Topics in Subtropics

Biochar is a partially burned organic matter that can be used as a soil amendment. Its use was identified in the Amazon jungles where the terra preta (black earth) was first identified in areas where humans had incorporated the charcoal and improved plant growth was noted.

Travel can be enlightening. In Turkey I learned that sour orange rootstock is routinely used with lemon and mandarin scions without any fear of tristeza virus, a formidable disease of oranges.

'Bitters', 'Carpenter' and 'Furr' trifoliate hybrids are three new citrus rootstocks released in August 2009 by the University of California Riverside. These three rootstocks are hybrids of Sunki mandarin x Swingle trifoliate orange.

California Avocado Growers Seminar Series 2013 Presented by: California Avocado Society, Inc.

The polyphagous shothole borers (Euwallacea sp.) that spread fungal diseases (Fusarium sp. and possibly Graphium sp.) to susceptible trees in Los Angeles County have now been found in mid and northern Orange County and western San Bernardino County.