All Issues

Seed size of hybrid sweet corn can affect total percentage of germination, and clearly affects the size of young plants, under winter planting conditions in the Coachella Valley. It can also affect the percentages of ear shoots which silk early and the number of ears ready for market at first pick. Experiments conducted with December and January plantings in 1958, 1959 and 1960 indicate that small seed should be avoided. Possible advantages in planting re-selected large seed are still uncertain, particularly when close planting, followed by thinning, is practiced.

Years with January mean temperatures approaching the 50° F level are likely to be years of poor olive production unless the temperatures in the immediate post-January period are cool enough for flower bud development. Intermediate yields can be expected in years with only moderately low January temperatures and moderate to high temperatures in February and early March. Highest olive yields are most likely when both January and February temperatures are cool. In Tehama County, where in most years the January temperatures are cold enough to favor some flower bud initiation in olives, the temperatures of February and early March are also critical in relation to the number of flowers formed and the ultimate yield.

A wild oat plant (Avena fatua)–resistant to both crown and stem rusts, and with grey seed, and stiff straw–discovered in 1945, led to the actual breeding of Sierra oats which began in 1947 and was completed in 1960. Foundation seed was produced at Davis in 1961 and was distributed to growers for certified seed production in 1962.

High summer temperatures appear to be an important contributing factor—in combination with psylla feeding—adding to tree losses from pear decline. Thus far, none of the sprays, ground applications, injections, or scoring treatments have had any discernible effect on the progress of pear decline. None of the treated or control trees improved, a few apparently held their own, but most have deteriorated.

An apparent mix-up within commercial sources of the vegetatively-propagated Marianna plum stocks with some other similar plum stocks has been revealed. Myrobalan plum seedlings, several vegetatively propagated myrobalan selections and two Marianna clones (2623 and 2624) have been commercially propagated for roostocks of stone fruits for a number of years. Of these, only the two Marianna stocks can be used successfully for almonds, and then only for certain varieties. Marianna 2624 is the more important because of its resistance to oak root fungus and is the one most often propagated for almond rootstock.

Methods of irrigating cotton—whether furrow or sprinkler irrigation—apparently have no effect on yields. These tests on Panoche clay loam at the West Side Field Station, Fresno County, also indicate that irrigation methods caused no significant differences in soil conditions, soil moisture content and plant nutrient levels.