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Timing walnut harvest so that nuts are removed as soon as kernels are mature is an important concept both in terms of kernel quality and in the prevention of insect damage, particularly that from navel orangeworm.

These studies demonstrate that attempts to control the sorghum midge with insecticides do not work under California conditions. Yield losses can be minimized, however, by strict adherence to a planting cutoff date. Fields planted before June 15 will probably escape midge damage. Those planted between June 15 and 22 may or may not escape damage, depending on the season. Virtually all plantings made after June 22 risk severe midge infestation and yield reduction. Plant population had no significant influence on yield, and high plant population (12 plants per foot) are not recommended because of increased seed costs. It is suggested that double-crop sorghum in in the San Joaquin Valley be planted no later than June 22 with a plant spacing of 4 to 8 plants per foot for maximum grain production and minimum midge damage.

Anyone who has spent a summer in the San Joaquin Valley hoeing johnson grass, bermudagrass, or nutsedge (nutgrass) out of a young orchard or has labored on a hot summer afternoon trying to pull perennial bindweed out of a young vineyard or a cotton field will be much interested in Roundup (glyphosate). This new herbicide showed promise in earlier studies (California Agriculture, February 1973) and has since proved to be an outstanding product against most annual and perennial weeds.

The so-called “alkali disease” syndrome observed widely in California rice, causing chlorosis in seedling plants and often effecting a partial to complete loss of stand, has been identified as zinc deficiency. This problem is extensive in both the Sacramento and San Joaquin valleys. In some areas, entire fields are affected; in others, the problem occurs in irregular patterns, depending particularly upon soil conditions.

Imidan, methoxychlor, Guthion (azinphosmethyI), methyI parathion, malathion, Zolone (phosalone), Furadan (car-bofuran), Vydate (oxarnyl), and Lannate (methomyl) were evaluated in three field experiments at selected dosages for control of the Egyptian alfalfa weevil on first cutting alfalfa at Salinas, California. All the insecticide treatments resulted in significant weevil control compared with unsprayed check plots. Furadan, Zolone, and Vydate controlled the pea aphid,

Since leafhopper populations on silage corn increase rapidly late in the season, early plantings are able to escape serious damage. Chemical control measures are svailable for areas where late plantings are necessary or lesirable. Leafhoppers have not been a pest every year.

UC Signal barley, developed at the Imperial Valley Field Station, El Centro, within 40 miles of Mount Signal for which it was named, is well-adapted to the lower desert areas of California. In comparative tests over a 3- to 7-year period, it has shown an 8 to 30 percent yield superiority over varieties previously recommended for the Imperial Valley.

Watermelon Rind Necrosis (WRN) is a perennial problem in Imperial Valley. As much as 25 percent of the fruit of some local fields may be mildly or severely affected. Last year about $100,000 worth of fruit was lost to this disorder. Watermelon Rind Necrosis has been reported from Hawaii, Texas, and Florida. Bacteria, Er