RESUMO Nematoides formadores de galha, como Meloidogyne incognita, representam grande problema na tomaticultura, demandando o uso de diversas medidas para o seu manejo. Buscando alternativa eficaz, o objetivo desse trabalho foi testar o extrato de alecrim (Rosmarinus officinalis) em formulação com hidrogel para controle de M. incognita em tomateiro. O formulado foi utilizado nas doses 0,25; 0,50; 0,75; 1,00 e 1,25 g por cova no momento do transplantio das mudas e, como testemunhas, 1,25 g de hidrogel (sem alecrim) e testemunha absoluta (apenas água). As variáveis nematológicas analisadas foram número de massa de ovos, de galhas, de nematoides por raiz e fator de reprodução. Para verificar se houve indução de resistência, amostras de raízes foram recolhidas em diferentes tempos e medidas as atividades das enzimas fenilalanina amônia-liase (FAL), peroxidase (POX) e polifenoloxidase (PFO). Nas variáveis nematológicas, houve redução proporcional ao aumento da dose do formulado, indicando controle efetivo do nematoide. Para as enzimas, a FAL não mostrou alteração significativa em nenhum tratamento ou tempo testado, enquanto que POX e PFO tiveram picos de atividade em diferentes tratamentos em diferentes momentos, principalmente para a dose 1,25 g do formulado. Isto evidenciou que o controle obtido de M. incognita pode ser resultado tanto pelo efeito direto do formulado de alecrim sobre a população do nematoide como pela indução de resistência da planta em reposta à ação do patógeno.

ABSTRACT Root-knot nematodes (Meloidogyne incognita) are responsible for causing great damage to tomato crop, demanding various specific management strategies. In order to find an effective alternative to control this pathogen, the aim of this study was to test the rosemary (Rosmarinus officinalis) extract in formulation with hydrogel. The formulation was used at doses of 0.25; 0.50; 0.75; 1.00 and 1.25 g per pit, at seedling transplanting, and as controls, 1.25 g of hydrogel (without rosemary) and absolute control (only water). The nematological variables evaluated were number of egg masses, number of galls, total nematodes per root, and reproduction factor. To verify whether plant resistance induction occurred, root samples were collected at different time periods and the activity of the enzymes phenylalanine ammonia-lyase (FAL), peroxidase (POX) and polyphenoloxidase (PFO) were measured. For the nematological variables, we verified proportional dose-dependent reduction of nematode infection, indicating its effectiveness in disease control. For the enzymes, FAL showed no significant change in any treatment or time period tested, whereas POX and PFO showed peaks of activity in different treatments and times, mainly at the dose 1.25 g of the formulation. These results indicated that the control of M. incognita in tomato crop can be achieved by a direct effect of the rosemary extract on the nematode population as well as by plant resistance in response to the pathogen action.

ABSTRACT Swine wastewater (SW) has high organic load, becoming an important source of macro and micronutrients to plants, promoting the improvement of soil quality and development in various cultures. However, when done without agronomic and environmental criteria, it can cause soil problems, nutrient leaching, water resource damage and plant toxicity. The objective of this study was to evaluate the soil chemical properties and the leachate in face of the association of swine wastewater and mineral fertilization (MF) in oat cultivation. An experiment in drainage lysimeter was carried out, using SW applications associated to MF or not, where treatments consisted of doses of 0, 100, 200 and 300 m3ha-1 with the absence or presence of MF, under field conditions. We concluded that swine wastewater provided significant increases in sodium, copper, zinc, and nitrite + nitrate as well as pH and calcium reductions in the soil; and in the leachate, significant increase in sodium. Moreover, the use of mineral fertilizer comprising nitrogen, phosphorus and potassium induced a significant increase in phosphorus, potassium and electrical conductivity and a significant reduction in magnesium in the soil; however, in the leachate, electrical conductivity was increased.