Seedbed

The level of seedbed salinity present at sowing time. 

No tillage or zero tillage the soil is left undisturbed from harvest to planting except for nutrient injection. Planting or drilling is accomplished in a narrow seedbed or slot created by coulters, row cleaners, disk openers, in-row chisels. Weed control is accomplished primarily with herbicides. Cultivation may be used for emergency weed control... 

Rodriguez Perez A, Diaz Hernandez S, Gallo Llobet L (2004) Eradication of Phytophthora nico-tianae and Rhizoctonia solani by double layer solarization in tomato seedbeds. Acta Hortic (ISHS) 698 207-211... 

Rasmussen IA (2004) The effect of sowing date, stale seedbed, row width and mechanical control on weeds and yields of organic winter wheat. Weed Res 44 12-20 Reddy KC (2001) Effects of cereal and legume cover crop residues on weeds yield, and net return in soybean (Glycine max),. Weed Tech 15 660-668 Reynolds LB, Potter JW, Ball-Coelho BR (2000) Crop rotation with Tagetes sp. is an alternative to chemical fumigation for control of root-lesion nematodes. Agron J 92 957-966 Rice EL (1984) Allelopathy. Academic, New York, p 317... 

Practically all the coffee planted commercially comes from seed, except in the rather limited Robusta-growing region of Java where grafted plants are used. Coffee seeds are planted in seedbeds and are treated in about the same way all over the tropics. The mature and apparently healthy fruits are selected and the seeds are pressed out, washed and dried in the shade, and planted rather soon, because coffee seed viability is lost within a comparatively short while. Handled in this manner, the chances are lessened that coffee diseases will be carried by seeds. However, it has been proved experimentally that infected plants can be produced from seeds contaminated with both the coffee Colletotrichum and the coffee Cercospora from either field material or artificial inoculation. This contamination is probably not uncommon in plantation practice and thus far it is not of extreme importance. The Hemileia rust is probably not carried on the seed (93). The American leaf spot is not carried on seed (97). 

Work is in progress on these problems. Copper sprays have been used to advantage in seedbeds and nurseries. Recent tests (2U-26) have shown that in the especially difficult lowland area of Turrialba in Costa Rica Colletotrichum leaf in-... 

Internal tissue breakdown in melons such as Galia and Cantaloupe occurs around the seedbed and eventually results in collapse of the seed bed into a mixture of liquid, seeds and tissue pieces. Unfortunately this disorder does not affect the skin or hardness of the outer layers so cannot be detected by visual inspection. Preliminary reports from the Volcani Center in Israel have shown that the tissue breakdown results in a small increase in T2 from, typically, 35 to 45 ms and a corresponding increase in signal intensity in spin-echo projection images acquired with a 4.7 T (200 MHz) imaging magnet. There is therefore a reasonable possibility of being able to detect this disorder by on-line projection MRI. 

L. S. Dochinger (personal communication) was able to predict chlorotic dwarf on seedbed white pine with greater than 90% accuracy. Taylot found that susceptible and resistant tobacco could be identified in seedbeds. Both suggested that, for some sensitive plants, time could be saved by visual screening of transplant beds and the use of only the more resistant members of the population as transplants. 

The soil in the chinampa was prepared in the traditional way of peasants at Xochimilco, by making a seed bed with mud from the bottom of the channels that surround the chinampa. When the mud was dry, it was cut in small cubes where the seeds were planted. The seedbed was then covered with soil and twigs. Once the seedlings reached 10-15 cm they were transplanted to a plot previously weeded and plowed. Treatments were placed randomly and covered with mud. These were 1. control (without fertilizer) 2. inorganic fertilizer (10 10 15), 250 g/m ... 

For sensitive tree species, it was found 10) that irrigation of the seedbeds with an overhead sprinkling system, just before spraying with mineral spirits, reduced injury to a minimum. The weed kill in watered plots was as good as on imwatered plots. Application of the oil sprays in the evening or on cool days also tended to lessen injury to conifers. Seed beds protect by half shade showed much less injury from oil sprays than those in full sunlight. 

With the above outfit, a three-man crew is able to spray a seedbed 450 feet long and 4 feet wide in 3 minutes. Its lightness and cheapness of construction should make it equally adaptable to rather small nurseries. 

Rasmussen, I.A. 2004. The effect of sowing date, stale seedbed, row width and mechanical weed control on weeds and yields of organic winter wheat. Weed Research 44(1) 12-20. 

Rasmussen, J. 2003. Punch planting, flame weeding and stale seedbed for weed control in row... 

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