Assessment of allelopathic properties of Aloe ferox Mill. on turnip, beetroot and carrot

Turnip (Brassica rapa var. rapa L.), beetroot (Beta vulgaris L.) and carrot (Daucus carota L.) are common vegetables in South Africa. The allelopathic potential of aqueous leaf and root extracts of Aloe ferox Mill.- a highly valued medicinal plant- was evaluated against seed germination and seedling growth of the three vegetables in Petri dish experiments. The extracts were tested at concentrations of 2, 4, 6, 8, and 10 mg/mL. Leaf extract concentrations above 4 mg/mL inhibited the germination of all the crops, while the root extract had no significant effect on germination irrespective of concentration. Interestingly, the lowest concentration of leaf extract stimulated root length elongation of beetroot by 31.71%. Other concentrations significantly inhibited both root and shoot growth of the vegetable crops except the turnip shoot. The most sensitive crop was carrot, with percentage inhibition ranging from 29.15 to 100% for root and shoot lengths. Lower percentage inhibition was observed for the root extract than the leaf extract against shoot growth of beetroot and carrot. The results from this study suggested the presence of allelochemicals mostly in the leaves of A. ferox that could inhibit the growth of the turnip, beetroot and carrot.

Produção da araruta comum, solteira e consorciada com alface e cenoura / Yield of comum arrowroot in monocrop system and intercropped with lettuce and carrot

O objetivo do trabalho foi avaliar a capacidade produtiva da araruta (Maranta arundinaceae) ‘Comum’, da alface ‘Grand Rapids’ e da cenoura ‘Brasília’, em cultivos solteiros e os consórcios araruta-alface e araruta-cenoura, em Dourados- MS. Para a alface e a cenoura constatou-se efeito significativo do tipo de cultivo, com os maiores valores nas plantas sob cultivo solteiro. Não houve produção de alface comercial. As características das plantas de cenoura solteiras foram aumentadas de 7,46 cm de altura; 5,36 Mg ha-¹ de massa fresca de folhas; 12,13 Mg ha-¹ de total de raízes; 11,23 Mg ha-¹ de raízes comerciais e 4,18 Mg ha-¹ de raízes não-comerciais, em relação às plantas consorciadas com a araruta. A altura das plantas da araruta variou entre 99,14 cm nas solteiras e 99,84 cm nas consorciadas com alface. As menores massas frescas dos rizomas e de raízes (19,87 Mg ha-¹ e 9,91 Mg ha-¹) foram das consorciadas com alface e as maiores (20,21 Mg ha-¹ e 11,96 Mg ha-¹) foram nas solteiras. Não obstante, a razão de área equivalente (RAE), para o consórcio araruta-alface foi de 0,98 e para o consórcio araruta-cenoura foi de 1,28. Como o valor da RAE do consórcio araruta-cenoura superou 1,0, concluiu-se que foi efetivo e que pode ser recomendado.

The objective of this work was to evaluate yield capacity of ‘Comum’ arrowroot (Maranta arundinaceae), of ‘Grand Rapids’ lettuce and of ‘Brasilia’ carrot, in monocrop system and in arrowroot-lettuce and arrowroot-carrot intercrops, in Dourados- MS. For lettuce and carrot, it was established a significative effect of cultivation type with the highest values in plants under monocrop system. There was not yield of commercial lettuce. The characteristict of the carrot plants in monocrop system were increased of 7.46 cm of height; 5.36 Mg ha-¹ of fresh mass of leaves; 12.13 Mg ha-¹ of total roots; 11.23 Mg ha-¹ of commercial roots and 4.18 Mg ha-¹ of non-commercial roots in relation to plants intercropped with arrowroot. Height of arrowroot plants varied between 99.14 cm in monocrop system and 99.84 cm intercropped with lettuce. The smallest fresh masses of rhizomes and roots (19.87 Mg ha-¹ and 9.91 Mg ha-¹) were from those intercropped with lettuce and the highest (20.21 Mg ha-¹ and 11.96 Mg ha-¹) were in monocrop system. However, the Land Equivalent Ratio - LER for arrowroot-lettuce intercrop was of 0.98 and for arrowroot-carrot intercrop was of 1.28. As the value of LER of arrowroot-carrot was superior to 1.0, it was conclude that it was effective and it can be recommended.

El objetivo del trabajo fue evaluar la capacidad productiva de la yuquilla (Maranta arundinaceae) ‘Comun’, de la lechuga ‘Grand Rapids’ y de la zanahoria ‘Brasília’, en monocultivo y en las asociaciones yuquilla-lechuga y yuquilla-zanahoria, en Dourados-MS. Para la lechuga y la zanahoria se constató efecto significativo del tipo de cultivo, con los mayores valores en las plantas en monocultivo. No hubo producción de lechuga comercial. Las características de las plantas de zanahoria en monocultivo fueron aumentadas de 7,46 cm de altura; 5,36 Mg ha-¹ de masa fresca de hojas; 12,13 Mg ha-¹ de total de raíces; 11,23 Mg ha-¹ de raíces comerciales e 4,18 Mg ha-¹ de raíces no comerciales, en relación a las plantas asociadas con la yuquilla. La altura de las plantas de yuquilla varió entre 99,14 cm en las en monocultivo y 99,84 cm en las asociadas con la lechuga. Las menores masas frescas de los rizomas y de las raíces (19,87 Mg ha-¹ y 9,91 Mg ha-¹) fueron de las asociadas con lechuga y las mayores (20,21 Mg ha-¹ y 11,96 Mg ha-¹) fueron de las en monocultivo. No obstante, la relación de área equivalente (RAE) para la asociación yuquilla-lechuga fue de 0,98 y para la asociación yuquilla-zanahoria fue de 1,28. Como el valor de la RAE de la asociación yuquilla-zanahoria superó a 1,0, se concluyó que fue efectivo y que puede ser recomendado.