The following is the latest California Crop Weather report from the National Agricultural Statistics Service’s Sacramento, Calif., Field Office:

• Weather

A high pressure ridge lay over California at the beginning of the week (Jan. 4) producing stagnant atmospheric conditions across the Central Valley which caused widespread fog trapped under a strong inversion.

The inversion kept fog and cool air trapped across the valley up to an elevation of about 1,300 - 1,500 feet. Locations above that level enjoyed sunny and mild conditions, while those below that had cool, foggy weather to contend with for much of the week. Southern California enjoyed sunny and warm weather as an offshore flow kept any fog from forming.

By Thursday, a Pacific storm system brushed northern California resulting in moderate amounts of rain along the North Coast, and lighter amounts in the northern portions of the Central Valley.

By Saturday, the system had exited the state, and fog returned to the Central Valley. Southern California was unaffected by the system and remained dry and mild.

• Field crops

Winter wheat and barley continued to progress well due to adequate soil moisture. Dryland fields of oats and other small grains progressed with the help of recent rainfall. Ground preparation continued for spring crops as allowed by wet soil conditions.

• Fruit crops

Grape growers pruned vineyards, shredded prunings, and managed cover crops. Dormant sprays to control pests were applied in prune and peach orchards. Tangerines, Navel oranges, and grapefruit were picked in the Central Valley. The lemon harvest continued normally in the desert region while picking up in the Central Valley.

• Nut crops

Pruning continued in nut orchards while herbicide applications to berms in almond and walnut orchards also took place. Some almond growers applied strip sprays in the preparation for bloom sprays.

• Vegetable crops

The radicchio harvest continued in Merced County while field preparation for spring planting of radicchio was also underway. Kern County’s cabbage, lettuce, onions, and carrots progressed. Spraying took place to control weeds on tomato beds in Colusa County. The harvests of winter vegetables in Fresno County, including beets, broccoli, cabbage, turnips, daikon, eggplant, green onions, herbs, choys, chards, and kale were in full swing. Lemongrass was covered for protection from the cold.

Growers applied pre-emergent herbicides in preparation for 2010 crops. Field fumigation for onion, melon, and tomato fields continued. Growers were also cultivating, shaping beds, controlling weeds, and pre-irrigating for spring vegetables. Processing onions were planted by seed. Spring lettuce and garlic were also planted.

In Tulare County, broccoli, greenhouse cucumbers, and winter cauliflower were harvested. Ground preparation continued in Sutter County. Some broccoli and cabbage was harvested in Stanislaus County early in the week.