1: Broccoli
Welcome to the first entry in my new blog, which is all about different domesticated species. Each entry will cover a different domesticate, both plant and animal. This is a longstanding interest of mine, and also might help me get better at home gardening - so let’s start with a new crop I planted this year, broccoli.
First of all, where is broccoli grown? I love this chart from Our World in Data which allows you to select different foods and see where they grow. Today, broccoli is mainly grown in China, India, and the USA - with China and India being around an order of magnitude greater than the USA in pounds grown per year. Spain and Mexico also grow quite a bit.
As I’m sure you’re aware, broccoli is a member of the brassica family. I love this figure which shows the many types of food derived from brassica. Brassica oleracea, of which broccoli is the italica variant, includes such diverse foods as cauliflower, brussels sprouts, and kohlrabi. Like artichokes, what you eat of broccoli is the flower and stem - the leaves are bitter and rarely included in food.
Broccoli rabe, by the way, is a different type of brassica and actually more closely related to the turnip.
Broccoli is a landrace crop, meanwhile a locally adapted, traditional crop. The Etruscans in modern-day central and southern Italy likely grew the first varieties in the 6th century BCE and farmers in the Roman Empire continued to cultivate it. It remained popular in Italy for many centuries, known as broccoli, derived from Latin brachium, referring to its branching arms; when it came to England in the 18th century, Philip Miller's Gardener's Dictionary of 1724 described it as unknown and called it “Italian asparagus”. Thomas Jefferson experimented with broccoli seeds in the late 1700s, but it did not become a popular and well known food in North America until the late 19th/early 20th centuries, arriving with southern Italian immigrants.
Like many popular crops, industrial agriculture has dramatically transformed the broccoli that we see in supermarkets in the USA, especially after WWII - in short, they are grown much faster and much bigger than they were less than a hundred years ago, but the strains that most people eat are very closely genetically related and have reduced diversity. This interesting paper tracing broccoli genetic heritage describes how Calabrese broccoli came to the United States in the late nineteenth and early twentieth centuries as part of the traditional food of Italian immigrants. However, it did not gain popularity outside that community until the Green Revolution immediately after WWII.
Broccoli, like all brassicas, is a cross-pollinated vegetable, meaning that it is pollinated in the open air by via insects, wind, or water. It has to be kept in its own field or risk cross-pollination. During the Green Revolution, scientists used intensive plant breeding to improve the chance of pollination and increase yield. The first cultivar of broccoli to achieve that was Waltham 29 in 1950, at the University of Massachusetts Agricultural Experiment Station. Further increases in yield - through better pollination, increase in broccoli head size, and decreased growing days - occurred through American and Japanese breeding of hybrids in the 1970s and 1980s. At that time, crop production also moved to the US west coast to promote year-round production of the plant. The Chinese cultivars that have led to it being the largest producer of broccoli in the world today are derived from the Japanese hybrids of the previous century.
I suspect that this will be a common story as we go through the different domesticated plants - a post WWII expansion of growth and loss of diversity.
I drew one of the broccoli plants currently sprouting in my garden. Unfortunately I am not sure which variety of the plant I have. I’m very interested to see how it develops from here!
