Wheat Rust

Of all the diseases of wheat, and there are many, rust is by far the worst. All plant rusts are caused by the infection of a plant by a Basidiomycete fungus. Most Basidiomycetes are fleshy fungi that produce mushrooms, conks, and puffballs and are either saprophytes or wood decaying organisms. But the Basisiomycetes also included two destructive groups of plant pathogenic fungi, the rusts being one of them. Wheat plants are susceptible to three different rusts, stem rust (Puccinia graminis), leaf rust (Puccinia recondita), and stripe rust (Puccinia striiformis). Of these, the most serious one is stem rust. Stem rust affects wheat where ever it is grown, decreasing yields and in bad years even killing the plants. Bad rust years in North America, for example, can cause losses of tens to hundreds of million metric tons of wheat.

The stem rust fungus attacks the stem, the leaves, and the tissue around the seed heads of the wheat plant. It causes blisters that eventually rupture the epidermis, exposing a powdery mass of rusty red-colored spores, hence the name. These spores, called uredospores, can reinfect the same wheat plant or infect other wheat plants. The uredospores are easily picked up by wind currents and blown hundreds of miles away from their original source. If a uredospore lands on wheat plant, it will germinate in the presence of moisture and send a hyphal strand, called a germ tube, into a stomata. The fungal hyphae ramify through the plant tissue, penetrating mesophyll cells and draining them of their soluble foods. Within 8-10 days after infection, the fungus makes spore-producing structures that rupture the epidermis and produce more uredospores.

The importance of the East Wind to the rust fungi in Ancient Egypt was two-fold. First the winds pick up the fungal spores from infected plants and deposit them in the wheat fields of Egypt. Second the winds are followed by heavy rain clouds that sweep over the coast into the Eastern Mediterranean providing rain and thus the moisture for spore germination. Wheat rust is always much worse in moist or wet weather because more spores germinate and infect the wheat plants. The pharaoh did not stand a chance. With little understanding of the causes of disease, there was nothing he could do to preserve maat in the face of “blasting” East Wind.

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A Bible Story

During the time Egypt was ruled by the Hyksos, Jacob and his twelve sons were living in the Levant, in Palestine. As the story goes Jacob loved one son, Joseph, “best of all his sons” and Jacob gave Joseph a special long tunic. His brothers were jealous of Joseph and his new tunic so one day, when they were tending their flocks, they striped Joseph of his tunic and sold Joseph as a slave to a passing caravan of traders on their way to Egypt. The bothers then tore the tunic, stained it with blood, and told their father a wild beast had devoured Joseph. Joseph’s father “mourned his son for many days”.

When the traders reached Egypt, Joseph was sold again to the Pharaoh’s chief steward. Joseph served his master well and soon was put in charge of his master’s affairs. Then one day he was falsely accused of molesting this master’s wife and thrown in to jail. In time, the chief jailer put Joseph in charge of all the prisoners including two prisoners that had been in the service of the Pharaoh. One night while in prison, the Pharaoh’s servants each had a dream. The next morning Joseph interpreted their dreams. He told them that in three days one of them would be hanged and the other would be released to again serve the Pharaoh. As it turned out, the third day was the Pharaoh’s birthday and the dreams came true. One was reinstated and the other was impaled.

Two years later the Pharaoh had two disturbing dreams. The next morning he summoned his “magicians and sages” to interpret his dreams but they could not. Then the servant that had been in jail remembered Joseph and told the Pharaoh about him. The Pharaoh summoned Joseph from the dungeon and asked him to interpret the dreams, telling him:

In my dream, I was standing on the bank of the Nile, when up from the Nile came seven cows, fat and well-formed; they grazed in the reed grass. Behind them came seven other cows, scrawny, most ill-formed and gaunt. Never have I seen such ugly specimens as these in all the land of Egypt! The gaunt, ugly cows ate up the first seven cows. But when they had consumed them, no one could tell that they had done so, because they looked as ugly as before. Then I woke up.

In another dream, I saw seven ears of grain, fat and healthy, growing on a single stalk. Behind them sprouted seven ears of grain, shriveled and thin and blasted by the east wind; and the seven thin ears swallowed up the seven healthy ears.

Genesis 41 17-24

Joseph told the Pharaoh that the dreams meant that there would be seven years of great agricultural abundance in Egypt followed by seven years of famine. He recommended that the Pharaoh appoint someone to collect and store grain during the seven good years to protect against the famine in the seven bad years. The Pharaoh was so impressed, he put Joseph “in charge of the whole land of Egypt” to do just that.

Now the importance of this story is not its happy ending for Joseph, but the words “grain...blasted by the east wind.” or in the German translation of the Hebrew word “yeraqon”, “yellowed by the east wind”. According to the authors of Famine on the Wind (G.L Carefoot and E.R Spout, 1967), the east wind refers to a weather pattern that brings cyclonic storms over the Mediterranean that bring rain and moisture to the East Coast of the Mediterranean during the winter and early spring months. This is during the time of Late Emergence and Early Drought, when the grain of Egypt would be growing and most susceptible to disease. And the disease that probably blasted or yellowed the grain was wheat rust.

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What Happened?

The story of the rise and fall of Egyptian civilization is one of many ups and downs. Egyptian scholars have suggested “that the ups and downs of Egyptian civilization can be traced to successful or unsuccessful adaptations to fluctuating ecological conditions along the Nile and the management of agricultural and labor surpluses in face of those conditions” (from First Cities by A. P. Andrews). Clearly one of those ecological conditions was one the Egyptians had little control over despite their faith in their religious rituals, the weather.

Egyptian life revolved around the rise and fall of the Nile’s waters and the growing and harvesting of crops. The Egyptian year began in the middle of July when the water from summer rains in the African tropics flowed over and inundated the flood plains of the Nile. This time of the year was called the time of Innundation. The next season, from September to January, was the time of Emergence as the land reappeared from under the flood water and it was tilled and planted. The third season was the Drought. It started in February and was the time the crops were harvested and the state collected surplus grain (taxes). This surplus fed the pharaoh, his household, the households of all the government officials, and anyone else in favor with the king. It also fed the army and the monument builders. When the annual flood did not come, neither did the surpluses.

Generally the cyclical pattern of the Egyptian seasons was dependable and predictable, a phenomenon the ancient Egyptians believed was due to the activity of their gods. The Egyptians called this godly power maat , a term that roughly encompasses our concepts of justice, truth, and order (cosmic and social). When the power of maat failed, as it did at several times in early Egyptian history, social order broke down and the prestige of the pharaoh, who was charged with the administration of maat, was undermined. But the fault was not always due to the pharaoh’s incompetence. It has been suggested that one of the reasons for maat ‘s failure might have been the phenomenon we know today as El Niño. Scientists believe that there have been major El Niño events for at least the last 5000 years and recent El Niño’s have been linked to a decrease in the flow of the Nile. When an El Niño event ends there are usually very heavy rains and floods. More likely, however, the drop in global temperature which started around 3000 BC was to blame.

Soon after 3000 BC actual records of the time show that the level of annual floods of the Nile dropped, and after 2200 they came at roughly 200-year interval. There were some sequences of years when the level was so low as to cause starvation in Upper Egypt. The worst of all these times may have been 1200 BC, when it is suspected that widespread aridity provoked migrations of peoples throughout the Near East.
H. H. Lamb

But there may be more to it than that….

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Egypt: The History

Historians divide the history of Egypt into four periods: the Pre- and Early Dynastic period (3150-2700 BC), the Old Kingdom (2770-2200 BC), the Middle Kingdom (2050-1786 BC), and the New Kingdom (1560-1087 BC). Notice the dates. Egypt was in flux from 2200-1087. Then go back to our climate graph…. This is the same time that Sumer and Mycenae faltered – when the climate was getting cooler.

Good weather for farming: the Pre- and Early Dynastic period (3150-2700 BC)

During the first period, Egyptian society moved from an egalitarian society to chiefdoms and then to a state. By the end of the Pre-dynastic period several regional chiefs from the larger towns had gained administrative control over other settlements and the surrounding countryside. Their power came from their ability to manage food production and distribute food in times of shortages. Grave goods found in burial sites excavated from this era indicate there as an increasing social stratification and the emergence of an elite.

Sometime around 3050 BC, Upper and Lower Egypt were united under a single leader and the Egyptian State was born. Cities grew larger and the power of the ruling “chief“, now called a pharaoh, grew stronger. An elaborate religious institution formed, a standing army was created, and an administrative bureaucracy of scribes, tax collectors, census takers, and irrigation managers emerged. Controlling this bureaucracy was the grand vizer, second only to the pharaoh. Along with the bureaucracy came the development of the Egyptian’s hieroglyphic writing and major innovations in the arts.

By 2650 the power of the pharaoh was absolute and the pharaoh became a “God King”. He (or she - there was one she) controlled the Nile “through the magical powers of his godliness” as well as through the irrigation projects he authorized. As high priest, the pharaoh presided over rituals to assure the cooperation of the Nile and the fertility of the soil. As the powers of the king increased, so did the preparations for his burial. It was during the time of the Old Kingdom that the famous pyramids and the Great Sphinx of Giza were built.

Bad weather for faming…Drought then Flooding

Then the power of the pharaoh to control the Nile failed. Sometime around 2200 BC, the monsoon rains that feed the Nile did not come, crops failed, and the Old Kingdom collapsed. The country descended into turmoil. For a period of about 100-200 years Egypt was ruled by local chiefs who fought among themselves for power.

Finally, around 2065, one of the more powerful chiefs managed to reunite Egypt. Over the next 150 years the successors of this powerful chief again gained total authority over Egypt. This was done partly by overseeing ambitious irrigation projects that were to protect Egypt from another failure of the Nile’s land nourishing floods (remember China?). A canal 300 feet wide was dug to natural depression in the landscape that served are a reservoir which could be filled during the flood season and the water used during the dry season. With food surpluses, Egypt flourished for over two hundred years (the Middle Kingdom) only to be betrayed by the Nile again. This time it was excessive floods. Egypt again descended into chaos. This time famine was aggregated by a challenge from without, migrants and warriors from the south, the west, and the north.

From about 3000 -1000 BC tribes from Arabia and North Africa (Semites) and from the Eurasian Steppes (Indo-Europeans) began to migrate toward the centers of civilization. The warm climate that had precipitated the move towards a state society in Mesopotamia and Egypt had also allowed for an increase in the population of tribal lands around the Near East. When the climate began to cool (carrying capacity fell), these people began to move. These migrations started slowly around 2500 BC and reached a crescendo between 2000-1000 BC. A group of Indo-Europeans moved into Greece and became the Myceneans. Several groups of Semites moved into the lands around Mesopotamia, including one group called the Hebrews who settled in a place called Palestine. Around 1650 BC, Egypt too was taken over by “rulers from foreign lands”, a group of Semite people history calls the Hyksos.

For the next 100 or so years, the Hyksos ruled Egypt from the Delta, extracting tributes from Upper Egypt and building resentments. They adopted the traditions of Egyptians and continued their tradition of divine rule even calling their rulers pharaohs.

Then around 1560 BC, a chief from Upper Egypt challenged the rule of the Hyksos. Using military techniques learned from the Hyksos (horse-drawn war chariots and bows), and some help from Myceane, he expelled the Hyksos and the time of New Kingdom began.

The rulers of the New Kingdom were militarily aggressive and managed to forge an empire far beyond the boundaries of the Old Kingdom including Nubia to the south and Palestine to the North. Egypt became rich extracting tributes from the conquered lands and again built huge monuments, like the Temples of Karnak and Abu Simbel .They buried their dead mummified pharaohs in the Valley of the Kings. In the North, they ran into another group of Semites, the Hittites who had forged an empire as large and as powerful as that of the New Kingdom of Egypt. For many years there was a stand-off at their respective borders. Then in 1200 BC (oops - there is that date again!) the Hittite Empire vanished, the Myceaneans were routed by migrating tribes, and Egypt was about to enter yet another time of turmoil and decline (1070-712 BC).

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