Semeadura conjugada à aplicação de herbicidas em plantio direto e convencional, na cultura do milho (Zea mays L.)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Potencialidade do uso do lodo de esgoto como fonte de macronutrientes no cultivo de milho (Zea mays L.), no município de Maringá - PR

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Disposição de lodo de esgoto: acúmulo de metais pesados no solo e em plantas de milho (Zea mays L.)

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Diferentes sistemas de manejo do solo e espaçamentos na cultura do milho (Zea mays L.)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Infestação de Spodoptera frugiperda e Helicoverpa zea (Lepidoptera: Noctuidae) em híbridos comerciais de milho (Zea mays L.)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Herança da resistência ao complexo enfezamento em milho (Zea mays L.)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito de rodas compactadoras submetidas à cargas verticais em profundidades de semeadura nas características agronômicas do milho (Zea mays L.)

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Comportamento e dano de tripes na cultura do milho (Zea mays L.)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Bioprospecção de bactérias endofíticas como agentes de biocontrole da mancha de Exserohilum turcicum e como promotoras do crescimento de plantas de milho (Zea mays L.)

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Caracterização de Híbridos Simples Experimentais de Milho (Zea Mays L.)

Pós-graduação em Agronomia - FEIS

Productivity, Leaf Nutrient Content and Soil Carbon Stocked in Agroforestry and Traditional Management of Maize (Zea mays L.)

The aim of the work was to evaluate the productivity, leaf nutrient content and soil nutrient concentration in maize (Zea mays L.) grown in sequence with black oats (Avena strigosa Schreb.) under Leucaena diversifolia alley cropping agroforestry system (AFS) and traditional management system/sole crop (without trees-TS), after two years of cultivation following a randomized block design. The experiment was carried out in the Brazilian Association of Biodynamic Agriculture, in Botucatu—S?o Paulo, Brazil. Treatments were: control (C), chemical fertilizer application (F), biomass of L. diversifolia alley cropping application (B), biomass of L. diversifolia alley cropping + chemical fertilizer application (B + F). In the second year of management it was observed that black oat yield was higher in treatments B + F and F with significant difference in relation to the others treatments in both systems, followed by treatment B. Between systems, only treatment B showed significant difference, with higher yield value corresponding to AFS, reflecting the efficiency of AFS to promote soil fertility. Maize production presented the second year of cultivation an increasing trend in all treatments in both production systems. This result may be due to the cumulative effect of mineralization and maize straw and oats, along the experiment. How productivity was higher in the AFS system, could also be occurring effect of biological nitrogen fixation, water retention and reduction of extreme microclimate through the rows of L. diversifolia. Comparing the AFS and TS, it was observed that the concentration of N in leaf tissue was higher in the AFS treatments, probably due to nitrogen fixation performed through the rows of L. diversifolia, that is a nitrogen fixing tree species. After two years, carbon stocked in soil show higher values in the treatments biomass + fertilizer and biomass application, in both systems, AFS and TS.

Heterosis in maize (Zea mays, L.): characterization of heterotic quantitative trait loci (QTL) for agronomic traits in near isogenic lines (NILs) and their testcrosses

In a previous study on maize (Zea mays, L.) several quantitative trait loci (QTL) showing high dominance-additive ratio for agronomic traits were identified in a population of recombinant inbred lines derived from B73 × H99. For four of these mapped QTL, namely 3.05, 4.10, 7.03 and 10.03 according to their chromosome and bin position, families of near-isogenic lines (NILs) were developed, i.e., couples of homozygous lines nearly identical except for the QTL region that is homozygote either for the allele provided by B73 or by H99. For two of these QTL (3.05 and 4.10) the NILs families were produced in two different genetic backgrounds. The present research was conducted in order to: (i) characterize these QTL by estimating additive and dominance effects; (ii) investigate if these effects can be affected by genetic background, inbreeding level and environmental growing conditions (low vs. high plant density). The six NILs’ families were tested across three years and in three Experiments at different inbreeding levels as NILs per se and their reciprocal crosses (Experiment 1), NILs crossed to related inbreds B73 and H99 (Experiment 2) and NILs crossed to four unrelated inbreds (Experiment 3). Experiment 2 was conducted at two plant densities (4.5 and 9.0 plants m-2). Results of Experiments 1 and 2 confirmed previous findings as to QTL effects, with dominance-additive ratio superior to 1 for several traits, especially for grain yield per plant and its component traits; as a tendency, dominance effects were more pronounced in Experiment 1. The QTL effects were also confirmed in Experiment 3. The interactions involving QTL effects, families and plant density were generally negligible, suggesting a certain stability of the QTL. Results emphasize the importance of dominance effects for these QTL, suggesting that they might deserve further studies, using NILs’ families and their crosses as base materials.

Effect of compost and slow-release fertilizers addition on soil biochemistry and yield of maize (Zea mays L.) in Oaxaca, Mexico

The effect of Bokashi (B, a fermented compost), slow-release fertilizers (SRFs) and their combined application on mycorrhizal colonization (MC), soil invertase, cellulase, acid (AcP) and alkaline (AlP) phosphatases activities and maize (Zea mays L.) yield was investigated in terrace (TS) and valley (VS) soils in Oaxaca, Mexico. A complete randomized design, seven fertilizer treatments and four replications were used: unamended control (C); conventional fertilization (90-46-00 NPK) (CF); B; SRF1 (Multigro 6®, 21-14-10 NPK); SRF2 (Multigro 3®, 24-05-14 NPK); B+SRF1; B+SRF2. Highest root colonization percentage: CF in VS, and SRF2 in TS. Highest extraradical mycelium length: B, B+SRF1, CF in VS, and B+SRF1 in TS. In both soils, B increased the spore number. Highest AcP activity: B, SRF2 in VS, and B+SRF1, B+SRF2 in TS. Highest AlP activity: B+SRF1, CF in VS, and C in TS. Highest invertase activity: B+SRF1, SRF2, CF in VS, and B in TS. Grain yield only increased with B in VS. The significant interaction soil type × fertilizer treatment for the majority of the biological soil properties analyzed suggests that MC and soil enzyme activity response to fertilization was influenced by soil type. Bokashi, alone or combined with SRFs improves biological soil fertility in maize fields.

El ciclo del conocimiento en la producción de maíz (Zea mays L.)

El estudio tuvo por objeto caracterizar el ciclo del conocimiento en la producción de maíz (Zea mays L.). Venezuela tiene una importante producción de este rubro que forma parte de su dieta diaria. El conocimiento se crea, se almacena, se transfiere, se aplica y se preserva, en un ciclo que tiene la finalidad de incrementar la competitividad y sustentabilidad de las organizaciones. Se dise- ñó y aplicó una encuesta de 36 ítems a una muestra de 234 productores. El índice de conocimiento fue de 69,78% y el índice de percepción de resultados fue de 76,06%, encontrándose una relación positiva entre ambas variables. Se evidenció la ocurrencia del ciclo del conocimiento en cuatro etapas en las que interactuaron medios explícitos y tácitos

Characterization of maize (Zea mays L.) Wee1 and its activity in developing endosperm

We report the characterization of a maize Wee1 homologue and its expression in developing endosperm. Using a 0.8-kb cDNA from an expressed sequence tag project, we isolated a 1.6-kb cDNA (ZmWee1), which encodes a protein of 403 aa with a calculated molecular size of 45.6 kDa. The deduced amino acid sequence shows 50% identity to the protein kinase domain of human Wee1. Overexpression of ZmWee1 in Schizosaccharomyces pombe inhibited cell division and caused the cells to enlarge significantly. Recombinant ZmWee1 obtained from Escherichia coli is able to inhibit the activity of p13suc1-adsorbed cyclin-dependent kinase from maize. ZmWee1 is encoded by a single gene at a locus on the long arm of chromosome 4. RNA gel blots showed the ZmWee1 transcript is about 2.4 kb in length and that its abundance reaches a maximum 15 days after pollination in endosperm tissue. High levels of expression of ZmWee1 at this stage of endosperm development imply that ZmWee1 plays a role in endoreduplication. Our results show that control of cyclin-dependent kinase activity by Wee1 is conserved among eukaryotes, from fungi to animals and plants.