Americans cut back on their spending in June for the first time in nearly two years and their incomes grew by the smallest amount in nine months, the Commerce Department reported on Tuesday. Consumer spending dropped 0.2 percent in June, the department said. Excluding falling prices for such items as energy and food, consumer spending would have been unchanged in June. Incomes rose 0.1 percent, making it the weakest growth in income since September. High gas prices and unemployment have lead to slow overall economic growth in the second quarter. The economy expanded at an annual rate of 1.3 percent in the second quarter after only 0.4 percent growth in the first three months of this year. The combined growth for the first six months of this year was the worst since the recession ended two years ago. Many Americans are cutting back on purchases of cars, furniture, appliances, and electronics. Consumer spending is closely watched because it accounts for 70 percent of economic activity.