Effect Of Different Plant Densities Research Articles

Biomass Production and Chemical Composition of Moringa oleifera under Different Management Regimes in Nicaragua

The effects of different planting densities (250,000, 500,000 and 750,000 plants ha−1) and cutting frequencies (45, 60 and 75 days) on the biomass production and chemical composition of Moringa oleifera was studied in a completely randomised split plot design with four blocks, in Managua, Nicaragua, located geographically at 12°08′15′′ N and 86°09′36′′ E. The 75 day cutting frequency produced the highest fresh matter yield, 100.7 and 57.4 Mg ha−1 year−1, and dry matter (DM) yield, 24.7 and 10.4 Mg ha−1 year−1, during the first and second year, respectively. All planting densities produced the highest DM yield at 75 day cutting frequency. In the first year, the density of 750,000 plants ha−1 produced the highest fresh matter yield, 88.0 Mg ha−1 and highest DM yield, 18.9 Mg ha−1, but in the second year the density of 500,000 plants ha−1 gave the highest yields, 46.2 Mg ha−1 and 8.1 Mg ha−1, respectively. During the first year, DM (22.8%), neutral detergent fibre (NDF) (30.8%) and ash (9.14%) contents were highest and in vitro DM digestibility (IVDMD) (68.2%) was lowest in the longest cutting interval, while contents of crude protein (CP) (22.8%) and acid detergent fibre (ADF) (22.8%) were not affected significantly by cutting frequency. In the second year, DM and CP contents and IVDMD were not significantly affected by cutting frequency, whereas NDF, ADF and ash contents were lowest in the 60 day cutting frequency. Planting density had no significant effect on chemical composition or IVDMD. These data suggest that Moringa forage could be an interesting protein supplement for ruminants.

Effect of different planting densities on yield and yield components of wild thyme (Thymbra spicatavar. spicata)

The study reports the effect of the planting density of wild thyme (Thymbra spicatavar. spicata) on plant height, fresh herbage yield, dry herbage yield, dry leaf yield, essential oil content and essential oil yield. The results show that the highest fresh and dry herbage, dry leaf yield and essential oil yield were obtained from narrow row spacing and in-rows. However, fresh herbage, dry leaf yield and essential oil yield showed a variation of 0.993-1.463 kg m-2, 0.179-0.279 kg m-2and 33.6-50.9 L ha-1, respectively.

SELECCIÓN COMBINADA DE GENOTIPOS DE CALABAZA PIPIANA (Cucurbita argyrosperma Huber var. stenosperma) EN EL SISTEMA MILPA

The present study was carried out with the purpose of generating information related to genetic improvement of pipiana squash, with the following objectives: to estimate, for 14 traits, the genetic parameters: mean, additive variance, dominance variance, heritability, coefficient of additive variation and phenotypic correlations, and to learn the effect of different plant densities in the agronomic performance of squash. The experiments were established in 2001 in Chapingo, Mexico, in two locations and at two plant densities per location: D1: 13,890 and D2: 9,260 plants·ha-1 of squash in association with maize (50,000 plants·ha-1) in alternating rows of each crop species. Results indicated that additive variance was of 15,184 for fruit weight and 35.98 for seed weight. When selection was practiced, dominance variance appeared. Additive variation coefficients were less than 15 % in 13 out of 14 studied characters, and heritabilities oscillated between 20.35 and 88.39 %. Seed weight (SW) varied with location and plant density, and it was higher at density one in San Martin (SW: D1=68 g·plant-1, D2=62.09 g·plant-1) and at density two in San Juan (SW: D1=74.60 g·plant-1, D2=78.40 g·plant-1).

Produção de maracujazeiro-amarelo sob diferentes densidades de plantio

O adensamento de plantas em cultivos do maracujazeiro-amarelo é importante por propiciar maior rentabilidade em menor área. O objetivo deste trabalho foi avaliar o efeito de diferentes densidades de plantio na produção, qualidade dos frutos e rentabilidade do maracujazeiro-amarelo. O experimento foi instalado e conduzido em pomar comercial da Fazenda Sant'ana, Município de São Tiago, MG. O delineamento experimental utilizado foi o de blocos casualizados com cinco tratamentos e quatro repetições. Os tratamentos constituíram-se de diferentes espaçamentos na linha de plantio: T1, 1,0 m (3.330 plantas/ha); T2, 1,5 m (2.220 plantas/ha); T3, 2,0 m (1.660 plantas/ha); T4, 3,0 m (1.100 plantas/ha) e T5, 4,0 m (830 plantas/ha). O espaçamento entre linhas foi de 3,0 m em todos os tratamentos. Cada parcela foi constituída de 12 m de comprimento por 3,0 m de largura (36 m²). O plantio foi realizado em outubro de 2001, e a colheita, a partir de abril, estendendo-se até agosto de 2002. A maior produtividade foi estimada em 11,9 t/ha na densidade de 1.841 plantas/ha. O adensamento não altera a qualidade do fruto. A máxima eficiência econômica foi alcançada na densidade de 1.340 plantas/ha, com rentabilidade de R$ 1.321,92/ha.

The Effects of Different Plant Densities on Yield, Yield Components and Quality of Artemisia annua L. Ecotypes

ABSTRACT This study was conducted between 1997 and 1998 at Çukurova University, Faculty of Agriculture to determine the effects of different plant densities (5, 10, 15, 20, 25 and 30 plants/m2) on yield and yield components and quality of Artemisia annua L. ecotypes (Adana, Samankaya and Serinyol from Turkey). In the study, the plant height (cm), fresh weight (kg/da), dry weight (kg/da), dry leaf weight (kg/da), essential oil content (%), essential oil yield (l/da), artemisinin content (%), and artemisinin yield (kg/da) of ecotypes were investigated. The results of this study showed that the highest essential oil content and the highest essential oil yield were found in the Samankaya ecotype when planted at 15 plants/m2. However, the highest artemisinin content and highest artemisinin yield were found in the Serinyol ecotype when planted at 15 plants/m2.

Produção da bananeira 'Nanicão' em diferentes densidades de plantas e sistemas de espaçamento

O objetivo do presente trabalho foi verificar o efeito de diferentes densidades de plantio e sistemas de espaçamento sobre a produção da bananeira 'Nanicão', avaliando-se os primeiros quatro ciclos. Quatro densidades (3.333, 2.222, 1.666 e 1.333 plantas ha-1) e dois sistemas de espaçamento (retângulo e triângulo) foram testados para as condições de Piracicaba,SP. O aumento da densidade de 1.333 para 3.333 plantas ha-1 diminuiu a massa do cacho em 15% a 20%, em decorrência do menor número de frutos por cacho, massa e tamanho do fruto. A produção foi sempre maior com o aumento da densidade, porém não ocorreu o mesmo quanto à produtividade. Até o terceiro ciclo, a produtividade das plantas no tratamento de maior densidade superou a das demais. No quarto ciclo, não houve diferença de produtividade entre as plantas, nas densidades testadas, em razão do aumento na duração do ciclo de produção do plantio mais denso. Comparado com o retângulo, o sistema de espaçamento em triângulo promoveu maior massa do cacho no primeiro ciclo e produtividade levemente superior ao longo dos quatro ciclos.

Effect of different planting densities on yield and yield components of Mungbean (Vigna radiata L.)

Effect of different planting densities on yield and yield components of Mungbean (Vigna radiata L.)

Plant Density and Inter-row Polyethylene Mulch Treatment Affect Growth and Yield of Tomato

A field study was conducted to compare the effect of different planting densities and polyethylene mulch treatments on growth and yield of `Mountain Fresh' trellised tomato grown on raised beds on 1.8-m centers. The experiment design was a split plot with four replications and four mulch treatments as main effects: 1) standard black mulch (B), 2) Sonoco red mulch (R), 3) black mulch with interrow (between beds) reflective white on black mulch (B/W), and 4) red mulch with inter-row R/W. Subtreatments were three within-row spacings: 1) 0.60 m (8966 plants/ha); 2) 0.45 m (11955 plants/ha; standard spacing), and 3) 0.30 m (17932 plants/ha). Yield was determined from eight-plant plots and adjacent plants were harvested at regular intervals to determine plant biomass accumulation and partitioning of biomass among roots, stems, leaves, and reproductive organs. There was a linear increase in yield among mulch treatments with increasing plant density. The B/W mulch treatment increased midseason and total yields ≈20% over that of the other mulch treatments. Fruit yield of plants with the B/W mulch treatment at the 0.3-m spacing was 54% higher (151 MT/ha) than that of plants grown on black mulch with the standard plant spacing of 0.45 m (97.9 MT/ha). There was a linear decrease in fruit size with increasing plant density; however, plants grown at the 0.30-m spacing on the B/W mulched plots exhibited only a 2.7% decrease in fruit size as compared to plants grown at the standard 0.45-m spacing on black mulch.

スイートコーンの雌穂先端部における発育不良粒の形態

Unfilled grains (caryopses) at the tip of 'Honey Bantam 36' sweet corn ear are classified as unfertilized grains (UG) and fertilized but poorly ripened ones (PRG) according to their morphological characteristics. The anomaly was induced by: a) bagging the ear (female inflorescence) before or after the appearance of the silk (filamentous style and stigma) to obtain UG and b) cutting of leaf blade to obtain PRG. Untreated control corn stalks were kept to obtain normal, filled grains (FG). The effect of different plant densities and cultivars on occurrence of UG and PRG were also investigated.1. An ear of corn usually consists of FG, UG, and PRG. The filled and unfilled grains are easily distinguished by the length of the ovules.2. The UG and PRG at the tip of an ear are differentiated anatomically because in the PRG, remnants of an embryo and the endosperm would be present. In addition, the PRG would exhibit browning at the chalazae, partially developed glume, palea, and lemma, and an intact silk.3. Fertilized grains can be differentiated from unfertilized ones 16 days after silk emergence by their size, whereas the difference between UG and PRG are detectable 20 days after silk emergence by their external and internal characteristics.4. The occurrence of UG and PRG varied among cultivars and was affected by plant densities; the higher plant densities favored the formation of PRG to lack of photosyn- thates.

Yield Structure of Winter Faba Beans Grown in Northern Germany in Dependence of Different Environments, Seed Rates, Sowing Rates and Genotypes

AbstractTwo series of field trials were performed at three sites in Schleswig‐Holstein between 1981 and 1988 to inquire into the yield structure of European winter types of Vicia faba L. and to compare their yield potential with that of spring types. Due to low winter survival, 6 winter types could be evaluated only in 4 environments in dependence of 1–3 sowing times (series α: seed rate 30/m2) and 1 winter type in 5 environments in dependence of 3 sowing times and 3 seed rates (series β: seed rate 15, 30, 45/m2).Seed yield of winter type averaged 410 g/m2 (D.M.) surpassing spring types by about 14 %. Environments caused a considerable variation in yield (275–620 g/m2) and in each yield component of winter types, while sowing dates and seed rates hardly affected the components seeds/pod and seed weight, which displayed stable genotypic rank orders. Compensative forces among the components plants/m2, tillers/plant and pods/tiller, were established. Plant densities of less than 10/m2 in spring, generally led to seed yield below 350 g/m2. Variation between 15–30 plants/m2 due to environments, sowing times or seed rates were frequently not fully compensated by tillering of plants, but often variation of the thus formed yield potential was reduced by pod set of tillers resulting in 210–270 pods/m2. The direction of correlations of pods/tillers with tillers/plant and plants/m2 differed due to experimental conditions whereas negative correlations between pods/tiller and tillers/ m2 were generally evident.Tillering was significantly influenced by the sowing time, though the increase because of early sowing was often covered by compensative effects of different plant densities. A genotypic capability to produce reproductive tillers was demonstrated using an approach which considered different plant densities and compensative forces. Neither a genotypic capability of tillers to set pods nor direct effects of environments or sowing time on pod set were established.

The Effect of Different Planting Densities on Yield Trends in Oil Palm

SUMMARYSixteen years' yield and growth data from an oil palm planting experiment, comparing 56, 110, 148 and 186 palms ha−1, and additional records from a progeny experiment, were used to study the effect of palm age and planting density on carbohydrates incorporated in total above-ground dry matter production per palm (TDMc) and its components: fruit bunch yield (Yc) and vegetative growth (VDMc). The canopy efficiency (e), the amount of carbohydrate incorporated in dry matter production per unit of absorbed radiation per hectare, decreased from the fifth to eighth year then levelled off, but increased once crown expansion was completed. The decrease in e paralleled the expansion of the intercepting leaf surface, and might therefore be linked to an increase in maintenance respiration losses. These losses were apparently not compensated for by an increase in photosynthetic production. The subsequent increase in e in older palms appears to have been due to improved light distribution as a result of an increase in light penetration. The effects of changing levels of light interception and distribution on e were more pronounced at higher density, and resulted in marked differences in changes of TDMc with age between densities. Corresponding differences occurred with Yc, so that the optimum density for current yield decreased until 12 to 13 years from planting, then markedly increased. These findings are discussed in relation to the measures which might be used to increase yield per unit area.