Question: What two tools are used to harvest cereal crops in developing countries?
About the article "Cereal", section "Period".

Candidate passages:
There is a wide variety of tools in "Harvest Moon 2 GBC".
Tools are used to carry out chores, care for livestock, and tend to crops. 
Once the cereal plants have grown their seeds, they have completed their life cycle.
The plants die and become brown and dry.
As soon as the parent plants and their seed kernels are reasonably dry, harvest can begin.
In developed countries, cereal crops are universally machine-harvested, typically using a combine harvester, which cuts, threshes, and winnows the grain during a single pass across the field.
In developing countries, a variety of harvesting methods are in use, depending on the cost of labor, from combines to hand tools such as the scythe or cradle.
If a crop is harvested during wet weather, the grain may not dry adequately in the field to prevent spoilage during its storage.
In this case, the grain is sent to a dehydrating facility, where artificial heat dries it.
In North America, farmers commonly deliver their newly harvested grain to a grain elevator, a large storage facility that consolidates the crops of many farmers.
The farmer may sell the grain at the time of delivery or maintain ownership of a share of grain in the pool for later sale.
Storage facilities should be protected from small grain pests, rodents and birds.
A cereal is a grass, a member of the monocot family Poaceae, cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, germ, and bran.
Cereal grains are grown in greater quantities and provide more food energy worldwide than any other type of crop; they are therefore staple crops.
In their natural form (as in "whole grain"), they are a rich source of vitamins, minerals, carbohydrates, fats, oils, and protein.
However, when refined by the removal of the bran and germ, the remaining endosperm is mostly carbohydrate and lacks the majority of the other nutrients.
In some developing nations, grain in the form of rice, wheat, millet, or maize constitutes a majority of daily sustenance.
In developed nations, cereal consumption is moderate and varied but still substantial.
The word "cereal" derives from "Ceres", the name of the Roman goddess of harvest and agriculture. 
"M. barbarus" is a seed predator in cereal fields.
This is beneficial to crops, as it serves as a form of weed control.
There is some evidence which indicates this harvesting can lead to a decline in total yield at harvest.
Studies show however that the real effects of this hypothesis are minimal, with only an average of a 0.2% decline in potential yield from seed predation in newly sown seed populations and an average of a 0.6% decline in yield losses at harvest.
Thus, the negative impacts on yield are outweighed by the benefits to crops through the weed control function of the harvesters. 
There are a total of 101 Harvest Sprites to be rescued.
They belong to different teams based on what skills they have (such as fishing or watering crops), and are divided into two sets.
The first set of Harvest Sprite teams, after rescue, can be hired to help the player.
The second set of teams cannot be hired, and fulfill specific purposes, such as running the casino or television stations.
Rescuing the Harvest Sprites requires various farm related activities; activities related to a Harvest Sprite's skill will generally result in its rescue.