Physiological disorders of apples, such as cork spot and bitter pit, are a result of low soil calcium, low or excessive soil moisture, large fruit size, and environmental conditions. We report on the effect of microirrigation treatments on apple fruit when irrigation is applied as water alone or water plus a calcium (Ca)/boron (B) solution with applications applied over the tree canopy or under the tree canopy. Apples were harvested from trees in their 4th to 7th leaf and the number of fruit and size of fruit varied from year to year. In most years, there were no significant differences among treatments for fruit Ca. Fruit B was significantly higher in treatments where B was applied through the irrigation. Fruit N/Ca levels were lower when the fruit size was smaller, which was due to a higher number of fruit per tree. Year to year variations in fruit Ca levels also were likely to temperature, humidity, rainfall, fruit size, and shoot growth.
Richard C. Funt, M. Scott Biggs, and Mark C. Schmittgen
Richard C. Funt, Mark C. Schmittgen, and Glen O. Schwab
The performance of peach trees [Prunus persica (L.) Batsch cv. Redhaven/Siberian C.] on raised beds as compared to the conventional flat (unraised) orchard floor surface was evaluated from 1982 to 1991. The raised bed was similar to the flat bed in cation exchange capacity (CEC), Ca, P, K, Mg, B, and Zn soil levels in the 0-15 cm depth. Microirrigation, using two 3.7 L.h-1 emitters per tree vs. no irrigation, was applied to trees planted in a north-south orientation on a silt loam, noncalcareous soil. Raised beds increased trunk cross-sectional area (TCA) and yield-efficiency over 5 years. Irrigation increased fruit mass mostly in years of highest evaporation. Significant year to year variations occurred in yield, fruit mass, TCA and yield efficiency. There were significant bed × year interactions for yield and TCA. Irrigation increased leaf boron content regardless of bed type. Leaf potassium was higher in flat beds. Nonirrigated trees had the lowest tree survival on the flat bed, but the opposite was true on the raised bed.
Richard C. Funt, Henry M. Bartholomew, Mark C. Schmittgen, and John C. Golden
Annual yields of thornless blackberries may be inconsistent due to low winter or early spring temperatures. Under ideal conditions thornless blackberries can produce two or three times more berries per acre and ripen over a longer period of time than the erect, thorny type.
Yields of several thornless blackberry cultivars were improved by using straw mulch. In experiment one standard cultivars were compared to numbered clones. In experiment two Chester, Black Satin, Dirksen and C-65 were compared. Over a six year period, straw increased yields from 1670 to 8300 pounds per acre. Straw mulch appeared to be effective during years where low temperatures did not affect bearing surface.