( Khurana et al., 1993 ). Properly timed straw mulch can suppress early germinating annual broadleaf and grass weeds and will be sustainable for a long period of time. Mulch, whether living or dead, inhibits the light necessary for weed shoot emergence and
Makhan S. Bhullar, Simerjeet Kaur, Tarundeep Kaur and Amit J. Jhala
Angela M. O'Callaghan
Garlic (Allium sativum L.) has been cultivated in much of the world for millennia. Little scientific research, however, has focused on improving cultural conditions for production in the temperate regions of the northeastern United States, where garlic is gaining importance as a horticultural crop. To study the effectiveness of wheat straw (Triticum aestivum) mulch on garlic, experiments were conducted at the Cornell Univ. research facilities in East Ithaca, N.Y., during the 1993–94 (year 1) and 1994–95 (year 2) growing seasons and at the Homer C. Thompson Vegetable Research Farm, Freeville, N.Y., during the 1994–95 growing season. Two clones, one bolting and one nonbolting, were studied in year 1, and four varieties, three bolting and one non bolting, in year 2. All were fall-planted (mid-October), and mulch treatments were covered with wheat straw early in the following December. Control plots were not covered. The mulch either remained on the crop throughout the growing season or was removed early in the spring to expedite soil warming. This is the common practice among growers who use mulch only for winter protection. The presence of mulch during the winter increased the survival rate. Soil temperatures under the wheat straw were significantly lower during the summer than soil temperatures in unmulched plots, which could have contributed to the increase found in the yield and average bulb size of several of the cultivars. Maintaining the mulch through the entire growing season reduced weed pressure >30%. We found no significant increase in the amount of basal fungal infection. The results indicate that using straw mulch can improve garlic produced in the northeastern United States.
Xinhua Yin, Lynn E. Long, Xiao-Lan Huang, Ngowari Jaja, Jinhe Bai, Clark F. Seavert and Jac le Roux
systems included straw mulch cover (6 inches thick and 10-ft wide) and the control (no mulch or fabric cover, but herbicides were used in the 10-ft row width to control weeds). The two irrigation systems and two groundcover systems were assigned to the
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.
In September of 1991, 1.1 m × 20 cm raised beds were built near Lane, OK. The beds were covered with straw or woven plastic mulch, or were left uncovered. Heavy rains in October left the uncovered beds about 20 cm wide × 13 cm tall. A gully was formed at the end of this field, and soil was deposited across several beds. Strawberry plants were set into all beds in mid-February 1992. At this time, the straw-mulched beds, although settled into an inverted “V” shape, were still about 1 m wide and about 18 cm tall. A very intense hail and rain storm struck the fields on May 13. Most of the hail was about 1.3 cm in diameter. The hail fell for about 30 minutes in early afternoon. The hail was accompanied by about 12.7 cm of rain. The strawberry plants on the woven plastic mulch were almost completely destroyed. The strawberry plants on bare ground were severely damaged by the hail, and their roots were often washed out of the ground. About 85 to 90 percent of these plants died. Strawberry plants on the straw-mulched beds appeared to be less damaged by the hail than other plants, and were not washed out of the ground. About 95% of these plants survived.
C.R Roberts, Dean E. Knavel, John Snyder, Terry Jones and Dave Spalding
Internal brown spot (IBS) was found consistently in the `Atlantic' cultivar at Lexington in 1967, 1968 and 1989, and at Owensboro and Quicksand, KY in 1987, Treatments of foliar and soil applied CaSO4 in 1987, soil-applied CaSO4 in 1988, and straw mulching in 1989 did not reduce IBS. Irrigation increased IBS because of larger tubers and increased Ca content of plants as compared with non-irrigated plants. Tubers showing IBS had higher Ca content in affected tissue than in non-affected tissue. Both IBS and Ca content of leaves increased as the plants aged.
Jomo MacDermott and D.L. Coffey
Some chicory (Cichorium intybus L.) cultivars, especially early and extra-early cultivars, often bolt and flower the first year of growth, contrary to the expected behavior of biennials. The extra early hybrid cultivar `Daliva' was grown in the field under bare soil and straw mulched conditions to examine possible correlations between growth rates, leaf and root sizes and bolting. Plants, sown on 19 June, were harvested weekly from 4 July to 1 Oct.; a total of 14 harvests. Root variables of length and diameter were best described by linear equations but root dry weight was decidedly quadratic in response. Leaf number, area and dry weight and crown diameter data were fitted to the Richards function to describe their sigmoidal phases of growth. In most cases, when using the Richards function, the two treatments (mulch vs. no-mulch) required different parameters to fit a line to the observed points with r 2 values >0.95. A statistical comparison between treatment parameters (as obtained from SAS PROC NLIN and SigmaPlot) will be discussed.
Charlie G. Summers, Jeffrey P. Mitchell* and James J. Stapleton
Trials were conducted in 2002 and 2003 in California's San Joaquin Valley to determine the efficiency of reflective plastic and wheat straw in managing silverleaf whitefly and aphid-borne virus diseases in late planted cantaloupes. In 2002, the incidence of aphid-borne viruses was lowest in plants growing over reflective plastic followed by those growing over wheat straw and then those growing over bare soil. Wheat straw mulch was as effective as reflective plastic during the early part of the growing season in reducing the incidence of virus disease, but by mid-season, the reflective plastic was superior. The incidence of virus diseases in plants growing over wheat straw was significantly (P < 0.05) lower than that in plants growing over bare soil throughout the season. Whitefly numbers (nymphs per cm2) and aphid numbers were significantly reduced on plants growing over both reflective mulch and wheat straw mulch compared to those growing over bare soil. Yields of all sizes of melons were significantly higher in the reflective mulch plots and yield for the straw mulched and bare soil plots were not significantly different. Results in 2003 were similar to those of 2002. Both whitefly numbers and aphid numbers were significantly lower in plants growing over both mulches than in those growing over bare soil. Virus incidence was initially low but following an aphid flight in late August, the number of infected plants increased rapidly. Both the reflective plastic and straw provided equal protection form aphid-borne viruses throughout the growing season. Yields were highest in the reflective plastic plots, followed by the straw mulch and finally the bare soil. Differences were significant (P < 0.05) among all three treatments.
Timothy Coolong and Mark A. Williams
of garlic ( Allium sativum ) in southern Illinois when grown on black-plastic mulch compared with plants grown with straw mulch on bare soil. Mansour and Hemphill (1987) reported a yield improvement for spring-planted green onions grown in Oregon
Kebede Woldetsadik, Ulla Gertsson and Johan Ascard
Two field experiments were conducted with shallot (Allium cepa var. ascalonicum Baker) on heavy clay soil to evaluate growth and yield response to mulching and nitrogen fertilization under the subhumid tropical climate of eastern Ethiopia during the short and main rainy seasons of 1999 with rainfalls amounting to 240 and 295 mm, respectively. The treatments included wheat straw, clear and black plastic mulches, and an unmulched control, each with nitrogen rates of 0, 75, or 150 kg·ha-1. Straw and black plastic mulches increased soil moisture while clear plastic reduced it considerably. Weed control was best with black and clear plastics in the short season and with black plastic or straw mulch in the main season. Both plastic mulches elevated soil temperature, especially clear plastic, which also caused most leaf tip burn. Yield increased nearly three-fold with the black plastic mulch in the short season and by one fourth in the main season compared to the bare ground. The straw and clear plastic mulches increased yield during the short sea son, but slightly reduced yield in the main season. The growth and yield of shallot were related to the weed control and soil moisture conservation efficiency of the mulches. Mulching did not alter the dry matter and the total soluble solids contents of the bulbs. Nitrogen fertilizer increased leaf numbers, plant height, mean bulb weight, bulb dry matter, and total soluble solids while reducing marketable bulb number, but did not significantly affect yield, leaf tip burn, or weed abundance.