Does a Specific Location of Composted Poultry Litter in Soil Influence Nutrient Use Efficiency and Vegetable Production? A Mesocosm Experiment

Animal wastes may be promoted as an alternative to mineral fertilizers that remain unaffordable to the overwhelming part of smallholder farmers in Sub-saharan Africa. However for an efficient use, mechanisms that underly their impact on crops should be well understood. This study was conducted in mesocosm to evaluate impacts of two ways of composted poultry litter (CPL) addition on growth and nutrient use efficiency by cucumber. It included three treatments with five-bucket replicates each: Control, CPL applied on soil surface (CS) or buried to 10 cm-depth (CB). Dry CPL was added at the rate of 0.5 kg bucket-1. At harvest, root distribution was examined in the 0-5, 5-10 and 10-20 cm depths. Dry biomasses of roots, shoot and fruits were also determined and allowed for calculation of diverse indexes of biomass allocation (root:shoot ratio, root weight ratio, stem weight ratio, leaf weight ratio) and nutrient use efficiency (factor productivity of the compost, partial factor productivity of nutrients, agronomic efficiency of compost, and apparent agronomic efficiency of nutrients). The results showed that application of CPL led to a significant improvement of all considered parameters except for the leaf weight ratio which was higher in the control (44.1±3.3) than in CS (28.1±1.9) and CB 31.2±3.5). Total lateral root length was significantly higher in CS than in CB (113.5±10.7 cm vs. 75.5±9.0 cm). The number of lateral roots per plant in the 0-5 cm soil layer was higher in CS than in CB (5.4 vs. 1 root plant-1); the reverse was observed in 5-10 cm (1.2 vs. 4.4 root plant-1). Both fresh fruit yield and total dry mass were positively correlated to root attributes. These were themselves negatively impacted by soil acidity. All nutrient use efficiency indexes were higher in CS than CB. The CPL improved the agronomic performance of cucumber particularly when applied at soil surface.

Efeito da adubação orgânica e mineral no crescimento de plantas de orégano cultivadas em ambiente protegido

O orégano é uma das plantas aromáticas e condimentares mais utilizadas no Brasil e a maior parte do produto consumido é proveniente de importação, mesmo o País apresentando condições de clima e solo favoráveis para o cultivo desta erva. Este trabalho teve como objetivo avaliar o efeito da adubação orgânica e mineral em plantas de orégano cultivado sob malha colorida. Foi adotado o esquema fatorial 4x4 (sendo quatro ambientes de luz modificada e quatro fontes de nutrientes: Latossolo Amarelo, esterco bovino, composto orgânico e NPK), adotou-se o DIC com seis repetições. Avaliaram-se as seguintes características de crescimento: altura das plantas, produção de massa seca e razão de peso foliar. Constatou-se que as plantas adubadas com esterco bovino obtiveram maior altura e maior produção de massa seca; e as plantas cultivadas no ambiente protegido pela malha azul tiveram maior altura, massa seca de raiz e massa seca total.Effect of organic and mineral fertilizers in growth of oregano's plants grown in protected environmentAbstract: The oregano is one of aromatic and spice plants most used in Brazil and the more part of the to consumption comes from imports, even the Country presenting favorable conditions of soil and climate for growing this herb. This study aimed to evaluate the effect of organic and mineral fertilizer in oregano plants cultivated under colored mesh. It was adopted a factorial scheme 4x4 (four modified light environments and four sources of nutrients: Oxisol, bovine manure, organic compound and NPK), was adopted the DIC with six replications. We evaluated the following growth characteristics: plant height, dry matter yield and leaf weight ratio. We evaluated the following growth characteristics: plant height, dry matter yield and leaf weight ratio. It was found that plants fertilized with bovine manure had presented greater height and higher production of dry matter; and plants grown under blue net had greater height, root dry weight and total dry mass.

Compensatory Growth of Ludwigia (Ludwigia hyssopifolia) in Response to Interference of Direct-Seeded Rice

Ludwigia is an important broadleaf weed of direct-seeded rice in Asia. Crop interference that relies on shading may have potential as a component of integrated weed management strategies but it requires understanding the extent to which rice can interfere with weed growth and how these weeds may respond. The growth of ludwigia was studied when grown alone and in competition with 4 and 12 rice (cv. IR72) plants. Rice interference reduced ludwigia height, number of branches, and shoot and root biomass. However, ludwigia showed the ability to reduce the effects of rice interference by increasing leaf weight ratio, increasing stem and leaf biomass in the upper half of the plant, and increasing specific stem length. At 11 wk after seeding, for example, ludwigia grown with 12 rice plants had 38% greater leaf weight ratio compared to plants grown alone. When grown with 12 rice plants, the weed had 82% of its leaf biomass in upper half of the plant compared to only 25% in weeds grown alone. The results showed that ludwigia responded to rice interference with a combination of adaptations typical of many weed species. Despite such plasticity, the control of ludwigia may be achieved by dense rice stands and increasing interference.

Analysis of interspecific variation in plant growth responses to nitrogen

Plant species differ greatly in their growth responses to nutrients, but little is known about the physiological and morphological factors that are responsible for this variation. To address this question, I measured the responses to added nitrogen of relative growth rate and three of its components (specific leaf area, unit leaf rate, and leaf weight ratio) for 17 C3 grass species. Plants were grown in sand culture in a greenhouse and were fertilized daily with either 5 or 0.05 mM NH4NO3. For most species, growth response to nitrogen was primarily associated with an increased mass allocation to leaves at high versus low nitrogen. Across all species, the average response at high versus low nitrogen was a 37% increase in leaf weight ratio, a 12% increase in unit leaf rate, and a 4% decrease in specific leaf area. Interspecific differences in growth response to nitrogen, however, were associated primarily with species differences in the response of unit leaf area to nitrogen supply. I determined the nitrogen response ratio of each parameter as the value of the parameter at high nitrogen divided by the value at low nitrogen. The rank-order correlation between the unit leaf area response ratio and the relative growth rate response ratio was 0.88. Reanalysis of previous experiments on plant nutrient response showed a similar pattern. In all studies, interspecific variation in the response of relative growth rate to nutrients was associated primarily with interspecific differences in the plastic response of unit leaf area.Key words: leaf weight ratio, net assimilation rate, plant growth analysis, relative growth rate, specific leaf area, unit leaf rate.

ANÁLISE DE CRESCIMENTO NA CULTURA DA BATATA (Solanum tuberosum ssp Tuberosum), SUBMETIDA A DIFERENTES LÂMINAS DE IRRIGAÇÃO: RAZÃO TUBÉRCULO-PARTE AÉREA, ÁREA FOLIAR ESPECÍFICA, RAZÃO DE ÁREA FOLIAR E RAZÃO DE MASSA FOLIAR

ANÁLISE DE CRESCIMENTO NA CULTURA DA BATATA (Solanum tuberosum ssp Tuberosum), SUBMETIDA A DIFERENTES LÂMINAS DE IRRIGAÇÃO: RAZÃO TUBÉRCULO-PARTE AÉREA, ÁREA FOLIAR ESPECÍFICA, RAZÃO DE ÁREA FOLIAR E RAZÃO DE MASSA FOLIAR[1] Antenor de Oliveira Aguiar NettoUniversidade Federal de Sergipe, Departamento de Engenharia Agronômica, CEP: 49100-000, São Cristovão-SeJoão Domingos RodriguesUNESP, Instituto de Biociências, Departamento de Botânica, CEP: 18600-000, Botucatu-SPNelson Augusto do Nascimento JúniorEscola Agrotécnica Federal de Satuba, Satuba-Al 1 RESUMO Conduziu-se um experimento na Fazenda São Manoel, pertencente à Faculdade de Ciências Agronômicas da Universidade Estadual Paulista, objetivando avaliar os efeitos de diferentes lâminas de irrigação no crescimento da cultura da batata, cultivar Aracy. O ensaio foi instalado em um Latossolo vermelo-escuro textura arenosa, sob uma cobertura de plástico. O delineamento experimental utilizado foi o de blocos ao acaso, com cinco tratamentos, cinco coletas de plantas para fins de análise de crescimento e quatro repetições. Os tratamentos consistiam em irrigar a batata quando a tensão da água no solo atingia 15, 35, 55, 75 e 1500 kPa. Verificou-se que o aumento nas lâminas de irrigação induziu incremento na razão de massa foliar e razão de área foliar, e decréscimos na razão tubérculo parte-aérea, sem interferir no comportamento da área foliar específica. UNITERMOS: Batata, irrigação, crescimento. NETTO, A.O.A., RODRIGUES, J.D., NASCIMENTO JÚNIOR, N.A.N. GROWTH ANALYSIS IN THE POTATO CROP (Solanum tuberosum ssp Tuberosum), UNDER DIFFERENT IRRIGATION LEVELS: TUBER-SHOOT RATIO, LEAF ÁREA SPECIFIC, LEAF ÁREA RATIO, LEAF WEIGHT RATIO. 2 ABSTRACT In order to obtain a good productivity and costs reduction is very important to perform a proper irrigation management in the potato crop (Solanum tuberosum ssp Tuberosum). An experiment was carried out at Fazenda São Manoel, in the Faculdade de Ciências Agronômicas, of the Universidade Estadual Paulista, to evaluate irrigation levels in the potato growth, cv aracy. This work was installed in a sandy dark red latosol, under a plastic cover. The experimental design was a entirely randomized block composed by irrigation in the potato plots when the soil water potential have reached - 15, - 35, - 55, - 75 and - 1500 kPa, and five plant sampling time with four replicates. It was found that higher irrigation levels led to increase of the leaf Área ratio and in the leaf weight ratio. Otherwise, higher irrigation levels induced decreases in the tuber-shoot ratio without interfering in the leaf Área specific. KEY-WORDS: Potato, irrigatio, growth.[1]Parte da tese do primeiro autor, para obtenção do título de Doutor em Agronomia - Irrigação e Drenagem.

Effect of Wind and Soil Moisture on the Growth of `Bluecrop' (Vaccinium corymbosum L.)

This study was conducted in the greenhouse by running two experiments at different temperature regimes (22°C day and 13°C night and 33°C day and 22°C night). One-year-old tissue culture propagated plants were irrigated at three different soil moisture tension levels (5, 15, and 30 cnbars) and either exposed to moving or still air. The moving air treatment was created by two 51-cm-diameter fans running at either low (5.6 mph) or medium (8.2 mph) speed. Each experiment included, forty-eight plants arranged in a randomized complete block design. Each block consisted of a greenhouse bench containing two fans, a plastic dividing wall and two plant replications for each treatment. Canopy volume measurements were taken at the beginning, middle and end of each experiment to estimate growth rate. At the end of each experiment, total leaf area and leaf, stem and root dry weight data were collected. In the moderate temperature experiment, the still air treated plants had the highest canopy volume and leaf weight ratio while the moving air treated plants had the highest stem weight ratio. The only difference for the moisture treatments was the 5-cnbar treatment had the highest canopy volume. In the high temperature experiment, the still air treated plants had the highest canopy volume, total leaf area, leaf dry weight, shoot/root ratio, leaf weight ratio and leaf area duration while the moving air treated plants had the highest root weight ratio. The 5-cnbar treatment had the highest canopy volume and biomass accumulations. The 30-cnbar treatment had the highest root weight ratio.

Seedling Growth of Catawba Rhododendron. I. Temperature Optima, Leaf Area, and Dry Weight Distribution

Catawba rhododendron (Rhododendron catawbiense Michx.) seedlings of two provenances, Johnston County, N.C. (35°45′N, 78°12′W, elevation = 67 m), and Yancey County, N.C. (35°45′N, 82°16′W, elevation = 1954 m), were grown in controlled-environment chambers for 18 weeks with days at 18, 22, 26, or 30C in factorial combination with nights at 14, 18, 22, or 26C. Shoot and root dry weights and total leaf areas of seedlings of the Yancey County provenance (high elevation) exceeded (P ≤ 0.05) those of the Johnston County (low elevation) provenance at all temperature combinations. Leaf area was maximal at 22/22C, 18/26C, and 22/26C and minimal at 30/14C (day/night). Shoot dry weight responded similarly. Root dry weight decreased linearly with increasing day temperature, but showed a quadratic response to night temperature. Leaf weight ratio (leaf dry weight: total plant dry weight) increased, while root weight ratio (root dry weight: total plant dry weight) decreased with increasing day temperature. Leaf weight ratio was consistently higher than either stem or root weight ratios. Day/night cycles of 22 to 26/22C appear optimal for seedling growth.