?lise multivariada. Houve diferen?a significativa para todos os par?metros avaliados. Os gen?tipos EES-02, EES-08, EES-26, EES-47, Feij?o-Caupi e Feij?o Mau? reuniram caracter?sticas mais adequadas para colheita de gr?os verdes, apresentando porte semi-ramador, h?bito de crescimento determinado, com florescimento at? 45 dias ap?s semeadura, diferindo apenas pela colora??o da vagem e do gr?o. Os resultados da an?lise univariada demonstraram alta variabilidade entre os gen?tipos. Por?m, para o caso de se reunir v?rios atributos fitot?cnicos, constituindo grupos de gen?tipos, a an?lise multivariada se mostrou mais eficiente e pode ser de valia para o melhoramento do feij?o-caupi. Foi avaliado, ainda, o desempenho agron?mico dos cons?rcios do milho com o feij?o-caupi submetidos ao manejo org?nico, atrav?s de dois experimentos conduzidos no SIPA. No Experimento 1, avaliou-se o desempenho de tr?s cultivares de feij?o-caupi para aduba??o verde do milho (cv. AG-1501) em cons?rcios simult?neos. As cultivares de feij?o-caupi Mau?, BRS Mil?nio e Olho de Peixe foram utilizadas, adotando-se delineamento de blocos ao acaso, em esquema fatorial 2 x 3 (dois espa?amentos de milho e tr?s cultivares de feij?ocaupi). No Experimento 2, avaliou-se o cons?rcio entre feij?o-caupi (cv. Mau?) e milho (cv. AG-1051) para colheitas de gr?os verdes e de espigas verdes, respectivamente. Os tratamentos constaram de quatro intervalos entre as semeaduras de feij?o-caupi e de milho. No Experimento 1, o espa?amento do milho em fileiras duplas favoreceu a produ??o de biomassa a?rea fresca de feij?o-caupi, muito provavelmente pela maior entrada de luz no sistema. Os resultados do Experimento 2 indicaram que o cons?rcio n?o interferiu na produtividade do milho, colhendo-se, em m?dia, 9,5 e 5,9 Mg ha-1 de espigas verdes empalhadas e desempalhadas, respectivamente. Com rela??o ? produ??o de gr?os verdes da cv. Mau? de feij?o-caupi, o monocultivo superou os cons?rcios com o milho, ultrapassando 1400 kg ha-1. O cons?rcio correspondente a 21 DAM (dias antes do milho) diferiu dos demais tipos de cons?rcio, sendo superior, em produ??o, que atingiu 978,75 kg ha-1. Concluiu-se que o sistema de cons?rcio com o feij?o-caupi pode ser adotado na regi?o sem risco de perdas na produtividade do milho por efeito de competi??o, sendo de tr?s semanas (21 DAM) o intervalo mais adequado entre as semeaduras.

MENVSC / Department of Ecology and Resource Management / The study investigated the impact of cover crops (Medicago sativa, Lotus corniculatus, Trifolium pratense, Melilotus alba and Phacelia tanacetifolia), bare soil and natural ground cover on pest and beneficial arthropods, soil health, crop yield, pest damage and weed suppression in avocado orchards. The trial plots were sited within established commercial avocado orchards with trees of similar cultivar (‘Hass’), soil-type and age, located in Levubu, Limpopo, South Africa. Mixtures of cover crops were planted in the alleys of avocado orchards and the effects were compared to that of a control (other half of the orchard). Mechanical clearing of vegetation in half of the alleys of different avocado orchards were compared to the other half that was left undisturbed. Data were collected during the flowering and fruit set stages of the avocado trees in the months of September - November 2019. Results revealed that there was higher abundance and diversity of flowering plants in the orchard alleys of the cover crop treatment compared to the control comprising of natural vegetation. Cover crops had a significantly positive effect on the soil health of the orchard but little or no effect on beneficial arthropods within the orchard nor any positive effect on the pests of avocados. However, the number of thrips scouted on the fruit were significantly less where cover crops were established. Avocado scale infection rates were also significantly lower where cover crops were established. There were significantly less arthropods, and specifically pests, pollinators and herbivores where the topsoil was removed mechanically. The yield resulting from the orchard half where cover crops were established were significantly higher. More research still needs to be done about the use, management and impact of cover cropping on not only commercial avocado orchards but on other fruit crops. This study shows good evidence for the benefits for using cover crops and the negative effects in having no vegetation cover in the orchards. / NRF