Memory in Plants

"In the mimosa we find memory, but no consciousness. Memory of course involves no image in the plant... Memory has nothing to do with nerves or brain. It is a primal quality."

 ~ Friedrich Nietzsche

When we say that plants have memory it means that they have a past, "which they bear in their extended being and which they may access at any given moment," writes Michael Marder in Plant-Thinking. He gives two examples:

Barley leaves will unfurl if they are exposed to red light, so long as they contain calcium. If calcium is removed from the plant, the leaves will not unfurl. Yet, if the calcium is added a couple hours later, the plant will unfurl without the red light shining, "remembering" how it had shone earlier.

Plantlets of flax, likewise, respond to the stress of drought or wind by depleting calcium from their cells in a process that takes about a day, and yet they will continue to remember the traumatic event for up to a week as evidenced by their calcium depletion.

"These examples demonstrae that what Nietsche chanced upon in his reflection on the mimose is in fact a more general tendency of vegetal beings to store imageless and non-representational material memories in their cells, and so to retain a trace of the remembered thing iteslef, in place of its idealized projection," Marder concludes.

Plant-Thinking

A Philosophy of Vegetal Life

by Michael Marder

Columbia University Press, 2013

Plants and Seeds
Plant Roots: Growth, Function and Interactions with the Soil
Artwork: Magical Mimosa by Jessica Jenney

Less Fertilizer, More Nutrition.

Giving too much phosphorus to wheat and barley plants has been shown to raise the amount stored as phytate, rather than as more digestible forms of phosphorus. This finding is important for two reasons:

    * Livestock that are fed high-phytate grains excrete more phosphorus in their manure, which can pollute water.
    * Phosphorus is a finite resource that could be irreplaceable once it has been thoroughly mined -- which could happen in the next 25 years.

The researchers found that soil phosphorus levels may affect grain phytate levels as much as plant breeding can, offering two complementary solutions to the nutritional and environmental problems caused by high phytate levels in grains. Besides being more environmentally sound, getting the application rate for phosphorus fertilizers just right might improve the nutrients delivered by grain crops such as wheat and barley.

Not only is the phosphorus in low-phytate grain crops more digestible by people, but low-phytate grains free up minerals essential to human nutrition: zinc, manganese and iron.

Source: Agricultural Research Service

Fertilizer
Farm Supply
Growing Guides

Down South, Apply Poultry Litter in Spring.

Poultry litter is a popular fertilizer in many southern states because that is where most of the U.S. broiler chickens are produced. The litter's nitrogen content boosts crop yields and saves on the expense of commercial fertilizers.

But farmers in Mississippi and other southern states are applying  litter at the wrong time of time, according to a U.S. Department of Agriculture (USDA) agronomist.

Farmers in Mississippi often apply poultry litter in the fall, months before planting cash crops in the spring, because it's cheaper then and they have more time than in the spring, but Haile Tewolde at Mississippi State has found that spring is the optimal season for applying litter in the South and Southeast.

Tewolde and his colleagues applied poultry litter in the spring and fall to test plots of corn planted each April for three years. They applied the litter at two rates - four tons per acre and eight tons per acre - and incorporated it into the soil by "disking," a process that turns the soil and pulverizes it so that the litter blends in with the soil. For comparison, the researchers applied nitrogen fertilizer to other test plots in the spring and fall.

The results showed that over three years, yields were cumulatively higher in plots with litter applied in the spring than in the fall, regardless of the application rate. At the four-ton rate, spring-application yields were 16.7 percent higher, and at the eight-ton rate, they were 12.8 percent higher.

The results also showed that while using litter produced less corn than using fertilizer in the first year, those results were reversed in the second and third years. Higher yields in the second and third years were likely because nitrogen in the litter applied during the first year stayed in the soil and benefited crops in subsequent years.

Source: Agricultural Research Service

Plants and Seeds
Farm Supply
Growing Guides
Artwork: Manure Spreading

Seed Saving For Species Preservation

A new study has found that careful tailoring of seed collections to specific species and situations is critical to preserving plant diversity. Once seeds are saved, they can be reintroduced for planting in suitable locations if conditions are favorable.

In the study, researchers from the National Institute for Mathematical and Biological Synthesis and the University of Tennessee used simulation-based planning to make sampling recommendations, confirming that a uniform approach to seed sampling is ineffective.

First, collectors must choose their plant populations from a wide area rather than a restricted one. Sampling widely can capture up to nearly 200 percent more rare genes than restricted sampling. Collecting from about 25 maternal plants per population versus 50 plants appears to capture the vast majority of genetic variation.

The study also showed that collecting more than eight to ten seeds per plant leads to high overlap in genetic diversity and wasted effort.

Increasing concern over agriculture and food security and recognition of how fast biodiversity is disappearing has prompted seed banks to ramp up their collections. Botanic gardens that were once focused on showcasing plants now increasingly have a conservation mission as well, according to the study's lead author Sean Hoban.

"Our approach can be used to further refine seed collection guidelines, which could lead to much more efficient and effective collections, allowing us to preserve more diversity of the world's plants. These collections could benefit future ecosystem restoration projects as well as improve agricultural and forestry efforts."

Source:  National Institute for Mathematical and Biological Synthesis

Plants and Seeds
Farm Supply
Growing Guides
Artwork: Seed Bank

The Big Get Bigger, Whatever the Weather

The size and age of plants has more of an impact on their productivity than temperature and precipitation, according to a landmark study by University of Arizona researchers.

A fundamental assumption in most ecosystem studies is that temperature and precipitation directly influence how fast plants can take up and use carbon dioxide. Warm and wet environments allow plant metabolism to run fast, while cold and drier environments slow down metabolism and lead to lower biomass production in ecosystems.

This assumption is mostly true, as countless experiments have demonstrated that temperature and water control how fast plants can grow. But when applied to an entire ecosystems, the assumption appears to be flawed.

To test the assumption on the scale of ecosystems, the researchers developed a mathematical model that analyzed data from more than 1,000 different forest locations across the world. The analysis revealed that plant size and plant age control most of the variation in which plants thrive, not temperature and precipitation as traditionally thought.

"This general relationship shows that climate doesn't influence productivity by changing the metabolic reaction rates underlying plant growth, but instead by determining how large plants can get and how long they can live for," said Sean Michaletz, lead author of the study.

"This means that plants in warm, wet environments can grow more because their larger size and longer growing season enable them to capture more resources, not because climate increases the speed of their metabolism."

Source: University of Arizona

Growth Spurts
Plants and Seeds
Farm Supply
Growing Guides
Artwork: Pine Sapling Sprouting

Delay Harvest to Increase Sweetpotato Yield

Cultural practices such as early planting and delaying harvest are likely to increase yield and economic benefits for sweetpotato producers.

Field studies by researchers from Mississippi State and Louisiana State Universities show that yield increase was inconsistent with delaying harvest, and appears to depend on environmental conditions at harvest late in the season. Results also indicated that marketable yield of the sweetpotato cultivars was consistently greater in early plantings than late plantings.

Using economic assessments, the researchers determined that delaying harvest in early sweetpotato plantings showed a gain in net benefit for both hand harvesting for fresh market and field-run bulk harvesting for processing.

"Growers need to be cognizant of the market demands and adjust their practices accordingly to meet market expectations," the authors said. "Prices received by growers depend on the particular grade and market, and the difference in prices is a factor in the net benefit and marginal rate of return when delaying harvest."

The assessments also revealed that changing plant density resulted in no changes in economic benefit.

Sweetpotatoes are grown primarily for the fresh market, where consumers prefer medium-sized, uniformly shaped products that are free of imperfections. The sweetpotato processing industry, on the other hand, can use product of all sizes. For making sweetpotato fries, for example, large roots are preferred because they are longer and a more consistent fry length than medium-sized sweetpotatoes. Shape is not as critical as it is in the fresh market, and total yield is more important. Consequently, diverse production strategies are necessary to optimize returns.

Source: ASHS HortTechnology

Sweet Potatoes
Farm Supply
Farm Magazines
Growing Guides
Artwork: Sweet Potatoes Poster