Yara Crop Nutrition
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Agronomic Principles
Crop Characteristics
Potatoes produce a fibrous root system. These roots are at best no more than 24in long. Thus potatoes are shallow rooted compared to cereals for example, which can root to at least 47in depth. As a result, potatoes are often unable to exploit nutrients and soil moisture at depth within a soil profile.
While root growth occurs when soil temperatures are between 50 to 95˚F (10 to 35˚C), best, most active root development is at soil temperatures of between 59 and 68˚F (15 and 20˚C).
Leaf (haulm) growth occurs at temperatures of between 44.6 to 86˚F (7 to 30˚C) , but optimal growth is at around 68 to 77˚F (20 to 25˚C). Optimum temperatures for stolon growth are similar.
effects of soil temperature on root development
The potato tuber is an enlarged portion of the stolon. The initiation of this tuber is triggered by short day lengths (photoperiods), and involves growth hormones. The colder the soil temperature, the more rapid the initiation of tubers and the greater the number of tubers formed. The optimum soil temperature for tuber initiation is 59 to 68˚F (15 to 20˚C).
Under these conditions, the potato plant will have short stolons and shoots. Longer day lengths delay tuber initiation and favor the growth of the stolon and shoot. High temperatures also reduce tuber formation. Late varieties seem to be more sensitive to long day lengths or high temperature conditions.
Low nitrogen and high sucrose levels in the plant favor the formation of more tubers.
Once formed, tubers grow rapidly, reaching a maximum rate of up to 1,249 lb/ac/day in temperate climates. See figure below:
potato tuber growth rate, germany
Physiological Aging
By planting sprouted seed, crop growth can be advanced. The magnitude of this response and its effect on increasing crop yield is related to the physiological age of the seed at planting.
The correct answer is B
Subduction of a ocean plate.
Aleutian islands extend westward from southern Alaska to form the northern boundary of the Pacific Ocean when the Pacific plate gets subducted under North American Plate at a dip of 45 degrees. The pacific is an oceanic tectonic plate that lies beneath the Pacific Ocean. And thus the correct answer is option B
Answer:
yes
Explanation:
Compounds: are pure substances that are made up of more than l type of atom and can be broken down or decomposed into its individual elements by chemical methods, but cannot be separated by physical methods. The ratio of the elements in a compound are always constant. (Water is always 11 % Hydrogen and 89 % oxygen).
Growing taller would be an example of Mitosis
Answer:
Typically, the more massive the planet, the more massive the atmosphere it can acquire and maintain. This is important because the mass of a planet's atmosphere will directly influence its climate. The location of the “habitable zone” around a star will therefore be a function of the mass of the planet in question.
Explanation:
