: Asparagus its culture for home use and for market A practical treatise on the planting cultivation harvesting marketing and preserving of asparagus with notes on its history by Hexamer F M Fred Maier - Asparagus

@FreeBooks

Posted in: #FreeBooks #FreeBooksIndia #FreeBooksApp #gg

Vote Up Vote Down   0 Reactions

Login to give Reaction!

est can be kept in check by pulling and burning the old stalks. He points out the fact that the stalk should be pulled in the fall rather than in the spring, as it is difficult to pull them early in the season, and in many cases the dormant stage of the insect is left in the ground.

FOOTNOTES:

Condensed from an official report by J. H. Chittenden of the United States Department of Agriculture.

FUNGUS DISEASES

The first mention of asparagus rust in the United States was by Dr. Harkness, who claimed to have observed it on the Pacific Coast in 1880, although it is doubtful whether the genuine asparagus rust was ever found there. The first mention of it in the Eastern States was in the fall of 1896, and since then its range has been widening each year. Dr. Byron D. Halsted, of the New Jersey Experiment Station, was the first to call attention to it, and made it the subject of careful study. The results and conclusions derived from his experiments were published in a special bulletin, and from this the greater part of the following has been condensed.

RECOGNITION OF THE RUST

When an asparagus field is badly infested with the rust the general appearance is that of an unusually early maturing of the plants . Instead of the healthy green color there is a brown hue, as if insects had sapped the plants or frost destroyed their vitality. Rusted plants, when viewed closely, are found to have the skin of the stems lifted, as if blistered, and within the ruptures of the epidermis the color is brown, as shown in Fig. 47. The brown color is due to multitudes of spores borne upon the tips of fine threads of the fungus, which aggregate at certain points and cause the spots. The threads from which the spores are produced are exceedingly small and grow through the substance of the asparagus stem, taking up nourishment and causing an enfeebled condition of the victim, which results in loss of the green color and the final rustiness of the plant, due to the multitude of spores formed upon the surface. These spores are carried by the wind to other plants, where new disease spots are produced; but as the autumn advances a final form of spore appears in the ruptures that is quite different in shape and color from the first ones produced through the summer. The spores of late autumn, from their dark color, give an almost black appearance to the spots.

There is another form which the rust fungus assumes not usually seen in the asparagus field, but may be found in early spring upon plants that are not subjected to cutting. This is the cluster-cup stage, so named because the fungus produces minute cups from the asparagus stem, and in small groups of a dozen to fifty, making usually an oval spot easily seen with the naked eye. This stage of the fungus comes first in the order of time in the series, and is met with upon volunteer plants that may grow along the roadside or fence row, or in a field where all the old asparagus plants have not been destroyed.

METHODS OF TREATING THE RUST

All the cultivated varieties of asparagus are readily affected by the rust, although it has been found that some varieties, notably Palmetto, are less susceptible to its attacks than others. The most effectual means of controlling the disease are spraying, burning of the brush, cultivation, and irrigation.

In the spraying work conducted by Professors G. E. Stone and R. E. Smith, at the Massachusetts Experiment Station, the results were more encouraging. The solutions used were potassium sulfide, saccharate of lime, and bordeaux mixture. The spraying was done with a knapsack sprayer, provided with a Vermorel nozzle, and after the first application it became evident that the practice was of little importance on account of the difficulty in making the solution stick to the plant. For successful spraying of asparagus a finer nozzle is required than any that is now in the market.

In some other experiments carried out on a small scale the asparagus plants were practically covered with solutions, when they were put on with an ordinary cylinder atomizer, and the lime solutions showed excellent sticking qualities; but with the ordinary coarse nozzle the solutions would run off of the glossy epidermal covering of the plant very readily. Should the spraying of asparagus ever become a necessity, then some apparatus which can be strapped to a horse's back should be used. The narrow space between the rows forbids the use of the ordinary mounted appliances, and if spraying is to be carried on upon a large scale, it would be better to have the spraying mixture carried in some manner on the horse's back. In this way it would be possible to carry some thirty or forty gallons of mixture through the narrow rows.

Free books android app tbrJar TBR JAR Read Free books online gutenberg

(0)

Login to post a comment!