Ratooning

Key takeaways

Ratooning belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Ratooning to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Ratooning from memory before moving on to harder problems.

Reference excerpt

Ratooning is the agricultural practice of harvesting a monocot crop by cutting most of the above-ground portion but leaving the roots and the growing shoot apices intact so as to allow the plants to recover and produce a fresh crop in the next season. This practice is widely used in the cultivation of crops such as rice, sugarcane, banana, and pineapple. Ratoon crops cannot be perennially renewed, and may be harvested only for a few seasons, as a decline in yield tends to occur due to increased crowding, damage by pests and diseases, and decreasing soil fertility.

History The earliest record for ratooning, in a crop plant, can be traced back to the Vedic period in India. The Atharvaveda mentions that farmers cultivating barley (yava) used to cut barley plants many a time (20/125/2, Richa or Shloka No. 5755). Chinese records of sugarcane ratooning exist from 1757, in Fujian Province.

Etymology The word ratoon probably owes its origin either from the Latin words retonsus, meaning 'to cut down' or retono, which means 'to thunder back' or 'resound'. In Spanish, the close words retoño and retoñar mean 'sprout' and 'to sprout'. Terminology of ratooned crops varies, based on how far the crop extends from the original planting. The first harvest is called the plant crop, main crop or principal crop. Subsequent harvests are called first ratoon, second ratoon, etc.

In sugarcane Ratooning is an ancient method of propagation in sugarcane in which subterranean buds on the stubble (the part of cane left underground after harvesting) give rise to a new crop stand, which is usually referred to as the 'ratoon' or the 'stubble crop' as opposed to 'plant crop', which is raised from seeds or seedlings. Ratooning reduces the cost of cultivation by dispensing with additional seed material and some cultural practices such as land preparation and preparatory irrigation (palewa). It also results in early ripening of canes by at least a month or so, thus it adds to the effective crushing period. Sugarcane has a tremendous ratooning potential, and the oldest cultivated ratoon, being ratooned since 1757, in East China, in Fujian Province, stands to its testimony. The number of ratoons in sugarcane production cycles varies throughout the world, i.e., from one plant crop in Indonesia and some parts of China, one plant crop and a ratoon crop in India, Fiji and some parts of China, to six or more successive ratoons in Mauritius, Cuba, Venezuela, clayey soils of Zimbabwe, some parts of Puerto Rico, etc. The latter is also referred to as multiple ratooning. A decline in cane yield in successive ratoon crops, the so-called "ratoon decline", on the order of 20%, had been reported from many sugarcane-growing areas in India; the decline is more (up to 40% ) in subtropical India. Causes for this decline are: poor ratoon management, inherited differences in potential (ratoon) productivity, increasing incidence of diseases (like smut, grassy shoot disease, and red rot) which result in stands with gaps (studies conducted in India have shown that a gap over 10% significantly affects productivity of a ratoon crop), relatively less efficient enzyme systems (particularly nitrate reductase) activity, in vivo and prevalence of low temperatures during harvest, especially for early-ripening varieties and ratoon crop(s) in subtropical India which affects sprouting of stubble buds, etc. Insect pests also assume importance in a ratoon crop as stubble acts as a 'carry-over' of the inocula of pests both for coming up ratoon and for the neighbouring sugarcane crop(s), improperly looked-after crop gets infested by a number of insect pests, emerging sprouts of a ratoon crop favour rapid development and multiplication of some of the insect pests, and insect associated with stubble affect sprouting causing gaps which ultimately affect productivity of the ratoon crop, per se. In Indian context, in subtropical India, ratoon initiated during spring (March) resulted in higher number of millable canes, cane yield and sucrose % juice in comparison to ratoon crops initiated either in winter (January) or summer (May). In peninsular India, however, as the sugarcane crop does not suffer extremes of weather conditions during summer and winters, differences in time of planting and harvest do not significantly influence the yield of succeeding ratoon crop. Such a decline could be effectively prevented by proper ratoon management. Need for the latter stems from the famous Kalai (Aligarh, India) experiments conducted during 1939-1949. A good example of ratoon management and multiple ratooning is from Hoshalli village (in district Shimoga, Karnataka, India) where good yields of sugarcane ratoon crop (125-134 t/ha) were harvested year after year since 1968 without much loss in cane yield and quality. The crux for such a success was trash mulching, application of lime and irrigation after harvest of the crop every year. Ratooning has now become so much important in sugarcane production system that ratooning ability has become one of the important selection criteria for release of sugarcane varieties for commercial cultivation.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Ratooning

Start with the simplest possible case. Write down what Ratooning claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Ratooning before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Ratooning ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Ratooning

In research: Ratooning appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Ratooning in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Ratooning is common in secondary-school and first-year university syllabi. It links to neighbouring topics Harvest, Rice production, Sugar production, so understanding it makes those chapters shorter.
In everyday life: Look for Ratooning outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Ratooning in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Ratooning means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Ratooning out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Ratooning in simple terms?

Ratooning is the agricultural practice of harvesting a monocot crop by cutting most of the above-ground portion but leaving the roots and the growing shoot apices intact so as to allow the plants to recover and produce a fresh crop in the next season. This practice is widely used in the cultivation…

Why does Ratooning matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Ratooning?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Ratooning.