NPK and flavonoids affecting insect populations in Dimorphandra mollis seedlings

The study evaluated the influence of different levels of nitrogen (N), phosphorus (P) and potassium (K), and flavonoids on the population of insects in Dimorphandra mollis Benth (Leguminosae) seedlings. The treatments associated with the highest level of attacks by Frankliniella schulzei (Trybon) (Thysanoptera: Thripidae) were 600 mg dm-3 of P and 50 mg dm-3 of K. The highest level of attacks by Coccidae occurred for 300 of P and 150 and 250 mg dm-3 of K. The last two treatments also exhibited the highest level of attacks by Pseudococcidae. On the other hand, the control exhibited higher levels of flavonoids and a lower level of insect attacks. We observed a small positive effect of N levels on attack by F. schulzei. The levels of N, P and K negatively affected the levels of flavonoids in the leaves of D. mollis. We detected no significant effects of flavonoid levels on the populations of Coccidae, Pseudoccocidae and F. schulzei. Higher numbers of Coccidae and Pseudococcidae were observed in the abaxial face of apical leaves. However, higher numbers of F. schulzei were observed on the adaxial face at lower heights in the canopy. The preferred treatment for the production of D. mollis seedlings is the control (without fertilization) because it showed higher flavonoid levels than other treatments and did not result in higher insect numbers

Omissão de nutrientes em plantas de pinhão-manso cultivadas em solução nutritiva

Jatropha curcas L. belongs to the Euphorbiaceae family. It is an oleaginousplant and it has received much attention because of the production of biofuels. The objective of this study was to evaluate the nutritional status of Jatropha curcas under deficiency of macro and micronutrients in nutrient solution. The experimental design was completely randomized with thirteen treatments and three replications.The treatments consisted of a complete solution and individual omission of each of the following nutrients: N, P, K, Ca, Mg, S, B, Cu, Mn, Mo, Zn or Fe. The decreasing orderofproductionrestriction ofdry matterwasN>Mg>S>K>Ca=P>Zn>B=Fe. Omissions of N and P affected mots the contents of macronutrients in the shoots of physic nut and the deficiency symptoms observed were chlorosis, reduced growth and deformed leaves.O pinhão-manso (Jatropha curcas L.), pertecente à família Euphorbiaceae, é uma planta oleaginosa que tem recebido expressiva atenção para produção de biocombustível. O objetivo deste trabalho foi avaliar o efeito da deficiência de macro e micronutrientes no crescimento e estado nutricional de pinhão-manso, cultivado em solução nutritiva. O delineamento experimental utilizado foi o inteiramente casualizado, com treze tratamentos e três repetições. Os tratamentos constituíram-se de solução completa e omissão individual de cada um dos seguintes nutrientes: N, P, K, Ca, Mg, S, B, Cu, Mn, Mo, Zn ou Fe. A ordem decrescente de restrição da produção de massa de matéria seca foi N>Mg>S>K>Ca=P>Zn>B=Fe. As omissões de N e de P foram as que mais afetaram os teores dos macronutrientes da parte aérea das plantas e os sintomas de deficiências observados foram clorose, redução do crescimento e folhas deformada

Spatial Distribution of Phytophagous Insects, Natural Enemies, and Pollinators on Leucaena leucocephala

Leucaena leucocephala (Lam.) de Wit (Fabaceae) is widely used to regenerate degraded landscapes in tropical and subtropical regions and serves as a protein source for animals in agrosilvopastoral systems. Thus, our objective was to assess the spatial distribution of insects on the tree crown (vertical: upper, middle, and basal canopy; horizontal: north, south, east, and west) and leaf surfaces (adaxial and abaxial) of L. leucocephala. Phytophagous insects, natural enemies, and pollinators were quantified fortnightly in 20 trees for 2 yr. North-facing tree branches had the greatest numbers of phytophagous insects, natural enemies, and pollinators. Branches facing west had the most species-rich and biodiverse phytophagous and pollinator assemblages, whereas for natural enemies, species richness and biodiversity were greatest on branches facing north or south. The greatest numbers of individuals and highest levels of species richness of phytophagous insects, natural enemies, and pollinators were observed in the upper and middle parts of the L. leucocephala canopy. The most individuals and highest levels of species richness and biodiversity for phytophagous insects, natural enemies, and pollinators were observed on the abaxial face of L. leucocephala leaves. The species with the highest abundance and k-dominance (common or constant species) on L. leucocephala trees were the phytophagous insects Trigona spinipes F. (Hymenoptera: Apidae: Meliponinae) and Tropidacris collaris Stoll (Orthoptera: Romaleidae) and the natural enemies Camponotus sp.2 (Hymenoptera: Formicidae) and Brachymyrmex sp. (Hymenoptera: Formicidae). These results can inform strategies related to pest control and maintenance of natural enemies and pollinators in L. leucocephala plantations. Biopesticide application, for example, may be more effective at eliminating target organisms if directly applied on their preferred sites, and a targeted application can minimize negative effects for non-target organisms

Spatial distribution of phytophagous insects, natural enemies, and pollinators on Leucaena leucocephala (Fabaceae) trees in the Cerrado

Leucaena leucocephala (Lam.) de Wit (Fabaceae) is widely used to regenerate degraded landscapes in tropical and subtropical regions and serves as a protein source for animals in agrosilvopastoral systems. Thus, our objective was to assess the spatial distribution of insects on the tree crown (vertical: upper, middle, and basal canopy; horizontal: north, south, east, and west) and leaf surfaces (adaxial and abaxial) of L. leucocephala. Phytophagous insects, natural enemies, and pollinators were quantified fortnightly in 20 trees for 2 yr. North-facing tree branches had the greatest numbers of phytophagous insects, natural enemies, and pollinators. Branches facing west had the most species-rich and biodiverse phytophagous and pollinator assemblages, whereas for natural enemies, species richness and biodiversity were greatest on branches facing north or south. The greatest numbers of individuals and highest levels of species richness of phytophagous insects, natural enemies, and pollinators were observed in the upper and middle parts of the L. leucocephala canopy. The most individuals and highest levels of species richness and biodiversity for phytophagous insects, natural enemies, and pollinators were observed on the abaxial face of L. leucocephala leaves. The species with the highest abundance and k-dominance (common or constant species) on L. leucocephala trees were the phytophagous insects Trigona spinipes F. (Hymenoptera: Apidae: Meliponinae) and Tropidacris collaris Stoll (Orthoptera: Romaleidae) and the natural enemies Camponotus sp.2 (Hymenoptera: Formicidae) and Brachymyrmex sp. (Hymenoptera: Formicidae). These results can inform strategies related to pest control and maintenance of natural enemies and pollinators in L. leucocephala plantations. Biopesticide application, for example, may be more effective at eliminating target organisms if directly applied on their preferred sites, and a targeted application can minimize negative effects for non-target organisms