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, Mark C. Schmittgen and Glen O. Schwab
Julie M. Tarara, Bernardo Chaves and Bernadine C. Strik
minimally disturbed relative to production practices for a crop like blueberry where a tilled, mulch-incorporated and mulch-covered raised bed may be prepared. Thus, the blueberry plant’s crown and root system is established in three strata: mulch, mulch
Corn planted to originally acidic grassland soils with a low phosphorus (P) content and fertilized at normal rates produced low yields. A factorial study was designed with three application methods (banded, broadcast, tilled) at four rates (34, 67, 101, 134 kg/ha) P2O5. Sweet corn (Zea mays (L.) was planted in double rows on raised beds (0.9 m wide, 1.8 m centers) with 30 cm spacing in and between rows. Most yield parameters increased linearly with increasing rates of P. Banded P produced best yields, but growth was variable between the two double rows per bed. In a second study, P2O5 ranging from 0 to 403 kg/ha was applied by conventional methods. There was a positive response of most yield parameters to increasing rates of P. In a third study, soil plugs (2 cm diam., 10 cm depth) were removed 5 cm to the side of each plant. Rates of P2O5 ranging from 0 to 202 kg/ha were placed in the plugs. Yield responded positively to increasing rates of P. P applied in the plugs produced yield responses similar to P applied conventionally.
Ronald D. Morse
Potato (Solanum tuberosum L.) yields in Virginia and other hot climates are considerably lower than in cooler areas, predominately because of high soil temperatures during set and bulking of the tubers. Although organic surface mulches conserve soil moisture and lower soil temperature, often resulting in increased tuber yields, applying organic mulches is commercially cost-prohibitive. Preliminary experiments were conducted in 1995 and 1996 at the VPI&SU Agricultural Research Farm to compare production of `Yukon Gold' potato in no-till (NT) raised-bed systems with standard conventionally tilled (CT) methods. No-till yields were higher than CT both years, although differences were not significant. Based on these data, the NT production system used in these experiments is a viable management option, at least in hot climates such as Virginia. Rainfall during tuber bulking in 1995 and 1996 was above average, even excessive at times, which possibly negated the beneficial soil-cooling and moisture-conserving effects of the in situ mulches on potato yield enhancement. Greater yield increases would be expected in NT plots in normal rainfall years.
K.E. Maloney, W.F. Wilcox and J.C. Sanford
`Titan' red raspberry (Rubis idaeus L.), highly susceptible to root rot caused by Phytophthora fragariae Hickman var. rubi Wilcox & Duncan (syns. P. erythroseptica Pethyb., “highly pathogenic” P. megasperma Drechs.), was planted in June 1990 in a silt loam naturally infested with the pathogen. Raked beds (0.36 m high) dramatically reduced disease incidence and severity relative to flatbed treatments. In contrast, metalaxyl at 372 mg·m-1 of row provided little benefit when applied to flat beds and provided consistently moderate but statistically insignificant effects when applied to raised beds. Relative to the flat bed system, primocane vigor was increased in 1992 by 16%, 190%, and 224% in the flat bed plus metalaxyl, raised bed, and raised bed plus metalaxyl treatments, respectively; total yields were increased by 7%, 231%, and 272% with these same respective treatment. The results indicate that raised-bed planting systems can provide substantial control of phytophthora root rot of red raspberries even when highly susceptible varieties are grown on otherwise marginal sites. Metalaxyl appears more effective as a supplement rather than substitute for raised beds under such conditions. Chemical name used: N- (2,6-dimethylphenyl) -N- (methoxyacetyl)alanine methyl ester (metalaxyl).
T.E. Baumann, G.W. Eaton and D. Spaner
Eight day-neutral and seven short-day strawberry (Fragaria ×ananassa, Duch.) varieties were evaluated on raised beds during 1990 and 1991 in the Fraser River valley, B.C. Among day-neutral varieties in 1990, total variation in marketable yield originated in fruit count (26%), total yield (18%), average leaf size (22%), and runner count (19%) per plant. In 1991, total variation in marketable yield originated in fruit count (38%), runner count (23%), crown count (13%), and total yield (16%) per plant. `Selva' was one of the most productive day-neutral varieties and had the heaviest fruit and the fewest culls during both years of the study. The short-day varieties had uniformly low yields of marketable fruit during the establishment year, 1990. Variation in marketable yield in 1991 originated in runner count (34%), total yield (18%), and fruit count (16%) per plant. Of the short-day varieties in 1991, `Shuswap' had the highest marketable yield and, along with `Pajaro' and `Sequoia', had the fewest culls. `Shuswap' was a prolific producer of runners, while `Sumas' and `Redcrest' yielded well without prolific runner production.
Handell Larco, Bernadine C. Strik, David R. Bryla and Dan M. Sullivan
production system can be developed for northern highbush blueberry. Highbush blueberry requires well-drained soil and is often planted on raised beds ( Strik, 2007 ). Raised beds help prevent saturated soils, reduce compaction, improve internal drainage
Christian A. Wyenandt, Wesley L. Kline, Daniel L. Ward and Nancy L. Brill
grown in a single row on black plastic mulch with drip irrigation (Sheppard system), 11% when grown in single rows on raised, bare ground beds with buried drip irrigation (Laning system), and 8% when grown in single rows on high, ridged beds with
Michael D. Meyer and Mary K. Hausbeck
Phytophthora crown rot development. Growing plants on raised beds improves water drainage, thereby limiting the conditions favorable for disease development. Phytophthora blight incidence on pepper was 18% in flat beds and 5% in beds raised 45 cm ( Hwang and
James W. Julian, Bernadine C. Strik, Handell O. Larco, David R. Bryla and Dan M. Sullivan
well-drained, high organic matter, acid soils ( Eck, 1988 ). Planting on raised beds is a common production system in blueberry fields ( Strik, 2007 ) to improve drainage and help protect plants from standing water ( Scherm and Krewer, 2008 ). In