Plant population and row spacing effects on corn: Phenotypic traits of positive yield‐responsive hybrids

AbstractWith a growing number of long-term, individual-based data on natural populations available, it has become increasingly evident that environmental change affects populations through complex, simultaneously occurring demographic and evolutionary processes. Analyses of population-level responses to environmental change must therefore integrate demography and evolution into one coherent framework. Integral projection models (IPMs), which can relate genetic and phenotypic traits to demographic and population-level processes, offer a powerful approach for such integration. However, a rather artificial divide exists in how plant and animal population ecologists use IPMs. Here, I argue for the integration of the two sub-disciplines, particularly focusing on how plant ecologists can diversify their toolset to investigate selection pressures and eco-evolutionary dynamics in plant population models. I provide an overview of approaches that have applied IPMs for eco-evolutionary studies and discuss a potential future research agenda for plant population ecologists. Given an impending extinction crisis, a holistic look at the interacting processes mediating population persistence under environmental change is urgently needed.

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Inter-row plant spacing effects on grain and fodder yields, growth performance, digestibility and manure quality of sheep

Peanut Science ◽

10.3146/ps20-34.1 ◽

2021 ◽

Author(s):

Joshua Adda ◽

Weseh Addah ◽

Nurudeen Abdul Rahman ◽

Timothy A. McAllister

Keyword(s):

Growth Performance ◽

Farming Systems ◽

Daily Weight Gain ◽

Row Spacing ◽

Smallholder Farming ◽

Farming Communities ◽

Dry Matter Digestibility ◽

Spacing Effects ◽

Natural Pasture ◽

Arachis Hypogaea L

In Ghana, peanut (Arachis hypogaea L.) grain and fodder serve as important sources of protein for human and livestock nutrition, respectively. Experiments were conducted in four farming communities to determine the effects of planting annual peanut at four inter-row spacings of 30, 45, 65 and 75 cm on grain and fodder yields (experiment I), growth performance and manure quality (experiment II), and in situ digestibility (experiment III) of Djallonké sheep fed fodder from these plant spacings. Planting peanut at 30 cm inter-row spacing dually increased grain and fodder yields compared to planting at 60, and 75 cm. Peanut fodder from 30 cm inter-row spacing also had comparatively higher concentration of crude protein and lower concentrations of acid detergent fiber and acid detergent lignin, resulting in significant improvements in dry matter digestibility at 48 h and superior average daily weight gain of sheep. The concentration of N excreted in the manure of sheep fed the 30 cm fodder was greater than those fed peanut grown at 60, and 75 cm inter-row spacing. Planting peanut at an inter-row spacing of 30 cm therefore gave dual benefits of increasing grain and fodder yields as well as increasing the digestibility and growth performance of sheep fed peanut fodder as a supplementary diet to natural pasture for 70 days. Higher concentration of N in the manure of sheep fed 30 cm fodder could have additional benefits of improving soil fertility in smallholder farming systems where inorganic fertilizers are expensive and inaccessible to farmers.

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Increasing population density reduces soybean yield components and productivity

Bioscience Journal ◽

10.14393/bj-v37n0a2021-53612 ◽

2021 ◽

Vol 37 ◽

pp. e37042

Author(s):

Marcelo De Almeida Silva ◽

Ana Carolina De Santana Soares ◽

Melina Rodrigues Alves Carnietto ◽

Alexandrius De Moraes Barbosa

Keyword(s):

Grain Yield ◽

Yield Components ◽

Spatial Arrangement ◽

Plant Population ◽

Row Spacing ◽

Individual Plant ◽

Growth Type ◽

Soybean Yield ◽

Plant Densities ◽

Plant Yields

Studies addressing the interaction of different spatial arrangement in soybean are needed in order to achieve management that leads to higher grain yield associated with rational seed use. The objective of this work was to evaluate the yield components and productivity of an undetermined growth type soybean as a function of different row spacing and plant densities. The treatments consisted of three row spaces (0.25, 0.35 and 0.45 m) and three plant population densities (30, 40 and 50 plants/m²). There was no interaction of row spaces and plant population on soybean yield. Regarding the overall spacing average, the grain yield of the population of 30/m² plants was higher than the productivity of the populations of 40 and 50/m² plants. The largest populations reduce plant sizes due to greater competition between plants. In addition, smaller populations promote higher individual plant yields due to the increase components of the production. This characteristic is defined as the ability of the plant to change its morphology and yield components in order to adapt to the conditions imposed by the spatial arrangement.

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