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Carrot (Daucus carota L.) is a vegetable crop that is grown throughout the year across various regions of Brazil in rotation or in succession to other cultures. Herbicide residual effect has emerged as a concern, because of the possibility of carryover. Thus, the objective of this study was to evaluate the effect of tembotrione and atrazine residues - in mixture and isolated - on carrot planted in succession to corn. The experiment was designed in randomized blocks with five replications. Treatments consisted of tembotrione (50.4 g ha(-1)), tembotrione (100.8 g ha(-1)), tembotrione + atrazine (50.4 g ha(-1)+ 2 L ha(-1)), tembotrione + atrazine (100.8 g ha(-1)+ 2 L ha(-1)), and atrazine (2.00 L ha(-1)) applied eight months before carrot seeding, plus a control treatment with no herbicide application. Investigated variables were shoot dry mass, productivity, and classification of carrot roots. The presence of atrazine and tembotrione decreased dry mass in the area, and only tembotrione reduced total root productivity. Thus, there is a carryover effect to tembotrione application that reduces the dry matter accumulation of shoot and total productivity, and an atrazine + tembotrione (100.8 g ha(-1)) mixture reduces the total productivity after application of these herbicides to soil.

-The application of a bionematicide based on chlamydospores of Pochonia chlamydosporia (Pc-10) can be an important strategy for reducing the damage caused by Meloidogyne incognita on carrot. Based on this perspective, the nematicidal effects of 0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kg ha -1 of Pc-10 were evaluated on carrot cv. Juliana under field conditions. Carrot yield and nematode population were influenced by increasing doses of Pc-10. The application of 3.0 kg ha -1 of Pc-10 increased the marketable production of carrot roots by 41.7% compared to the untreated control, whereas the production of unmarketable roots and the nematode population in the soil were reduced by 48.7% and 61.4%. The application of 3.0 kg ha -1 of Pc-10 reduces M. incognita population and improves carrot quality and yield.Keywords: Biological control. Daucus carota. Nematophagous fungus. Root-knot nematode. EFEITO DOSE-RESPOSTA DE Pochonia chlamydosporia SOBRE Meloidogyne incognita EM CENOURA EM CONDIÇÕES DE CAMPORESUMO -A aplicação de um bionematicida à base de clamidósporos de Pochonia chlamydosporia (Pc-10) pode se tornar uma importante estratégia para reduzir os danos causados por Meloidogyne incognita em cenoura. Baseado nessa perspectiva, o efeito nematicida de 0; 0,5; 1,0; 1,5; 2,0; 2.5 e 3,0 kg ha -1 de Pc-10 foi avaliado em área de produção de cenoura cv. Juliana em condições de campo. A produtividade de cenoura e a população do nematoide foram influenciados por doses crescentes de Pc-10. A aplicação de 3,0 kg ha -1 de Pc-10 aumentou a produção de raízes comerciais de cenoura em 41,7% comparada com aquela obtida na testemunha não tratada, enquanto que a produção de raízes não-comerciais e a população do nematoide no solo foram reduzidos em 48,7% e 61,4%, respectivamente. A aplicação de 3,0 kg ha -1 de Pc-10 reduz a população de M. incognita e aumenta a qualidade e a produtividade das raízes de cenoura.Palavras-chave: Controle biológico. Daucus carota. Fungo nematófago. Nematoide de galhas.

Exposure to climatic conditions on the soil surface reduces P. chlamydosporia viability.